https://guitarnoise.forum/live-sound/how-many-watts/ Guitar Noise Discussion Board en-US Thu, 04 Jun 2026 00:18:09 +0000 wpForo 60 https://guitarnoise.forum/live-sound/how-many-watts/paged/2/#post-226750 Sun, 04 Feb 2007 10:05:14 +0000
You want an amp that can provide big volume without distorting.

Guitar players are just the opposite, they love distortion. One reason the EVJ amp is so popular is because it is only 5 watts and begins to break up at reasonable volume.

I am sure a 30 watt bass amp would work fine in small clubs or really anywhere if the rest of the band is considerate and doesn't drive the volume way up. Once the volume goes up you will have to crank your amp and it will begin to distort.]]> Live Sound Wes Inman https://guitarnoise.forum/live-sound/how-many-watts/paged/2/#post-226750 https://guitarnoise.forum/live-sound/how-many-watts/paged/2/#post-226743 Sun, 04 Feb 2007 09:24:51 +0000
It's true, bass carries a lot more, and it's not directional - the waves go everywhere. Low-frequency waves aren't stopped by much. I guess you're right - distance would make a huge difference. In a world of SPL, and theoretical tolerances, you could get two identical decibel levels. Unfortunately, we live in a much more complicated world, so one might very well need to have more amp power depending on the situation.

For instance, I know that PA systems commonly biamp their subs, because the subs need a lot more power. As you had stated before, it's probably because these subs have a lower sensitivity - thus, they'd need more power. Odd how that works...

Yeah, I'll head over to a bass forum and check it out. There's little bass activity here and bass has become my main thing, at the moment. Very good thoughts, though, I do appreciate. Thanks!]]> Live Sound lunchmeat https://guitarnoise.forum/live-sound/how-many-watts/paged/2/#post-226743 https://guitarnoise.forum/live-sound/how-many-watts/paged/2/#post-226735 Sun, 04 Feb 2007 08:47:06 +0000
If I had to guess (and that's what it would be), I would say a 30 watt bass amp would deliver as much volume as a 30 watt guitar amp both playing through a speaker rated 100dB.

I think you are correct that higher frequencies are perceived as louder. That is both true and false. I believe high frequencies sound louder up close, but bass carries. You have probably heard a car going down the street pounding out bass, even if the driver has all the windows rolled up. Bass carries, nothing really stops it. That's why you can put subwoofers on the floor, nothing blocks the sound. However, high frequencies are easily blocked by objects and bodies. This is why PA speakers are mounted on stands with the horn at top over everybody's head. If you put a PA speaker on the floor in a crowed club and go to the back, all you will hear is bass. Try and see for yourself.

So up close the guitar amp will sound louder. But at a distance, the bass will sound louder.

I am not a bass player, so I can't tell you if a 30 watt bass amp will work for gigs. I have played with bass players who did not use powerful amps that worked fine. But in any band the members have to be considerate of the other players to get a good mix.

Maybe you should go on the Bass forum and ask a few regulars there about their experience with low power bass amps.

Sorry if I did not answer your question.

Wes]]> Live Sound Wes Inman https://guitarnoise.forum/live-sound/how-many-watts/paged/2/#post-226735 https://guitarnoise.forum/live-sound/how-many-watts/paged/2/#post-226718 Sun, 04 Feb 2007 06:28:50 +0000
I'm trying to get a specific answer, though. Disregard details about frequency range and whatnot - if you have two equally loud speakers (my example was 100SPL; we could make that any number we want), what would it take to get a sound at 120 db? We know, according to the furmula you posted before, that it would take 16 watts of power to push the guitar speaker to 112 db. My main question; if you give 16 watts of power to an equally loud bass speaker, will you achieve 112 db?

I'm not looking for super-loud bass or anything. In fact, I'm asking this because I'm cheap - if I can get away with a tiny amp, I'm good! :D I've heard many people say that if a guitarist has 100 watts of power or so, a bassist should have 300. I don't know the validity of these claims. I suppose that it could make sense due to frequency response - higher-pitched sounds seem louder, and they're more directional - but that can easily be overcome using a variety of methods. However, if I could seriously get away using a 30-watt power amp to drive my 4x10 bass cab, and get a good sound, I would totally do so. I've been told that that wouldn't work, whereas I've heard different for guitar.

What's the verdict?]]> Live Sound lunchmeat https://guitarnoise.forum/live-sound/how-many-watts/paged/2/#post-226718 https://guitarnoise.forum/live-sound/how-many-watts/#post-226672 Sun, 04 Feb 2007 00:58:46 +0000
First, always feel free to ask any question you like.

Second, I am no expert on this stuff, although I did lots of study and reading on the subject when I wanted to purchace and understand PA systems a few years back.

The example you gave of two 100 dB @ 1W/1M speakers would be that both would be equally loud. The rating itself is a measure of volume. :D

But you are correct that it takes more power to produce lower frequencies. And the reason why is pretty simple. It generally takes far larger speakers (or multiple smaller speakers) to produce the low frequencies. Bass guitar speakers are normally 15", 18" or multiple 10" speakers, where guitar speakers are usually smaller 12" or 10" speakers. So the larger speakers are pushing more air, they are performing more physical work. So, naturally it requires more power to perform this extra work.

But two speakers rated exactly the same will be almost identical volume.

The thing is, you will not see too many bass speakers rated 100dB @ 1W/1M. Bass speakers will normally have lower ratings like 93dB @ 1W/1M. But that is because it is a larger speaker, usually constructed of heavier materials, and is doing far more physical work.

And high SPL ratings are not always a good thing. When you see a speaker rated 105dB @ 1W/1M, right away you know this speaker is super loud. But this speaker probably produces very high frequencies and no lows. So it is misleading. It is loud, but it is shrill and harsh with no bottom end.

And you might see a speaker rated only 95dB @ 1W/1M and think it is no good. This is not necessarily so, this might be a fantastic sounding speaker that produces huge, rich low end. But it takes more power to do this, so this speaker is rated lower. But it may sound FAR better than the loud harsh speaker.

So a speakers rating can also give you an idea of how the speaker sounds, whether it has rich low end or is shrill or harsh.

There are many other ways speakers are measured. For instance frequency range:

Look at these two bass speakers.

Eminence Omega 18" speaker

This speaker is rated 97dB (sensitivity, SPL, efficiency all mean the same). That's pretty good. The frequency range is a low of 40Hz up to 800Hz. 40Hz is very low frequency.

Now, here is another bass speaker:

Eminence Legend 15"

This speaker has a sensitivity rating of 98dB. So it is a little (very little) louder than the 1st speaker with the same exact power applied.

But the frequency range is quite different. This speaker will produce lows to 47Hz up to 3kHz. So this speaker will not produce the amount of lows as the 18", but it will produce highs the 18" cannot.

There is a big difference in power rating too. The 18" could handle 800w (continuous), the 15" only 300w. So this tells you the 18" is of much heavier construction and materials. This also helps explain why the 18" is far more expensive. But the 18" can handle extreme volume far better.

So now it comes down to what kind of tone you are looking for. If you play in a modern Rock band with down tunings, you probably would want the 18" speaker. But if you played bass in a Jazz band, you might like a speaker that can produce some highs as well, maybe a little tighter or punchier tone.

So SPL is only one spec you should look at. You want a speaker that sounds great. Volume isn't everything. Look at the frequency rating and power ratings as well.]]> Live Sound Wes Inman https://guitarnoise.forum/live-sound/how-many-watts/#post-226672 https://guitarnoise.forum/live-sound/how-many-watts/#post-226660 Sun, 04 Feb 2007 00:05:42 +0000
I've been wondering about this...

Another way to put it; take two speakers. One is a guitar speaker rated at 100SPL. One is a bass speaker rated at 100SPL. If I want to push these speakers, to, say, 120 decibels...the bass amplifier would have to work harder to do so?]]> Live Sound lunchmeat https://guitarnoise.forum/live-sound/how-many-watts/#post-226660 https://guitarnoise.forum/live-sound/how-many-watts/#post-97373 Fri, 08 Apr 2005 13:56:35 +0000
http://195.178.239.50/ax84/p1.html]]> Live Sound hero132 https://guitarnoise.forum/live-sound/how-many-watts/#post-97373 https://guitarnoise.forum/live-sound/how-many-watts/#post-97372 Fri, 08 Apr 2005 13:51:55 +0000
BTW, I just bought Sound And Recording - An Introduction ISBN 024051680X

It seems to be a very good book that answers a lot of the questions that crop up on here. A bit technical but in a friendly way. Get yer local library to get it if you don't want to spend the dosh.]]> Live Sound hero132 https://guitarnoise.forum/live-sound/how-many-watts/#post-97372 https://guitarnoise.forum/live-sound/how-many-watts/#post-97369 Fri, 08 Apr 2005 13:31:52 +0000
They aren't cheap . . . though if you're halfway decent with electronics you can make 'em for about half of what you can buy them fo . ..but with low wattage you can get the rich, full tone of a power tube saturation at low volumes, which means you can hear what you'll sound like on stage in your practice room without rattling the neighbors windows.

That's a good thing.

While solid-state sounds the same at any volume, solid state just doesn't sound like a tube amp yet. They're getting closer and maybe one day soon someone will figure it out, but you can hear the difference.

Amptone has more information than you can possibly imagine on amps and how you can stage them to get different sounds.]]> Live Sound kingpatzer https://guitarnoise.forum/live-sound/how-many-watts/#post-97369 https://guitarnoise.forum/live-sound/how-many-watts/#post-96530 Sun, 03 Apr 2005 13:29:32 +0000
If you are going to make the investment, there are some other things to think about. No doubt other contributors will have further things to add...

I would get an amp with 2 channels with each channel having as much independent control as possible. I would also get an amp with what is called an effects loop.

I think I'm right in saying that, if you have 2 channels, you can split your guitar signal and mix the two together again at the amp, one in each channel. One signal may have gone through some effects and the other...etc.

The effects loop allows you to use effects after the preamp and before the power amp stage of the amp. This also opens up many sonic possibilities.]]> Live Sound hero132 https://guitarnoise.forum/live-sound/how-many-watts/#post-96530