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I mentioned in an earlier thread that i was planning this, ive bought an av reciever, 165watts to 7 channels, 1 channel driven. The speakers i want to use for this need to be around 30- 50watts rms i think, someone correct me if im wrong, but i also want the speakers to be quite small. I just like small speakers with big sound. And speaking of the sound, i want to be able to have the surround speakers play down to around 50hz. So in total i need a sub, two fronts, one centre and at least two surrounds, eventually atmos speakers too once ive learned how to design and make those. Would the rs100 drivers be a good choice for all of the above apart from the sub? The sub im thinking i could use the tang band w5. Or are there better options i could use?
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Also, i took this picture from the instruction manual if that gives more specific details, it only makes me worried that id be way overpowering single 30 watt satalite speakers if i went with a 30 watt 4ohm midrange or full range and added a 4ohm tweeter to make it an 8 ohm load, but honestly im so unsure about how much power these speakers will get, especailly the front left and right ones on the stereo setting that im hesitant to design anything yet as i could be way off with my thinking. Anyway im sure you can make more sense of the specs than i can lol
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Looks like the Sony STR-DN 1080. And looking at the photo,you’d probably want to go with something a bit more sturdy. And it would be judicious to go with the 8 ohm versions of whatever you decide to use, just to keep it safe for everything,, that is, if you plan on running it wide open. Now, if you don’t plan on really pushing it past about 1/3 – 1/2 power, you could probably go with the PC83-8 for all the drivers. At least for now.
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Thanks, im just kinda skeptical about the 165 watts to the channels on the surround setting, ill send you a link to the video of a review on this avr when i get home from work, the guy says he thinks its around 50 watts per speaker, but then because ive seen other things claiming thats wrong im just massively confused by what i need in regards to the power handling, id like to get away with using the pc83 if i can though.
A quick question about tge ohms part of this is, if i put two 4ohms in the surrounds, that gives me the 8 ohms, does that mean the 165 watts, if true, drops to around 130, and if i do that does the wattage handling of the two drivers become 60 watts rms or does that drop too back diwn to around 40 watts for both speakers? Sorry if that doesnt make much sense, im trying to type quickly as im on break at work
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Thanks, im just kinda skeptical about the 165 watts to the channels on the surround setting, ill send you a link to the video of a review on this avr when i get home from work, the guy says he thinks its around 50 watts per speaker, but then because ive seen other things claiming thats wrong im just massively confused by what i need in regards to the power handling, id like to get away with using the pc83 if i can though.
A quick question about tge ohms part of this is, if i put two 4ohms in the surrounds, that gives me the 8 ohms, does that mean the 165 watts, if true, drops to around 130, and if i do that does the wattage handling of the two drivers become 60 watts rms or does that drop too back diwn to around 40 watts for both speakers? Sorry if that doesnt make much sense, im trying to type quickly as im on break at work
That would be much better, two of the 4 ohm units in series to make an equivalent 8 ohm speaker.
When you combine multiple speakers to make 1 equivalent unit, regardless of series or parallel, you are just adding the power ratings together. Reason being that you are pushing just 1 signal through that particular combination’s number of speakers, effectively dividing it up at the beginning and then recombining it at the end so that it only sees the equivalent impedance. Lots of theory that could be thrown out there, but for resistance and impedance, that’s pretty much it in a nutshell.
So ultimately, you’d get 60W-120W ratings, double the Vas and then go from there. If you are using WinISD, it’ll do all that for you. Another bonus is that for the same amount of power, that combo would only use 1/2 the Xmax that a single driver would, which means you’ve got more headroom.
Plus, once you hit 10 units, the price per unit drops!
As to the true power of the amps, you’d have to feed a 1K signal into the amp, into a non-inductive load (power resistor) of the appropriate value (with all channels driven), look at it with a O-Scope to see when distortion starts, then measure the RMS value (scopes usually do this for you), square that value and then divide it by the load. I mentioned JohnAudioTech on YouTube as a guy I’ve been watching even before that was his channel’s name. He does this quite often.
Reason I said that If you were not going to use that much power from the amp is because most use a Logarithmic Volume control that slowly ramps up and then really puts the juice to it nearer the end, so that most times, when the volume seems loud or at the normal level you’d use, it really runs between 2-10 or 20 watts. Lower levels, like background type levels where you are able to hold conversations with others over the content are actually well under 1 watt, say 125-250 milliWatts. I think that tidbit came from Nelson Pass. He’s a cool guy to listen to, too – Check out his interviews on The Audiophiliac Daily Show with Steve Guttenberg on YouTube.
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As usual a very detailed reply, thankyou for that, so yeah i think ill go for the two drivers, basically ill make 3 identical speaker units, one for the centre and the other two for the surrounds, i dont how to work out what adding a tweeter to the speakers will do to the ohms though. If i added say a 4ohm tweeter to the two 4ohm pc83’s, how will that effect the ohms of the completed speaker? Or does that depend on how its wired?
Given that i have to keep the volume down to avoid upsetting the nieghbours i definately wont be maxing out the avr, so i think you might have helped me finally get to a decision on how to get started on this. I now just wanna check that making two of the dinas speakers for the left and right is a good match? Replacing the rs100 drivers for the pc83 just so they visually look part of the set.
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**(For those following along, here’s the Manuals page of the AVR we are talking about)**
If you were to add a tweeter, you could do a MTM style speaker. Again, the 2 mid-woofers/full range drivers would be wired in series to get 8 ohm equivalent. For the tweeter, it is usually good form to follow along with a similar impedance, so you would be looking for a single 8 ohm tweeter. There are many to choose from.
Your question about what using a tweeter with the other speakers is a good one. The answer is that the crossover takes care of maintaining the correct impedance by dividing up the frequencies and directing them to the appropriate drivers.
The DINAS, I’d refer that to Nick since they are his design. I can say that you’d have to do some recalculations for box size, crossover, and maybe more. It would be a different voicing, that’s for sure.
One thing you could do is use the Sub Outs one your AVR (they look like line level) and build either a pair of Mini Earthquakes or a pair of Voxels. Or design one on your own / with help. Power them with a decent Class D. It’d work out well, I bet. That way, you could run all your surround channels with the exact same voicing.
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Ok great, now i think i know what im doing about the centre and the surrounds, ill do the mtm style as you mentioned since i was unsure about the finished ohms, due to my reciever only going as low as 6ohms, but thanks for clearing that up for me.
I was goung to ask nick about tgat, but given hes feeling under tge weatger right niw i decided to try and wing it and learn what i could about them from his video, im a bit worried i might be overdoing the amount of subs if i went with dinas design, id then have one in each left and right aswell as the main sub, so im considering using the same design mtm speakers for everything but then it might be too lacking in bass on the stereo setup lol i hate overthinking things so much. What would you think to be the best choice of the two ideas?
I would probably need sone help designing a sub to be honest, since ive bever done one before, what benifit do you get from 2 subs over just the one?
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Im trying to design the crossover using xsim, but no matter what i try it will only let me upload one of the 4 frd files when i click the driver to tune it, why is it doing that? Surely it needs all 4 of them to give me the correct response?
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I was looking at the AVR’s data sheet, going over what mode does what. I see that when it is in 2 channel mode (regular stereo), the sub outs are not used. I see now why you were thinking of going with a slightly different L & R speaker style.
Which got me to thinking…
Some of the other posts within a month or so highlight the modular system with the bass unit integrated, yet detachable. Since one of the goals of an AV system is to have similarly voice matched speakers throughout, you could do 5 of the same MTM for LCR RR LR, and if you wanted just a single driver for the 2 Height channels. Voicing is pretty well matched. (From what I’m hearing about the height channels, they don’t get that much use, and the power they’d use is fairly low, so it’d probably be okay to use the same driver).
Then, for the AV subs, you would do the line in powered units.
Pretty standard so far.
Now, for when you want music, you’d want a bit more substance from L+R. You could use a ~5-1/4″ to 6-1/2″ woofer (not a sub-woofer, you want it to be musical) built into a box that could wrap around behind the L+R speakers to enhance their low end, bolstering from about 100-120Hz down to around 40+-Hz. These would be low-passed in the crossover, but you could put a switch in line to turn them off for movies. Or, you may find they enhance the L+R enough to keep them always on.
Anyway, that’s a thought I had to try to address your concern when in stereo mode.
Back to what’s on the drawing board. You’ve settled on the PC83-4 wired in series and a tweeter. What 8 ohm tweeter are you looking at?
I ran a quickie and it looks like a .38 CuFt box (allowing for some extras taking up space inside with a 1″ port at 1″ long ( or 1.5″ port at 2.75″ long) will put them down at a FB of ~58 Hz and a F3 of ~49 Hz. Not too shabby, I’d say.
The interior measurements of the box, I like the Acoustic Ratio of ~11″x8.5″x7″. That way, you can choose whatever thickness you want.
For a companion woofer, I’ve looked at a lot of drivers from 4″ & up, I think that these two 6-1/2 drivers look promising in 1 CuFt boxes that can be fit around the MTMs. The Goldwood would have FB of ~44 Hz, F3 of ~37 Hz with a 1.5″ port 1.4″ long and a 4.7 dB peak near FB. The Peerless would sit both the FB and F3 at ~42 Hz with 2″ port 3.2″ long with a 2.2 dB peak near FB. I kind of like the Peerless a bit more atm, just on spec. Of course the 1CuFt box is just a way to keep it small and volume is subject to change and recalculation.
Again, that is just an out loud thought/suggestion, not a requirement.
For the XSim question, just load the 0 degree frd file. That is the one you should be working with. The other ones are the off axis measurements.
PS, almost forgot, are these dimensions doable in your room or do you need something smaller? Wouldn’t hurt to draw a scale mock-up of your room to see how it all fits, or if a bit of a rethink my be needed. It’d be a bummer to go through all this to find out it’s crammed in tight. You say you are in an apartment, so I don’t have any idea what you can and cannot do with your area.
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Thankyou for all of that, the integrated but detachable idea is a good one, maybe a little too complex for me though, what i think i will do is firstly make all of the mtm speakers, and the sub so that i can get it working at least. Then add the extra bass as you mentioned at a later date, im limited for time as my girlfreind is due to give birth in december, so whatever i make has to be finished by then as all my free time will be given to my son, at least for the first few months. So i have 5 mtm to make and atleast one sub, whuch tbh i havent even started to design yet, i wanted to use the w5 as i said before but its 40watts rms is a drawback, can you think if theres away i can bring that into the mix or just go for a bigger sub?
The working out you did is pretty much what i got too, i planned to make the box 13x6x8.5 internal giving .343ft. With a 20mmx40mm port at a leng if 46mm.Trying to keep the box a bit smaller but i guess i sacrifice bass by doing that though, maybe they will still sound ok, as tge one i made for my girlfreind soubds really good, but ut is in a slightly bigger box.
I definately plan to do like you say about adding the extra woofer to help with bass, its a good fix if the mtm are lacking a bit, im stuck on the crossover at tge minute though, i cant seem to get xsim to put a baffle step circuit in, it only puts the componsnts in in series when i try to add them and there is no already made circuit to add to it that i can tell, do you know how i put componants in in parallel on that software?
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Ironically, I have the PC83-4 files from when we started the “Who wants to design a speaker with me?” thread. I tried throwing together a quick MTM 1st order X-Over using the ND90, and there was a big dip at about 16.5 KHz. Out of curiosity, I pulled the tweeter out of circuit and the graph looked amazing. I wish I had some hands on experience with them to really see what’s going on.
Does anyone here have experience with the PC83-4? We’d like to hear from you.
As to the Baffle step and XSim, I am still learning them myself. I’ll let you know when I figure that out.
( Still learning WinISD as well. You are never too old to learn. )
Almost forgot – the subwoofer. You should be connecting that to the Sub Out on your AVR, which is at line level. Therefore, it will be self-powered by it’s own plate amp. We can work on that once you get the main speakers worked out.
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I hadnt noticed the dip, as i said i cant get that far in xsim yet lol i havent fully decided on a tweeter yet, i was planning to try crossover with multiple different ones to see which seemed to match best, but i think i might go for the hivi t20, if i can ever get a baffle step circuit into xsim 🙄
Ahh i hadnt realised the sub worked like that, i assumed the avr was what powered it, im glad you told me that, so the w5 is a possibility then? But as you say, get the mtm’s sorted first lol
I really appreciate the help your giving me on this, my system of speakers is sure to sound way better now than if id gone at this alone
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Ive just realised i made a mistake when i said about not being able to put a baffle step circuit into xsim, xsim was the frd file issue, but youve told me how to add that now, it was ‘vituixcad’ that i cant put the componants in in parralell, i got confused and called it xsim. On vituix cad theres componants that you click on and they appear in the driver wiring, its there where i cant add a BSC, because every single componant goes into the circuit in series as far as i can tell, i was following one of kirbys crossover videos but he doesnt show how to do that. Sorry, i just had to correct what i wrote above.
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Can someone explain to me what im doing wrong with the xsim software please? So i found 123toids video on basically the exact build i want to do, only ive slightly changed box size and the tweeter as i like the look of the hivi tweeter. Now i tried putting in the exact drivers he used in that video and put the exact crossover details as his into the software, but i got this graph that looks terrible. I know ive done something wrong because i know that nicks crossover will be as good as it can be for those drivers. But why cant i reproduce it?
This is nicks crossover taken from his video
And this is the graph i got by adding the same values and the same drivers
I appologise for the very bad picture, i had to take a photo of my laptop screen, but hopefully you can see it if you enlarge the photo
Now this is what i got by messing with the values, only i changed the baffle step to allow for my wider baffle
Ive no idea where its crossing over, or if its even a good graph, im literally just messing about trying to understand this software but i feel im failing
My idea was that if i reproduced his crossover and get a nice graph, id be able to learn a bit about this xsim, i suppose it would help if i knew what the hell the graphs are showing me lol, but from what i can gather its around 7ohms nominal impedance? As i said ive no idea how to see where the drivers crossover, the tweeter i want to use is 3000 to 20000, so i imagine i need to cross at around 4500?
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Take note of the tweeter orientations. The one in Nick’s video is reversed: positive of cross over goes to negative of tweeter and ground goes to positive of tweeter. Yours is the standard way around.
Sometimes it helps to invert/change polarity of a driver to get the correct response. Flip your tweeter over and you’ll see the change.
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Oh i had missed that, thankyou, ill put that into xsim and see how it changes it, im just trying to get this one crossover done, then i can move onto the sub/subs and maybe the rear support speaker you mentioned in an earlier post
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Im about to give up on this, ive changed the pos and neg connections and got this
If i cant even recreate a ready made crossover with this software i imagine trying to get one of my own done will be a challenge, there must be something in the settings or something that i have wrong, but ive no idea what, this shouldnt be this hard, speaker buildings easy, right? Lol
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Ok so ive had one last attempt, this is using the td20f tweeter, i know your probably sick of this forum thread now, but if you could take a glance at this and let me know if its ok or if its way off before i move on to the next thing. I think because im using a full range driver that im not seeing a crossover point like i first expected, because the tweeter is there to enhance the sound rather than take its place? Please correct me if im wrong as id like to learn as much as possible. Anyway this is the graph ive come up with
Sorry for the shitty pic again, and i know tge impedance is crazy in the trebble are but im hoping thats ok for this project as its higher not lower?
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No probs
The diagram is at 2.55 ish, but thats all he shows of the crossover, its a free build plan he created. I could build it to his design as hes given everything for it, but im basically trying to use it to understand the software. The last pic i uploaded is using a different tweeter purely because i like the look of those over the rear mounted ones.
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Well i hope your feeling better soon, theres no rush as i can still make the boxes and even fit the drivers, i mean i like the look of the graph i came up with, i added the baffle step to match my baffle, and notch filter, and it evened out pretty good i think, but the tweeter seems to have dropped way down in db when i click to show the curve of that on its own. Tbh with the notch filter the response of the pc83 on its own, to me, looks good. Im not even sure it needs a tweeter, but if you are able to add it with some benifit to the sound in your graph ill be glad of the result. And i appreciate the help as im really unsure of the results i got even with the flatish response on the graph. Its the impedance that worries me most as i cant go below 6ohms with this avr
I wish there was a full tutorial of how to use xsim, the ones ive found are high speed or just focus on one part, if i could buy an actual txtbook to learn that from id buy it tomorrow, knowing whats good or bad would be a big help to me
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I was able to reproduce the Reveal X-Over and then applied the same basic one to your tweeter choice, changing the Cap and Resistor values slightly to flatten things out. Reveal First:
Now a slightly revised version specific to the TD202F-4:
Take note, this keeps the Impedance at or above 8 ohms – definitely in the safe zone of your amp.
You could drop the 2.7uF down to 2.2 and it’d smooth it just a tad more. What that does is moves the crossover frequency up a bit more.
As an exercise, this is just the 2 PC83-4’s in series (8 ohm) in case you want to do that for the Height speakers.
For your Future picture outputs for XSim, Go up to the :FILE: pulldown and select Snapshot>To Picture File and select the size you want. I chose “As Shown” for mine.
Let me know if you have any questions on how I got these into and out of XSim. I’ll be happy to help if I can.
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Thankyou for that, theres a few things i could use some help to understand, but i have to sleep now for an early shift tomorrow, so ill post properly after work, thanks again
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Oh what an idiot i am, i hadnt realised until i just read your comment, no wonder it wasnt working. So my last attempt where i put the right componant inplace, the one with the notch filter, is that an ok crossover then, as in i could use it and it all work fine? I noticed on your crossover you didnt bother with the nitch filter, is that not needed in a crossover containing a tweeter like this is?
Also i wondered, do you have to input the volume of the box these drivers will be contained in to get the right response from the xover? Surely box size affects everything were doing in this simulation?
Im just in the middle off adding your crossover design into xsim, to check i get the exact same response as you, so i can be sure my settings are right. Ill probably use exactly what you came up with as its less componants than i used with the NF
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Oh also, is it better to make a xover in this software without a baffle step circuit, as depending on the baffle that will change wont it? For mine i need 0.9 inductor, but wont the results be lying if a baffle step is added to this software instead of a flat respoonse then adding it in later using the online calculator?
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I think you have helped me finally figure this out, it was driving me crazy, as i thought that my settings were wrong or something, turns out im just an idiot lol. I put in all your components as you did, and i got the same result as you, thank god. So now i should be able to make future crossovers on my own and i can finally move onto the subs, and then i can order all my parts and get on with this build, thankyou!
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Yes, the last one you did works correctly.
I just copied the one that Nick did, since it was basically the same type of setup, just a different tweeter. Then I played with the values to flatten things out. So if you use the one I did and switch the cap between 2.7 and 2.2, you’ll see a slight difference. It’d be up to you to choose which you’d think best. My hearing is colored now, so I’d probably like a more tilted top end. (Age does that to you).
The notch, I would only use that if necessary to correct something that couldn’t be fixed with the original first x-over.
Baffle step, this is one I’m one the fence about. Usually it drops the output of the top end to match the bottom end, ultimately lower efficiency, and really like most of the stuff we are pre-designing, needs to be verified in a build and measurement. Since you are using MTM style with a port, you are already helping to mitigate the effect of baffle step. Not really sure if it’d be needed.
One last tip, if you are not already doing so, keep a page open on your website of choice, ie Parts Express or similar, to the caps, coils and resistor pages. That way you can choose from what’s available instead of trying to track down a nonstandard value.
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Baffle step, this is one I’m one the fence about. Usually it drops the output of the top end to match the bottom end, ultimately lower efficiency, and really like most of the stuff we are pre-designing, needs to be verified in a build and measurement. Since you are using MTM style with a port, you are already helping to mitigate the effect of baffle step. Not really sure if it’d be needed.
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Nick, I know you are still on the mend. If you could, at some point, chime in with your thoughts on whether Baffle Step is needed in this instance, we’d appreciate it.
Get stronger and better each day.
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I really apreciate all of your help with this, i would probably have given up trying to do that crossover if you hadnt noticed my mistake. As for the tilted top end, i would prefer it to be lower if poss, ill probably adjust slightly to see if i can get it a bit lower, only reason being is that the review i watched about this avr said it can be bright on the trebble end if matched with the wrong speakers, as its coloured in a way to imorove the voices etc. So it may be best to lower it a little.
With the baffle step i use the online calculator, which worked well for my last two builds, so i just wondered, since xsim doesnt have the ability to add volume and baffle size maybe getting a flat response without the BS circuit, then adding that in to the wiring later might have a more accurate response. But as you know, im a complete novice so my question was mainly a way to understand how it works in that xover. And if this was a midrange or sub in this build, would they too need a baffle step or is that purely for full range drivers?
Speaking of subs, im looking at which to use, i think im going to go for 2 (seperate) w5’s in vented enclosures. Alot of the bigger ones dont seem to go as low as those and are 4 times the price in some cases. I also need to find a good quiet amp, do you have any recomendations?
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For the top end, mess with the resistor value to see it peak up or down. And like I said earlier, if you go with 2.2 uF, it will smooth it just a tad more. You could always order several values and try them out.
Baffle step is something I don’t mess with much, so I’m still very much the neophyte there. Very basic understanding, but that’s more or less it. Plus, you have to weigh the pros and cons of using it. Is the efficiency loss worth it for the response, or will it be compensated by the subwoofer’s upper range? You sound like you know the baffle step frequency, what would that be and will the sub play high enough to smooth that out?
Amps? Since you want to use 2, why not go with a Class D stereo amp, at least 50 watts. You could try the Dayton Audio dspb-250, 2 channel , 50W with built in DSP. I only know what the reviews say, so take it with a grain of salt. I’d like to hear from others who have more first-hand experience with specific amps. Anyone? Bueller? Bueller?
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Yeah ill try that tonight after work, im happy with it as it is but im just a bit wary of making that avr sound too bright, better safe than sorry
The frequency is 723hz, with an 8 db drop. In that case i need a 6ohm resister and a 1.3mh inductor, tbh the way i see it, its because the tweeter is taking over the high frequencys, then the baffle step is just to bring down the full range to create the crossover point. And the extra inductor after the bsc brings it down even more. Allowing the tweeter to take over, so now i think about it, maybe the baffle step in this case is just a way to bring down the full range’ highs completely, to almost nothing? Instead of just slightly, im on break again so appologies if this doesnt make much sense lol. Basically i think, its meant more as a high frequency killer in this xover rather than to even out the response?
Thanjs, ill take a look at that amp later, as i have some questiins about how it will all work together
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A quick reminder. Assuming your receiver has a setup microphone, it sets trim adjustments for each speaker. The 165w is typically just 2 channels driven. On top of that, if your trim is set down, -3 for left surround, for example, this will also lower the wattage to that speaker. Also speakers handle more wattage the higher they go up in frequency. Said differently, the higher you cross it over (to an extent) the more power it can usually handle. Most surround speakers are not full-range, so crossing over by 80hz should not be a problem for most speakers. Think about, the Bose cubes, there’s no way they could handle 100w, yet they are fine on most surround sound receivers.
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This is the post with the link to the AVR’s manuals. Page 11 of the operating instructions shows a calibration mic, so there’s that. It’s actually a nice looking AVR, spec wise.
@123Toid , what is your opinion on a BSC network for this MTM build? I’m unclear as to if it’s needed.
Also, what do you think of using the amp I linked above with a pair of W5’s? DSP would help out with keeping it simple, I’d think.
Lastly, the 2 main L/R speakers, when they are to be used in 2 channel mode, I have a couple ideas to toss around, mainly a big bass blocker cap to limit bottom end to them and maybe a 6″ or 6-1/2″ woofer to add onto the bottom to give it the lows it needs for music. Not necessarily a sub, but a good, matching, musical woofer. Obviously, that would be @Dameo182 ‘s call as to what to do. Of course, that would be later on, after all the extra work has settled down with that special arrival coming soon.
Only reason I mention it is that the AVR only uses the Sub Outs for multi-channel. 2 channel deactivates them.Again, that’s for down the road. And of course, you guys know that once something starts running through my head, it tends to spill out.
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It is needed, just not as much. Should only need about 3db attenuation. The issue that I have with the current crossover is the huger hump caused by the tweeter at 1800hz. That will be very audible and will sound quite forward. If it were me, I would work on that area some.
I didn’t see the amplifier but I am sure it is fine.
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That hump is from the Tweeter x-over cap. A 2.2 would drop that hump down to almost flat. It’s basically your Reveal x-over slightly modified to work with a different tweeter.
I suggested the Dayton Audio dspb-250, 2 channel, 50W with built in DSP. That way he could use that DSP to help get rid of anything over what’s not needed and still have enough oomph to drive the W-5’s. Or would you recommend something a bit more higher powered?
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That is a good amplifier and you could make some basic adjustments to it. I knew it was the Reveal MTM with a different tweeter, I am just concerned with the crossover still. That tweeter should be crossed over closer to 3500hz. The FS is around 1700hz, which is one of the issues with the hump. It will probably add a lot of distortion to the tweeter. I would completely rework the crossover to help crossover much higher with that tweeter. The basic rule of thumb, is to crossover twice the FS (2nd order) and FS should be about 20db down or more. Currently FS is closer to 7db down. All in all, without measurements of distortion, I am confident to say it is not going to work out well.
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Firstly i hope your feeling better now, nice to see you back on this forum!
Well i figured it saying 165 watts per channel was a bit exhagurated so are you saying i might get away with making the surrounds to contain just one pc83 and a tweeter rather than the mtm style? It would save me some cash, and im always happy about that lol
As for the crossover, my initial thought on that was that the tweeters range is from 3000hz to 20000hz, and i wondered if crossing over so low was an issue, but given that ive literally got no experience or much understanding of the way crossovers work, as in whats good and whats bad, i was planning to try it out and adjust it from how it sounded if needed. So after your input, thanks for that btw, ill have another go at it tonight and see what i can come up with. Ill post it in here for you to critique, if you dont mind that is.
I think ill use the amp that @tvor-ceaser suggested for the subs, im not sure how the dsp works though as i dont see any adjustments on it, i may figure it out if i spend more time looking through the specs. Ive just been preoccupied with these mtm speakers, they’re kinda stressing me out now
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Ok so ive had another attempt, ive done the best i can from my ability and i feel a bit anxious posting this as i feel like your gonna say this doesnt work either, im losing hope in ever being able to be competent at designing crossovers for my builds without having to come to you for help all the time, i dont mean to be a pain, i just dont know where else to learn this from. Anyway if you could cast your eye over this and let me know how far off i am, and be gentle please lol @tvor-ceasar @123toid
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Yeah its no problem, thanks for getting back to me, i couldnt seem to flatten out the area after 10000 without changing the crossover point, it flattens nicely if i raise the point to around 6000hz but im not sure if going higher will be any kind of issue, i would think it would be ok..but there could be some hidden reason to not do that that im not aware of yet.
Are you feeling back to normal now since your surgery? I hope so
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It looks pretty good, it might be a little dark sounding, but some people really enjoy that. Your high end is probably about 3db down from the low end. But if you like that type of sound, you will be fine.
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So glad you said it looks ok lol, i was trying to enhance the bass that i could get from these speakers as the subs wont work in the stereo mode of the avr, i know theres the option of adding a seperate bass speaker into it at a later point but i figured id see how they sound first to see if its needed. So i should be aiming for a more level graph than what i have there in general? I dont know if you read my earlier post about the reviews of this avr, saying its a little forward if matched with already bright speakers, so i was trying to avoid that too. I can mess around with it still, at least im on the right track, thanks again
*edited
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Are you feeling back to normal now since your surgery? I hope so
Getting there. Better day by day and definitely more energy. Thanks.
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So im getting ready to order all my parts, and ive just been looking at that amplifier. It seems i need to use ‘sigma studio’ to use the dsp function? Ive just watched this video to try to figure out what that is
It seems very complicated to use, i wouldnt even know where to get that software, so im hoping either i can use that amp without having to do any equalising, or that theres another option to run these subs? The plate amplifiers are rediculously priced on the website i use, so buying two of those isnt an option, but what about a normal 2×50 amp like i used in my other builds, wouldnt they work fine or is it a crossover problem then? Maybe put a low pass filter between amp and w5? It would be so much easier if this avr’s sub outs were powered 🙄
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They come ready to run – Hook up the power supply, input and speaker wires and you go. If you want to program them, you need the DSPB-ICP1, which you only need to use to program it, no need to keep it in circuit. Of course, since this is the LFE channel, you probably don’t need it. You “could” go with on of the lower priced ones too. Just make sure it’s in stock and you can get the power supply.
This is the lowest price in-stock amp they have. Look around and see what they have.
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Oh i see so i dont need to adjust the frequency of the sub its attached to? I was thinking it was like the 2.1 lapai one, that needs the crossover point to be set. So if i just plug it in and go the avr speaker calibration setup will handle how it all sounds?
And i assume your idea was to just buy one amp, placed into one of the enclosures and just wired into the other sub? Or is it better to just put terminals on the back of each sub box and place that amp in a seperate little box to allow for different amps to be used in the future if needed?
I use a website called ‘sound imports’as shipping from parts express is expensive with the tax, ill have a look and see what they have, ill probably get the amp you originally suggested, im just worried about having to use that computer software if my avr cant dial the subs in.
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@dameo182 Since they are hooked to the LFE channels, they only get those signals, so they don’t actually need any crossover, either physical or electronic. Where you put it depends on how long your input cable runs are going to be. If they will be too long, it’s better to run speaker cables. So, personal preference and placement situation.
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Thankyou for clearing that up for me, i learn something everytime i speak to you lol
So given the amp is 50w at 4ohms, and my avr isnt powering the subs as such, so need need to stick in the 6-12ohm range, i can get one of those amps and two 4ohm w5s and it should work ok? Or would you get 8ohm ones to reduce the stress on the amp?
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As long as the amp is rated to 4 ohm, you’re good to go. All you are getting from the AVR is the signal.
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Yeah i thought so, ill get the 4ohm drivers then, well i think im almost done with this design, unless theres something i encounter along the way that i need some advice on, thankyou for all of your help with this project, hopefully in a month or so time i can update this thread with pics of all my speakers installed and working effortlessly lol
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You could always base it on The Voxel box and port, minus the electronics. It’s already designed.
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I may do, i think ive seen that mentioned on youtube so ill have a gander at it, ive literally just ordered all the parts, 42 items lol. At a cost of £382, i could probably have bought a full ready made set of speakers for that lol but i enjoy the uniqueness of diy speakers. I just hope it all works. Im hoping my £450 (including wood) for all these speakers gives me a sound equal to £1000 worth of ready made ones. I might be being a bit optimistic there though 😂
If i decide to change how im doing the subs, and make the voxel i think they should let me return the amplifier i bought to replace it with the parts for that instead, if not ill use that amp on another project
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Im considering buying a microphone and the software, so i can measure these speakers in the box, i know theyre cheap speakers in comparison to almost every other home cinema system but id still like to do the best job i can and get the best sound possible from these, being a perfectionist, if i dont like how they sound ill end up spending hours and hours trying to fix them
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It is fairly complicated to use. However, what I would do is download Sigma Studios. It is free to download and use. Then just start messing around with it. I’ll have to see if I can find some beginner videos. If not, it might be something I can do sometime. It is a very powerful program that offers a lot. But even if you just use it for parametric EQ or high pass and low pass, it is very powerful. Having said that, powerful, also means it takes time to learn. Especially if you want to go way past the basics.
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If you could do some videos on how to use it that would be great, im sure theres many peoole in my position, that want to use amps like that but have no clue how to get the best out of them. Ill try to download it once i get my amp and i might even start a new thread specifically for my trails with that software. I didnt even know it existed until i saw it in the amps description.
I have a quick question about the BSC in the crossover i made, does the resistor always have to stay at the same ohm as the driver its adjusting? Or is that just how the online calculator arranges it?
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I’ve finally managed to make a start on these speakers, after finishing up my other build, but I had a quick question, if I wanted to change the surround design by making them mmt style instead of mtm, is that ok to do with my current crossover? Just switch around the orientation or is it way more problematic to do that?
I don’t plan to do this, it was just a question I thought of and realised I didn’t know the answer, I mean if it is possible then I can decide which I prefer once the boxes are built, and if not at least Ill have got a bit wiser from asking the question lol
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I need a bit of help please if you have the time, im considering flush mounting the tweeter and leaving the pc83 on the surface, can that cause any issues? I literally have no idea about fase alignment ( if thats even the correct term) ive seen videos about it but i just cant seem to understand it, especailly when it comes to checking for that in xsim, if you culd help me understand that id really appreciate it.
Also i plan to buy a calibrated microphone soon to see if these speakers work ok and to see how close the xsim crossover was to how it is in real life, but i watched a couple videos about using rew and i think it may be way out of my league right now to do that, is it really as complicated as those videos seemed? Or is it something i could manage? I literally just want to see the real freq response of these speakers and then upload the files to xsim to adjust whatevers needed.
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You are thinking of the Z-Offset which is used to time align the drivers in order to keep them in phase. For example, if a tweeter and a midrange both put out a 2000 Hz tone, and the bases if the cones are not lined up, the driver that has the cone base further forward would reach your ear just a hair before the other driver. Ideally, you would measure from where you would mount the driver back to where the cone/voicecoil former meet, compare to see if they are close to “0” alignment when mounted. The less offset, the better. It can be compensated for in the crossover, but I’ll let the other more advanced designers help with that.
REW – just like any other software, there’s a learning curve. I’m sure that once you dig into it, it’ll become easier. I still have yet to really use it as life has been very hectic.
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Thank you for getting back to me, i have to say im not too sure about what you mean, as in were to measure too, ive taken these pics of the drivers as if they were mounted both on the front of the baffle, can you please edit my picture by drawing lines on the points i need to measure too? It looks to me as if the tweeter needs to be inset to make the bottom of the cones match better? If thats the point of the driver you mean to be ”in line’? Although how im going to measure that i dont know yet.
And thanks for correcting me, now i know that its the z offset i can see if i can find any info that can help me to do this, as for rew, i will try it, but im not filled with confidence lol
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I show how to figure out the z-offset in this video. However, you do need a measurement microphone.
You could try to guesstimate it or even do a measurement with a tape measure. This will not be exact, but might get you close enough in the ball park to estimate it. Really, though I recommend a measurement mic.
Just make sure to input this in to Xsim when you simulate your crossover.
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Thanks for that video, as im so new to anything microphone related, i dont fully understand some of the things you talk about in that video. You say to take measurements of both the woofer and the tweeter independently but without moving the microphone, so you take both driver measurements from tweeter hieght? And will that be the same for my mtm style? Also ive already done the crossover and bought the parts, is this going to drastically change everything i did before?
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That is correct. You put the microphone at tweeter level and take all the measurements. You also need to get it’s impedance. If it is an MTM, you would leave it at tweeter level. The mids would be wired as the will be in the final arrangement (series or parallel). The mic measurement will be both of them playing at the same time. In reality, this is acting as one driver. The only reason you would take these separate is if you were doing a 2.5 way versus a 2 way.
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Thank you,
Can i ask how you got so knowledgeable with speaker building and all the things that come with it?
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I posted this once but it seems to have disappeared lol anyway, ive bit the bullet and ordered the omnimic and the dats, i just didnt trust myself to be able to use rew properly, so hopefully i can use these to get the best sound possible from my speakers, i want to be able to say i did everything in my power to improve them, i can use it for future builds too i guess. Like ive said before, i would really appreciate any help you can spare as i really want to learn, but not knowing anyone personally that can teach me is causing me to go in circles and then i just feel hopeless. So much information on the internet, but trying to intragrate it to my specific builds is confusing, just like this z-offset that i missed the first time doing this crossover lol
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Let me know when you get it. If you need help figuring anything out, I’d be happy to help you. As far as how I learned, from others, research and experimentation. That is why I am always happy to pay it forward to others.
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No doubt i will need to get in touch with you, i should receive it on Tuesday, maybe Wednesday, and its great that you are willing to do that, not many people would take the time! I wondered if you had done some kind of course with how involved and knowledgeable you are in audio. But if you ever need any advice on welding or fabrication, im your man, but thats all im able to pass on lol
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Like everyone else, I started out not knowing a thing other than “the speaker goes in a box and there you have it.” Then I read (because there was no such thing as the internet as we know it) and read, and read some more. I still read up on many things, both in print and virtually. Then just messing around with what I’ve learned to see the outcome. And I joined here because I really wanted to be in a place that is, at the heart of it all, a true DIY home, as that has always been my passion. There are many other big, well established forums that can help, but tend to be a bit on the, well, kind of snobbish side of audio. Not that you can’t get the info out of them, but you may have to deal with long termers that have a bit of ‘tude. Here I want to give what help I can, and learn more so I can give more. I want people to be knowledgeable about how things work so that they aren’t just “end-users”. This can give “you” a leg up on the marketing speak to weed out the wheat from the chaff.
REW – I bought an iMM-6 mic because I have a dedicated 1/8″ mic in and 1/8″ headphone out on my laptop, and it saved me a lot of money over other calibrated mics. I have to get into using it. Watching instructional videos and just using the pulldown menus, I’ll figure it out. When I learn it, I’ll help.
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Ive tried to find things to read and learn from, but mostly its all without context, so it confuses me more. And as for other forums, like you say they seem to not like outsiders lol which for a beginner is hard work, so far this forum has been completely the opposite. From a couple of threads and informative comments ive learned al lot, well enough to complete projects i couldnt have done alone. As for the mic, it took me a whole day to convince myself to pay for the omnimic, but i want to get the best results, im a perfectionist, and if i had to use rew id have failed, its just too complicated for my experience. I do want to understand it but the fact i have two weeks to get these speakers finished means ill have to learn it later, but if you do figure it out id love some tips.
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Couldn’t agree move regarding some of the other forums online, I was on a few of them before this one and I’ve got to say, even when being polite and all, it seems like you’re such a hassle for those who end up answering you. My thoughts on that? Why would you even spend your time to answer me then? Or better yet, why would you want to join a forum in the first place?
Anyway, I too want to thank you guys on here for being the kind you are. You are genuine people and this is a great place to share and learn and I am sure that we can all do great stuff together,
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I appreciate hear that. This is the exact reason I started this forum. I found that there are a lot of unhealthy forums. It can be hard, because you know some people come just to have a question answered. Even still, those that are helped, the hope is, is that they pay it forward to someone else. That way everyone can continue to grow. That is the way it should be. And I am excited to see everyone on here supporting each other.
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Let me know. If you want we can do a google hangouts or even skype so I can see your screen as you go. Not sure where you are located, but here in the US, we have a national Holiday this Thursday, Thanksgiving.
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Thank you for the offer, i live in wigan, Manchester, UK, i should receive the mic within a few hours, firstly i just want to check with you my method. As i wouldn’t want to waste your time by not having everything set up properly. I may be able to work this out from instructions rather than you having to take the time to personally walk me through it on your day off but maybe im being to optimistic.
Anyway, ive got my box built, including the port, and today i plan to add the drivers and run the wires out the back and seal it with hot glue just for now. Two wires from the tweeter, and two wires from the woofers connected in series. Ill then take the impedance of each driver. Then ill swap to the mic, measuring 16inches away from tweeter level. Ill connect the tweeter first and run a sweep, then the woofer, then both connected as they would be in the final design. Is that ok or have i missed something or done something wrong?
Also im having major problems downloading pcd, i click the download button, it starts then nothing happens, it doesn’t download. I noticed at the beginning of your video on z-offset that you mention omnimic has built in z-offset calculator, so will the software work that out for me without having to use the pcd method?
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It won’t cause any issues. You’ll get reflections, but the 16 in is to reduce those to everything below 500 Hertz. we will set your gate and put Omni mic to blended and that does a really good job getting you an fairly accurate depiction of what’s going on below 500 Hertz as well.
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Ok great, does the method i mentioned above seem ok? Im trying to get everything set up so i can measure it tomorrow, im gonna get on the laptop later and down load the files.
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You will be fine without the absorption material. But you can add it if you like. The Omnimic software is pretty extensive. It will show you the first reflection and you will select it while taking your measurements. There are a few options from there. You can select, only to, which will show you only the response after the first reflection or you can do blended. Blended, does a really good job of taking out the first reflection while giving you a fairly accurate low end – there will still be some room in the response though. Otherwise, if you do only to, you will do a close mic measurement of the woofer and splice them. You can do that all in the Omnimic software.
Jeff Bagby has a good write-up here.
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Sorry, i meant the method i wrote for testing everything above the post i made about putting the foam down, im not sure you read it as i put another post right after it. Ive just got the dats working and ive taken the impedance for the tweeter in the box, and another for the two woofers in the box wired in series. You say in your video to save them as zma files, i just clicked on file then save, and it put them in a folder for me, but will they have been saved as zma or do i have to save them in a different way? Im sorry for all the questions, i just want to do it right.
At the minute im trying to download and install the omnimic software, my computers fighting me on it though. Im hoping to get it all installed and ready for tomorrow, i cant take any measurements tonight as its almost 10pm and i think the neighbours would hate me lol
What time (london) will you be available tomorrow if i am struggling? I dont want to take up your time tbh but i dont really have any idea what im doing
You replied as i was writing this 😁
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Yeah I think we are misunderstanding each other. You’re fine taking that 16 in away. You don’t need the foam. You can use the foam if you want to but you don’t need it. the distance to microphone is away from the speaker determines where the first reflection is going to be from period and it’s going to be in your lower frequency range at 16 in period so that’s going to be somewhere between 800 and 500 Hertz most likely. Dominy Mike has a couple different options when you take that measurement period one of them would be to cut all the sound before that first reflection out. That would only give you a response of say 800 Hertz on up. In order to get the low end information, you would do a close milking of the woofer period when the microphone gets close enough it will get rid of the room interaction. Then you would splice the two graphs together. And if you have a port then you’d have to splice the port in as well. The other option is to use Omni Mike’s blended option. That option will do the splicing for you, but it will still have a little bit of the room below that 800 or 500 Hertz area. It still gives you a really decent representation of what’s going on.
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Yeah, thats seems really complicated, maybe id be able to figure it out after messing around on the software for a bit, thanks for explaining that for me though, i have a bit more understanding of it now.
In regards to the pcd method of getting z offset, i still cant get it to download, once ive taken the tweeter and woofer measurements seperately will the omnimic software work it out for me to add into xsim?
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It’s not complicated at all. Once you get used to it. It’ll only take you a little bit of time to understand.
Yes you can still find the z offset. you’ll take your woofer measurement your Tweeter measurement and then both of them wired in parallel together. Those are the three measurements you’ll need.
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I hope your right because im not great with computers, but i think so far everything has gone ok with the dats. Im just not sure ive managed to save the impedance measurements as zma, i didnt take much time with it as i was anxious to get the omnimic installed. So ill give it all a go tomorrow and see what happens, thank you so much for your help with this, i feel a bit more at ease having your input to help me deal with my mistakes
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Well since im struggling to sleep ive been reading up on the omnimic manual, as i was reading how to use the z offset calculator i noticed it mentions to add a blocking capacitor to the tweeter, having never had to do that before i thought i had better check with you, or anyone else who reads this and can advice me on what size of capacitor is needed. Will the one i had in my original crossover for these speakers be adequate? Im thinking yes but im far from an expert, and i dont fancy breaking my tweeter on the first attempt tomorrow
Btw, i plan to use one side of my 2×50 watt amplifier to do the sweeps, i thought about just using the dats to send the omnimic audio into the speakers, but then i realised both mic and dats use usb and i only have one usb port on the laptop
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There is a z-offset calculator in the software. I find it rather confusing, so I just stick with the way I know. But if you can really get it down pat, let me know.
As far as the cap goes, they have to put that in the manual. Here’s the truth to that though. If you notice all my measurements are typically under 1w. If you don’t play it really loud, you typically won’t damage a dome tweeter. There are some you can, but a dome tweeter or compression drivers, you typically will not.
If you can wait until Friday, I would be happy to hop on the computer with you and help you through your first attempt. It won’t take very long if you are all set up. I won’t do it tomorrow, as I have thanksgiving. Just PM me if you ae interested.
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I may get in touch on friday then if im really struggling to get good results, thanks for that, ill mess with it today just as a learning experience, not too confident in the results but ill post them on here if i can figure how to so you can see where im at.
So regarding the volume, as the sine sweep repeats constantly i can set the amp to low to start with and just turn up the volume until its a reasonable level and that will protect the tweeter without the cap? I only ask as i haven’t noticed a place on the software where i can adjust the wattage, it may be clearer to me though once i take a proper look at it today.
The z offset calculator, if i can figure it out, is really my only way of working out the difference between drivers as i still cant get pcd to download, i wish i could use your method instead as i could follow your tutorial, but my computer just wont behave.
Anyway have a great thanksgiving!
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So ive had a mess around with it, omnimic wants you to take a measurement of the woofers first (driver B), save it then take one with tweeter and woofer together (drivers A and B) and save that too. Then you open up the added curves menu and add the file from both playing together. Next you add the driver (B) response to the graph also. After that you connect just the tweeter (A) to the amp and play a constant sweep while adjusting the seconds tab in the little window that contains the z-offset calculator until the tweeter response line best matches the curve of A and B playing together.
This isnt as accurate as i was hoping, the tweeter curve rises and does match better, but it doesnt match perfectly especially higher in the frequency, if you adjust too much it overshoots but without bringing the mid section into line. So i set it so the shape of the curve matched rather than overlaying the dual curve exactly, because it just doesnt seem possible to do that. Now i could/probably have done it wrong in some way, maybe ill try the same but invert polarity on the tweeter see if that helps.
these are my graphs
Before
The black line is the frequency on both drivers together
After
It says the z-offset is 0.571, how does that sound given the drivers im using?
EDIT: I realised that i measured the tweeter wrong, the polarity was backwards, so the graph dipped, it was better when i swapped the wires around, but i got mixed up with saved files so i plan to delete them all and re test.
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I’m having a nightmare trying to download pcd, i cant find a download link, like anywhere, on the homepage theres only a workbook download and a user manual available. Where can i get this programme? Ive been trying for days, and ive just installed excel thinking that might be the problem, but still no luck
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The workbook file (.XLSM) is the file you want. Jeff Bagby wrote PCD as an Excel worksheet. You’ll need a “New Enough” version of Excel or equivalent (not just a reader) to run it. For example, I have versions 2003 and 2013 at my disposal, but only the 2013 will run the workbook. 2003 just crashes massively.
You may also see a “Enable Editing” button at the top of your screen, which you’ll have to press in order to activate the file for use. It seems to be a default safety feature for things you’ve downloaded from the internet. Once you’ve enabled editing, save it and that should set it to work from then on.
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The workbook file (.XLSM) is the file you want. Jeff Bagby wrote PCD as an Excel worksheet. You’ll need a “New Enough” version of Excel or equivalent (not just a reader) to run it. For example, I have versions 2003 and 2013 at my disposal, but only the 2013 will run the workbook. 2003 just crashes massively.
You may also see a “Enable Editing” button at the top of your screen, which you’ll have to press in order to activate the file for use. It seems to be a default safety feature for things you’ve downloaded from the internet. Once you’ve enabled editing, save it and that should set it to work from then on.
Ahh i see, thank you so much, ive been going insane with it trying to figure out why its so hard to find the download 🙄 i actually had the workbook downloaded but figured it was an example as i couldnt add or change anything on it. Youve just saved my computer from early retirement as i was getting close to taking a hammer to it 😄
I wonder if you could help me with something else? So the onminic graphs i saved as frd dont seem to load into xsim, well they load but they dont actually show a graph on the right. Im wondering if i have to rename them a specific thing or if maybe ive done something else that xsim doesnt recognise as an frd file?
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The FRD file (and ZMA file, for that matter) is just a plain ASCII text file with a specific file extension. If you were to open it up with NotePad (Windows) or a plain text editor (no clue what that would be in Apple-speak), you’d see something like this:
So, just to double check, open one of those applications and try to open up the FRD file to see if it is similar. If you get some sort of “gobbledygook”, then you’ll need to re-export the file as plain-text.
Once you verify the quality of the file, maybe you could share it here. Might be a setting or a step being overlooked or missed. Let us know what you find.
Just an FYI, I will be cooking for a good bit of the day, since I will be celebrating Thanksgiving a day later (tomorrow) and am prepping, so there might be a bit of a lag in answers.
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Its no problem at all mate, i understand, im just grateful your taking the time out to help me.
So i opened the file i made in word and it looks exactly like the picture you posted with all the numbers in a line. So if thats nit the issue can you think of anything else it could be?
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If you’ve added the driver and connected it to the source (in XSim), then added the FRD file to the driver, it should show up on the graph. Have you checked that the graph goes out far enough, ie, not zoomed in too close? There should be a setting in the drop down for the graph that does that – zoom in or out. Not at my laptop, so no access to XSim to check just yet, but I seem to remember being able to do that.
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Well i think ive sorted some issues. Ive got pcd working now, added all my data, at first i couldnt find my zma files until i realised it had saved them as txt not zma. So i got them added and started the process of adjusting z-offset. I couldn’t get it lined up right though, the middle just wouldn’t rise, i realised that i changed polarity of the tweeter when i measured it so its inverted in the graph now, i measured tweeter normally when i did both together, im an idiot. Anyway thats as far as ive got, if i can get them added to xsim ill see if i can find that option, thanks. I think i might have measured them too quiet tbh, the graph shows about 65db at its highest, ill turn it up a bit tomorrow. So im going to re-measure everything in the morning and try again, and see if it will let me add to xsim next time. Ive been at this since 11am. Its now 10pm at least it cant be said that im not commited haha
I still have to rework that whole crossover too, and ive already bought all the componants 🤦i guess you never fail, you learn
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Funnily enough thats exactly what my girlfriend says haha if im not building speakers, im welding/fabricating on other projects, i make knives too when i get the time lol rather that than being in the pub 24/7 i say
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Ive just re-done all the measurements, but with the tweeter positive to the amp positive, and it came out a lot better, it worked out my offset at -0.416 but im going to try it in pcd aswell to confirm it. If i get the same then the software on omnimic should be ok to use in future, its still not matching perfectly but im assuming since im matching a live response the room is slightly affecting the top end?
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Sorry for the bad quality, dont know how to screenshot my laptop
So im still having issues with this, i just cant get the high end to get anywhere near, and after i did this on pcd,i tried to upload my frd measured files into xsim again. I got further this time but it had a wierd effect on the ohms, and the tweeter curve wouldn’t change at all while changing the values of the crossover componants, like it didnt rise or fall in the slightest
• should i be measuring the tweeter with bass removed in the sine sweep? And if so how do i change the audio file to be played on omnimic? All it uses at the minute is the short sweep
•could the answer to the above question be the reason i cant make adjustments to the tweeter in xsim?
Honestly i feel like giving up, i just cant get this right, ive wasted two days on this now and got nowhere near a usable design.
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Im just wondering if you can help me understand something please?
If i miraculously manage to work out the z-offset of my drivers, and then i add that delay into the woofer of the xsim crossover, how does that actually delay the tweeter in real life? Like i can see when i add a delay into xsim that it lowers the overall response of the tweeter section, but the crossover circuit stays exactly the same as it was before , so how do i actually tell the tweeter to have a delay in the actual box?
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Why don’t you PM me the files you have and I’ll take a look at it. Then I can better answer your questions.
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Actually you don’t need the PM them just post them here as a zip file
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Ok thanks, ill have to get the laptop, ill send them shortly
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Sounds good. and then if I can I’ll even make a little video to show you how I’m doing it. That way maybe it’ll help.
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That would definately help, thankyou. Now these are my measured files, but im not sure i even did that right, the tweeter seems to be way off what it should be but you will know better than me, hopefully ive uploaded these right for you
1516-tweeter.zip
1517-woofer-and-tweeter.zip
1518-woofer.zip -
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You accidentally sent the tweeter impedance twice. Can you resend the woofer impedance?
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1521-Exported-Impedance-Data-woofer.zip
Is that the right one? If not ive no idea what ive done
But yes if its the right one, i took the measurement with both drivers wired in series
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No that is the tweeter impedance. It looks like you accidentally saved over it. Don’t worry we have all ben there. If you can take a quick zma of the woofer, I can finish it for you.
This might also be the reason you haven’t been able to get it working right.
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I appologise, ill try and retake the measurement now, ill be as quick as i can
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The impedance is correct, but there is something going on with your response measurements. First, they should be a little louder, closer to 80-85db. Do you have your measurements in omnimic taken as blended? Did you move the mic or change the volume when taking measurements? Were they all taken at tweeter level about 16″ away from the tweeter?
Which tweeter and woofers are these?
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Yeah i took the measurements from tweeter level, 16inches away and i didnt move either the speaker or the mic. But i was using an amplifier with a low level as i was worried about the tweeter, should i have turned it up as it was running sweeps until it got up to 85db? But yeah i had a big hump at 50hz with the tweeter measurement
Oh and yes i had it at blended but i didnt realise i needed to add 5ms in the other box so that was zero. I didnt change the volume between sweeps either,
the drivers are pc83 and td20f-4
Also just so you can check what i did to produce the sweeps was right, i played them from my laptop, out through the headphone jack and into the amplifier, i let it run for 10 seconds or so then paused it. I then went to the top left corner and saved the curve, i did that for all the measurements. But obviously i had the amplifier too low (schoolboy error)
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The main concern when playing that low is that it might pick up other noises in the room. No worries. Something happened with the high end on it. I am not sure why. I just finished the video and here it is.
I hope this helps
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PS – you don’t really have to leave it running. When you get a good measurement, just pause the program and save it. You probably weren’t getting a big hump at 50hz from your tweeter. That was probably something else in your room. Just make sure you are using an amplifier that is not dsp’d. Same with your computer. ANy special audio processing should be turned off. No added bass or treble.
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Thank you for taking the time to teach me with this, i really, really appreciate it, i appologize for not replying sooner, it was after 4am here and i fell asleep.
Ill have a watch of the video you kindly made and i will try and get new measurements taken today or tomorrow, using what ive learned from you and once ive done that ill upload them on here, if you wouldn’t mind just taking a quick look to see if they are better this time?
As far as i know the laptop and amplifier play with normal settings, i think the 50hz tone was being picked up from my radiators being on, everything in the graph was moving slightly but the 50hz peak was stable, didnt move at all, so ill try turning up the volume this time and having the heating off.
edit: so ive just watched the video, that helps immensely, thank you, hopefully my new measurements and crossover can benefit from this.
With regards to the ‘delay’ of the tweeter, i thought that a componant of the crossover would physically delay it so that the sound left at the same time, i hadnt realised it was just allowed for in the crossover, thats clearer for me now too
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Ive just noticed you said to take the freq resp first then the impedance so that it’s already set volume wise, im not sure how to do that as the dats produces its own tone, i dont use the amplifier for that test, and the dats sweep sounds quite low to be honest, probably around the same level as i took my original measurements. Is there a way to increase its volume to match?
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Ive re run these measurements today, i increased the volume and turned off any source of noise i could find in this room, but im still getting that shitty tweeter response. Could it be that behind my speaker i have a metal radiator set back about 4 feet? or could it be a port issue?
Ill add all my new measurements in this post just in case you can spare a minute to see where im going wrong. If not i understand, and im grateful for the help youve already given me. While using xsim to work out the z offset (which is way easier than the other way, thankyou for that) i found that they line up better if i add a 0.7 delay to both woofers, as im running them in series. I know im being a pain with this, i apologize, i just wish i could just get it to work and not have to bother you anymore. I think the tweeter issue is whats causing me to have these problems though, so ive taken a port measurement too, 2mm inside the port at exactly the same volume of the amp etc as the other measurements. And if i re run them again im going to set up in a different room. Also i had it set to blended with 5.0ms
1525-Exported-Impedance-Data-woofers-together.zip
1524-Exported-Impedance-Data-tweeter.zip
1526-Exported-Impedance-Data-single-woofer.zip1528-tweeter.zip
1527-woofer-in-series.zip
1529-woofer-and-tweeter.zip1530-port-2mm-inside-on-centre.zip
At this rate im gonna have to start paying you for your time!
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Thank you,i appreciate that, and its no problem, im going to finish the speakers and leave the tweeters and crossovers disconnected until i can find the reason for the wierd tweeter high end when i try to overlay them. The tweeter response on its own seems to be not too bad? The problem occurs when i try to put them all together. But at least i can use the system with just the woofers for now as luckily i picked full range ones lol
Just thinking out loud here, but as i typed that, i realised something, as the woofers are full range, and im testing with no crossover, could the wierd dips at the high end be due to the woofers also playing the same frequency during the tests but having a different response to the tweeter? If not i must be doing something wrong during the measurements, although im trying to match instructions the best i can
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