high efficiency small sub

[sub_arctor]

hello every body

i have a work in progress concerning a high efficiency system

i built one full range ribbon (250 hertz -20000 hertz) based on a design by francois demisniere, a French diy man
the sensibility is about 102 Db

(on the photo, it's the thing that doesn't look like a speaker)

i have still one to build


i am now looking for an high efficiency subwoofer (min 97 Db) able to rise 300, 400 hertz and go down to 20-30 in a small box
do you know any
thank you for your answer?

Julien

[Cal Weldon]

Originally posted by sub_arctor
i am now looking for an high efficiency subwoofer (min 97 Db) able to rise 300, 400 hertz and go down to 20-30 in a small box
do you know any
thank you for your answer?

Hi Julien,

There's no such thing. You are asking too much. You will have to change your requirements. If you want 97 dB, small box you need a PA woofer. These will be good down to about 50-60 Hz with some EQing.

[sub_arctor]

thank you for the answer
i will investigate this point

and the photo is here

[electroaudio]

Originally posted by sub_arctor

i built one full range ribbon (250 hertz -20000 hertz) based on a design by francois demisniere, a French diy man
the sensibility is about 102 Db

Hi, do you have any link to that driver or any other information to share?
I may be interesting for me to build a couple too i think...

[Cal Weldon]

Yes, more pictures of the ribbon would be nice. And the rest of the drivers we can see there. Good looking stuff.

[banana]

Cal is right, this will be a miracle sub.

If you use seperate amplifier to drive the sub, high efficiency is not necessary. Thus you can apply Linkwitz Transform to make it go down to 30Hz in a small box.

[badman]

Indeed, it's commonly called Hoffman's iron law. A speaker box can have 2 out of 3: efficiency, low frequency extension, and small box size.....

The ideal way around this is to go with an infinite baffle subwoofer setup, where another room acts as an enclosure. These are also sometimes done with the backwave firing outdoors.

[freddi]

a 15" in a 6th order reflex with ~6dB boost from a underdamped 2nd order highpass filter ~1-1.07*fb might be one option --- in US, sometimes EV Interface A or B EQ boxes can be found on Ebay cheap

[navin]

why have a box. What about dipoles. I assume 2 15" woofers on an 18" wide baffle might work. Something like the Emience Alpha.

[el`Ol]

Or a low-Qts low-FS driver with 6dB linearization.
http://http://www.audiocircle.com/ci...?topic=41297.0
The Alphas are more for huge baffles.