AMP HELP!!!

themaidenmaniac · #1 08-18-2004, 07:35 AM

Dear amp guru's,

I am planning on buying a 120 watt head and a 400 watt cabinet, however I need to clear up something.
Could anybody tell me if the head will only make the cab produce a max of 120 watts out of it?

and this would mean that i wud only use less than 1/2 its power, Right??

HELP!

cheers

bammbamm · #2 08-18-2004, 09:41 AM

Are you playing huge theaters or venues where you'll actually NEED that much power?

Even in the largest clubs / venues I've ever played, I've rarely gotten to turn my amp's volume past the half way point. In fact, I don't think I EVER HAVE. Most times you're going to be mic'ed out and played through a P.A. so you only need your amp for some stage volume as a monitor.

Don't get caught up in the bigger is better thing, as it doesn't really work out that way for live shows.

(btw, whatcha getting?)

Bamm

themaidenmaniac · #3 08-18-2004, 10:16 AM

Cheers for the reply mate!

Basically, im looking for the cheapest possible option of more power.

Im hopefully gonna buy the crate head:

http://www.soundcontrol.co.uk/mod_1....1.2-109-18-111

And was looking at this behringer cab:

http://www.behringer.com/BG412H/index.cfm?lang=ENG

however, there is a 200w version, but what im getting at here is:

Because the crate head is only 120W and the cab would be 400w , would i only get 120w out of the cab? So it wud make it pointless buying something so big and mite as well buy a 200w?

I have know idea about big amps whatsoever, so cheers if u can help me mate!

themaidenmaniac · #4 08-18-2004, 10:19 AM

I keep saying about the "we're getting mic'd up anyway!" factor, cause we always do in the clubs anyway, (i already have a 50w marshall), but need a little more power for times when i may not be mic'd up e.g. playing outdoors, or in gardens at bdays etc.

bammbamm · #5 08-18-2004, 10:23 AM

You'll get more dispersion out of a 4x12 cab than a 1x12 combo. Just out of curiosity, have you tried your 50 watt Marshall through a 4x12 cab?
Even if you double your head's power from 50 to 100 watts, you only increase your volume by 3 decibals, I think just getting a bigger cab will help you out.

What do you have now?

Bamm

Drew · #6 08-18-2004, 10:24 AM

You're running a marshall 50-watt tube head flat out, and it's still not loud enough? Dear lord...

Well, cab wattage is slightly different than amp wattage- a 120 watt head will put out 120 watts at a given level of distortion. A 400 watt cab, on the other hand, is safely rated to be able to handle up to 400 watts coming into it; it doesn't have any "output" wattage of it's own, it's just saying that "you can hit this speaker configuration with 400 watts of power without risking hurting anything." Odds are, you can drive it a bit harder, too, but it's always ebtter to err on the side of caution, especially in light of the fact that a tube amp's wattage is only measured at a given total harmonic distortion, not flat out- i believe (can someone back me up on this?) that most 100-watt heads are probably pushing closer to 120 when they're fully open.

hope this helps a bit... A cab with a wattage higher than the amplifier is fine. An amp with wattage higher than the cab is fine if you're not going to turn it up much, but will get you into problems, long-term, if you crank the thing; blown speakers, etc.

-D

bammbamm · #7 08-18-2004, 10:31 AM

I think you mean RMS or average power. The peak is the RMSx1.414.

Bamm

Allen Garrow · #8 08-18-2004, 10:56 AM

Yeah, I agree with Bammbamm and Drew. A 4x12 cab is going to move alot of air. 120 out put on a head is going to be more than enough through a 4x12. You could probably get away with using your 50 watt through a 4x12,, however it's nicer to have that bigger head for a little harder, more solid push at higher volume. Head room is better with a larger amp,,, gives you room to stretch your arms.

Compression, EQ are some other tweaks that may help cut through the mix as well.

~A

themaidenmaniac · #9 08-18-2004, 11:32 AM

hi again guys, i must say thanks for the help- its increasing my little knowledge of amps.

Nah, my amp is a piddly 50w Marshall 50DFX. Plus, its not possible to attach a cab to it (no sockets), so short of rewiring that wont work. Therefore i will hopefully be buying a CRATE 120W head (solid state)

basically, there is a cheap behringer cab rated at 400w and has

4 x 12" 100w speakers (so this is bound to be out more volume than the one below) ?????????

OR another with

4 x 12" 50w speakers .

Im looking to keep things digital at the mo cos my whole rig is digital e.g. BOSS GT6, and cause of money restrictions.

Cheers again

themaidenmaniac · #10 08-18-2004, 11:35 AM

What does RMS stand for and mean also?

Allen Garrow · #11 08-18-2004, 11:50 AM

Here man check this out: http://www.carvin.com/doctorsound/drsound04.php This explains some stuff in great detail that seems to be what you are looking for.

~A

Allen Garrow · #12 08-18-2004, 11:57 AM

OOOPS sorry,, RMS by definition is "Root mean square", or something like that. Do a search for a technical explanation for RMS if it causes you to loose any sleep. In general RMS is the only true measurement of output power of an amp. Some manufacturers call it "peak" power. Or at least that's what I came up with. So to be on the safe side I'm power my rack system with a Carvin DCM1000

gotta love the head room.

~A

Algiman · #13 08-18-2004, 12:08 PM

root mean square.

Allen Garrow · #14 08-18-2004, 12:12 PM

DOH! thats what I meant,, but that certainly isn't what came out...lol.
Thanks for catching that. This poor dude would have been tweaking over some B.S. Acronym definition I gave him....

~A

Drew · #15 08-18-2004, 12:24 PM

See, I on the other hand have a thing for low-wattage tube amps- they sound "rounder," imo... It's tough to describe, but there's something "squishy" about the tone of a small amp that I'm just in love with. Sure, for devastating crunch, higher power is probably the way to go, but I think the 45 watts my current amp puts out is overkill.

-D