i found this empty boxes, they are old, i bought them very cheap...the guy said they should play 100hz-2khz. i would like to use them above 18"folded horns from 140hz, and below 2"horn and tweeters...
on speakerplans people say they should be playing 250hz-1khz, thats too narrow for the use i have intended them for....if its not 100hz, it should be 120hz minimum
no problem cross them at 1khz, a 2"horn will go above
if u already saw this design please let me know something about it, first suitable drivers. they are old but never loaded, just stored in a room for years
I've done a few basic calculations taking in acoustic length if the horn was morphed into a round bottomed cone etc and the result was that it really won't go much below 250hz. Don't trust my maths though and work it out.
The MT12 section goes down to 120hz just about, check out it's dimensions.
Besides, with a dispersion like that, you'd need a fair few boxes anyways.
\'bits of ply round a driver\'
It was a big surprise to se these speakers. I was buildind these in 1992, the measures are accurate 420x520x720 ! They were finished in blue color scratch-resistant laminate with corners and stainless steel profiles. I still have twenty of these. Double 12" RCF or B&C speakers were mounted on these. The subwoofer section with 18" RCF woofer had been patended. The intersection of frequency was 120 hertz. On this PA System I mounted, only on request, Fostex speakers. I still have the picture taken at the fair SIB in Rimini Italy, if you want I can send them.