SPL levels

Steven Paris · From: Los Angeles

I have a question for you club/bar band steelers out there----have you ever measured, or know what SPL a typical band plays at? And, approximately, what SPL level is the pedal steel guitar player at, within that band?

Donny Hinson · From: Glen Burnie, Md. U.S.A.

The perceived loudness depends mostly on where you are in relation to the source. You can't hazard a guess on levels unless you know where they're being measured. Two feet from the amp? Across the stage? In front of the stage? In the middle of the club or venue? You'll get tremendously different readings from the same band, depending on where you are measuring.

All that said, most bands I've heard (and played in) are louder than they need to be. Sad

Richard Sinkler · From: aka: Rusty Strings -- Missoula, Montana

I played at a place once where the owner had an SPL meter and would walk around the room and take notice of the levels in various spots.
_________________
Carter D10 8p/8k, Dekley S10 3p/4k C6 setup,Regal RD40 Dobro, Recording King Professional Dobro, NV400, NV112,Ibanez Gio guitar, Epiphone SG Special (open D slide guitar) . Playing for 55 years and still counting.

Bill Moore · From: Manchester, Michigan

I got an spl meter recently. I have often felt the stage volume could get out of hand and sometimes it has seemed way too loud. So, because I still have to play, I just laid the meter on the keyhead of my guitar, turned on, pointing to the right, towards the rest of the band. I'm sure this does not give a super accurate reading, but I needed to be able to see the meter as I played. Typically, it showed readings of 100-105 db as we played. This did not seem super loud to me. But I see that this is right on the border line of reaching levels that would be too high. There have been other times when I know the stage volume was a lot higher, to the point of being very uncomfortable to me. I have not used it to take any readings from in front of the band, I just wanted to get an idea of the sound level at my location on the bandstand. I try to be reasonable with my volume. I play loud enough so I can hear myself, sometimes that means I need to play at least as loud as the guitarist standing next to me. I'd much rather play at a more reasonable volume.

Steve Collins · From: Alaska, USA

When I am running sound I meter the sound check, and get the band to level off below 90 db (which to me is already loud), knowing full well they will absolutely get louder as the night goes. A drummer can easily hit 90db in a relaxed state, so yes, this is a challenge. It really can depend on the room, and how much human sponge material is in it, and how different frequencies are being managed.

Dave Grafe · From: Hudson River Valley NY

These numbers mean little without the associated weighting and sample time information. An "A" weighting rolls off low frequencies to approximate the hearing response of the human ear and associated potential for damage thereto. A "C" weighting includes the full audible spectrum and will often show a considerably higher SPL reading for the same actual sound than the "A" weighting will.

A fast sample time will show the transient peak levels, even if the actual program is much lower, while a slower time will round them off and generate a lower, averaged SPL reading.

Finally, the dB scale is logarithmic, which means that every 10dB increase indicates a tenfold increase in sound pressure.

Most, but not all, noise control laws specify "A" weighting and an averaged sample, with different allowable levels for different environments. Rocking out at an "A"-weighted 90dB may not seem terribly loud for some, but venues often set this as a maximum allowable level in order for their servers to do business efficiently. Bear in mind that a band with a bass that reads 90dB "A" weighted and averaged will easily top 100dB or even 105dB when measured with a "C" weighted, peak reading meter. And that is probably loud enough.

http://science.howstuffworks.com/question124.htm

http://www.gcaudio.com/resources/howtos/loudness.html

http://www.physicsclassroom.com/class/sound/u11l2b.cfm

Steve Collins · From: Alaska, USA

All true. I use the 'A' weighted function on my meter, and I only really use it as a reference, as ears are notoriously fallible. If I am tired or not feeling 100% I might be much more sensitive to sound levels, so the meter give me a ballpark. It also comes in handy when I have to tell a guitar player (who's ears might be fatigued) he is too loud. When he shoots back 'that's where I set my levels last time we played here' I can explain to him (if he is not the cro-magnon type) that I meter the levels, and know what the room needs.

Glenn Uhler · From: Trenton, New Jersey, USA

Mr. Paris posts an interesting question, but as nearly everyone points out, it's difficult to answer because it depends on so many different conditions.

If you have a Sound Pressure Level meter, you can measure the level, but all you get is s number. To understand the level better, compare it to other real-life sounds. A good comparison of the levels is found in Mr. Grafes' second url: Decibel (Loudness) Comparison Chart. The quietest library comes in around 30dB and a telephone dial tone about 80 dB. Inside your car, city traffic (with no radio) is about 85dB and heavy truck traffic ccan hit 90dB. Your hand-held electric drill is about 98dB and your hand-held electric cirular saw is about 110dB.

On to real life at a 3-hour gig: OSHA says you can be exposed to 97dB for 3 hours in an 8-hour day, but the rest of the day should be below 85 dB. This doesn't leave much noise exposure time for practice or rehersal, but with the breaks and intros between songs, you should be under the limit. A good starting volume is 90dB, but a band can get up to 100-105dB very easily. Hearing protection is recommended above 85 dB and required above 90 dB. That's why you see lots of high-end acts moving to ear buds instead of stage monitors.
_________________
1974 Marlen S-12 1968 Tele 1969 Martin D-35H

Forum Index > Electronics		Next oldest topic :: Next newest topic

All times are GMT - 8 Hours	Jump to: