Why so much power?

[thinman]

I'm a bit struck by the huge amounts of power (500/600 watts +) some people have in their rigs and I'm a bit curious why.

Are some of the cabs out there very inefficient?

Is it required to get certain tone at volume?

Do people want 130db at 30Hz?

Do they never really use it?

Do they play just too loud?

Am I just being an old fart?

I've always thought that if you can get your desired tone and keep pace with a loud unamplified drum kit there's not a lot of point being able to go much louder. Once your drum kit is getting mic'ed up then there's probably a PA available that can handle bass reinforcement too and then the soundman won't appreciate your backline being too loud.

[The Burpster]

You need big Watts to shift big speaker cones.

You need big speaker cones to shift a lot of air.

You need to shift a lot of air to produce good clear low frequencies.

You need to produce good low frequencies for bass.

Or....


We're blokes + we like lotsa power!

[Muppet]

It's all about having headroom. I have 1200w. I don't need it of course. Never have. But I like knowing it's there. Comfort headroom if you like.

[bnt]

It's also an unavoidable fact of human hearing, which is less sensitive at low frequencies. To get a given perceived sound level, you need more RMS power the lower you go. That extra power is not wasted in the amp, it goes towards carrying the bass signal further. If the amp was just wasting hundreds of watts as heat, it would need much bigger fans! There's an article about SPL and power, [url="http://www.usmotors.com/products/ProFacts/sound_power_and_sound_pressure.htm"]here[/url].

[thinman]

I understand the science bit - it's more the application.

If you can drown out an unamplified drummer then what's the point? Demolition, internal organ damage? Won't your band sound terrible? I know some very flat cabs need a fair bit more power but 1kW!!?

I think burpster's closing comment may be nearer the truth. Marketing men know us blokes too well.

Some of Bill Fitzmaurice's forum posts are very interesting on this. It's quite astonishing how little power quite highly rated cabs will absorb before they stop doing anything useful with the extra power being shoved into them before just turning the rest into heat (which is really what the RMS rating is giving - voice coil power handling before it melts).

But then a big stack is a bit more rock 'n' roll.

[warwickhunt]

re. the OP comments

I've considered for a while that I used to gig 25 years ago with 150 - 200 watts and I had no problems whereas now most of us recommend 300-500watts to the various posters asking questions about power required for various band situations. I don't think we 'need' more power these days, I just think that higher power amps are cheaper to produce now, are readily available and are the norm in the marketplace!

I don't think we've consciously needed or wanted more power (though headroom is desirable) but we've just been handed it on a plate

[bnt]

[quote name='thinman' post='199297' date='May 15 2008, 09:00 AM']I understand the science bit - it's more the application.

If you can drown out an unamplified drummer then what's the point? Demolition, internal organ damage? Won't your band sound terrible? I know some very flat cabs need a fair bit more power but 1kW!!?

I think burpster's closing comment may be nearer the truth. Marketing men know us blokes too well.[/quote]
At least bass amp marketing is honest compared to the marketing you get with e.g. car stereos. The RMS figure is the one that matters, not "peak music power", whatever the heck that is. I also agree with the need for headroom, and the components last longer if they are run underpowered. (Heat is the #1 killer of transistors.)

Did any of you see that Mythbusters episode where one of the guys stood in a circle of Meyer Sound PA speakers and got blasted with subsonic frequencies? They were testing the "brown note" myth. SPLs were over 150dB, but he felt nothing, though I felt sorry for any elephants in a ten mile radius.

[gilmour]

Interesting thread this.

FWIW I've never needed more than the 250W my head kicks out. For smaller gigs this is fine, and for any larger venue you're going through the PA anyway so I can never understand the need for that massive amount of power. To my ears it also sounds better when you have to drive your system a little, leaving it all on low voulme settings always sounds a little to clynical to me, so can't really understand the need for 'headroom'

[MythSte]

I know for me at least, i need the power to keep up with all the synths on stage. They get full monitor mix so i have to rely on my amp.

And as said before, its nice to know that if i turn up to a gig that for whatever reason i cant go through the PA i can just crank it and not worry!

[chris_b]

I spent years with a 100 watt Marshall, then a 100 watt Hiwatt through 4x12 cabs. The sound we all got back then was very woolly, but as long as was bassy we were happy. That was then, now we seem to be looking for a clearly defined, clean sound which not many people wanted back then. I probably spend 90% of my time using less than half of my 550 watts. It's not marketing, but if you decide you want "headroom" then you need a big amp.

[johnnylager]

[quote name='chris_b' post='199333' date='May 15 2008, 09:54 AM']I probably spend 90% of my time using less than half of my 550 watts. It's not marketing, but if you decide you want "headroom" then you need a big amp.[/quote]
Ditto. 575w, never been above 10 o'clock except when I hired a rehearsal room to see how loud it went.

Edit: very loud.

Edited May 15, 2008 by johnnylager

[bass_ferret]

Cos we can

[john_the_bass]

i gigged for years with 80 watts and 1x15 - it was enough for me, when it stopped working, i tried some new rigs, went for the lowest powered ABM ashdown because i liked the tone (yes, i know what you're all thinking you buggers ). The first time i plugged it into a "big" cab - an ampeg 610 - I was told to turn it down because it was coming over the top of the house 12k PA.

I don't need any more than that

[elros]

More power is needed for a clean sound, particularily with solid state amplifiers. The short transients need lots of power reserve to avoid clipping. This is of course in large part due to the rather slow transient response of most box speakers. Horns are often much better in this regard, but they need to be rather too large to give the desired bass response.
How was it? you need to double amplifier power in order to attain a 3dB increase in sound pressure level? I'm not quite sure, perhaps I remember wrong.

My own amplifier is the Eden WT800 head, it will give 400W RMS per side in 4 ohm. But my cabs are 8 ohm, so it'll probably let out between 200W and 300W RMS. More in peak, luckily.
It gives a pretty clear sound through my two AccuGroove Tri-112L cabs. It is powerful enough for most situations. But still, I've been in venues that seem so eat up the bass sound, and I've felt the need for more power.

IMO high power amplifiers are a good thing. Too many times have I felt the inadequacies of low(er) power combos, we have many of those at school.

[BTGAndy]

I've got 1500W and I will honestly never need that much power, it's good as Muppet said for comfort headroom, it's nice knowing you've got that extra power. I bought the amp because of the features not the power, I'd be happy with 500W but I suppose it mostly depends on what you're doing, if you want to run 4 8x10s in a huge stadium then that kind of power might be useful but a small 4x10 and 1x15 stack it's perhaps a little unnecessary. They exist so there is obviously a market for them so some people deem them to be necessary and at the end of the day if you can afford it and carry it then why not?

[thinman]

Certainly agree that a big amp is less stressed at lower volumes and that power comes cheaper these days. And, yes, the commonly recommended 300-500w is usually adequate and not excessive.

For those of you that play with a full PA and have a large rig, is the sound man usually asking you to keep it down as it makes getting the FOH sound right difficult?

I think it would be interesting if we all knew how much power we were actually using typically. IIRC, a typical cab with 500w drivers doesn't get any louder when the input power goes above about 150w! (Obviously that varies with driver/cab design) so I'm always suspicious that we get a bit misled. Some like Alex Claber or Bill F can probably elaborate on/correct this statement.

[JakeBrownBass]

[quote]Did any of you see that Mythbusters episode where one of the guys stood in a circle of Meyer Sound PA speakers and got blasted with subsonic frequencies? They were testing the "brown note" myth. SPLs were over 150dB, but he felt nothing, though I felt sorry for any elephants in a ten mile radius.[/quote]

Those speakers are bloody awesome! THE best pa gear i have EVER heard.
I work in my uncles hire dept at www.proaudiosystems.co.uk in braford and they have an entire MILO set-up. The sheer volume from a single of one of them is mind blowing and the Subs are amazing!

If only i had the money ey? lol.


edit: back on topic

As everyone has said, the higher watts is there for the added headroom really. I'd much prefer turning up with an over powered amp, than an underpowered. Plus the amp will last longer if your not pushing it as hard

-Jake

[The Funk]

I have a 1000W power amp for my rig. It's nice to know there's more there if I need it.

That's still half the Watts of your average ladies' hair dryer: [url="http://basschat.co.uk/index.php?showtopic=18779&hl=hairdryer"]http://basschat.co.uk/index.php?showtopic=...mp;hl=hairdryer[/url]

[crez5150]

From listening to lots of live bands...... I think too may players are too loud on stage.... I use an Eden Metro 2 x 10 combo.... play gigs from the small pub to 400+ functions.... never need more.

[Adrenochrome]

[quote name='crez5150' post='200131' date='May 16 2008, 08:14 AM']From listening to lots of live bands...... I think too may players are too loud on stage....[/quote]

...it's true and often the vocals suffer because of it. I don't need more then my 300watts, and as I often use just 1 cab (1x15 or 2x10) I'm usually running at 180 watts (with about double that in reserve). Tonight we're going through a smallish house PA so I'll take both cabs just in case there isn't much oomph from the PA.

[NancyJohnson]

[quote name='crez5150' post='200131' date='May 16 2008, 08:14 AM']I think too many players are too loud on stage....[/quote]

I played in Reading a couple of weeks ago in a real metal pub. Our drummer is a fantastically loud player. The guy doing the sound said to us we needed to ramp the sound up, so we did.

During the set, we were getting a bit of feedback off the stage microphones and one of the venue staff tweaked the mixer (which was at the side of the stage) - he shouted over to me that we were the loudest band he'd ever had in there, which I took some pride in considering the venue.

Loud = good IMO.

P

[gilmour]

Nothing will compare to the volume of the Samba band I play with, when we do a street procession you walk down the road watching car alarms go off. I'd hate to think of the size of rig a bass player would need to keep up!

[Jase]

[quote name='BeLow' post='200167' date='May 16 2008, 09:26 AM']Loud = deaf soon?

I know that reads a bit like stuff your parents might say but you apprciate these things far more when you have lost them and then it is too late.

Perhaps its my age but getting home from gigs with ear damage is even less appealing than it was 15 years ago, and I didn't think it was a great idea back then either.

Drumers are often the culprits in bands playing too loud and the rest of us are to often willing accomplices. I have a rig which can do loud and occasionally when it is ticking over it is a bit too controlled, but at least I can still hear it.

I must ask our drummer if he has thought more about a compact kit.[/quote]


Agreed, loud is bad. Even if I think it's an acceptable volume I use protection, there's nothing worse than coming home from a gig with ringing ears.

[warwickhunt]

[quote name='BeLow' post='200167' date='May 16 2008, 09:26 AM']Loud = deaf soon?

I know that reads a bit like stuff your parents might say but you apprciate these things far more when you have lost them and then it is too late.

Perhaps its my age but getting home from gigs with ear damage is even less appealing than it was 15 years ago, and I didn't think it was a great idea back then either.

Drumers are often the culprits in bands playing too loud and the rest of us are to often willing accomplices. I have a rig which can do loud and occasionally when it is ticking over it is a bit too controlled, but at least I can still hear it.

I must ask our drummer if he has thought more about a compact kit.[/quote]

Simple answer ear plugs!

The amp/power/volume debate reminds me of a motorbike riding mate who sold his 1000cc bike because it went too fast for him! Funny but I find that twisty thing on the right handlebar goes as far as you want it too go and it can be turned down as well as up

[stevie]

[quote name='bnt' post='199320' date='May 15 2008, 09:36 AM']At least bass amp marketing is honest compared to the marketing you get with e.g. car stereos. The RMS figure is the one that matters, not "peak music power", whatever the heck that is. I also agree with the need for headroom, and the components last longer if they are run underpowered. (Heat is the #1 killer of transistors.)[/quote]

They may not be as bad as the car stereo makers, but I do think there's a certain amount of wishful thinking involved on the part of bass amp manufacturers' when they specify power output. After all, have you ever seen an independent test of a bass amp's distortion at maximum output? I've looked inside a few of them and they seem woefully underspecified in terms of mains transformer and reservoir capacitor size.

I did find one independent test on the web of a well known and respected American bass amp, whose actual output was only two thirds of its rated output. It could be that many bassists don't actually have as much power as they think they do. I'd feel more confident judging an amp's output by weighing it rather than looking at its specification. Just a theory, of course.