Any thoughts on what best to do with these?

dromunds

This is a JBL professional series 15" driver model No. 2235H that was incorporated into a DIY subwoofer made by a stereo salon. There are two of these subwoofers with separate bases. Any thoughts concerning best use? Drivers recently had new surrounds.

dromunds

I should add these subs were made in the late 80's as I understand it.

dromunds

JBL drivers are 8 ohm

westmassguy

Those old JBLs are quite efficient. Provided the enclosures were constructed and tuned properly, they should perform quite well as subwoofers. A good 8 ohm power amp in the 250-300 watt range, with a high damping factor should suite them.
http://www.jblpro.com/pages/components/2235h.htm

Those front hold-down clips should not be required for home duty.

mhardy6647

Extremely nice drivers -- Fs of 20 Hz suggests they actually could do subwoofer duty, in fact.

dromunds

Thanks fellas. This little device came with the deal. Anybody know anything about it and how it functions? Guy said he never used it.

mhardy6647

Looks like a passive(?) LF crossover that sums stereo to mono and has an adjustable XO frequency and output level.

EndersShadow

mhardy6647 wrote: »

Looks like a passive(?) LF crossover that sums stereo to mono and has an adjustable XO frequency and output level.

What he said (but he said it better than I woulda)

dromunds

Let's see if this works. Looks like this may be close to what I have here. It appears the BX63A is an integral part of the system, and can be used with a stereo amp for the subs. From what I can discern out there, the JBL 2235H drivers are quite exceptional. Any body have any thoughts on whether I should try them with a stereo amp or a sub amp, and if so, any suggestions?

http://www.lansingheritage.org/html/jbl/reference/technical/1983-subs.htm

westmassguy

They're 8 ohms, most plate amps are 4 or 2 ohm, not sure about separate subwoofer amps

dromunds

Looks likes cabinets are a DIY version of these JBL low frequency speakers

http://www.lansingheritage.org/html/jbl/specs/home-speakers/1983-b380-b460.htm

westmassguy

Don, found this: http://www.jblproservice.com/pdf/Vintage JBL-UREI Electronics/UREI- BX63A ts.pdf
Appears to be a line level active crossover. Your pre-outs go to the inputs, the outputs go to your left and right main power amp, and the separate bass outputs go to a separate power amp for the Subs.

Interesting typo at the bottom, says "capacitors are in ohms"