High Output Subs that play 20hz to ≥200hz

[BP1Fanatic]

With post #18, remove 2.84" from the depth.
Add 2.84" to the height.
Now you have a front L-vented enclosure!

 

[camplo]

Shes a ringer... But After crossing, she rings no more... Sorta impressed? Is this too good to be true? Why aren't these things all the craze?

 

[BP1Fanatic]

Efficiency. Distortion. Boring.
Bandpass is where it's at.
See Tom Danley.

 

[BP1Fanatic]

BR = 7 pieces of wood.
TH in it's simplest form = 7 pieces of wood.

With those 7 pieces, I can have a low distortion high output kick bin TH or a low distortion home theater TH, both with built in grill cover.

 

[camplo]

yes but the Topic of this thread is

High Output Subs that play 20hz to ≥200hz​

Thats not happening with a TH, can you explain the distortion part? The 1w sensitivity in these sims are 5db over a similar sized Sealed cabinet, at 20hz and 30hz

Bandpass? A 4th order bandpass? You are talking about a TH as a 6th order bandpass?

I guess I asked the question lol! OK I see your point... but for the thread title I mean, This offset BR business seems to fit.

 

[BP1Fanatic]

I was only answering your question, "Why aren't these things all the craze?"
It's just a BR enclosure. Nothing special other than 2 x 18" drivers in the same enclosure.

 

[BP1Fanatic]

Look at my avatar.
On the left is a 2 x 12" BP4 coffee table on its side.
On the right is an 18" BR bin...nothing special.

 

[BP1Fanatic]

Hmmm...
SODBR @ 411.50 liters (grey) vs T-TQWT (black) @ 309.38 liters.

 

[BP1Fanatic]

SODBR @ 411.50 liters (grey) vs TQWP (black) @ 410.99 liters.

 

[BP1Fanatic]

SODBR.

 

[camplo]

It's just a BR enclosure. Nothing special other than 2 x 18" drivers in the same enclosure.

if you don't offset the drivers properly and tune the massload properly you won't get that wide nice smooth FR, so its not just another BR

 

[GM]

Well, one can argue it's a crude inverse TQWT, but to be a TL its acoustic pathlength must be a 1/4 WL of the tuning, which at a glance I'm guessing not.

 

[Booger weldz]

good ole offset driver 'qw' resonator with three 60 cm folds? your driver has a super compliant suspension and a low QES, kinda interseting. Might need to enlarge all of this to fatten up the bottom end ?

(there’s a bit of stuffing in the 4800cm2 x 60 cm offset stub section)

 

[BP1Fanatic]

Offset Driver Mass Loaded Transmission Line @ 504.39 liters.

 

[Booger weldz]

You left off the ‘mass loaded’ port/shaped section? That might have shortened the resonator down to 120 cm (~216 hz as the (3x 1/4 wavelength) pipe resonance @ top off requested bandwidth )

3 fold again? port @ like 1/3 Sd though? didnt you used to design them like this back in the qw group court?

 

[BP1Fanatic]

ODTaperedTL @ 404.916 liters.
Dude wants 20hz, hence longer than 10 foot path.

 

[BP1Fanatic]

Also, a 305cm2 mouth is kinda small for two 18's.
(1218cm2 x 2 drivers)/3 = 812cm2.
858.06cm2 = 19" x 7" mouth.

 

[BP1Fanatic]

Oh, you modeled one 18.
305cm2 mouth still seems too small.
I'm thinking at least 406cm2 mouth for that 18.

 

[weltersys]

ODTaperedTL @ 404.916 liters.
Dude wants 20hz, hence longer than 10 foot path.

As the Dude states in the thread title and OP, he also wants accuracy in the ≥200Hz range, hence your simulations in posts #28,29,34 & 36 fail to provide for his want, as they all have huge cancellations in the ≥100 range.

 

[BP1Fanatic]

And I see where he got that range from.

https://en.wikipedia.org/wiki/Subwoofer

"The typical frequency range that is covered by a subwoofer is about 20–200 Hz for consumer products,[1] below 100 Hz for professional live sound,[2] and below 80 Hz in THX-certified systems."

He came to a DIY site for a CONSUMER PRODUCT frequency response.