Which Horn for linear response down to 20Hz?

[Bass-Depth]

Hi !

I want to build a Subwoofer for my Homecinema and thought of a LAB-Horn,the Lab Horn is really nice but i want a Subwoofer which goes down to 20Hz with more Output than a SVS PB12 Ultra 2
It's important for me to have a clear Bass so I only want to build a Horn
Max.SPL @30Hz should be more than 120dB @ 1m

Please can you say which DIY-Sub would do all I'm dreaming of and isn't more expensive than the LAB-Horn???

David

Sorry for my english...i'm from Austria

[johninCR]

A LABhorn is only a 35hz horn. A true 20hz horn is huge. Plan on building something that utilizes a corner as part of the final flare to keep the size down. Personally, I would use a vertical array of drivers in a corner horn to make use of the vertical space that would otherwise be wasted and create a false corner that would actually be a huge horn without looking too intrusive.

[planet10]

Originally posted by Bass-Depth
Please can you say which DIY-Sub would do all I'm dreaming of

It will need to be BIG. Really BIG.

dave

[RobWells]

Surely it must be time to post this badboy again


http://www.royaldevice.com/custom.htm#HORN%20SUBWOOFER


Rob.

[Ron E]

That 20Hz horn will be larger than Ober Oesterreich

I guess if you want to build a 20Hz horn, you should get Hornresp and spend a lot of time on "horny" forums. You can shorten the horn quite a bit and reduce the mouth area by the use of boundaries, but there is a limit to what you can do without making the response very ripply. In a high SPL environment, 35Hz is more than enough - the lower frequencies will just rattle stuff and waste amp power. I wouldn't knock the labhorn's extension until you heard it.

I lived in Austria a while back - in der Wachau.

[quiet]

Surely it must be time to post this badboy again
http://www.royaldevice.com/custom.htm#HORN%20SUBWOOFER Rob.

funny i thought the same thing -

still a vertical array using the hight of the room and a corner
or the hole wall..... seems like a good idea

20hz is loooow for a horn

[simon5]

I played with Hornresp a bit to help you.

Best results I had was with Acoustic Elegance AV15.

It's a Catenoidal horn.

Length of 6 meters and mouth area of 16612 cm^3 if it's a corner horn. You also need a rear compression chamber of 125 liters. Ripple is about ±3 dB with 110 dB sensivity with 2.83V RMS imput. I tried to design the smallest 20 Hz horn with ±3 dB ripple.

You'll need to be creative to build a catenoidal horn and to fold the 6 meter length in three so it can stand up in a corner of the room.

Good luck!

[simon5]

Just beaten what I said.

I used a Ascendant Audio Avalanche 18. I know it's discontinued but if you can get one...

Catenoidal horn
12100 cm^3 mouth area
5 meters long
250 liters rear chamber

In theory with a 800W RMS amplifier into 4 ohms, this horn could do 135+ dB from 20 Hz to 80 Hz.

[rcw]

Back in the 70's an Australian electronics magazine had a feature about a man who had an extension built on his house in the shape of a 16Hz. horn, it had a listening area at the big end and an array off 15inch woofers at the small end.
The report was that it sounded quite impessive with organ music.
Anything less than this would seem to be an inedequate compromise.

[planet10]

Originally posted by rcw
Back in the 70's an Australian electronics magazine had a feature about a man who had an extension built on his house in the shape of a 16Hz. horn, it had a listening area at the big end and an array off 15inch woofers at the small end.

I had a customer (in the late '70s) with similar -- don't know how low it went, but he used a single B139.

dave