20 watts x 2 vs. 40 watts

bkdavidson · #1 03-22-2011, 01:08 AM

Ok, I know the topic of wattage/volume comes up a lot. I know there's lots of variables and marketing double-talk when it comes to wattage and volume. What I want to know, is assuming all other things being equal, is a stereo amp that does 20 watts per side going to be as loud as 40 watts?

Dad3353 · #2 03-22-2011, 12:41 PM

Quote:

Originally Posted by bkdavidson

...assuming all other things being equal, is a stereo amp that does 20 watts per side going to be as loud as 40 watts?

Good evening, bkdavidson...
In a word: yes, but it ain't that simple, as you imply in your question. All other things will not be equal. If it's just an academic question, we may leave it there, but may there be another reason for asking..?
Wattage and loudness are not so simple to link together. Speaker efficiency is one (of many...) considerations. Loudness itself is not the be all and end all, either, as a loud lousy tone is usually less appreciated than a cleaner lower level.
Hope this helps (but it isn't much, I know...)...

mambosun · #3 03-22-2011, 12:57 PM

Quote:

Originally Posted by bkdavidson

Ok, I know the topic of wattage/volume comes up a lot. I know there's lots of variables and marketing double-talk when it comes to wattage and volume. What I want to know, is assuming all other things being equal, is a stereo amp that does 20 watts per side going to be as loud as 40 watts?

I won't say that: each speaker will see 20W not 40w, but two speakers, when installed distant from each other would have a better diffusion ratio than a single one, not louder, just more even.
Having said this, in theory, a speaker driven by a 40w amp would only be 3db louder than a 20w amp.

mattymel · #4 03-22-2011, 01:44 PM

the whole wattage thing is kind of misleading in terms of VOLUME. it also varies quite a bit in the difference between solid state and tube amps. solid state is designed to stay clean through any volume level. though you might get some speaker breakup depending on which one is being used. so, using a low wattage speaker with a high wattage amp would be useless.

i have a 18 watt marshall that is WAY louder than my BF Deluxe thats 22 watts, and my 12 watt Headstrong Lil King seems a almost as loud as the Deluxe...

what does seems to be the case, is the more watts, the more HEADROOM.

as far as your typical jazz guy goes, they want as much headroom as possible as MOST guys dont want any breakup. personally i like to hear just a touch. but for any jazz gig i have ever played, a 20 watt tube amp should have plenty of headroom to stay relatively clean.

BigDaddyLoveHandles · #5 03-22-2011, 02:19 PM

Quote:

Originally Posted by mattymel

as far as your typical jazz guy goes, they want as much headroom as possible as MOST guys dont want any breakup. personally i like to hear just a touch. but for any jazz gig i have ever played, a 20 watt tube amp should have plenty of headroom to stay relatively clean.

It's really hard to compare tube watts and SS watts. With tube amps you want to be in their "sweet spot". With SS amps, you really can't have too many watts.

mambosun · #6 03-22-2011, 05:00 PM

For a similar wattage, volume will depend on speaker sensitivity too.

bkdavidson · #7 03-22-2011, 10:59 PM

Thanks, guys. Here's the deal; I recently switched over to a setup that is a 2x12 cab with Tone Tubbies, a Mesa/Boogie 20/20 stereo power amp, and a POD. This was slowly pieced together and some components were given to me which is why it's kind of an odd setup. It's been a pretty cheap setup as well that allows me to get any sound I want or need which I think will be handy out here in L.A. Eventually I'd like to be doing a lot of studio playing or be in a band (not a jazz band), but still can't convince myself that it will be loud enough. What do you guys think?

Dad3353 · #8 03-23-2011, 03:00 AM

Quote:

Originally Posted by bkdavidson

...can't convince myself that it will be loud enough...

Good morning, bkdavidson...
2 x 20 EL84 valves is a very respectable amp; the 2 x 12 is capable of spitting fire. I would suggest that, if volume lacks because of venue size, you will be mic'ed through the PA anyway. In club/bar/hall situations, you can surely cut above the drummer (well, perhaps not for thrash metal, although he'd get a run for his money...). Not such an oddball set-up; sounds good to me.
A Vox AC30 has this type of configuration (30w mono, but close...), and Vox owners know all about having to turn down..!
Just for comparaison, my son uses a Mesa SimulClass 90/90 into a 4 x 12 Mesa, for modern rock. The volume knobs are at 0.5, any more is way over the top (and we play quite loudly...). Volume will not be the problem for you; tone may be more delicate (not too much 'headroom' there...)
Depends somewhat on the style and repertoire, and the backline of your band colleagues, but I don't see any huge problems here. Let us know, please, how it turns out..?

medblues · #9 03-24-2011, 05:01 PM

I had thought about buying 2-4 Vox Pathfinders ($100 each) and wondered how the combined loudness would be relative to a single Pathfinder.

mattymel · #10 03-25-2011, 12:37 AM

...im finding the overall implied understanding of how tubes function, and also the term "watts" (in relation to how it relates to amplifiers) to be kind of lacking in these posts.

2 EL84s=roughly 20 watts. anything above that and it is basically the wrong tube to be using.

people that are interested in figuring out what the sound is they are hearing in their head (and not through their amps) should do a quick google definition of the term "solid state amplifier" vs. "tube amplifier".

the quick answer is...every brand seems to claim they are 100 watts or 50 watts, or 20 watts or 12 watts...the reality is that the volume of all of those amps may be drastically different from 100 watt amp to 100 amp or even 100 watt amp to 50 watt.

if you dont believe me, take a fender twin (100 watts, 4 6l6s) and turn it to 10, then take a marshall 1959 (100 watts, 4 el34s) and turn it to 10. two completely different worlds. and thats just tube amps. Solid state, whole different ballgame.