[daz.diamond]

I recently had the pleasure of working in a lovely wide hall with
limestone floor and walls and a glass roof. The job was basically to eq
and compress material running on a 22 channel soundwall and I spent
several days listening to material derived from classical recordings of
english 'pastoral' works. What I think i noticed was a slight treble
lift in there when the sun was shining bright and the room was warm ...

Is this possible?

or am I just being suckered by beautiful architecture and the 'aesthetic
experience' ?

I guess the rt60 was about 2s, and understand that this won't noticably
change with temperature/pressure, but as stone warms up, could it's
acoustic properties change enough for me to actually notice ?

tia
daz
xxx

[Don Pearce]

On Thu, 20 Sep 2007 14:49:19 GMT, "daz.diamond" wrote:

I recently had the pleasure of working in a lovely wide hall with
limestone floor and walls and a glass roof. The job was basically to eq
and compress material running on a 22 channel soundwall and I spent
several days listening to material derived from classical recordings of
english 'pastoral' works. What I think i noticed was a slight treble
lift in there when the sun was shining bright and the room was warm ...

Is this possible?

or am I just being suckered by beautiful architecture and the 'aesthetic
experience' ?

I guess the rt60 was about 2s, and understand that this won't noticably
change with temperature/pressure, but as stone warms up, could it's
acoustic properties change enough for me to actually notice ?

tia
daz
xxx

The big change you will notice is with relative humidity. High
frequencies are strongly attenuated by dry air.

d

--
Pearce Consulting
http://www.pearce.uk.com

[Roy W. Rising[_2_]]

(Don Pearce) wrote:
On Thu, 20 Sep 2007 14:49:19 GMT, "daz.diamond" wrote:

I recently had the pleasure of working in a lovely wide hall with
limestone floor and walls and a glass roof. The job was basically to eq
and compress material running on a 22 channel soundwall and I spent
several days listening to material derived from classical recordings of
english 'pastoral' works. What I think i noticed was a slight treble
lift in there when the sun was shining bright and the room was warm ...

Is this possible?

or am I just being suckered by beautiful architecture and the 'aesthetic
experience' ?

I guess the rt60 was about 2s, and understand that this won't noticably
change with temperature/pressure, but as stone warms up, could it's
acoustic properties change enough for me to actually notice ?

tia
daz
xxx

The big change you will notice is with relative humidity. High
frequencies are strongly attenuated by dry air.

d

In my experience, the opposite is true. The Hollywood Palace Theater had
some evaporative A/C. We'd rehearse all day without it, break for a meal
while the audience loaded in (and the A/C was amp'd to handle more bodies)
and return to tape the show.

The room always was "deader", not because of the bodies but from the
moisture of the A/C.

It may be that the warming of your venue noticeably changes the humidity.

--
~
~ Roy
"If you notice the sound, it's wrong!"

[Arny Krueger]

"Roy W. Rising" wrote in
message

In my experience, the opposite is true. The Hollywood
Palace Theater had some evaporative A/C. We'd rehearse
all day without it, break for a meal while the audience
loaded in (and the A/C was amp'd to handle more bodies)
and return to tape the show.

The room always was "deader", not because of the bodies
but from the moisture of the A/C.

The effect of adding more bodies is not to be ignored, particularly in a
very live room.

It may be that the warming of your venue noticeably
changes the humidity.

http://www.csgnetwork.com/atmossndabsorbcalc.html

Is a calculator that lets you study the effects of both temperature and
humidity as well as frequency and air pressure.

[Don Pearce]

On 20 Sep 2007 15:43:07 GMT, Roy W. Rising
wrote:

(Don Pearce) wrote:
On Thu, 20 Sep 2007 14:49:19 GMT, "daz.diamond" wrote:

I recently had the pleasure of working in a lovely wide hall with
limestone floor and walls and a glass roof. The job was basically to eq
and compress material running on a 22 channel soundwall and I spent
several days listening to material derived from classical recordings of
english 'pastoral' works. What I think i noticed was a slight treble
lift in there when the sun was shining bright and the room was warm ...

Is this possible?

or am I just being suckered by beautiful architecture and the 'aesthetic
experience' ?

I guess the rt60 was about 2s, and understand that this won't noticably
change with temperature/pressure, but as stone warms up, could it's
acoustic properties change enough for me to actually notice ?

tia
daz
xxx

The big change you will notice is with relative humidity. High
frequencies are strongly attenuated by dry air.

d

In my experience, the opposite is true. The Hollywood Palace Theater had
some evaporative A/C. We'd rehearse all day without it, break for a meal
while the audience loaded in (and the A/C was amp'd to handle more bodies)
and return to tape the show.

The room always was "deader", not because of the bodies but from the
moisture of the A/C.

It may be that the warming of your venue noticeably changes the humidity.

Have a look here

http://www.sfu.ca/sonic-studio/handb...opagation.html

the graph in part 2 is informative. What is shows is that the
attenuation of higher frequencies relative to lower frequencies
increases as relative humidity drops, reaching a peak at about 10%RH.
Below that it starts dropping again.

d

--
Pearce Consulting
http://www.pearce.uk.com

[Roy W. Rising[_2_]]

(Don Pearce) wrote:
On 20 Sep 2007 15:43:07 GMT, Roy W. Rising
wrote:

(Don Pearce) wrote:
On Thu, 20 Sep 2007 14:49:19 GMT, "daz.diamond" wrote:

[snip]
I guess the rt60 was about 2s, and understand that this won't
noticably change with temperature/pressure, but as stone warms up,
could it's acoustic properties change enough for me to actually
notice ?

tia
daz
xxx

The big change you will notice is with relative humidity. High
frequencies are strongly attenuated by dry air.

d

In my experience, the opposite is true. The Hollywood Palace Theater
had some evaporative A/C. We'd rehearse all day without it, break for a
meal while the audience loaded in (and the A/C was amp'd to handle more
bodies) and return to tape the show.

The room always was "deader", not because of the bodies but from the
moisture of the A/C.

It may be that the warming of your venue noticeably changes the
humidity.

Have a look here

http://www.sfu.ca/sonic-studio/handb...opagation.html

the graph in part 2 is informative. What is shows is that the
attenuation of higher frequencies relative to lower frequencies
increases as relative humidity drops, reaching a peak at about 10%RH.
Below that it starts dropping again.

d

Thanks, Don! Excellent info on several aspects of propagation. Now I'm at
a loss to explain what I experienced.

--
~
~ Roy
"If you notice the sound, it's wrong!"

[Roy W. Rising[_2_]]

"Arny Krueger" wrote:
"Roy W. Rising" wrote in
message

In my experience, the opposite is true. The Hollywood Palace Theater
had some evaporative A/C. We'd rehearse all day without it, break for
a meal while the audience loaded in (and the A/C was amp'd to handle
more bodies) and return to tape the show.

The room always was "deader", not because of the bodies but from the
moisture of the A/C.

The effect of adding more bodies is not to be ignored, particularly in a
very live room.

Of course. However, the theater was not unusually "live" and it's comfy
seats were of the type designed for constant absorption wheather empty or
occupied.

It may be that the warming of your venue noticeably changes the
humidity.

http://www.csgnetwork.com/atmossndabsorbcalc.html

Is a calculator that lets you study the effects of both temperature and
humidity as well as frequency and air pressure.

Useful! Thanks, Arny!

--
~
~ Roy
"If you notice the sound, it's wrong!"

[daz.diamond]

The big change you will notice is with relative humidity. High
frequencies are strongly attenuated by dry air.

let me try and understand :

as the sun shines, temperature rises, the porous limestone releases some
of its moisture to humidity

as humidity rises, the air becomes more dense and then sound at higher
frequencies propogate quicker/more efficiently, and there is therefore
more of this content reaching my ears compared to changes due to the
same effect, but at lower frequencies ?

the building has a couple of humidity monitors (don't know the right
term) - perhaps I'll go have a look

daz
xxx

[[email protected]]

On Sep 20, 8:43 am, "daz.diamond" wrote:
The big change you will notice is with relative humidity. High
frequencies are strongly attenuated by dry air.


the building has a couple of humidity monitors (don't know the right
term) - perhaps I'll go have a look


Hygrometer.

bobs

Bob Smith
BS Studios
we organize chaos
http://www.bsstudios.com

[Tobiah]

The room always was "deader", not because of the bodies but from the
moisture of the A/C.

Dude... A/C removes moisture from the air. That is an effect of
air conditioners that is intentional, and as important to increassed comfort
as the reduction of temperature. I have a small unit in my bedroom
that can remove about a pint of water from the 10'x15' room in a couple
of hours on a hot humid day. I know because it collects the water in
a pan.

--
Posted via a free Usenet account from http://www.teranews.com

[daz.diamond]

Hygrometer.

(cough) thankyou

[Roy W. Rising[_2_]]

Tobiah wrote:
The room always was "deader", not because of the bodies but from the
moisture of the A/C.

Dude... A/C removes moisture from the air. That is an effect of
air conditioners that is intentional, and as important to increassed
comfort as the reduction of temperature. I have a small unit in my
bedroom that can remove about a pint of water from the 10'x15' room in a
couple of hours on a hot humid day. I know because it collects the water
in a pan.

'Dude' ~ Perhaps you missed the part about the old Hollywood Palace Theater
on Vine St. having "some" evaporative A/C ... good ol' swamp coolers! Ever
heard of Ken Murray's Blackouts? In the '40s it was called The El Capitan
Theater, not to be confused with the one on Hollywood Blvd.

More history: http://en.wikipedia.org/wiki/Palace_...e%2C_Hollywood

--
~
~ Roy
"If you notice the sound, it's wrong!"

[[email protected]]

On Sep 20, 11:33 am, "daz.diamond" wrote:
Hygrometer.

(cough) thankyou

You're welcome. I'm getting mine along with the thermometer and
barometer back from ISO 17025 calibrations in a day or so.

bobs

Bob Smith
BS Studios
we organize chaos
http://www.bsstudios.com