Dirty Digital [sic.]
 

Interesting bit of research here - throws some bright light on trumpet
loudness too.

http://www.mne.psu.edu/psgdl/Pandya+Settles-JASA.pdf

Horns are LOUD.

WTF were they thinking of using dBA though ? MORONS (or should I say
'academics' ?).
At those SPLs the A weighting just muddles the figures and
under-measures them.

" In the 118–124 peak dB(A) range, they are near the weak limit of shock
wave
visibility by schlieren optics. The schlieren evidence confirms that the
frequency
of the emitted shock waves corresponds to the frequency of the note
being played.
Ancillary laminar and turbulent jet phenomena associated with the
performer’s breath
are also visible in the images. "

Now I'd like to know what dB(C) numbers would have been. At a guess,
peaking over
140 dB.

Graham


I doubt it. Over the frequency range of a trumpet dBA is pessimistic by
probably no more than 5 or 6dB for the fundamental and probably a bit
optimistic for the harmonics. 250Hz is the lowest note available which
would be 8dB low, but as they were going for volume I suspect they chose
something more like 500Hz which is only 3dB down in dBA relative to dBC.

A dBA measurement is fair enough for this application as it reduces the
amount of background mush that might otherwise interfere.

d

Dirty Digital [sic.]
 

Eeyore wrote:
the ventilation noise was quite noticeable, and on
Audacity seemed to be about -45 dB.


Relative to a peak level of ?

0dB is full scale, but I can't remember if there was excessive headroom,
I don't think so. This isn't my field by the way, so excuse me if I say
something daft.


NC20 is readily achievable and NC25 is routine WITH the a/c most definitely ON.

He suggested this link.
http://www.ambthair.com/

Graham
HVAC is only slightly closer to my field, the noise from ventilation
doesn't need to be high. The sound increases steeply with air speed (I
seem to recall the seventh power of the air velocity, but that seems far
too high) I suspect that it's only the specialist installers (as above)
that care about it though.
Roger Thorpe

Dirty Digital [sic.]
 

"Eeyore" wrote in
message

Ok, just talked to him. Now he mentioned the typical
measure is an 'NC' meaning noise contour.

No, in this context NC means "Noise Criteria"

http://www.acousticalsolutions.com/e...e_Criteria.pdf

The spectral weighting depends on the specific criteria, such as NC20. For
NC20, the SPL can be like 50 dB at 63 Hz.

What he didn't
know offhand was whether this is a 'flat' measurement or
weighted such as A weighting.

The phrase "Noise Contour" relates to maps of geographic noise levels.

The BIG problem he says is LF, such as in London,
vibration from tube (and surface) trains. Now A weighting
would make mincemeat of that for example, plus due to how
the ear works, would be inaudible in the noise floor
anyway (see Fletcher Munson).

Lincoln Center suffers from that, big time. One nice thing about Detroit -
no subways, no elevated trains, almost no trains downtown, and not that much
traffic of any kind near our so-called Cultural Center area.

The best studio he knows of has an NC of 15 (dB) but this
may be 'flat' of course.

NC 15 is by definition spectrally weighted.

NC20 is readily achievable and NC25 is routine WITH the
a/c most definitely ON.

He suggested this link.
http://www.ambthair.com/

Very HVAC-centric.

http://www.acousticalsolutions.com/e...e_Criteria.pdf

Makes lots of things very clear.

Dirty Digital [sic.]
 

"Eeyore" wrote in
message
Arny Krueger wrote:

"Eeyore" wrote
Arny Krueger wrote:
"Eeyore" wrote
Arny Krueger wrote:
"Eeyore" wrote:
David Looser wrote:
"Eeyore" wrote
Arny Krueger wrote:

The noise floor of a well-made recording is on
the order of 75-80 dB.

Have you gone completely MAD ?

I can beat you by easily 50dB.

Do you do all your recording in an anechoic chamber
then?

What do you think the noise floor of a competently
designed studio is ?

30-ish dB.

Good Lord ! You're WAY off the mark. 30dB is NOISY to
me. I'm talking about proper commercial high-end music
recording facilities that have cost MILLIONS to build.

That sounds more like European-style recording, not U.S.
style recording.

I suspect you're dead right.

You said "competently-designed", not SOTA.

Ah well ... different base of reference I guess.

I've been in some of the best studios in Detroit. One of
them shared a building with an auto body repair shop. Go
figure.

LMFAO !

I'd name names, but they are nice people.

I know several recentish studios supervised by my 'mate'
that have had whole building EMC screens installed.
Indeed I helped with doing the site measurements for one
of them.
http://www.westwick.com/

They just recently finished a job (Neve install) in
Poland, and before that a LARGE installation in Singapore
(University theatre or somesuch?). They regularly do jobs
for 'name' musicians.

Musician's studios are generally vanity items. A few are actually very
productive, but then there are the rest...

Of course the most famous
studio in town and arguably the most productive was
built in two wood frame houses, side-by-side on a busy
street. Several were built in suites in typical
industrial parks.

Yeah, well the ones I know are made of solid brick or
STONE !

That's Europe for you. The US has always had plenty of trees and iron, so
the solid masonry buildings are very rare.

The buildings I lived in when we were in Germany seemed to be very solid -
the walls were about 2 feet thick and solid masonry.

You need to visit some top London studios I know. The
silence is deafening.

Most studio music is made in far lesser studios.

Not top chart or rock and roll music.

Yes, number one hits. Top 40, top 100.

Whatever. 'Top' chart stuff in this country is banale
these days anyway aside from a few albums.

That's the nature of much popularity. The music is often unhhh, acessible.
;-)

Orchestral's another ball game entirely of course since
it depends on the venue..

Detroit's Orchestra Hall is one of the best in the
world, for live performances, and recording. It is a
pretty quiet room. Well, if you keep the people out of
it. I've had numerous chances to audition it both ways.

Fancy taking a B&K SPL meter in there ?

Never had one on loan on any of the days where I had access. I have to admit
that I prefer to enjoy art or make art rather than measure it.

Also, a lot of that silence goes away after you add
living, breathing musicians. Just sitting there, they
make noise.

But that's part of the *recording*.

It follows the spectral trends of red noise. If you have
enough musicians, the noise floor they produce is just
as random as anything. Noise due to air turbulence can
be wonderfully random stuff.

Mmmmmm, whatever. I do like to be able to hear the
musicians taking their places, adjusting their stands etc.

Again, been there, done that. Those sorts of noises are *very* loud and tend
towards the midband. They are very audible, even when the HVAC noise is very
bad.

Dirty Digital [sic.]
 

"Eeyore" wrote in
message
Arny Krueger wrote:

There's a balance between the required dither and the
largest nonlinearity in the recording chain

If you want to know it all just search the AES archives
on the subject using the name "Graham Boswell" and / or
"Ian Dennis".

I have the complete AES archives through 2002 or so in my office. Believe me
when I say, "Been there, done that".

Thing is, I knew about dither back in the late 60s. There has been very
little new under the sun since then, when it comes to practical
implementations.

Dirty Digital [sic.]
 

"Don Pearce" wrote in message

Eeyore wrote:

David Looser wrote:

"Arny Krueger" wrote
130 dB takes an aircraft carrier launching jets, etc.
It also causes real pain (not just discomfort) and
temporary damage to the hearing. If continued for any
length of time (minutes) the damage is permanent.

It caused me no pain at all. A sense of awe for sure,
and a skin rash. And no, I didn't continue it for long.

The idea of 130dB (peak) causing direct pain is IMHO
associated with the noise of the majority of kinds of
things that are most likely to create 130dB ! In itself it doesn't hurt.

Graham


Interesting bit of research here - throws some bright
light on trumpet loudness too.

http://www.mne.psu.edu/psgdl/Pandya+Settles-JASA.pdf


"A fortissimo middle C and a mezzo-forte high G both
produce roughly a measured 100 dBA rms level at 1.23 m..."

Every time you double the number of trumpets, you add 3 dB.

2 trumpets - 103 dB
4 trumpets - 106 dB
8 trumpets - 109 dB

And that is at 4 feet. If you record 4 trumpets with one mic, the mic
might be 8 feet from the bells of the horns, which knocks off an easy 3-6
dB.

Dirty Digital [sic.]
 

"Phil Allison" wrote in message


Quote " aus.hi-fi" 17-6-2008:

"For the record I have no idea why Terry (TT) solicited
me for Kiddie Porn, and I have of course denied his
request on the grounds that I have none, never have, and
have no interest in any such thing."

Did the dumb, aggressive "TT" bite you - poor diddums ??

Not at all. Terry is the one who solicited me. Being solicited out of the
blue, which is what Terry did to me, is no fault of mine. However,
soliciting KP is a crime.

So Terry, in his stupidity and arrogance solicited me for KP. His harm, his
foul.

Dirty Digital [sic.]
 

"Eeyore" wrote in
message
Arny Krueger wrote:

"Eeyore" wrote

Many acoustic instruments can produce nearly 130dB close
up. Why do you think rock drummers go deaf first ?

Because of sustained loudness above 100 dB.

100dB average for a couple of hours a day, maybe a couple
of days a week does NOT make you go deaf.

Here are the OSHA standards, which many authorities say still permit ear
damage:

90 dbA for 8 hours,
95 dbA for 4 hours,
100 dbA for 2 hours,
105 dbA for 1 hour, or
115 dbA for 15 minutes.

Dirty Digital [sic.]
 

"Eeyore" wrote in
message
Arny Krueger wrote:

"Eeyore" wrote

I'll bet you close miking a brass section wouldn't be
far off peaking in that area.

Been there, done that. It isn't *that* loud. Not 130 dB.

PEAK !

I understand.

See my recent post that references an ASA paper on the topic.

Not average. Why are there mics out there with clipping
points of 145 dB ?

Gun shots and the like.

An inch or less from a really loud vocalist screaming their poor little
heart out.

Mics are like speakers - if they run out of stroke they clip and distort,
but they are also likely to be physically damaged. So they are designed to
handle SPLs that are by definition, very unlikely.

Dirty Digital [sic.]
 

"Arny Krueger is a ****ing septic nut case"


** Stick a mic right up against the skin of a snare drum
- then get an ape man type drummer to hit the drum as
hard as he can.

The exception does not disprove the rule.


** You posted no rule and this example is no exception.

Thinking in silly cliches is so typical of those with Asperger's.


It's insane, but so are all of Graham
Stevenson's bizarre points.
Cos he is a total nut case.

Wake up Arny.

I warned you about " TT" ages ago and you ignored me.

No I didn't.


** Fraid you did - you pathetic, ASD ****ed liar.

Quote " aus.hi-fi" 17-6-2008:

"For the record I have no idea why Terry (TT) solicited
me for Kiddie Porn, and I have of course denied his
request on the grounds that I have none, never have, and
have no interest in any such thing."

Did the dumb, aggressive "TT" bite you - poor diddums ??

Not at all.

** Blatant lie.

He bit you very hard in order for you to feel the need to post such a public
denial.


So Terry, in his stupidity and arrogance solicited me for KP.


** In doing so - he made you out to be a child ****er.

My god you are one DUMB SEPTIC **** !!

Even a blatant fake and total nutter like Stevenson has you completely
fooled.

FYI:

Arny is yet another totally narcissistic, septic nut case.

Ex US armed forces puke, now computer geek, born again Jesus freak.

In case anyone here doubted he was nuts for one second.



...... Phil