How many Watts?

Yes, I understand that. I've read a lot about speakers, as I'd planned to build two cabs at one time; I did my homework, and I know about frequency range, SPL, whatnot.

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?

lunchmeat

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

Nah, you're good - you've given me what I needed, even if it is just an opinion. It's a good one.

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!

Another reason bass players need lots of power is because they do not want distortion.

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.