Dumb bass horn question or not?

[event horizon]

My apologies if this is going to appear stupid, or even just plain daft

This has been bugging me for a while tbh, knowing there are people on here with vastly more experience than myself who know about horn enclosures i thought i'd ask.

It might actually stimulate some kind of debate to, which can't be a bad thing.

I have never built a horn in my life but i know there are some fundamental principles involved.

To radiate into free space (4 pi steradians) the mouth of the horn needs to be of a certain size to get to cutoff frequency 'X'.

To radiate into half space (2 pi steradians) the mouth can be half of the area to get to the same cutoff..Please correct me if i'm wrong This would be the equivalent of the horn sitting on the ground.

Into quarter space the mouth area can again be halved (1 pi steradian), we now have a floor & wall to help matters.

In eighth space (pi divided by 2) it can again be halved in area for the very same cutoff, mouth in a corner...

Now here is my question, please any horn people please take time to think about this

If the horn mouth is the full height of the room & in a corner the wave front will no longer need to expand in the same way, as instead of expanding in 3 dimensions it'll only be expanding in 2.

So, could the mouth area be made smaller still, or will the standard mouth for a corner alignment (pi divided by 2) be needed?


I think it could be made smaller still, however i'd like a vastly more experienced person to mull this over (never built a horn)

Thanks in advance for any replies

[davygrvy]

Had to think about your Q for a while before I "got" it. I see what you're saying. Might be true. To construct a horn that exits full height to ceiling sounds difficult to design and would probably have to be in the next room instead or a complete build-out from the wall with the two corners. Maybe both front corners having mouth exits? Intriguing none the less. For me, thinking about this, I'd do a wall length exit instead on the floor due to how I imagine the wave would propagate in the room. Modes would more likely be in the vertical rather than the horizontal.

You might consider room (cabin) gain as the predominant factor and match for a 1/2pi (corner) response of the inverse for a single sub instead.