Hi, to anyone who may be kind enough to help,
For my keyboards rig, I am building a couple of 12" LF speaker boxes to be as close to a replica of the vintage JBL 4646A which uses 1 x JBL 2206H transducer.
For the top end, I will then biamp them with some 2426 HF drivers and 2370a flare's.
I have downloaded the JBL 4646A specification file from www.jblpro.com/pub/obsolete/4646a.pdf
The diagram of the box and components shows that there are 2 x Ports, JBL Part Number 57932 (these are not for sale).
From my study's of this cabinet so far, I assume that both ports might have an inside diameter of 3.0 inches (76.2mm), and might be 5.75 inches (146mm) in length.
The enclosure volume is known to be 34 litres or (1.2 cubic feet).
My Question Is:
If anyone out there has access to a JBL 4646a LF cabinet or knows the answer, I would be extreemly grateful for any help. I would like to ask if anyone could put a tape measure inside the port and measure the length as this is what I need to find out before I glue the ports that I have made into the front baffle. I think I'm on the right track but I like to check thoroughly and be correct with these things.
Please help????
Thank you,
robmuso