Danley BC-subs reverse engineered

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Hi all!

I have been trying to figure out the Danley BC line of subbs.
This is what i think is going on:

If you try to get a high power density from powerful (low Qes, High Bl, high mms) drivers like B&C 12NW100 in a tapped horn you get a very high compression or a very deep depression in the middle of the passband, like i show below:

http://oi59.tinypic.com/14mzaxv.jpg

I have two more posts to make, please wait until i have posted them before you reply.

Cheers,
Johannes
 
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And you get a combined output like this:

[image]http://oi61.tinypic.com/15wkvfq.jpg[/image]


The quarterwave based front resonator will increse the efficiency very dramatic, and will act like a filter, lowering distortion.

The phaserespons of this modified tapped pipe/tapped horn is very similar to the phaserespons from the BC412 and BC415.

This is not optimized and there are several more aspects of it that is not shown in the very simplified Hornresp-simms.

Cheers,
Johannes
 
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BC-TP-svacka.png

BC-QW-PEAK.png

BC-COMBINED.png


Here are the three series of Hornresp sims.

Thanks for the help Zero D!


Cheers,
Johannes
 
They all seem to be FLH not TH?

It does not look like a FLH. There is no visable expansion in the "chamber" inside the mouth. I can not see any reason to have souch a small mouth on an FLH if one wants efficiency and high spl.

Regardless of this idea being simiular to the BC412 or not, i believe it is a novel idea to get 4 - 6 dB more spl from any given driver compared to tapped horns like the THAM series.. Plywood is cheaper then extra drivers, and i have never simmed another kind of box with this kind of max spl and efficiency, except full size huge hyperbolic horns.


cheers,
Johannes
 
See, Post #23 for a quick trial sketch of the internals.

I had not seen the BC-218 before. That sure looks like a horn.

The BC412 nd 415 does not look like a regular front loaded horn.
Tom Danley says "The BC415 is another unique subwoofer alignment from Danley Sound Labs" and it does not sound like he means a normal FLH or Tapped Horn.

This is why i started another thread, since i believe there is something else going on here.

Cheers,
Johannes
 
Thanks for the info about the BDEAP patent. I am familiar with the BDEAP. I don't understand why Danley should say that it is a "unique subwoofer alignment " since BDEAP can no longer be considered "unique". It is a 10 year old patent.
I built my first Tapped Horn in 2003 or 2004. I saw Tom Danley post something about it on a forum (this?) and i built it with a small 5 inch driver. I did not simulate anything. It was way before Hornresp could sim tapped horns. I have been following his designs since then, and i believe this is something new.
I can not see why he would not say something about tapped horns, front loaded horns or BDEAP if that was all it was?

Cheers,
Johannes
 
BC210-spl.jpg

BC210-phase.jpg

BC210-maxspl.jpg

Here is three Hornresp pictures.
Please compare both phase and spl with his BC-415. Very similar.

The max spl is pretty impressive for two 10 inch Faital Pro 10HP1020 in an single enclosure, 2 pi. No tapped horn with a single 12 or two 10 inch drivers i have ever simmed or built can deliver this kind of spl with the pronounced peak around 90 Hz and this extreme efficiency.

Cheers,
Johannes
 
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Hi Circlomanen,

You may well have an interesting idea.

Google the the patent: US 2004/0238268 A1. Weltersys had a suggestion for the inside of the BC415.

Regards,

A quick estimate of the path length using this fold scheme yields a 2.08m distance which is only good for 80Hz. I think there needs to be more folds to it because the response curve has a knee at 36Hz.
 
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