Inlow 135hz mid bass horn?

[frangus]

I'm thinking of building this horn for B&C 8PE21.

Anyone have experience with it? It will cross to a HP640 horn above and multiple sealed subs below at 135 hz

Does anyone know what that approximate dispersion of this horn is?

 

[pcgab]

I built a pair last year, and I love em. I don't know dispersion, you could pm John, his handle here is Carpenter.

 

[AllenB]

I took a simplistic guess as to the horn parameters.

 

[AllenB]

I had another look at this sim and it seems to fit better when I use quarter space loading in hornresp. It still isn't identical to the one Carpenter shows but close all the same. The point of interest that I see is that the mouth (as shown in the above directivity plot where the 'kink' appears), runs out at 1k. As a result the directivity is going to be fairly reliant on the external boundary conditions, and due to this foreshortening the horn may be quite resonant when operating into free space.

The potential for this can be seen (for example) in the efficiency, acoustic impedance, electrical impedance and group delay plots comparing eg. free space vs quarter space loading or better.

 

[ra7]

I have heard John's front loaded horns (maybe not these ones). The term 'striking fear into you' seems appropriate