Dual 8" tapped horn = TH-SPUD

[geitmans]

the W8-740P indeed looks like a good alternative. Its cheaper and has a higher Xmax. I will try to model it.

I tried to model the mechanical behaviour of the cabinet if I would build it with OSB. The first renonance occurs at around 103 Hz. The weakest part is as expected around the mouth of the horn.



But 103Hz seems quite low to me. I don't know if anyone has a rule of thumb of how much the first renonance of the cabinet and the maximum operating frequency should be separated?

Maybe it is better to build it using birch plywood. When I find some good mechanical data for plywood I will try to model the effect of it.

[Clarkcr]

I've never seen solid modeling software like that. I don't understand exactly what I'm looking at, but it looks cool!

Also, why are you using OSB? I'm assuming you're actually referring to MDF, which has a much higher density and is preferred over all other types of cabinet material.

Nice work!!

C

[Chris8sirhC]

OSB is about the same strength as MDF, weighs less, and glues up better. If anything it is slightly better than mdf as far as strength goes. BB Plywood is the best though.

[bjorno]

Any design faults?

IMO, I fully agree with Eva:

‘In a tapped horn the phase varies wildly across the passband and above.’

See the bad phase response in picture: 2(7)

It runs out of xmax at only 12 V rms

No, earlier and even if you intend to use this design with most ordinary commercial bass-amps that often uses a 12 dB HP filters at 20 Hz for subsonic frequency protection. See picture 1(7)

This should give around 118 dB max with corner placement.

Yes, but only if you count the SPL above 60-70 Hz Hz. See picture 3(7)

IMO a better use of the 8NDL51 drivers for Tapped Horns: See the pictures 4(7) – 5(7) and if SQ is the most important goal: See the smaller BP-TQWT in pictures 6(7)-7(7).

b

1(7)

[bjorno]

2(7)

[bjorno]

3(7)

[bjorno]

4(7)

[bjorno]

5(7)

[bjorno]

6(7): BP-TQWT

[bjorno]

7(7): BP-TQWT