Q: Small (40cm/15" Max Height) Speakers

[LinuksGuru]

Hi !

My friend asked for DIY receipt of relatively small (40cm/15" max height) speakers for 20W 6p14p push-pull amplifier.

I like big boxes only - so have no ideas for him.

Probably it should be 2-way bass reflex with (at least) moderate sensitivity 91 - 93 dB*W/m. No audiophile boutique parts.

Please recommend something you have built yourself or heard somewhere.

Thanks in advance !

 

[planet10]

I can give lots of options for a single driver FR system that satisfy that criteria. 20W is lots to drive a much less sensitive speaker than you are asking for. The amp would like to see a nice flattish impedance curve — something very often missing in a 2-way speaker.

dave

 

[LinuksGuru]

I can give lots of options for a single driver FR system that satisfy that criteria. 20W is lots to drive a much less sensitive speaker than you are asking for. The amp would like to see a nice flattish impedance curve — something very often missing in a 2-way speaker.
dave

Hi, Dave,

Would be nice to have your suggestions. I personally don't care about underlying technology as long as objective is being achieved, so full range is OK. My friend has wood and metal working skills, yet not willing to spent a lot of $$$ for boutique drivers.

 

[miro1360]

is this good or bad for 2-way 60W system?
https://ctrlv.cz/shots/2017/09/24/NmVJ.png
https://ctrlv.cz/shots/2017/09/24/W6WM.png
https://ctrlv.cz/shots/2017/09/24/lHq6.png

 

[planet10]

Mark Audio Alpair 7.3/10.3/10p, Fostex FF165wk should all fit your requirements.

In slot vented enclosures A7.3 fits in 9 litre optimum, A10.3 13 litres, A10p in 17 litres but i have designed as small as 7 litre (not optimum but doable). FF165wk fits similar boxes to A10p, haven’t looked at anything as small as 7 litre.

http://www.planet10-hifi.com/downloads/A10p-7L-vented-0v81-140917.pdf

An externally hosted image should be here but it was not working when we last tested it.

Mark Audio can be had from KJF Audio at a minimum, Fostex are widely available.

dave

 

[LinuksGuru]

is this good or bad for 2-way 60W system?
https://ctrlv.cz/shots/2017/09/24/NmVJ.png
https://ctrlv.cz/shots/2017/09/24/W6WM.png
https://ctrlv.cz/shots/2017/09/24/lHq6.png

Frequency curve is close to perfect (if its correctly measured).
Impedance curve has a peak around 4 KHz yet its acceptable, and much smaller then many other designs.

 

[planet10]

Frequency curve is close to perfect (if its correctly measured).

Looks like a simulation not a measurement.

dave

 

[miro1360]

yes it is only simulation based on manufacturer data and box dimensions included bassreflex, I did these speakers few years ago, but I need measure them ...
midbass is monacor SPH-165KEP and tweeter Monacor DT-107

GrabCAD - CAD library

 

[suzyj]

If you can get Vifa P13WH woofers where you are, Rabbitz did a very nice small speaker with them and a Vifa D27TG tweeter. Not a huge amount of bass (they respond well to eq), but really nice speakers.

http://www.diyaudio.com/forums/multi-way/25590-diyaudio-reference-speaker-project-3.html#post308661

 

[LinuksGuru]

Mark Audio Alpair 7.3/10.3/10p, Fostex FF165wk should all fit your requirements.

In slot vented enclosures A7.3 fits in 9 litre optimum, A10.3 13 litres, A10p in 17 litres but i have designed as small as 7 litre (not optimum but doable). FF165wk fits similar boxes to A10p, haven’t looked at anything as small as 7 litre.

http://www.planet10-hifi.com/downloads/A10p-7L-vented-0v81-140917.pdf

dave

Hi, Dave,

Fostex FF165wk - how does it work in 7L slot vented enclosure ?
What if size will be increased to slot-vented (not bass reflex) 15 - 17L? Its still fits my friend dimensional requirements.

 

[planet10]

I will look at the size the FF165 works in. I recently drew up a 7 litre box for the Alpair 10p, not optimal but it looks like it will work. A10p optimum is the same as the FF165 at 16-17 litres so it could work in the small box as well. A free plan for a 13litre CGR will be posted once i get it drawn.

An externally hosted image should be here but it was not working when we last tested it.

Edit: above revised 28-sep-17 to move vent closer to optimal cross-section, box is deeper & shorter, vent could still be bigger in use should not be a big issue

dave

 

[miro1360]

this alpair 10p have nice specs ...

 

[planet10]

Sims show FF165wk should work fine in a variation of the 7 litre box above. F10 about 60.

dave

 

[miro1360]

what you say about this SPH-165KEP monacor which I used in my speakers as midrange?

 

[planet10]

SPH-165KEP monacor

If you are asking if it will fit into the 7 litre box above, maybe. It will work in 7 litre (F10 ~40 Hz) but tuning is low enuff that the vent may need modification in such a way that the box would be somewhat different. It would at least need to be less tall and deeper.

dave

 

[planet10]

...but tuning is low enuff that the vent may need modification in such a way that the box would be somewhat different. It would at least need to be less tall and deeper.

I figured that deeper & shorter would be good for the A10p anyway so the above has been revised. Vent still on the smallish size.

dave

 

[miro1360]

thanks dave, I am looking for your project with A10p

 

[rabbitz]

If you can get Vifa P13WH woofers where you are, Rabbitz did a very nice small speaker with them and a Vifa D27TG tweeter. Not a huge amount of bass (they respond well to eq), but really nice speakers.

http://www.diyaudio.com/forums/multi-way/25590-diyaudio-reference-speaker-project-3.html#post308661

FWIW, SB15MFC30-8 can replace the P13 in the 9.5 litre box with port changed to 160 long (F3 around 50Hz). Some of the original xo's will work with the SB15.