help me understand why my bandmate's amp is louder than mine

[Steve Conner]

Hmm, I guess I was wrong, sorry for the misleading statement.

When you hook up two identical amps side by side, the sound waves sum coherently on axis, so the SPL rating at 1 meter on axis goes up by 6dB, not 3, even though the electrical input power only went up by 3dB.

So it's as if the sensitivity of each speaker increased by 3dB: the efficiency gain mentioned earlier.

I suppose the reason is that two speakers side-by-side have more directivity than a single one. More sound gets beamed straight down the middle. However, there are just as many places where the waves from the two speakers interfere destructively, so maybe if you integrate the sound power over a full sphere round the speakers, you'll find that it only went up by 3dB, as conservation of energy demands.

I guess the logical conclusion of this line of thought is the line array, which harnesses constructive interference to put most of the sound where you want it, and hardly any of it where you don't.

[guitician]

OK, I found this nifty Calc..... Sound level SPL to dB - pressure level sound pressure sound intensity - dB conversion of sound units levels calculating spl sound level calculation air sound units level factor decibel Pa kPa acoustic power convert decibels to pascals - sengpielaudio

A chart towards the bottom of the page shows a 3db increase in sound level equates to a 1.23 times the perceived loudness.

It also shows what JJ's been trying to clear up with me about what 3db is.

[Jammin'John]

Explain

Yea,sometimes it's hard to explain things.
Ted Weber was a great one to ask.
That's how I found out.

JJ

[mlove3]

bought a eminence wizard, put it in my main cab. sounds a lot like the celestion g12h except bassier (which is cool) but is it that much louder??
I'll gig with it and see how it goes, but I'm still craving more clean headroom from the amp. Considering options for yet another homebrew project. What I want is a 100W boogie or fender style small box chassis, or a 50W with higher voltage and more headroom. Interested in the sovtek midget, but the schematic I have doesn't show voltages.

opinions welcome

[Jammin'John]

Loud

Man,you guys must be LOUD !
How can you hear your vocal harmonies ?
Doesn't the club owner bitch about the volume ?
Are you wearing ear plugs and screw the audience ?
Are there ANY dynamics in the music or is it chainsaw rock all night ?



JJ

[mlove3]

"How can you hear your vocal harmonies ?"

>>>beta 58 mics help. I also don't point my amp speaker at my head, it's about belt level.

"Doesn't the club owner bitch about the volume ?"

Naw. it's a decent size room and it fills up. I listened from the bar about 30 feet away while a friend sat in in my place, the vox and frontmans guitar were loudest (not surprising). As i said before he has a peircing middy sound, I'm a little surprised the bar owner hasn't asked HIM to turn down!

"Are you wearing ear plugs and screw the audience ?"

>>I use a bit of tissue usually. the audience never complains, they're mostly middle aged folks looking to cut loose and rock and roll like when they were young.

"Are there ANY dynamics in the music?"

>>oh yeah, of course. I prefer the quieter to medium stuff, ya know? The volume mostly centers around the frontmans guitar. Again, it's very mid heavy and robust, a little too much distortion for my tastes but he makes it work. He's a true pro too, except his one vice is loud ass guitar. Drives me crazy but he seems to be getting better about it, picking his spots to open it up. I think he's losing his hearing.

[Jammin'John]

Old

Yea,I jam with some guys that have played loud all their lives.
They can't hear the upper mids so they crank 'em up.
THEY think that they sound good but they don't SOUND good.
They PLAY good though.

JJ

[mlove3]

yeah JJ, that describes my guy, real solid player but not always crazy about his dirty tones. but in a two guitar band I try to fill in with a slimmer tone, because two guys blasting away with identical guitar sounds is trouble.

And as I get older I crave a big bottom end cleaner tone for the jangly bits and tom petty covers, ya know?

[Jammin'John]

Blue & Silver

A Blue & a Silver are a SWEET combo for big & jangly.

My Tele's love 'em !



JJ

[ThermionicScott]

Anybody else thinking that it would be better to "weaken" the bandmate's amp instead?

- Scott

[Jammin'John]

Deaf

Anybody else thinking that it would be better to "weaken" the bandmate's amp instead?

- Scott

That won't work.
We've established the fact that after years of playing loud that he is deaf.

JJ

[mlove3]

I'd bet his hearing is shot in a very narrow band, that lower-mid mid area that he cranks.

[Jammin'John]

Hurts

The trouble is that it hurts everyone but him.

JJ

[Steve Conner]

When dealing, err, jamming with guys like these, I just wear earplugs and crank everything as far as it'll go.

Doc's Proplugs are good, they're meant to stop surfers getting water in their ears, but make great attenuators too. They have a tiny hole that lets a little sound through.

[Jammin'John]

Yea

When I play with deaf people I don't try to match their tone or......
"just wear earplugs and crank everything as far as it'll go."

That would be inconsiderate to the audience AND would just make them turn up.

I try to position myself so that their instrument doesn't hurt MY ears and so that I can get MY idea of good tone and hear MY guitar.

Usually if I get my amp up on a chair and stay close to it I'm good.

If I have to sing as well then I set up on the other end of the stage and plug the ear facing the too loud player.

JJ