Collaborative Tapped horn project

[djk]

Whoop-de-do, a whopping 98dB/W/1M (assuming 135dB at 5KW average).

[epa]

but a 4:1 ratio for an 21 driver

[GM]

Yeah, I was thinking that 5 kW into a high, one way compression should make for some relatively expensive entertainment.

GM

[obeman]

two tapped horns, side by side, mouths forward:
1.22m high, 1.33m wide
from bottom up to 42cm forms rectangular horn mouth, full width. response of tapped horn about 40 to 140hz

simulating this to 2pi and having real difficulty figuring out exactly how much directional gain in the upper register im going to gain, because of the extra 80cm above the horn mouth and large width.

some attempts with this Online Baffle Step Calculation
questimating 6db level "corresponds" simulation to 1pi in hornresp. some rule of thumb would be useful.

[weltersys]

Originally Posted by obeman

simulating this to 2pi and having real difficulty figuring out exactly how much directional gain in the upper register im going to gain, because of the extra 80cm above the horn mouth and large width.

questimating 6db level "corresponds" simulation to 1pi in hornresp. some rule of thumb would be useful.

You may be able to make a reasonable estimate from the empirical data collected in these threads:
Multiple Cabinet Combined Response

Horn Extender/Wave-guide for TH

The short answer is from 2-3 (near Fb) to 4 dB upper end forward gain. To find out the exact amount will require measurement.

Art Welter

[iand]

Originally Posted by iand

It really is a crazy driver, huge output but very hard to design any kind of box for because of the huge BL/sqrt(Re) (30% higher than the 18sound 21NLW9600 which is the previous champ) and Mms -- a Qes of 0.22 with Fs=37Hz says it all, really.

You'd get almost exactly the same maximum output, efficiency and Vd with a couple of good 18" drivers like the BMS 18N850V2, which might even cost less and would certainly be easier to drive and design suitable boxes for.

I think this driver is a case of seeing what happens if you push driver design to the extreme rather than than something with real advantages over existing solutions -- unless you want to drive massive currents into a 1 ohm load from a class-D amplifier (which can use efficient low-voltage output transistors), like the custom Powersoft module...

There's a detailed explanation of how the whole IPAL system works here:

http://www.diyaudio.com/forums/subwo...palmod-system-...

Basically it uses pressure sensor feedback and a DSP to not only provide feedback to reduce distortion and improve transient response, but lets you "dial in" any virtual T-S parameters you want. Net result should be huge output and low distortion from a smaller than normal box. The improvement in transient response shown in the paper is phenomenal...

The huge BL is partly there to raise efficiency when used with the custom class-D Powersoft amp my making the back EMF as high as possible and making the load as reactive as possible -- not normally a good idea, but it is in this case.

Before objecting that this won't work, read the paper, it's a proper AES one not some technically illiterate publicity puff.

It all looks great apart from only being available to OEMs and horribly expensive -- the driver is said to cost double what a 21SW152 does so even if you could buy them the driver + amp would cost several thousand quid a pop :-(

And this is what it's used in -- cost is £10k each...

http://www.martin-audio.com/products...Xdatasheet.pdf

[babbudi85]

Hello friends,
Searching to make 5.25" tapped horn subs. Kindly guide.

[hm]

babbudi,
look my Subfanfare for 4" driver.
subfanfare

[epa]

Originally Posted by iand

There's a detailed explanation of how the whole IPAL system works here:

http://www.diyaudio.com/forums/subwo...palmod-system-...

Basically it uses pressure sensor feedback and a DSP to not only provide feedback to reduce distortion and improve transient response, but lets you "dial in" any virtual T-S parameters you want. Net result should be huge output and low distortion from a smaller than normal box. The improvement in transient response shown in the paper is phenomenal...

The huge BL is partly there to raise efficiency when used with the custom class-D Powersoft amp my making the back EMF as high as possible and making the load as reactive as possible -- not normally a good idea, but it is in this case.

Before objecting that this won't work, read the paper, it's a proper AES one not some technically illiterate publicity puff.

It all looks great apart from only being available to OEMs and horribly expensive -- the driver is said to cost double what a 21SW152 does so even if you could buy them the driver + amp would cost several thousand quid a pop :-(

And this is what it's used in -- cost is £10k each...

http://www.martin-audio.com/products...Xdatasheet.pdf

intersting(but expensive)stuff.
i like how you could emulate al ts parameters.
btw your link doesnt work
correct link

[riaz]

Hey guys,

Can you help me out, i have an 8" driver that goes down to around 30hz. I want to make a tapped horn for my econowave mains. It seems my econowave can only go down to 50 hz. I would like to augment this with a tapped horn. Can you point me to a good design please? I will post pictures of the finished product when done.

Thanks very much.

Btw, can tapped horns do slam?