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Over powering a bass cab?

#2
There is a philosophy of some companies (EAW, Bergantino to name two) that you should supply power that is 1.5 to 2 times the power rating of the cabinet. So in your case you should run an amp that will supply between 675 to 900 watts.

I've been following that philosophy for my bass rig and pa for 15 years; I have never damaged a speaker.
 
#3
as long as you realize that you have a volume knob that you can turn down when you think your cab may blow, and you never push it to that point, you'll be ok. if you think you don't have the discipline, then get something rated less than the cab.
 
#4
I used to use a power amp bridged at 800 watts through my old swr triad cab that was rated at only 400 watts with no problems. It just depends how abusive you are with the power and low end. Your not using the full power of the amp anyways unless you are really cranking it to rediculous levels and flooding it with too much low end. You can usually hear when your cab doesnt like what your throwing at it.
 
#8
I was using a 300 watt amp first of all through my triad and it would fart out easily because the cab wasnt that efficient and i was afraid of blowing it that way. By moving up to an 800 watt amp it solved that problem and ran nice and clean. Used it for years with 800 watts with no problems.
 
#9
Like what Jimmy said... with the volume knob (master knob) you control the wattage the amp will deliver. (And other factors like preamp, EQ setting, pedals, playing technique.)

An amp rated at (for example) 1000W does not put this out constantly and immediatly when you hook it up.
Most likely it's in that range of power with the master knob dimed and when you are playing loud.

A 1000W amp can deliver 200W... but a 200W will never deliver 1000W obviously. ;)
My car has a top speed of 250km/h... doesn't mean I drive that constantly... as a matter of fact it's parked right now.


username1 said:
It will fart out and sound terrible.
Click to expand...

Yup...

And I don't mean to bash the cab you have dudeonthebass... but the MAG cabs fart out fast. :hmm:
With the MAG 600 head I had this experience.

It's not a loud 4x10" cab, so think about what you are going to invest in.
 
#10
jmac said:
There is a philosophy of some companies (EAW, Bergantino to name two) that you should supply power that is 1.5 to 2 times the power rating of the cabinet. So in your case you should run an amp that will supply between 675 to 900 watts.

I've been following that philosophy for my bass rig and pa for 15 years; I have never damaged a speaker.
Click to expand...
that's all based on a myth that underpowering a cab can cause clipping that will blow the speakers. for some reason, even companies that should know better stick rigidly by this myth. and this philosophy, while being used by audio pros in pa's, should not be attempted by amateurs, as it will only cause them to turn up way louder than the cab should go and blow it.
 
#11
jmac said:
There is a philosophy of some companies (EAW, Bergantino to name two) that you should supply power that is 1.5 to 2 times the power rating of the cabinet. So in your case you should run an amp that will supply between 675 to 900 watts.

I've been following that philosophy for my bass rig and pa for 15 years; I have never damaged a speaker.
Click to expand...

It is not philosophy actually, just calculations.
450W is RMS power for a cabinet. It means that speaker's coils would not be overheated by signal of sine-wave with such power rating applied continuously. But bass guitar didn't produce pure sine wave as we know. But rather signal with high peaks and some tail.. RMS power of such signal would be less compared to sine wave with similar amplitude. So, we safely can use higher powered amps to handle those high peaks and produce enough loudness.

By the way, square wave has higher RMS power than sine wave. So if you play bass with some square-wave-synth-pedal you can overheat coils even if your amp is power matched with your cab.
 
#12
Sounds like it was probably your amp distorting rather then your cab farting if that was the case. Dunno how more power would sort out a speaker issue.

To the OP, you've also gotta take your EQ into account, that cab can probably take a fair **** load of watts in the mids, but I bet if you put a reasonable amount of sub bass into it then it would complain very quickly.

Unfortunately the whole equation is pretty complex, so the two general rules of thumb is so listen to your cab and listen out for when it's struggling, and making sure you don't turn your amp up to any sort of level where it's not comfortable. This includes by demanding loads of bass EQ out of it, if your cab isn't really putting much out in the first place boosting your lower bass EQ isn't gonna get you anymore, not in any way which is good for your amp or cab anyway. If your amp doesn't have the power for decent low end then your amp will just put out loads of distortion so you can usually tell when that's the case.

To be honest I still don't know exactly how cabs and amps are rated exactly, if a cabs 400W, even with an honest rating, there aren't gonna be any/many bass cabs out there that can put out this amount at say 40Hz, so I don't really get where these figures come from still. Same goes for amps, if an amp is rated at 700 watts does that mean it could put out 700 watts at any frequency? I'm totally clueless when it comes to the more in depth sound tech stuff, but the stuff you need to know to not break your stuff is fairly straightforward.

*EDIT* Forgot that it's a reasonable hour on the East Coast and you guys got quite a bit in before I finished that... well it's a pretty reasonable hour on the West Coast too now isn't it... I need to stop going to bed at 4am...

Alex Calaber (is that how you spell his name) told be the science behind why running my 1500W amp with my 600W NV215 was perfectly above board a while back, I'll find you the link, it wasn't owt to do with unpowering and all that cos obviously he knows better :p
 
#13
PJSShearer said:
Funnily enough I was under the impression that you should do the opposite - to always have a cab that was rated 1.5 to 2.0 times the power of the amp !!. I was told this in around 1972 when I first started playing.
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That advice is better than the alternative view. Using power amps with plenty of headroom was a necessity in PA applications 20 years ago and more, as any clipping in the system could damage tweeters and midranges. That caveat has been rendered pretty much obsolete in the PA genre with DSP. It never applied to musical instrument amps and speakers.

Where electric bass is concerned clipping is pretty much a non issue, as clipping cannot harm woofers. But electric bass woofers on average can't handle more than 50% of their rated power before farting out, so if you want to be sure that you can drive your amp to full power without the speakers farting out they need to be rated for at least twice the power that the amp is. There are exceptions, but they're rare.

Back in 1972 most drivers couldn't even take 1/4 of their rated power before farting out, so the advise given to you then was conservative. I remember having to run eight twelves to get full undistorted output with an open E from a 50 watt Bassman.
 
#16
jmac said:
There is a philosophy of some companies (EAW, Bergantino to name two) that you should supply power that is 1.5 to 2 times the power rating of the cabinet. So in your case you should run an amp that will supply between 675 to 900 watts.

I've been following that philosophy for my bass rig and pa for 15 years; I have never damaged a speaker.
Click to expand...

+1 YUP!
 
#19
René_Julien;8536473 said:
Like what Jimmy said... with the volume knob (master knob) you control the wattage the amp will deliver.
Click to expand...

Sorry René but this is incorrect. You can control the volume of the amp but not its output power. A 1000W amp @ 4Ω will always be able to provide 1000W@4Ω no matter where its level controls are. At almost minimum if the input signal is sufficiently high you'll still get that 1000W.

Paul
 

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