Posted by Frank Aponte on May 05, 2002

I usually average about 122dB at FOH when mixing for MDO (formerly known as MENUDO). This is generally considered very loud.

There are stories about a documented reading of over 132dB during MENUDO's heydey during the 80's. But I believe this was actually the crowd noise of 100,000 screaming girls in a soccer stadium, either in Mexico or Brasil.

The average crowd noise during most shows hovers around 115-118dB (mostly cenered right around 4kHz), sustained for the entire show. I've been known to hide under the desk when the screaming drowns out the PA.

172dB? Not very likely.

Frank Aponte
VACAudio Services
San Juan, PR

PS.. Monitors alone will sometimes get to 110dB at FOH, depending on the venue.


Posted by Mikael Holm on May 05, 2002

Monitors alone will sometimes get to 110dB at FOH, depending on the venue.

I was once setting up FOH board while monitor guys did ringing out. After that they tested monitors with human voice and it peaked up to 118dB at FOH. And that was with only one wedge/mix at a time. I was around 10m/30ft from stage in a very reverberant room. d&b wedges.

Miffe


Posted by Scott Pietig on May 05, 2002

This was during a test, not a concert at that church. the person mention that is was impossible.


Posted by david b. on May 05, 2002

Hmmmm.. interesting where they got that figure. Here in one of those dB tables (the one from an F.A.Everest book) he tells that 140 dB is one meter from jet engine at take off.

172 dB is more closer to several galaxies exploding.

But who knows..everyday you learn something new..or not.

David B.


Posted by Nathan Hamler on May 05, 2002

I know some of this is off topic, but since we're on the topic of SPL, here's my $.02. my friend is a huge car audio buff, as well as a master installer, and has outfitted many suv's etc for spl competition. He attended a competition in which one of the officials was inside the car before they tested it, hooking up his calibrated mic...someone started the tone burst generator and pumped out 170db at 50hz, killing the official inside.

But the presure inside a car at that spl/frequency would be astronomical. I guess that's why people fit they're cars with air bladder door and windshields from DC10's...Maybe in a concert venue it wouldn't be as bad, but it would still render you deaf. so, as you can see, outragous spl can be deadly.

regards,
Nathan Hamler.


Posted by Mike Crites on May 06, 2002

Sniff, sniff . . . I smell an urban legend!


Posted by Jason McLaurin on May 05, 2002

That's not true... put a soundboard 18 feet away from an EAW KF750 rig and you'll do it. In practice, however, the soundboard is much farther away from the PA stacks, so you will almost never see readings that high. If you did get 130db at the soundboard, you'd be inflicting pain upon the people around you, and possibly permanently damaging the hearing of the people standing closer to the PA.


Posted by Bruce Gering on May 05, 2002

If The threshold of pain for the human ear is near 128dB, and every 3dB is percieved as twice as much and takes twice as much wattage, you would be more than 14 times higher in SPL than the threshold of pain. Think about about it.

-Bruger