Do 2 X 20 watt amps = 1 X 40 watt amp?

[larry_emder]

Assuming they are connected to the same speakers and are built similarily......which will be louder?

Sorry for getting all 'walters' on you guys! Just curious!!!

 

[Boogie Bill]

Re: Do 2 X 20 watt amps = 1 X 40 watt amp?

My understanding is that two 20-watt amps will be louder than one 40-watt amp.

Bill

 

[Perry D]

Re: Do 2 X 20 watt amps = 1 X 40 watt amp?

ive always thought the more speakers you have the more sound you can get out of it. just look at the principal with 4x12's and 2x12's. way more low end with the 4x12

 

[greendy123]

Re: Do 2 X 20 watt amps = 1 X 40 watt amp?

The 40 watter should definitely be louder, but the 20 watt amps may seem louder because more sound is spread around.

 

[Lewguitar]

Re: Do 2 X 20 watt amps = 1 X 40 watt amp?

It's hard to say.

Are two Deluxe Reverb (one 12 each) amps louder than a 40 watt Pro-Reverb with two 12's?

The two amps will sound bigger and wider...especially if they're spread out from each other a foot or two or more.

The one 40 watt amp will sound more focused and probably be louder if you were standing right in front of it.

I LOVE playing through two 20 watt amps.

I plug into two Fender Deluxe Reverbs or two Fender tweed Deluxes.

 

[Scott_F]

Re: Do 2 X 20 watt amps = 1 X 40 watt amp?

I plug into two Fender Deluxe Reverbs or two Fender tweed Deluxes.

That's a nice luxury to have at your disposal. Just curious, do you ever pair up one of each? I wonder what that would sound like.

 

[Lewguitar]

Re: Do 2 X 20 watt amps = 1 X 40 watt amp?

That's a nice luxury to have at your disposal. Just curious, do you ever pair up one of each? I wonder what that would sound like.

I have! Sounds good.

I've read that the 60's DR's are out of phase with the 50's Deluxes and that in order to get them in phase you can reverse the leads to the speaker on one amp or turn the cabinet around so one amp faces forward and the other backward.

I didn't want to reverse the leads to my speaker so I tried it with one amp reversed (so I was listening to the back of the speaker) but alos tried them with both amps facing forward.

Didn't really notice the out of phase issue I'd read about but that doesn't mean it's not true. I didn't spend a lot of time with it...but both set-ups sound quite differant.

Roy Buchahan used to point his Vibrolux to the back wall and the back of the speakers towards the audience...I assume so he could turn the amp up louder without being to loud.

I usually just play through two DR's or two Deluxes or one Deluxe and one tweed Super.

Yes...it's NICE to have great old amps like that to play through. :laugh2:

Lew

 

[jeremy]

Re: Do 2 X 20 watt amps = 1 X 40 watt amp?

i use a '66 dr and your 5e3 togeather sometimes. very cool tone, the tweed has lots of meat in the middle, not so much top and a soft bottom where the dr puts the sparkle back on top and gives a more stout bottom with an overall cleaner sound.

 

[75lespaul]

Re: Do 2 X 20 watt amps = 1 X 40 watt amp?

I love running two amps at once. I mix and match my Fenders, Voxes, Univoxes. Sweet.

 

[Baltar]

Re: Do 2 X 20 watt amps = 1 X 40 watt amp?

hehe, nice question ... i'd say two cabs at half power, always produce
a fuller sound, than one.

if i try estimate it, based on two things ...
1)two speakers on the same surface (meaning, you staple the cabs)
at each one W power are 6db louder than one speaker at one W.
2)double the power is double the loudness, so +3dB

(for ease of calc we compare a 2x16W with 1x32W)

eg.. 1spk w avg spl 98dB 1W/1m

1W .. 98 dB
2W .. 101 dB
4W .. 104 dB
8W .. 107 dB
16W .. 110 dB
32W .. 113 dB

2W (2x1) .. 104 dB (98+6)
4W (2x2) .. 107 dB
8W (2x4) .. 110 dB
16W (2x8) .. 113 dB
32W (2x16) .. 116 dB

i dunno if it's correct that way, but that's the way i think it's correct.
btw i not an informactics/electrics guy. i'm testing software, so it's really
just a guess how it works.
if i am right. 2 cabs at half power should be 3dB louder, so twice the
volume - at least theoretically, if you staple them.

perhaps somebody smarter can proof me right or wrong.
or somebody haveing time and cal-micro just find it out

just my 2 cents

 

[aleclee]

Re: Do 2 X 20 watt amps = 1 X 40 watt amp?

I'd qualify my answer by asking "clean or dirty?"

IMO 40W is about enough to ensure clean headroom at volumes that can keep up with a drummer. In that situation, a 20W amp might get a bit hairy when you're playing clean.

 

[aleclee]

Re: Do 2 X 20 watt amps = 1 X 40 watt amp?

i dunno if it's correct that way, but that's the way i think it's correct.

It's not correct. First, I dunno where you got the 6dB number: 3dB is the number I've seen thrown around by techs in doubling speakers. Second, each speaker only gets half the total power, resulting in a 3dB drop in its input power.

Multiple cabs will give better spread and a fuller tone but any significant difference in perceived loudness is more a matter of psychoacoustics and dispersion than sheer amplitude.

 

[Stevo]

Re: Do 2 X 20 watt amps = 1 X 40 watt amp?

When you add power sources together, you get a linear result. On the other hand, loudness is rated logarithmically. For each db factor, you need a different amount of power behind it. That is why people get confused with the concept of (for example) double power equaling "only" 3 db more in loudness.

To answer your question, 20w + 20w does in fact add up to 40w, therefore, the loudness is theoretically equal - each speaker gets 20w - but then there is an issue of phase cancellation when using 2 amps.

 

[Lewguitar]

Re: Do 2 X 20 watt amps = 1 X 40 watt amp?

I prefer playing through two 20 watt amps to playing through one 40 watt amp. The tone wraps around me and I find I don't have to play as loud to get the sustain I like.

I can play cleaner and still get great sustain. And the tone is much wider with two amps.

Also, I can split the signal with a stereo effect (like a stereo chorus or delay) and the sound is HUGE!

A chorus in stereo can be a really beautiful efect...and sounds much better in stereo than mono.

Two 20 watt amps will also help save your hearing, IMO, compared to one cranked 40 watt amp.

 

[Baltar]

Re: Do 2 X 20 watt amps = 1 X 40 watt amp?

It's not correct. First, I dunno where you got the 6dB number: 3dB is the number I've seen thrown around by techs in doubling speakers. Second, each speaker only gets half the total power, resulting in a 3dB drop in its input power.

Multiple cabs will give better spread and a fuller tone but any significant difference in perceived loudness is more a matter of psychoacoustics and dispersion than sheer amplitude.

it's from a tech book for speaker enclosure construcion.

i wrote, that the +6db is for two speakers with EACH driven by 1 watt !!!

this is what you could also have thought of, when you looked to the
list i built.