Double (6th order) horns

Urm...

if the have a chamber and a horn on both sides of the driver, is there any way to get them to combine smoothly?

I've tried a few models in akabak and i'm getting 108db 1w1m! struggling to get it perfectly flat and low enough.

Confusing but possible?

I first read of it in the dinsdale horn articles. Makes sense in theory.Tricky to use properly.Double your volume for 3dB.

Dave

wow, nice one snowflake. 20minutes on akabak tought me the same thing. The winning formula i found was having one long horn - say 2.2m. then annother shorter horn from the rear of the driver - say 70cm.

I guess that at the low end below the short horns cutoff, it is not supporting wave modes and is acting as an attenuator so the driver "sees" a high impedance or closed box essentially?

Further up the short horn combines with the long one to smooth out the ripples you would normally get due to a small horn mouth and extends the frequency response past the long horns high cutoff?






Anyways, i played about with the expansions, front volumes, lengths etc and you can eventually get a nice smooth response all the way from 40-200hz! i bet you could do better too giving it a bit more thought.

efficiency goes from 104db to a whopping 110db at the higher end.

SO your gaining increased bandwidth, flatter response and efficiency at the expense of a much bigger complicated cab and less low end (for a normal horn in the same size enclosure).

Is it worth it? Surely someone has done this before - please post links guys cos i'd love to read up on it.

What I have found with the boxes I built in which the rear chamber ports into the throat of a relatively short horn is that the horn starts to act as an extension to the port. This is the conclusion I have come to as the hole in the rear chamber should tune it in the 70Hz region but is actually tuning it to 30Hz according to impedance and acoustic measurements.
Keep us updated on how this is going.

JaKe

Loading a helmholtz resonator with a horn above the horn 1/4 wavelength may destroy the helmholtz effect because of the resistance of the horn damping the resonance.

JaKe