Is ear compression a myth? And how does it relate to our amps?

[James Judson]

I'm taking Bill's advice and buying the smallest amp I can find (cheaper and easier to haul) cuz watts are meaningless.

Hey Bill!!! Why is my 300 watt amp so much louder than my 100 watt amp???

 

[will33]

I wouldn't say that. But it all depends on how loud you are and how fatigued your ears are. A fresh set of good ears will hear it all plain as day. An hour or two from then and who knows?

And the reason live recordings from the board don't usually sound that great is because board tapes don't have the benefit of signal processing all the individual instruments, noise gating, etc. Record everything onto individual tracks and do some judicious signal processing and it gets a lot better.

+1

True, and stereo separation that creates depth works differently and more complexly with our ears than it ever could with a couple microphones. Our minds do an awful lot of filtering of sound as well, we don't perceive a lot of the room echo and reflections and other 'stuff' going on when we're in the moment.

And +1

I like hearing live recordings, no matter how crappy they are. It's what those people did right then, without 30 tries at it with processing and "correction", etc.

Yes, I know a lot of live recordings are of multiple shows, picking the best performance and doing plenty of tweaking afterwards but it's still a step closer.

I especially like to hear old 40's, 50's recordings where everybody setup around one mic and took a step forward when it wad their turn for a lead....sort of mixed themselves on the fly.

High fidelity, surround sound, majical listening experience, it surely is not but it was these musicians doing what they could do, right then, and they didn't need 112 channels, digital manipulation, or 30 tries at it.....they were just good.

 

[JimmyM]

I once worked with the Del McCoury Band for a week, and they did that...one condenser mic in the middle and everyone else worked it as they needed, and the sound was magnificent. Probably doesn't work well for metal but very cool for bluegrass.

 

[billfitzmaurice]

I guess that's why listening back to live recordings never sound that great.

If you mean live recordings made with a mic or two in the audience, that has to do with your brain. It has the ability to separate the sound coming off the stage from the reflections bouncing about the room. Mics don't.
As Jimmy noted live recordings of major acts take direct outs from the board, each channel strip going to its own track. Those tracks are then mixed in the studio using all the same studio tricks as studio recordings. In many cases additional crowd noise and ambient sounds are added to the mix, otherwise you might not even be aware that it was recorded live.

 

[1958Bassman]

I'm taking Bill's advice and buying the smallest amp I can find (cheaper and easier to haul) cuz watts are meaningless.

Hey Bill!!! Why is my 300 watt amp so much louder than my 100 watt amp???

Adding power is the least efficient way to increase SPL from a rig. Double the power and you may get a 3dB increase but double the number of speakers and it increases more. Plus, if the speaker is running close to it's maximum power input, you'll have thermal compression and there's nothing that can be done to alleviate that, other than decrease the power to the speaker. Use a horn-loaded cabinet and the output increases even more. Plop the cabinet in a corner and you not only get more total output but also more low end.

 

[BagelBruin]

Plop the cabinet in a corner and you not only get more total output but also more low end.

REALLY! This explains why I am so effin loud in rehearsal.

 

[Bassamatic]

Lotta good advice here - My 2 cents:

I put my little MB 12 incher in a corner and it is amazingly loud. This really increases the acoustic output. It is a giant horn that greatly increases the efficiency of the driver coupling to the air.

Doubling the watts is nearly inaudible. It takes TEN TIMES the amp power to sound twice as loud to your ears. Better to increase cone area than add power.

Ear fatigue is well known in the studio so good mixers take frequent breaks.

I wear -10dB earplugs when I play to prevent ear damage and compression - it also lets me hear the band better!

 

[staindbass]

the good thing about relating the ear compression to our amps is that the compression only applies to what you hear, not to what you feel in your body. we have an edge on the guitarists.

 

[BurningSkies]

the good thing about relating the ear compression to our amps is that the compression only applies to what you hear, not to what you feel in your body. we have an edge on the guitarists.

In so many ways, staindbass, in so many ways...

 

[Rick Auricchio]

I put my little MB 12 incher in a corner and it is amazingly loud. This really increases the acoustic output. It is a giant horn that greatly increases the efficiency of the driver coupling to the air.

It isn't exactly coupling to the air. The increase in loudness is due to the boundary effect of the walls and floor. Instead of the theoretical spherical throw of the cabinet, you have the back wall reflecting half the sphere back at you, gaining 3dB of acoustic energy. The floor does the same so you gain 6dB. In a corner you've got three surfaces reflecting, giving you 9dB of extra bass output.

The terms are full-, half-, and quarter-space for "no walls," "back wall only," etc. I guess a corner is eighth-space.

 

[billfitzmaurice]

It isn't exactly coupling to the air. The increase in loudness is due to the boundary effect of the walls and floor. Instead of the theoretical spherical throw of the cabinet, you have the back wall reflecting half the sphere back at you, gaining 3dB of acoustic energy. The floor does the same so you gain 6dB. In a corner you've got three surfaces reflecting, giving you 9dB of extra bass output.

The terms are full-, half-, and quarter-space for "no walls," "back wall only," etc. I guess a corner is eighth-space.

Close. Half-space gives you 6dB over full-space. But you can only get full-space by using a skyhook to suspend the cab in the air, a few wavelengths away from the ground; that's why the standard for sensitivity is half-space. Compared to half-space quarter-space gets you 6dB, eighth-space 12dB. But other factors affect the result, mainly the baffle step. When the baffle is a wavelength across or more radiation is hemispherical, so even hanging from that skyhook it's in half-space already. A cab on the floor away from any boundaries is in half-space below the baffle step frequency, but in quarter-space above it. And above the baffle step those frequencies are directional, so they won't wrap around the cab to bounce back off a wall behind it. That's why most of the perceived gain from wall and corner loading happens in the low end, with less and less effect the higher in frequency you go.

 

[Rick Auricchio]

Thanks, Bill!