Speaker Cab Mods: Anyone Do This?

  • Thread starter Thread starter dfrattaroli
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dfrattaroli

dfrattaroli

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Some of you probably know that I've been trying to sell my Uberkab since Jesus was a baby. The reason for the sale is that I have a Mark V:25 coming and want an 8 ohm cab for it. The Uber is 16.

I've considered selling off the speakers and buying 4 8 ohm speakers but I'm not sure I want to go to the trouble of boxing and shipping speakers. So I'm thinking I may add a 2nd jack to the rear panel and wire the speakers in pairs and have 2 separate 8 ohm loads in one box. I could split them up left and right. In theory, I'd have a stereo cab but I'd never use it that way. I'd be able to connect them both to the Mark in the 4 ohm jacks and have the impedance matched. Thoughts?

Maybe it'd just be easier to get a Weber Z-matcher.

PS

I know the 16 ohm cab is a safe mismatch in the 8 ohm output. I've done that with the Mark IV I had. But I'm afraid that with the V:25s smaller tubes/transformer that I'll suffer some loss of punch. I'll try it before I do anything but the amp is still 5 weeks away as it's a custom order.

Thanks.
Dave
 
You can just rewire the cab to 4 ohms. No need for a separate jack.
 
Just rewire the entire cab to 4 ohms. One jack, no extra mods, simple :
 

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I re-wired the cab to 4 ohms last night. I was surprised to see how thick a 10 guage line was. I was also surprised that the solder joints weren't quite as good as I'd expect. I opted to use 12 guage Sound Runner cable instead since it was a little easier to work with. I didn't want to toast anything in the process.

I get a reading of 3.6 ohms now as opposed to 13.6 before. That's at the jack. It changes a little if I measure from the speaker cable. I also got slightly different readings by plugging in different speaker cables. Now, to wait 5 weeks to get the V:25.
 
dfrattaroli":2kht7jbs said:
I get a reading of 3.6 ohms now as opposed to 13.6 before. That's at the jack. It changes a little if I measure from the speaker cable. I also got slightly different readings by plugging in different speaker cables.
Click to expand...

That is correct and normal. You did it right.
 
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