Guitar Cab for use with Powerrack - 4 Ohms, should I change it to 16 ?

V8guitar · Oct 13th 2014

All,

Just about to get a Power rack ( this weekend...at last!!!) and I want to run it with my guitar cab which is currently wired at 4 ohms ( 16 x16 ohm speakers).

I have read it's OK to run the powerhead or rack at 4 ohms up to 300 watts but it also states in the manual run it at 8 or 16 ohms only?

Should I re-wire my cab in series parallel to run at 16ohms??

I know solid state maps are less sensitive than tube amps but I still don't want to fry it...

Do I need to ask Kemper for a defintive asnwer on this??

viabcroce · Oct 13th 2014

Hey V8

The powerrack will work fine @ 4 ohm. It's only more probable that it will go into protection (muting) if the driven current exceedes the specs. But you won't damage the unit because of this.
OTOH, as long ad your volume is low enough, the unit won't go into PM at all.

Basically, if you need to unleash all the power and some second of muting would be critical (i.e., public performance with your cab driven very hard) 16 ohms will put you on the safe side. But, depending on your cab's power acceptance, you might never want to drive it really hard.

HTH

V8guitar · Oct 13th 2014

Hi Viabcroce,

Cool. I don't play very loud so interesting to know when the muting might kick in, can't imagine it's anywhere near 300 watts. I'll play with it and if necessary re-wire.

I'm very excited to finally be getting one!

viabcroce · Oct 14th 2014

Yeah, you'll be able to find a balance, since the volume will be louder @ 4 ohm but you'll have to keep the volume down.
So basically I think it would be exactly the same SPL no matter the impedance, except that @ 16 ohm the unit will never go into protection mode

HappyKemper · Oct 14th 2014

viabcroce, did you get my PM conversation I just posted to you?
(I'm not sure PM works after the new forum update)

paults · Oct 14th 2014

"currently wired at 4 ohms ( 16 x16 ohm speakers)."

Do you have a cabinet with two 16 ohm speakers in it? Or, two 16 ohm cabinets?

Two 16 ohm speakers in parallel is 8 ohms.
In series, they would be 32 ohms.

V8guitar · Oct 14th 2014

Sorry Paults, it was a typo..its a 4 x12 with4 16ohm speakers wired in parallel.

paults · Oct 15th 2014

No apologies needed : ) I was just checking, to make sure you were looking at the right options for your cabinet.

viabcroce · Oct 15th 2014

Quote from HappyKemper

viabcroce, did you get my PM conversation I just posted to you?
(I'm not sure PM works after the new forum update)

Uh, had not noticed it, sorry!
Why doesn't the board warns when there's an unread "conversation"?

HappyKemper · Oct 15th 2014

Quote from viabcroce

Uh, had not noticed it, sorry!
Why doesn't the board warns when there's an unread "conversation"?

Good that it works.
New messages and conversations shows up on top left of the screen, next to the user avatar symbol/settings/login.
I will reply now. Sorry to the OP for going OT here.

viabcroce · Oct 15th 2014

I see the conversations, but in order to be aware of new entries I should remember the number of listed conversations... We need an alarm, a popup, a cloud, a hint, a bell!

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