Originally Posted by: RazboInteresting read. So (and not meaning to hijack Rick's thread)...

Does this mean that because Rick is running thru 2 x 10" Celestions that he's getting more volume at 2 watts than I think I am getting from 5 watts running thru an 8 inch "Fender Special Design"?

I think I will try running this weekend thru my Peavey speaker, which is a 10 inch-something inside a 20 watt combo. In theory, I will have a louder output from all the same amp settings, yes?

Couple things:

Speaker efficiency makes a big difference here.

A 5 Watt amp will not sound much louder than a 2 Watt amp driving the same speaker cab.

The efficiency rating mentioned by Bruce Egnater is a spec based on using the same conditions. That is, 1 Watt rms at 1 kHz, with the SPL (Sound Pressure Level) measured 1 meter from the front of the speaker.

Right away, that can tell you that a more efficient speaker is going to move more air at the same power than a less efficient speaker.

As a general rule of thumb, an SPL change of 3 dB is just barely noticeable. As it happens, 3 dB also represents a factor of 2 change in power (x2 or x1/2).

With the same speakers, the difference in apparent loudness between 2 Watts and 5 Watts is ... not much at all. If the 2 Watt amp happens to have speakers that are 3 dB more efficient than the ones in the 5 Watta amp, then its more like comparing a 4 Watt amp to a 5 Watt amp. Which is an insignificant difference, [u]in terms of how loud it is[/u].

The amp you choose should be one that sounds good to you. Don't worry about how much power it claims to have.

If you really need more reach in a club, mic your amp into the PA. Everyone will like that better than if you use a bigger amp, that's hard to mix.