Side firing woofers
Thanks for the regular encouragement and advice. I recently purchased some inexpensive Kasun brand 1” domes (vifa copies maybe?) from Aliexpress and I am pleased with them.
So Nick if I go with a sealed 2way for the upper section is volume still critical at all and just going for form factor? I’ve always felt like there are benefits of using a port.
The Kasun tweeter in a Dali 5a speaker.
4” mid range specs $25AUD Each from a local supplier.
sealed is still critical to a certain degree, but it is more forgiving. I would still try to aim for a q of around .7 if you can make that happen. And of course, you can use some polyfill if needed as well. Now if only I read Chinese...
The tweeter does look to have a nice response to it.
OK. So the C3017 has a Total Q factor Qts=2.22. Way too underdamped. So you mean look for a Qts around 0.7? This will give a much more punchy accurate mid frequency reproduction.
I have a question about the C3017. Is it a sealed driver? Hard to tell from the photos and not mentioned in the PDF. Sometimes a midrange comes as a sealed unit - no cutouts in the basket. If that is the case, it would pretty much negate the debate between box choices. Also, the super high Qts actually is in line with Open Baffle, so you could make the matching box open back, possibly with some sound absorption inside, such as "stuffing" or foam.
You also need to look at the Resonant Frequency (Fs). It is 477 Hz. You may be able to calc a lower Fb or F3, but in all reality, it doesn't want to go that low. AND, you'd want your Woofer to be able to play up to at least 1KHz, but you may be able to get away with 800Hz. All depends on how it measures "in cabinet" and how it sounds to your ear.
I looked up the Qts which is high and undesirable in the C3017 so I've found a 4" Peerless by Tymphany mid-woofer at a local supplier for $42.50 AUD which is about $30 US each. Much dearer than the Altronics driver but with a Qts of 0.44. Here are the full specs.
I'm thinking of going sealed box. Only the powered subs will be ported now. So the upper box can now be quite small just large enough for the drivers and cross-over. Similar to a KEF R107 but even more compact. I am inspired by something I found on Sketchup. Its day 2 with free Sketchup but hoping to document my design on this.
Let me know your thoughts on this driver. I'll need a cross-over design at some point. Kinda hoping you guys could help me with that.
Nice. I did a quick run of a sealed box and with a target Qbox of 0.7, the interior volume should be around 0.07 Cu.Ft. / 1.98 L, with a Fb of 100.6 Hz. That is usually low enough for that size driver to couple with a good Woofer / Subwoofer.
Sensitivity for the tweeter id 88 dB
Sensitivity for the Mid is ~84-85 dB
You can match them with the cross-over.
Wise choice switching to a small sealed midrange. That is going to be much better for integration. This is a really awesome project. Sorry I haven't been as accessible lately. I have been sick (sinuses), but when I get them bad, I get them bad. Which I hate. Finally tailing off now.
Thanks for the feedback guys and glad youre on the mend Nick.
I’ve drawn up my design on sketchup and for aesthetics decided to up the mid to 5” . It looked a bit strange with the tweeter face plate and mid the same diameter. Ill let you know the specs when I select one. Thinking even Fostex there is a local distributor and they have a budget range.
Here is a 5” mid woofer from Vifa Peerless probably Peerless India I’m guessing. $40 here.
Does it look good for a prototype?
I’d like it to sound pretty good.
Charlie I can send you my Sketchup drawing to your email if you send it. I already pm’d to Nick’s FB via PM.
Hi Nick and Charles,
Also thinking of upping the anti on the tweeter too with a
Scanspeak Discovery 1inch dome tweeter. These are $50AUD here from the local distributor. No waiting from Aliexpress.
The extra few $$ will gain the Scanspeak credibility over the Chinese Kasun brand.
Planning to go shopping this weekend so would appreciate any feedback you may have.
Cheers from downunder....Peter.
Pete, Check your PM on here.