The Smallest Tapped Horn

[Patrick Bateman]

I saw some amazing measurements of the Danley Sound Labs Tapped Horn Mini (TH-Mini), and decided it was worth investigation.

So here's some info on it.

First, the measurements here show that it has amazingly flat response when used in pairs:

http://www.cobrasound.com/MDSubwoofers

Which made me wonder, what's inside of that box? Based on the size of the enclosure (4.17cf), the power handling, and the impedance curve, I'll bet Danely is using a B&C 12PS100.

http://www.partsexpress.com/pdf/294-665.pdf

The TH-Mini can handle 1400 watts, Danley has been known to use B&C and BMS woofers, and the 12PS100 is the *only* 12" woofer in the B&C line that can cope with 1400 watts... So I think it's our best candidate.

[Patrick Bateman]

Here's the measured response of the th-mini, showing a F3 about 50hz or so.

[Patrick Bateman]

I have a P-Audio SN12MB laying around, so what can I say, I optimized this clone to work with the woofer I got!

Here's a pic.

[Patrick Bateman]

Here's the frequency response. This is with 200 watts into an 8ohm load, which is about 300 watts into the 5.5ohm P-Audio woofer. At this level, you're just about running out of excursion, and you'll need a subsonic filter at high SPLs.

The enclosure is basically equal to the TH-Mini. The TH-Mini has an external size of 4.17cf. This clone has an *internal* size of 3.4cf. Once you factor in the woofer and the wood, you're looking at an equal footprint.

Note the efficiency is lower - however the F3 is slightly lower also.

[Patrick Bateman]

Wanna buy that P-Audio woofer? Here's where you get it for $150:

http://www.loudspeakersplus.com/prod...cific=johmmrq0

[Patrick Bateman]

Don't want to use the SN12MB?

Well here's some simulations with the exact same enclosure, and different woofers.

Here's a simulation of the enclosure above, with the B&C 12PS100, the same woofer I believe Danley Sound Labs is using in the TH-Mini.

The response is all but identical; it's a bit shallower in the midbass. The B&C has more excursion, will play louder, and costs more.

[Patrick Bateman]

So you don't want to spend $207 on a B&C 12PS100?
You're too cheap to spend $150 on a P-Audio SN12MB?

Well how about $50 for a pair of MCM 55-2421 woofers?

Here's what the response is like with my favorite cheap woofer.



Admittedly it's rougher than the B&C or the P-Audio, but that's because the FS of the MCM is way too low. In the real world, it won't be as peaky, especially if you use two or three cabinets.

[Patrick Bateman]

Interestingly enough, a *quad* of MCM woofers has the best response of all. They offer the flattest response, the lowest excursion, *and* the lowest price. At 45hz the MCM has a full four DB more output!

The MCM 55-2421 is very hard to beat.

Check out the response graph.

[Patrick Bateman]

I wonder if Danley Sound Labs should start using a quad of MCM woofers? Half the price, less excursion, in the same box.

WOW!

[Patrick Bateman]

Here's the parameters, if you want to model it yourself. I kept the enclosure identical for all woofers; all I varied was the woofer itself.