Small midbass horn that would work in just 3.5 cu.ft?

[CZ Eddie]

Are there any ~95dB efficient 80-300hz midbass horns that could be used as the low end in a three-way that gets crossed over to subwoofer (also a horn) below 80hz?
Looking for something nice to use from 80-300hz in three-way with an 8" coaxial speaker like B&C or Tannoy.
I like the sound of horns and want nice midbass kick.

Driver size should be 8" to 12" max due to enclosure width constraints.

 

[anthonybisset]

The Turbosound TMS1 lower midbass horn enclosure comes to mind. Flattish to 90hz, down -6dB at 80hz. Optimized for cross at 300hz.

Specs here:
http://stagersound.com/studio/Turbosound TMS1.pdf

 

[djk]

"Are there any ~95dB efficient 80-300hz midbass horns that could be used as the low end in a three-way that gets crossed over to subwoofer (also a horn) below 80hz?"

No.

An Altec A7 horn is about 30"W x 20"H x 24" deep, is driven by a 15" woofer, and loads well down to about 160hz.

It would need to be 2x larger to work well at 80hz.

In theory an 80hz horn could be 1/4W deep (42") plus the depth of the driver, and would need a mouth of about 42" square, or a circumference of 168" (53" diameter).

 

[freddi]

you might just be able to use a K12 with the little coax. Make a test Karlson out of something cheap and play with the porting and lowpass gap. A K12 with Kappa 12A would be pretty kicky in that range.

 

[CZ Eddie]

"Are there any ~95dB efficient 80-300hz midbass horns that could be used as the low end in a three-way that gets crossed over to subwoofer (also a horn) below 80hz?"

No.

An Altec A7 horn is about 30"W x 20"H x 24" deep, is driven by a 15" woofer, and loads well down to about 160hz.

It would need to be 2x larger to work well at 80hz.

In theory an 80hz horn could be 1/4W deep (42") plus the depth of the driver, and would need a mouth of about 42" square, or a circumference of 168" (53" diameter).

Thank you.

 

[CZ Eddie]

you might just be able to use a K12 with the little coax. Make a test Karlson out of something cheap and play with the porting and lowpass gap. A K12 with Kappa 12A would be pretty kicky in that range.

No, a K12 won't work in this particular instance because of the mounting location & size available.
Only a Karlsonator Sk8 would fit. But the mounting location would not benefit the wings very well.

 

[anthonybisset]

Even a fully optimized corner horn is probably to large:

Spherovox

Apologies for recommending the TMS1 without doing any math, it's obviously a direct radiator for much of the LF.

 

[DorinD]

For exactly such a situation I use a rescaled (1:1.42) Bruce Edgar "Show Horn"

Project | Homebuilt Hi-Fi - A user submitted image showcase of high quality home built hi-fi components.

 

[wg_ski]

In theory an 80hz horn could be 1/4W deep (42") plus the depth of the driver, and would need a mouth of about 42" square, or a circumference of 168" (53" diameter).

Such a horn is at least 102dB/W, fully optimized it approaches 105. To get 95dB you should be able to make it smaller. For that matter, 95dB wouldn't even require a horn, just a pair of 12's in a box. My 2x12 conventional top cabs will beat that, and they're ony 4 cubic feet.

 

[djk]

"To get 95dB you should be able to make it smaller"

It won't be horn-loaded at that point, as per his request.

1/4W is the 90° point in a waveform, maximum amplitude. If the horn is smaller than this (or uses an external boundary) it will not load well. 1/4W horns don't really get smooth until they're 1/2W long, morst HF horns are made this size.

It's easy to get 95dB in the 80hz~300hz band, but not horn-loaded.