Difference between Super Scoop and Folded Horn Subwoofers

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The light grey line is not a simulation of a stack of 8 horns, it is a simulation of one circular exit of 8 times the area as one simulated cabinet.

To come close to that in half space, a stack of 8 would look something like the diagram below.

And the TH would have to have the entire frontal area as an exit.
I have not seen that type of TH or stack in the real world.

It's true that you don't see it often but it's easily possible. Put the mouth on what is usually the bottom, lay them on their sides and stack them and then the full frontal area is the mouth. See Bill Fitz's THT (low profile version) for an example of how this is done. It's a front loaded horn but you can do the same with tapped horns. It's the pic near the bottom of the page.

http://www.billfitzmaurice.com/THT.html

Maybe I can do a direct link.

An externally hosted image should be here but it was not working when we last tested it.


Once again, if you plan to stack from the beginning these are trivial details. If you don't plan ahead it's almost impossible to get anything resembling a good result.

But even if the mouths are on the side you can get a lot better approximation of a circular exit than the pic you showed. Laying on their sides, 2 stacks 4 high with all the mouths clustered together in the middle. I couldn't find an example on google so here's a really simple pic of a stack with all the mouths clustered in the middle. The mouth area is shown in red.

An externally hosted image should be here but it was not working when we last tested it.
 
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But even if the mouths are on the side you can get a lot better approximation of a circular exit than the pic you showed. Laying on their sides, 2 stacks 4 high with all the mouths clustered together in the middle. I couldn't find an example on google so here's a really simple pic of a stack with all the mouths clustered in the middle. The mouth area is shown in red.
The upper response of FLH or TH becomes relatively narrow, much less than 180 degrees.
The shape of the stack is reflected in the ground plane.
The stack you just drew does not look much like a circle (or a square) in the upper response, more like a line array.

A vertical sub line array with a narrow exit is a good thing, but not what Hornresp predicts ;).
 

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You are correct of course, there's no arguing with that.

But as long as you are aware of what Hornresp is doing you can get a reasonable correlation to the model. Obviously putting them in a horizontal row 16 feet wide isn't what Hornresp is predicting and won't match the model or be ideal in any situation I can think of.

As long as you at least try to do the right thing it's usually going to be close enough. (Usually way better than close enough. And easily close enough that my simulation is not invalid. The mouth shape is going to primarily influence dispersion pattern anyway, not frequency response.)
 
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Hello guys new to pa system building here but i recently bought a 18 inch scoop from a guy who said it was some hugo hugo plan from spr\eaker plan i loaded it with 18sound lw1400 bbe processor and crown xls 5000 amp but when i raise the volume it reaches a level and the bass dissappears even thoygh i raise limiter and output on processor help please
 
the lw 1400 should work fine in a hog scoop.
sounds like an amp problem.
did you try antoher amp?

I recently downloaded the spec from 18sound website of the horn loaded enclosure might build that and try it but could it be the parameters on my BBE DS26 dsp are set wrong? Here are the present settings on the low channel
GAIN 0.0DB
POLARITY (+)
DELAY 0.000FT
HPF 40hz Lnk Rly
LPF 272hz Lnk Rly
EQ 1 40HZ Q=1.0 +8db
EQ 2 50hz Q=0.5 +7db
EQ 3 63hz Q=1.0 +6db
EQ 4 100hz Q=1.0 +8db
EQ 5 160hz Q=1.0 +6db

Limiter +6db
Attack 12ms
Hold 0ms
Decay 120ms
 
I recently downloaded the spec from 18sound website of the horn loaded enclosure might build that and try it but could it be the parameters on my BBE DS26 dsp are set wrong? Here are the present settings on the low channel
EQ 1 40HZ Q=1.0 +8db
EQ 2 50hz Q=0.5 +7db
EQ 3 63hz Q=1.0 +6db
EQ 4 100hz Q=1.0 +8db
EQ 5 160hz Q=1.0 +6db
With those wide Q filters (a Q of 1 is over an octave wide, a Q of .5 covers almost the entire sub pass band) you have simply used multiple EQ bands to boost level an average of 7 dB. You could simply turn up the gain for a similar effect.

So yes, they are set wrong.
 
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