Rerurn to Romy the Cat's Site

Dominic wrote:

be careful here as mouth size is defined not by what you input, so much as the acoustic space and performance you want. The throat size can be fiddled with if you're careful but there's not much one can do to shrink the mouth. On a 'bass' horn you can lop off some of the final curve, because diffraction isn't a big problem at lower frequencies, but you change other things that way. You certainly can't change the mouth size by using the output of the back side of the diaphragm.

Dominic, yes and no. You are right - the diaphragm’s dumping is not something that affects mouth size but in some indict way it… does.

Let pretend that a horn has 50Hz rate and a driver with loaded resonance frequency of 40Hz. By minimization of back chambers it is possible to proximate the driver’s resonance to the horn rate and it will give substantial boost in horn equalization. So, if you have +2dB at 50Hz then would it possible to make the horn’s mouth not to be 50Hz but rather 55Hz? The difference in size will be a foot or two – I mean a lot. The bigger question would be if the bass reproduced by resonances would be the same as the bass reproduced by mouth size? I do not know the answer and I do not know that anyone knows certainly. There is too many “contingent upon” unloved.

Also, the cheating with mouth is another controversial subject. Certainly no one wish to cheat but in some case I have seen that small horn with ridiculously small mouth output OK bass. A good examples The Bruce Edgar’s Refrigerator bass module. Very lightly and cheaply built, electronically equalized, with underside mouth and reported response down to 20Hz. Ridicules, yes it is it but somehow it does not sound bad…. Could is be better if it was not cheated? I am sure it would. However, where is the balance between the efforts and benefiter with bass horns? No one knows…

Rerurn to Romy the Cat's Site