OHMS, OHMS, and OHMS...

[ClayD]

I just bought an Ampeg PB800.
In the Technical Specifications section of the manual it lists the Output Power Rating as follows:

800 watts RMS, 2 ohm load, 120 VAC.
550 watts RMS, 4 ohm load, 120 VAC.

It doesnt list what the watts RMS is with my 8 ohm cabinet.

I have found online that it will run 300 watts at 8 Ohms.

What I really want to know is if will be okay to run an 8 ohm cab, and a 4 ohm cab together?
What will be the watts? and will it hurt anything?

Thanks,
Clay

 

[Lo-E]

It will put you in the neighborhood of 3 Ohms at around 600W.
It shouldn't hurt anything.

 

[Clark Dark]

it will put you at 2.67 ohms and if that's a transistor amp it may cause a problem going below 2 ohms

 

[David Jayne]

it will put you at 2.67 ohms and if that's a transistor amp it may cause a problem going below 2 ohms

But that won't happen, so it's fine.
The 4ohm cab will receive about twice the power of the 8ohm cab, which you may or may not notice. There is no way to say exactly 'how many watts' you'll have on tap. But it'll be loud.

 

[fenderfunker]

I've wondered this too ( sorry for the hijack), but if I run two (410) 4 ohm cabs in series, from one side of a bi-amp, and 1 x 4 ohm (18"speaker) cab from the other side, I should get the 4 ohm amp rating from both sides of the amp? correct?...

 

[David Jayne]

I've wondered this too ( sorry for the hijack), but if I run two (410) 4 ohm cabs in series, from one side of a bi-amp, and 1 x 4 ohm (18"speaker) cab from the other side, I should get the 4 ohm amp rating from both sides of the amp? correct?...

No. Unless you've hacked or modded something, your two 4ohm 4x10 cabs will be in parallel, giving a 2ohm load. If they really ARE in series, they'll yield an 8ohm load. Parallel=divide load, series=add loads together.

 

[jmjbassplayer]

I'm glad you guys are helping each other out with this, but: why is this in my forum again?

Should I move this to amps? I'm cool leaving it here, I guess. Just want to make sure it's in the right place so the maximum # of people can help and/or contribute.

JMJ

 

[JimmyM]

i'd move it, j.

i think people do that just so they can say "i got jmj to talk to me on the internet." but you know, if you let one guy slide, then everyone will start doing it, and next thing you know, everyone's asking you about markbass and tiny little cabs that handle 5000w

 

[Mads]

+1

But then again:

I got JMJ to talk to me on the internet!
So now nobody else should ever...

Just kidding (on the second part that is... )

 

[jmjbassplayer]

All good, fellas. Let me move this over to amps, for the greater good.

Best,
JMJ

 

[BassmanPaul]

Besides this subject has been done to death and ALL the information ANYONE needs is in the FAQ section of the Amps forum. It just needs to be accessed.

Paul

 

[plankspanker13]

Ohm, Ohm Ohm
Mananan verbum fohat
Kali yug
Come to us, ghost of Blackbeard!


Sorry, just could not resist the paraphrase of the mantra from the book, "Blackbeard's Ghost."