BillFitzmaurice.info

That would be a terrible Idea essientially.

response above 40ish hz would likely be similar (Plus/minus 1 db)

below 40 it would drop like a rock (about 6 to 8 db), and then exhibit a 10db peak around 18 to 20hz range.

Rich4349 wrote:how badly would it work to build a plain old hollow tube of plywood (for argument's sake say 8 feet long) that is 27x30 in cross section, and with speaker gasket, join it up to the mouth of a t60? What would the net effect be?

You'd get extension down to about 18Hz, but it would be rolling off until it reached 18Hz, where there would be a narrow response spike.

Would it have any (deleterious or otherwise) effects above the (previous) 25 hz cutoff?

now if you made your 8 ft extension have about an 80 square foot mouth area

Oh, you mean like this??

http://www.royaldevice.com/custom.htm

not really.... I'd say each of those sides only has about 20 square feet of horn mouth.... and who knows what drivers are in there (some thing with extremely high VAS considering the size of that rear chamber)

what I'm saying is, for a single lab 15, if you were to increase the horn pathlength by 8 feet, you would need a VERY large mouth to maintain any semblance of flat response (80 square feet). Interestingly enough, this does NOT make it go any lower, but changes the design from a 1/4 wavelength box, to a 1/2 wavelength. Interestingly enough. response gets rougher as you stack more cabs at this point! lol.

Alternativly, with a mouth area of around 32 square feet, and 4 cabs, you are looking at VERY nice sensitivity (response gets rougher as you add cabs past this point though).

have fun with your mega horns