DB Meter readings for finals

[WayBackBuc]

So we know what the Db level was (and why it was),, what was the "Face Peel O Meter" for each Corps???

[CVQuesty]

I'd love to know. We had a more quality hornline this year, and even though we had fewer members in the line, we had several people tell us we were a louder line (which I would attribute to intonation & power exercises Dave Henry teaches us).

[JeromeyBush]

.

I can't wait to get '07 started!!

That may be difficult. :P

..and Sara,the pope's poo stinks only if youre in the "bush".

Edited September 8, 2007 by JeromeyBush

[cire]

very cool. you do this for DCI finals too?

[DNgo]

I wish these readings were available for prelims! I would love to have seen GCS' db meter readings ....... just out of curiosity. :)

[Gary Matczak]

check me if I'm wrong here,.............but aren't the readings from last year?

[camel lips]

[Big Bad Bari]

check me if I'm wrong here,.............but aren't the readings from last year?

That is soooo funny, I was wondering where these readings were posted that you guys were discussing!

Anyone got Db readings for 2007?

[Irish-Kiltie]

Pretty cool discussion, even if we dragged it into the next year...

Just a few things I wanted to clarify, as there were some items posted that were not quite true in the world of science and math. This is something that I deal with quite frequently in my daily job doing system design and product selection for industrial ventilation.

0) Sources produce sound POWER, you perceive sound PRESSURE. Typically when people are involved, sound levels in 8 octave bands are considered with their center frequencies being 63 to 8000 Hz. These 8 values are typically combined in a log sum to a single weighted value. The most common is "A" weighting which gives a single "A" weighted value dbA. Extremely low and high frequencies are given less weighting because a human can't hear them unless they are extremely high levels (dog whistle for example, blow all you want, only the dog in the room goes crazy).

1) dB is a log measurement. Increasing a dB value by 10 doubles the level. So for example 50 dB is twice as loud as 40 dB and 85 dB is twice as loud as 75 dB.

2) A change of 2-3 dB is considered insignificant and a typical person can not distinguish between two sound sources that close together. For example, if two sound sources were 78 and 75 dB, it is unlikely that the typical person could tell which one was louder.

3) I saw several posts which mentioned that 3 dB was "doubling" or "twice" the sound. I think what they meant (whether they knew it or not) is that if you have two IDENTICAL sound sources, the resulting perceived overall sound level is only 3 dB higher than one of the sources by itself. So if you had one source that was 75 db and another identical sound source at 75 dB, you would perceive a sound level of 78 dB, or as noted above, barely any different from the single source by itself.

4) As far as "danger" levels go, OSHA states that persons exposed to sound levels exceeding 85 dB for prolonged periods must wear hearing protection. NOTE: If you think OSHA is a small town in Wisconsin, your company likely has safety issues...

5) One must also consider the listening environment. Sound decays over distance and in all possible directions. For example if two sources of identical levels are placed in different locations, their sound levels are perceived to be different. A source in the corner of a room with hard walls, floors, and ceilings will seem much louder than a source in the middle of a football field because the second source can decay in a "hemispherical free field" (any direction other than downward).

5A) Each time you double the distance from a sound source in a "hemispherical free field" (like a football field) the dB level is reduced by 6.5 dB. So if the sound source is 96.5 dB at 5 feet, it would be 90 dB at 10 feet, 83.5 at 20 feet, 77 dB at 40 feet, etc. What this means is that if you are 40 feet from the source, the sound is now only 1/4 as loud as at 5 feet. (10 dB drop is half as loud, 20 dB drop is 1/4). How far do you sit from a drum corps? Now think how loud they would be if you were only 5 feet away... yeah, you better bring ear plugs to the warm-up arc.

6) As a drummer, I've worn earplugs since my second year of drum corps (I learned the hard way). Keep in mind, it isn't so much the overall level of the sound, but how rapidly it changes. A sharp increase in sound (rimshot??) is far more damaging than prolonged exposure at lower levels. Also, I think (my opinion now) that drummers are exposed to more of their own sound than a horn which is very directional in nature and directs much of the sound away from the player. Now you might have another horn right in your ear, but I'm talking just about the player's own sound.

I knew my engineering degree would come in handy for drum corps some day...

Ok that's enough "geek speak" for a Saturday,

Ryan J

[Big Bad Bari]

Ok then lets keep it simple!

Who was loudest?