Stupid Question

[Johnny Wishbone]

OK so I'm looking at getting a new amp after years of faithful service from my old Crate head (don't laugh). I like the sound but lately I'm starting to feel it's slightly underpowered.

Finally got my head around the whole impedance thing, but I've never had to think too much about power handling before. I currently run my head into a 4x10 and a 1x15, both rated at 300W. My question is this: Is the maximum power handling of my speakers 600W (ie the total wattage) or 300W (ie the total wattage divided by the number of cabinets)?

Many thanks in advance,

Matt

[philbillbass]

Well both cabinets are probably 300 at 8 ohms so that means that yes in total you wil have 600 watts at 4 ohms power handling.

[Johnny Wishbone]

[quote name='philbillbass' post='49442' date='Aug 23 2007, 11:59 AM']Well both cabinets are probably 300 at 8 ohms so that means that yes in total you wil have 600 watts at 4 ohms power handling.[/quote]
Magic. Cheers mate. I figured that would be the case but thought I'd better check before I went out and bought something that my cabs can't handle.

[ZPQ]

Yep - the lower impedance will affect the amp output not the speakers.

So the amp puts out more power into the total of 4ohms, but each speaker takes an equal share of the signal.

[Johnny Wishbone]

Great, so bearing in mind I have 2 x 300W 8 ohm cabs I should be looking at a head that puts out around 300W at 8 ohms (I tend to use only one cab for gigs unless the stage is big enough for a full stack) but can go up to about 600W at 4 ohms for when I'm running both cabs?

I know that with amp heads it's not as simple as double the impedance equals half the power (my Crate puts out 220W at 4 ohms and 150W at 4 ohms, for example) but that's the kind of ballpark figures I should be looking at, right?

I'm thinking of getting something like the Gallien Krueger 700RB-II. Most of the time my Crate pumps out more than enough volume when using 2 cabs, but I've had a couple of gigs recently with a tiny stage (hence using only one cab) and vocal PA only and the Crate has struggled to be heard. It's a rare occasion when my current head doesn't give me enough volume, but I'd rather have the extra power and not need it, rather than need the power and not have it.

Edited August 23, 2007 by Johnny Wishbone

[BOD2]

Yes that's right.

You can also use an amp with more power than your speakers can handle, provided you keep the levels under control and listen out for any distortion from the speakers.

[ZPQ]

Sounds like a reasonable plan.

What cabs are you using? Maybe someone has something similar and could throw in some suggestions for amps.


(just had a look at your bandsite - looks like things are going well...MM endorsement too, very nice!)

[Johnny Wishbone]

[quote name='ZPQ' post='49536' date='Aug 23 2007, 01:54 PM']Sounds like a reasonable plan.

What cabs are you using? Maybe someone has something similar and could throw in some suggestions for amps.
(just had a look at your bandsite - looks like things are going well...MM endorsement too, very nice!)[/quote]
No name cabs (custom made) with Eminence drivers, not sure of the model names or anything though. I got a good deal on the amp and cabs when I bought them years ago, and they've served me well. I regularly get complimented on my tone (more so than my playing!) and the no-name cabs do get the gear-heads talking.

Yeah, things are picking up for the band nicely at the moment. Couple more endorsement deals in the pipeline too. Might hold out and see what comes my way amp-wise in the next few months before I go and splash some cash. Pay little heed to the MySpace tracks by the way - they're a couple of years (and band members) old now, so don't really reflect our sound that much - the bass tone in particular isn't great! Still play a couple of the songs though.

Edited August 23, 2007 by Johnny Wishbone