How could I get a smaller volume by using just one woofer? In the horn I posted, I planned to have the woofers side by side (hence 60cm width or 55cm internal for two 25.7cm drivers + a few cm of wiggle room). If I dropped one of, the width could obviously go down to even 30cm, but to get the same mouth area and area along the whole horn the height and depth would have to be increased to make up for the area lost in the width... or do you use a more fancy method which could take up less space with 1 woofer?

After Wayne had a little snicker at my use of the word 'small' to describe my horn plan I posted I went away and refolded it totally different. I came up with this:

Its again for two woofers... but I managed to get height down from 109cm before to 95cm - had to decrease mouth area to 2000cm^2 but length is the same (well it was 3m now its 2.93m, practically nothing), no matter though its what I had originally wanted in the first place and doesnt change response curve barely:

Im still going at it, Im trying to find a way to get the height even less now that I've got the depth pretty small.

Adrian