DB Meter readings for finals

[standy]

All I know is that at last year's Alumni show, Park City Pride's hornline would have registered somewhere in the area of "space shuttle launch" on a DB meter. :P

Fran

AMEN

[jdheere]

Chicks dig geeks.

Well THANK GOODNESS!!!

Oh, I think, isn't db logrythmic in progression so higher numbers are multiplied sound volume rather than just degrees?

"Why not just make 10 louder?"

"But this one goes to eleven."

[K2SMA]

...Oh, I think, isn't db logrythmic in progression so higher numbers are multiplied sound volume rather than just degrees?...

Yes it is logarythmic (sp?), and I think Gene is correct on this, an increase of 3 decibels represents a doubling of pressure, and it's true in RF measurement as well as in sound pressure.

Who's the scientist in the bunch? "...a little bit of science in each and every show!" -- George Carlin

We always defined "decibel" as the level to which your teenager complied when asked to turn down their stereo...

It would be interesting to crossfoot Tornado's measured levels to the number of brass in each corps and come up with some kind of index. Now THAT'S geeky!

[torn8o]

Yes it is logarythmic (sp?), and I think Gene is correct on this, an increase of 3 decibels represents a doubling of pressure, and it's true in RF measurement as well as in sound pressure.

This is absolutely correct. However, there is another variable to throw all of our minds out of wack. A DB reading is not proportional. Meaning...85 DBs may be just a puny fraction of a difference in volume from 75DBs...where in contrast, 105 is probably about DOUBLE the volume of 95....THEN ...110 double the volume of 105!

It would be interesting to crossfoot Tornado's measured levels to the number of brass in each corps and come up with some kind of index. Now THAT'S geeky!

Give me all of the total brass membership of all of the DCA finalist as well as MCL's (since I added them to the list...wait, I taught and marched there so I already know...it's 31...unless you want to count Vinnie and I...then it's 33). Then, give me some time to do some math and I will throw this whole experiment into a whole new demension of "GEEK"!

Edited September 14, 2006 by torn8o

[ironlips]

Loud is good.

Loud and in tune is better, and if your drill writer knows how to stage, you have lift-off.

There are way too many variables here for this single measurement to mean anything significant, but it is a fun discussion. For instance, one profound quarter note from that big concert bass drum in the pit will send your little hand-held dB meter into overdrive for an instant. The average dB measurement over 11 minutes might mean something (perhaps), but realize that the ear perceives clarity as if it were volume, which is why things that are in tune and temporally aligned "sound" louder than those that aren't.

So play clean, in tune, with good quality and expression and you'll seem louder than those who don't. You'll also probably win the music caption.

[Fran Haring]

Loud is good.

Loud and in tune is better, and if your drill writer knows how to stage, you have lift-off.

There are way too many variables here for this single measurement to mean anything significant, but it is a fun discussion. For instance, one profound quarter note from that big concert bass drum in the pit will send your little hand-held dB meter into overdrive for an instant. The average dB measurement over 11 minutes might mean something (perhaps), but realize that the ear perceives clarity as if it were volume, which is why things that are in tune and temporally aligned "sound" louder than those that aren't.

So play clean, in tune, with good quality and expression and you'll seem louder than those who don't. You'll also probably win the music caption.

And when it comes to audio production, you can take what this man says to the bank.

Fran

[DrumCorpsLives]

This is absolutely correct. However, there is another variable to throw all of our minds out of wack. A DB reading is not proportional. Meaning...85 DBs may be just a puny fraction of a difference in volume from 75DBs...where in contrast, 105 is probably about DOUBLE the volume of 95....THEN ...110 double the volume of 105!

Give me all of the total brass membership of all of the DCA finalist as well as MCL's (since I added them to the list...wait, I taught and marched there so I already know...it's 31...unless you want to count Vinnie and I...then it's 33). Then, give me some time to do some math and I will throw this whole experiment into a whole new demension of "GEEK"!

Sound intensity is basically power per area, which could be thought of as volume I suppose. And someone said it, doubling the sound intensity basically raises the dB by 3.

But also remember that the intensity changes by the distance squared. Doing some calcs, the loudest corps, CV, had a 104dB rating. That equates to an intensity of 0.0251 Watts/square meter. Bucs at 102 dB has an intensity of 0.01585 W/m^2. Ratio those two gives CV as 1.58 x more intensity than Bucs.

The inverse square relationship says that you can get that difference in intensity by being a distance of 1.26 times further away. I1/I2 = (r2^2)/(r1^2)

Let's assume CV was 60 yards away from the db meter. If they backed up 15.6 yards they would have the same dB reading as Bucs. Or if Bucs were 15.6 yds closer they'd have a 104 dB reading.

I don't know where each corps earned their high dB reading, but if one corps was further away then you have to consider the inverse square law to really know who's hornline is louder. But then again, if you're going to be loud, the loudest the audience will hear you is if you are standing closest to them. So park your loud sound right there in the pit.

Btw, G bugles and Bb's don't necessarily have different size bores in general. Have to check manufacturers. e.g. Kanstul makes basically the same bore for trumpet as they do sops.

Last thing, get your calipers out, all G bugles and anykey brass are cylindrical from the mouthpeice to the valves. None have any conical shape until after the valves. The only one that stays cylindrical for a length after the valves are trumpets. All the other voices expand conically right after the valves. So that conical vs. cylindrical would be a good argument if it were true.

What is true is that the natural harmonics of a matched key set of horns will all have nodes that line up. Unmatched not nearly as much. So an all G line can theoretically be inherently louder because of the natural constructive interference provided by these harmonics lining up.

Edited September 15, 2006 by DrumCorpsLives

[torn8o]

Loud is good.

Loud and in tune is better, and if your drill writer knows how to stage, you have lift-off.

Absolutely, which again furthers my point in why a DB meter can be very valid in it's readings. For further info, see my response to Mike D on the reasons "WHY" I carry one.

There are way too many variables here for this single measurement to mean anything significant, but it is a fun discussion. For instance, one profound quarter note from that big concert bass drum in the pit will send your little hand-held dB meter into overdrive for an instant.

Not true in my case because I have mine set to a weighting where those types of of sounds are not the prominant voice in the tool's reading. I know this for a fact because I have tested it with my own marching ensembles during times where the percussion section is not present. The difference might AT TIMES be 1DB difference(depending on the level...remember, it's not proportinal). Now, if I change the settings to a different "weight", that would be another story. But, I have it set to a weighting that basically picks up more of the horns than the drums.

The average dB measurement over 11 minutes might mean something (perhaps), but realize that the ear perceives clarity as if it were volume, which is why things that are in tune and temporally aligned "sound" louder than those that aren't.

So play clean, in tune, with good quality and expression and you'll seem louder than those who don't. You'll also probably win the music caption.

And again, you are furthering my point in using the tool as a reference. Again, please see my response to Mike D. I explain very clearly that the DB meter best registers when a brass line IS IN TUNE and playing with great tone.

[torn8o]

And when it comes to audio production, you can take what this man says to the bank.

Fran

Indeed, he does sound like he knows his stuff. :) However, I DO disagree with him on one point (the bottom bass drum) because I've esperimented with it myself and know that it makes little difference because it depends on the settings of the tool.

His other point (about "playing in tune yada yada...") I TOTALLY agree with him and would only challenge him to note that this is exactly WHY I use the DB meter because of what I explained in my post to Mike D. Me thinks that he assumed that we were NOT as in agreement on this issue as we really are.

To make sure he understands that we are in agreement on this, allow me to respond to him this way....

And again, you are furthering my point in using the tool as a reference. Again, please see my response to Mike D. I explain very clearly that the DB meter best registers when a brass line IS IN TUNE and playing with great tone.

And you will also be the one getting the higher DB reading because you HAVE TO BE in tune and playing with good tone quality to get the higher readings.

See, I think he assumed that I assumed that the whole thing was about "blowing your brains out and get a higher reading". NO SIR! PLAY IN TUNE and you will get a higher reading.

Edited September 15, 2006 by torn8o

[torn8o]

Sound intensity is basically power per area, which could be thought of as volume I suppose. And someone said it, doubling the sound intensity basically raises the dB by 3.

But also remember that the intensity changes by the distance squared. Doing some calcs, the loudest corps, CV, had a 104dB rating. That equates to an intensity of 0.0251 Watts/square meter. Bucs at 102 dB has an intensity of 0.01585 W/m^2. Ratio those two gives CV as 1.58 x more intensity than Bucs.

The inverse square relationship says that you can get that difference in intensity by being a distance of 1.26 times further away. I1/I2 = (r2^2)/(r1^2)

Let's assume CV was 60 yards away from the db meter. If they backed up 15.6 yards they would have the same dB reading as Bucs. Or if Bucs were 15.6 yds closer they'd have a 104 dB reading.

I don't know where each corps earned their high dB reading, but if one corps was further away then you have to consider the inverse square law to really know who's hornline is louder. But then again, if you're going to be loud, the loudest the audience will hear you is if you are standing closest to them. So park your loud sound right there in the pit.

Btw, G bugles and Bb's don't necessarily have different size bores in general. Have to check manufacturers. e.g. Kanstul makes basically the same bore for trumpet as they do sops.

Last thing, get your calipers out, all G bugles and anykey brass are cylindrical from the mouthpeice to the valves. None have any conical shape until after the valves. The only one that stays cylindrical for a length after the valves are trumpets. All the other voices expand conically right after the valves. So that conical vs. cylindrical would be a good argument if it were true.

What is true is that the natural harmonics of a matched key set of horns will all have nodes that line up. Unmatched not nearly as much. So an all G line can theoretically be inherently louder because of the natural constructive interference provided by these harmonics lining up.

This is an absolutely GREAT post with very reasonable points made. In most cases, these hornlines reached their highest DB levels when they were front and center and TRYING to give us a smack in our face. Now, "HARMONICS"...wow! That definitely throws this experiment to a whole different spin because indeed...thicker and more stacked chords will create a more distorted overall timbre, resulting in a lower DB reading. WOW! This could REALLY get complicated now.