JVM Mixed Loads

[Davii]

Anyone know if this is ok:



The manual for the JVM says 2x8, or 2x16, and Marshall aren't responding to my Twittering.

 

[Gone_Shootin]

Re: JVM Mixed Loads

Das ist verboten, you run the risk of frying your output transformer.

I would use one cab or the other, or rewire one cab so it matches the other, which may mean that you only have two speakers in one cab hooked up.

 

[Davii]

Re: JVM Mixed Loads

I thought it a bit unlikely. I've the 2x12 combo with 8ohm speakers, a 2x12 external cab with 16ohm speakers, and I'm scratching my head trying to figure out what I can/can't get away with :-S

 

[Gone_Shootin]

Re: JVM Mixed Loads

8 ohm speakers in the combo, as in they're both 8 ohms each? If that's the case, they're more than likely wired in series and have a total of 16 ohms.

 

[Davii]

Re: JVM Mixed Loads

They are in series in the combo, so 16 in total, but the external cab is either 8 parallel, or 16 stereo, so I'd wondered about putting the combo's series speakers into one side of the 2x 16, and the external cab in parallel into one of the 2x 8ohm spots similar to the picture.

 

[devastone]

Re: JVM Mixed Loads

No. On the jack plate, 1 means 1 only, you have 2. You can't split the signal off the transformer which is what plugging them in that way will do. The cabs need to be matched, then use the appropriate 2 holes.

 

[Davii]

Re: JVM Mixed Loads

I thought the split thing didn't seem right. Can always run 16ohm from the combo, and just one of the external cab speakers for a 2x 16ohm, though looks like I've some splurging to do!

 

[dystrust]

Re: JVM Mixed Loads

The 16 and 8 ohm cabs in parallel would be 5.3 ohms, so they should be OK with both of them plugged into the 1x 4 ohm / 2x 8 ohm jacks.

 

[Gone_Shootin]

Re: JVM Mixed Loads

Might be easier to just get a pair of 8 ohm speakers for the extension cab, and sell the other ones.

 

[Davii]

Re: JVM Mixed Loads

I'd also thought of mixing the speakers for a 2x 24 safe mismatch using the 2x16 sockets.

As it's a 100w combo, am I really likely to notice enough of a drop for that not to be a worthwhile option?

 

[SlyFoxx]

Re: JVM Mixed Loads

What dystrust said. 5.3 ohms is no problem.

 

[PFDarkside]

Re: JVM Mixed Loads

Mismatch depends on the amp. Remember that they will be receiving different power levels too, based on impedance. If it’s a 2x12 and a 4x12, all speakers are the same impedance and it’s wired correctly, this wouldn’t be a concern.

 

[Van Noord]

Re: JVM Mixed Loads

Even if the mismatch is safe, it can/will/might have a negative tonal outcome.