Corner loading/horn loading in very small spaces (mouth size/horn length)

[dustman96]

What happens when you go beyond 1/8th space, like in a sealed car where all dimensions are constrained? Can you expect an extra 3 db for each additional dimension that is constrained?

I would like a general explanation as well as how it would relate to horn length and mouth size for horn loaded low frequency enclosure. Anyone know how to model for this in Hornresp?

Also are there good books out there that focus specifically on horn loading?

Thanks everyone!

P.S. If anyone can give me a definitive explanation of "room gain" and its principals I would be very appreciative. Getting very mixed signals on the subject...

[fbov]

Have you seen this discussion of room gain?
http://www.avsforum.com/avs-vb/showthread.php?t=1329334

[billfitzmaurice]

I would like a general explanation as well as how it would relate to horn length and mouth size for horn loaded low frequency enclosure. Anyone know how to model for this in Hornresp?
..It doesn't, and you can't. The usual cabin gain applies, but the horn Fc is unaffected. And since roll-off of a horn below Fc is fourth order the second order cabin gain can't offset it as can occur with a sealed box.

[dustman96]

From my understanding corner loading of a horn can shorten the necessary horn length/mouth size because the acoustic energy is being dissipated into a smaller area thus adding impedance and loading the diaphragm to a lower frequency. I don't understand why you could not shorten it even more if radiating into an area where there are 4 proximate walls which seems as though it would add more impedance. Am I way off or neglecting to take something into consideration?

[Sydney]

There are several definitions of what a horn is, based upon what is to be accomplished:
A impedance transformer or a pattern control device.
To be a pattern control device the horn walls/boundaries have to be large in reference to the frequency being propagated.
http://www.acousticdimensions.com/tools/hornbreak.htm