Converting PJB Suitcase combo to cab

[leroybasslines]

A while ago, my trusty old PJB Suitcase took a shit and died after many years of faithful service. Smoke from the amp, acrid smells, the works. 
 

It’s been replaced by a Tonehammer and an Ampeg SVT 212 cab. It’s brilliant, but the cab is a bit much for a rehearsal or a small gig. I need something smaller for that, really. 
 

So I was thinking of converting the old Suitcase into an occasional cab to fill that gap. I’ve gutted it, removed the amp etc. As it stands, it’s an enclosure with the 4 little 4B speakers in there. My guess is that I need to wire them up to a jack socket using some kind of wiring chocolate block, plug in the Tonehammer and hopefully not immediately burst into flames or die. 
 

Anyone done anything similar? Any advice/stern words of warning most appreciated…

[Bill Fitzmaurice]

Make the internal volume and port area and length the same as the original box. Wire the drivers series/parallel, use whatever type jack is on your other cab. 

[Downunderwonder]

First you want to test each driver that it

 

A, hasn't failed to a open circuit by putting multimeter on DCR ohms. Should measure somewhere from 3 to 14 ohms. Less than 3 I would suspect failed short circuit which would explain the amp going poof.

 

B, still makes a thump with 9v battery.

 

The DCR measure is a little less than the nominal impedance for the driver.

 

That will inform the choice of wring scheme.

 

Given your substitute amp has way far more power than you need it might not be a bad idea to go high on the cab impedance wiring, to cut down on risk of blowing it up.

 

Eg 4x16 ohm can be 16 as a series parallel instead of 4 ohm parallel.

 

4x4ohm can be 16 all in series instead of 4 series parallel.

 

Your pjb box may have had the amp taking up some internal volume? Probably not enough to upset the tuning if you block it off nice and good.