respeakering a sunn cab

[A9X]

haha so i need a new cab then i guess, this wasn't the original speaker that was in it btw the previous owner put this one in. i don't live in the US so the chances of me being able to get it coned for prices that aren't over the top are limited

I'm in Australia and don't have trouble getting affordable recones for about anything. If you measure the internal dimensions and any ports (diameter or area x length) I'll run it through the similator and see what will work acceptably.

Being in Europe, you have access to a great range of drivers from BMS, Beyma, Ciare, 18Sound, B&C, PHL, Precision Devices, RCF etc that absolutely cr*p on most MI stuff for bass.

 

[roflol]

right the cab itself is 24" X 24" and 15" deep. the bit where the speaker goes is about 34.8cm dunno if this helps http://www.lansingheritage.org/images/altec/specs/components/421a/page2.jpg
what else do i need to measure?

 

[edbass]

You have this cabinet. It originally came with either a JBL D140F or a "Sunn Transducer" labeled driver, most likely a CTS but I can't confirm that. The good news is it sounds good with a bunch of different drivers. I like the D140F that I have in mine currently, but I only really use the cabinet for low level preamp testing so I don't pump a lot of juice to it. I like the 421, but it won't take even as much power as the D140 will. Both of those old speakers sound great, but they come from an era where 100 watts was a monster amp.
For higher power applications, I would suggest an EVM 15L. I can verify first hand that it works very well in your cabinet, and while it is fairly efficient, it will take a pounding unlike it's older AlNiCo speaker siblings.
It's quite difficult to load however, because if the internal porting. You'll have to remove the heat sink from the driver magnet, and really do some wiggling to get it in. The EVM does fit in my Sunn 1X15 without altering the porting, however I do have some older Sunn cabs that only the older drivers will fit into unmodified.

 

[GreyBeard]

Eminence makes a USA series Kappa that is a 4 ohm. That would be a good place to start. As for mixing an 8 ohm with a 4 ohm. It won't hurt anything (2.666 ohms) but the 4 ohm will usually be louder than the 8 ohm.