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Dameo182
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Hope i didnt forget anything

20200731 224247

 


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123Toid
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@dameo182

It is the smallest area of your baffle.  For example if your baffle was 42" long and 8" wide, you would go off 8" wide.  

https://www.youtube.com/123toid


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123Toid
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@dameo182

In that example it looks to be 160mm. 

https://www.youtube.com/123toid


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TVOR-Ceasar
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@123toid Thanks for jumping in. Baffle step, even though I understand it, it is not one of my stronger points and I'd like to improve my standing there.

@dameo182 Thanks for the pic, that's exactly what I was looking for. Yes, like Nick said, 160 mm.

-Charlie
https://www.youtube.com/user/TheTrueVoiceOfReason


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Dameo182
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Thankyou both for your help, i knew it would most likely be a simple answer, just with all those different dimensions i didnt know where to start


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Dameo182
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Ive finally made a start on the little speaker that this thread was made for, i plan to power the drivers using the 2x50 watt amps and using a 12v 2amp power supply as @123toid suggested, but ive had an idea that i hope someone can advise me with. Ive decided since this speaker is for the bedside table that i want to add either an led strip or a single led bulb so it can be used as a reading lamp too. Obviously i have little knowledge when it comes to circuits and the like, so my first question is, can i use that one power supply to power both speakers and the lights? Or do i need a larger power supply for that? 

Also if i use a larger supply, when the lights arent being used will the speakers then recieve too much power? I ordered 4 ohm drivers

I really wish i knew more about this stuff to save these silly questions lol 


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TVOR-Ceasar
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Using the 12V supply makes things really easy. All you need to do is shop at the auto parts store for the appropriate LED light. Try looking for a "Map Reading Light", as that will usually be a type of spotlight, perfect for book reading. Or whatever light fits your design goal.

For the rest of the question, I think that if you will be reading in bed while listening to the speaker, you'll probably be using less than a watt of output, more likely 1/4 to 1/2 watt that close to your head. So really, the power issue isn't an issue at all. And when you turn the light off (which most likely will only use a watt or less), the amp will only draw what you ask of it. Yes, if you give it more power to work with, it will take more power up to the point of either the amp cannot request any more or the power supply can't give any more.

For example, if you have an amp that can deliver 100 watts on a 36V supply, it'll need 2.78A to go full wattage. If your supply can only deliver 2A, then you'll max out at 72W and a 1A supply will only allow the amp to deliver 36W. Now this is talking about Class D. Class A and AB are more voltage dependent, but we won't get into that just yet.

***If I ever seem to be rambling on, just let me know. Sometimes I get on a roll. 🙂

-Charlie
https://www.youtube.com/user/TheTrueVoiceOfReason


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123Toid
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A lot of this will depend on the wattage your LEDS will use.  You may want to bump up the pwoer supply.  Keep in mind, just turning down the volume will protect your drivers.  SO you won't send too much power to them, unless you turn it up too much  

https://www.youtube.com/123toid


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Dameo182
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@tvor-ceasar

No i like rambling, i learn more lol 

Thanks for the explanation of how this can work, i was imagining it to be really complicated because of the wattage etc, for future reference, google says that a 5mtre strip of LED consumes 72 watts, so each metre uses 14.4, does that sound right? I never really trust google anssers tbh 

So given that my 24 watt supply is fine for this build, my next stupid question, is how do i actually wire it up? Can i take two posotive and two negative wires straight from the back of the power input plug, run one set to the amp and one set to the lights? And add a switch in the lights supply? Or am i way off lol? 


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Dameo182
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@123toid

Yes thats a good point, as usual lol, only reason i was trying to stick with the 2a version is to avoid the big rectangular transformer that comes with the more powerfull supplies, they look so clumsy and are a pain to hide. Really i just want to fully understand how the different componants share the current so that in future i can work out what i need without any issues, you guys find it so easy lol maybe i think too much into it 


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TVOR-Ceasar
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Posted by: @dameo182

@tvor-ceasar

No i like rambling, i learn more lol 

Thanks for the explanation of how this can work, i was imagining it to be really complicated because of the wattage etc, for future reference, google says that a 5mtre strip of LED consumes 72 watts, so each metre uses 14.4, does that sound right? I never really trust google anssers tbh 

So given that my 24 watt supply is fine for this build, my next stupid question, is how do i actually wire it up? Can i take two posotive and two negative wires straight from the back of the power input plug, run one set to the amp and one set to the lights? And add a switch in the lights supply? Or am i way off lol? 

*LED strip W/m, yes it is that simple. 14.4 W/m. You just have to read the manufacturer's literature to make sure you can cut it apart like that and still have it run correctly on that voltage.

**Wiring, yes, that is the most common method to run parallel circuits. Just put the switch on the positive (usually red ) wire.

👍

-Charlie
https://www.youtube.com/user/TheTrueVoiceOfReason


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Dameo182
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@tvor-ceasar

Thankyou, ive been wondering if it was safe for me to attach the led strip in that way, so i feel a bit more at ease with the connection now, ill post a link to the strip i decide to buy, hopefully you dont mind checking the details for me to make sure i can cut them to any length and not cause a fire or similar lol 

Then i just have to build it, and then i can post pictures of the finished speakers on here


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Dameo182
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So i found these, says they are cuttable and the max wattage is 5.8w, so i will have 4 watts spare if the drivers are at full volume (as they take 10watts rms) so since i only need about 300mm of that strip length my 24 watt supply should have no problem running everything? Leaving a bit of room to charge a phone from the usb outlet on the amp at regular listening volumes?

The way i worked all of that out, is it right? 

Thanks again to everyone whos adviced me with this build, literally couldnt do it without you! 

https://www.screwfix.com/p/enlite-en-stk1200-led-cuttable-striplight-warm-white-1200mm-5-8w/9486V?tc=JC7&ds_kid=92700055281954481&gclsrc=aw.ds&ds_rl=1249401&gclid=EAIaIQobChMIlIbTuv_U6wIVB-7tCh3Bdw6mEAQYAiABEgLtxvD_BwE


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TVOR-Ceasar
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For your 300 mm strip, it'll use ~1.5W.

The specs say every 50 is a mm is a cut point, so each if those is a 12v unit, and all of those units run in parallel. So you take the 1200/50=24 sections. Your set of sections will total 6, so 5.8/24*6=1.45W. Gives you a little more headroom to work with. And if you go with a charger of 500 mA (1/2 amp - 2.5W), you can use all within limits and not tax the power supply. Well, it'll be real close. If you use a higher power USB charging unit, just keep the volume down.

-Charlie
https://www.youtube.com/user/TheTrueVoiceOfReason


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Dameo182
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@tvor-ceasar

Great thanks for that, i did wonder though about 24 watts being sent into the LEDS if the light is used without any music being played, and from what you said above about the 300mm strip only taking 1.5w, should i be concerned about that? Like overheating the lights, or will the lights only take 1.5w even if they have the whole 24w available? Does the load decide the current, or the supply? U may have answered that question for me in an earlier post, if so i appolgise, i just find circuitry and power usage so confusing still. Sometimes i dont know if what ive learned on something else can be transferred to other things. Do you know of any textbooks or information i can buy that i can learn from? Because i have so many quick questions that i cant seem to find answers to online.

How did you learn all of this btw?


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