How much power is REALLY needed on stage?

[eSmith]

It is measurable. The whole "It Depends" thing can be worked out.

Generally from a sound reinforcement point of view you are looking at a 4:1 ratio between people:Watts. So, 4 watts is loud enough for 1 person. 1000 watts is loud enough for 250 people etc....

1200 watts is enough to cover a crowd of 300 people, if your drummer is drowning you out, you need a drummer who can play with dynamics. He's too loud.

Just because some people perfer to play music at levels that damage thier hearing doesn't mean all voulmes are equally valid depending on opinion.

-eSmith.

 

[R. Laevinus]

I don't like to gig with anything less than 300w. However, I almost always bring along a couple of really long cables, so that I can tap into the LHC's primary supercapacitor bank if the drummer gets too excited.

 

[MikeyB]

Metric or Imperial ?

Imperial. But I'm not sure if it's Avoirdupois Buttload or Troy Buttload.

 

[R. Laevinus]

Imperial. But I'm not sure if it's Avoirdupois Buttload or Troy Buttload.

FWIW, the Avoirdupois Buttload, being French, is much smellier. Troy's is well within reasonable limits.


Oh, and forgot to mention: Remember Three Mile Island, Chernobyl, and the blackouts in 2003 and in Chile in 2010? Yeah, that was me, all four times. You can never have too much power! It's not my fault that nuke plants and international power grids don't take my needs into account!

 

[Pat C.]

The answer is highly personal. I'm a fan of having a lot of headroom, which necessitates using high-power amps. I've got a modular rig, and depending on the gig's volume requirements I'll use anything from 500 watts into a 1x12", 750-1000 watts into 2x12" up to 1500 watts into 4x12". Having power in reserve allows me to play with a light touch while maintaining presence as my baseline volume, while retaining the ability to play dynamically without running into amp limitations. Speakers with high power handling and adequate frequency response are a requirement, as well.

It's rare that I don't have enough rig for the gig, but there have been times in particularly harsh acoustic environments that I have had trouble hearing myself. In those cases additional power or cabinets would not have held much since the issue was typically with the venue or sound system and not with my rig.

Check out these links for expert opinions on amp power (a few links are .pdfs):

Acoustic Image: The Purpose of Power

Barefaced Bass: Mythbusters - Amplifiers

Invalid Link Removed - more about PA amps/speakers, but the basic concepts still apply.

Just for general research really.

Ive heard some people on here say that their 1200w stack gets drowned out by drums, others say they have used a 15w GUITAR amp with drums...

Here to find some answers, so feel free to give some input.

 

[KJung]

It is measurable. The whole "It Depends" thing can be worked out.

Generally from a sound reinforcement point of view you are looking at a 4:1 ratio between people:Watts. So, 4 watts is loud enough for 1 person. 1000 watts is loud enough for 250 people etc....

1200 watts is enough to cover a crowd of 300 people, if your drummer is drowning you out, you need a drummer who can play with dynamics. He's too loud.

Just because some people perfer to play music at levels that damage thier hearing doesn't mean all voulmes are equally valid depending on opinion.

-eSmith.

Sorry, but totally disagree. Without taking into account number of drivers, cabinet sensitivity, tone, etc. (all the stuff I mentioned in my earlier post), this formula doesn't really tell you much with bass amplification.

 

[JimmyM]

i don't know anyone who uses a 15w guitar amp anywhere but the studio, but i have used a 25w bass amp many times onstage, sometimes without even running it in the pa. give that rig to someone else used to playing much louder and they probably couldn't do anything with it.

but if you're looking for loud, doubling speakers will do a lot more for you than doubling wattage.

 

[JimmyM]

Sorry, but totally disagree. Without taking into account number of drivers, cabinet sensitivity, tone, etc. (all the stuff I mentioned in my earlier post), this formula doesn't really tell you much with bass amplification.

+1. 100w through an 810 is a whole different ballgame than 100w through a 110.

 

[Passinwind]

Imperial. But I'm not sure if it's Avoirdupois Buttload or Troy Buttload.

I use the Beyonce Scale, personally.

 

[Pat C.]

This formula has absolutely no grounding in objective reality. It get's passed around the internet as truth, but it makes no sense whatsoever. I would like to find the person who first stated this nonsense and smack them in the head. Please do not continue to perpetuate this "people:watts ratio" myth.

It is measurable. The whole "It Depends" thing can be worked out.

Generally from a sound reinforcement point of view you are looking at a 4:1 ratio between people:Watts. So, 4 watts is loud enough for 1 person. 1000 watts is loud enough for 250 people etc....

1200 watts is enough to cover a crowd of 300 people, if your drummer is drowning you out, you need a drummer who can play with dynamics. He's too loud.

Just because some people perfer to play music at levels that damage thier hearing doesn't mean all voulmes are equally valid depending on opinion.

-eSmith.

 

[kuys]

Lemmy uses a 100w head pushing a **** ton of speakers and Motorhead is considered one of the loudest bands on the planet.

I think that says a lot right there.

 

[KJung]

Lemmy uses a 100w head pushing a **** tone of speakers and Motorhead is considered one of the loudest bands on the planet.

I think that says a lot right there.

That falls under 'how clean and how much low end' part of the 'it depends' And of course, 90% of the volume is coming from the PA.

 

[WalterBush]

I've had very few gigs where an 810 and a 1000w amp were inappropriate. I've had equally few gigs that required anywhere near that much in the way of speakers and wattage.

Saying that, I try to avoid bringing any amp if I can avoid it. I haul the 810 out for looks with one group and still go through the monitors. With other groups or at church, I just go through the monitors.

IME the answer will vary from gig to gig, but it's hard to go wrong with a 1000w power amp and a fridge, just remember that the volume knob goes both ways.

 

[Electricblue]

How gig-worthy is this?

180wrms into a couple of 1x15 (sensitivity 97db) 8ohm cabs?

 

[shadow_FIX]

I think 200 would do well in a lot of situations, 300 would be better.

I use my LMIII at 8 ohms/300W into a 2x10 for small gigs, and 500W/4 ohms into a 4x10 for larger venues. I have yet to even come close to running out of gas with either setup.

 

[JimmyM]

That falls under 'how clean and how much low end' part of the 'it depends' And of course, 90% of the volume is coming from the PA.

well sure, but a 100w tube amp through a couple square 412's is not shy when you crank it like lemmy does. that's 200w in peak power.

 

[mellowyellow]

One thing to keep it mind is that adding more drivers (cab)to a head so that it sees 4ohm (if that's what your head will do) and can achieve max output delivers a better result than say going from a 300 RMS input to a 500 using the same cab even if that's still within its RMS rating. To get "louder" with the same cab (given same sensitivity/efficiency) it usually means at least doubling the input power or more. IME, adding another cab ( say 2X 8ohm) of the same sensitivity moves more air and adds low end reproduction as it receives max head output. I find this especially so if I keep the drivers the same size instead of mixing 15s&10s, e.g. - not that there's anything "wrong" with doing that. This is just one recipe, of course, and might not be relevant to some exotic, firebreathing, superflexible setup (jealousy). So it depends, as all agree. Adding more matched drivers often results in a louder system with more overall room to play with typical modern heads, and you can just use one cab for those smaller gigs.

 

[billfitzmaurice]

this formula doesn't really tell you much with bass amplification.

I disagree. It doesn't tell you anything. The simple answer is if you're loud enough, you've got enough. If you're not, you don't. Trying to peg a specific number is impossible, as there are too many variables involved.

 

[eSmith]

Well Pat, I suppose I could be wrong. I got it from this textbook, you should get in touch with these people and tell them you consider them and all the expirence they have is just a myth.

http://www.amazon.com/Live-Sound-Reinforcement-Mix-Audio/dp/0918371074

Sure you like lots of headroom, I'm sure everyone would love 10,000 watts of spare overhead ready to unleash on the unsuspecting masses but the reality is that simply isn't required regardless of your personal preferances.

Real world sound guys hate people like you because that overhead you covet so much is just you sabotaging the mix and giving the sound crew headaches because your constantly creeping up in the mix whenever you feel you are not loud enough.

Changing ohm's of course is going to make a difference. Adding speakers changes the power requirments for sure but not without changing the ohm's so your doing the "My apple tastes different that your orange and I like my apple better" thing. Try the expiriment WITHOUT reducing the ohm's and see what you get.

-eSmith.

 

[Electricblue]

One thing to keep it mind is that adding more drivers (cab)to a head so that it sees 4ohm (if that's what your head will do) and can achieve max output delivers a better result than say going from a 300 RMS input to a 500 using the same cab even if that's still within its RMS rating. To get "louder" with the same cab (given same sensitivity/efficiency) it usually means at least doubling the input power or more. IME, adding another cab ( say 2X 8ohm) of the same sensitivity moves more air and adds low end reproduction as it receives max head output. I find this especially so if I keep the drivers the same size instead of mixing 15s&10s, e.g. - not that there's anything "wrong" with doing that. This is just one recipe, of course, and might not be relevant to some exotic, firebreathing, superflexible setup (jealousy). So it depends, as all agree. Adding more matched drivers often results in a louder system with more overall room to play with typical modern heads, and you can just use one cab for those smaller gigs.

So, roughly, 2x15 at 180w 4ohm would be about 4 times as loud as 1x15 at 120w 8 ohm?