All:

Recorded a funk band last night live two track with open air mics and
noticed a lack of high end definition while monitoring on headphones.
Listening to the recording today I noticed a definite problem which is
also reflected in the spectrum analysis of the wave. Here was the
setup:

Schoeps CMC64 split 30 feet on posts inside the club. I boomed 2 feet
off to the interior side of the posts ( square about 10" wide hollow
wood) to try to avoid any nasty reflections. Ran cable through the
rafters. Ceiling was about 30 feet high and I was a good 8-10 feet
below the ceiling, which was treated with some kind of spray on foam.
PA speakers wre flying JBLs. Mics were oriented a few inches below each
speaker, about 20 feet back and pointing maybe a a couple degrees down
toward the stage --- very slightly. Cable run was 50 feet to a Sonosax
MX-2 Pre-amp into an HHB Portadat. No low cut or high cut filters
applied.

I thought what I was experiencing was a phase problem from splitting the
cardioids, but from looking at the waves that doesn't appear to be the
case. Both the left and right waves look similar in that the high end
is rolled off. However, the mix was very well balanced at the show.
There was plenty of high end. I've posted a screenshot of the spectrum
analysis at the link below. Any thoughts on what may have caused this?
Can I just chalk it up to some strange reflections in the room? Seems
odd it would happen in both channels with a split that wide.

Puzzled...

http://www.davidolney.com/temp/spectrum.html

Was the DAT set to some king Long Play mode - below 44.1k?

Was the DAT set to some king Long Play mode - below 44.1k?

No...48k...if it were at 32k, I would expect no information at all above
14.

I'm used to getting unpredictable results doing this kind of work due to
the lack of control, but for the situation, this is very extreme. I'm
disappointed about the recording, but more concerned with trying to
figure out what could cause this. The live engineer is a real pro. He
was checking frequencies with an Earthworks mic during soundcheck. And
the mix was gorgeous.

"Your Ad Here!" wrote:

Was the DAT set to some king Long Play mode - below 44.1k?

No...48k...if it were at 32k, I would expect no information at all above
14.

I'm used to getting unpredictable results doing this kind of work due to
the lack of control, but for the situation, this is very extreme. I'm
disappointed about the recording, but more concerned with trying to
figure out what could cause this. The live engineer is a real pro. He
was checking frequencies with an Earthworks mic during soundcheck. And
the mix was gorgeous.

"Your Ad Here!" wrote:

Was the DAT set to some king Long Play mode - below 44.1k?

tferrell wrote:

I thought what I was experiencing was a phase problem from splitting the
cardioids, but from looking at the waves that doesn't appear to be the
case. Both the left and right waves look similar in that the high end
is rolled off. However, the mix was very well balanced at the show.
There was plenty of high end. I've posted a screenshot of the spectrum
analysis at the link below. Any thoughts on what may have caused this?
Can I just chalk it up to some strange reflections in the room? Seems
odd it would happen in both channels with a split that wide.

What did it sound like at the microphone positions? If you are recording
PA stacks that have a very narrow angle of dispersion to deal with a live
room, when you get off-axis the high end will go away. You have to listen
before you put the mikes there.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

Scott Dorsey wrote:

What did it sound like at the microphone positions? If you are recording
PA stacks that have a very narrow angle of dispersion to deal with a live
room, when you get off-axis the high end will go away. You have to listen
before you put the mikes there.
--scott

Thanks, that makes sense. Regrettably, I did not get as good a listen as I
hoped. I had to clear out for the light guys very early into the soundcheck
before anything was even close to representative of what would be the final
mix. I'm assuming by "narrow angle of dispersion" you mean a smaller, low
profile PA as opposed to larger vertical stacks? The JBLs were two to a side
horizontally, probably 35" high and 50" or so wide each with very little
spcae between them. One pointed slightly in and down and one pointed slightly
out and down. The mics were pointed nearly dead center at them, ever so
slightly down and a few inches below. Don't know if that helps with any after
the fact assessment or not.

Tim

tferrell wrote:

Thanks, that makes sense. Regrettably, I did not get as good a listen as I
hoped. I had to clear out for the light guys very early into the soundcheck
before anything was even close to representative of what would be the final
mix. I'm assuming by "narrow angle of dispersion" you mean a smaller, low
profile PA as opposed to larger vertical stacks?

No, when you look on the data sheet for the speaker system, you will see a
polar plot of the speaker pattern, just like on the microphone data sheet.
And just like the microphone, the speaker system is more directional at higher
frequencies. How directional? I don't know, check the data sheet.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

"tferrell" wrote in message
...
No...48k...if it were at 32k, I would expect no information at all above
14.

I'm used to getting unpredictable results doing this kind of work due to
the lack of control, but for the situation, this is very extreme. I'm

Are you comparing this wth how it actually sounded through the JBL PA (or
any PA ?!!!) to yourself, at the mic position, or how you expected it to
sound 'direct' ... ?

geoff

"tferrell" wrote in message
...
No...48k...if it were at 32k, I would expect no information at all above
14.

I'm used to getting unpredictable results doing this kind of work due to
the lack of control, but for the situation, this is very extreme. I'm

Are you comparing this wth how it actually sounded through the JBL PA (or
any PA ?!!!) to yourself, at the mic position, or how you expected it to
sound 'direct' ... ?

geoff

Geoff:

Did you look at the link I provided of the spectrum analysis? I'm not talking
subtle here. I'm talking about a drastic rolloff of something like 50dbs of
all upper mids and highs. It looks like a ski slope. And the sound at the
show was well balanced.

Based on experience, what I was hearing at the show and the decent results I
got the following night (which rule out a gear problem), I'm pretty sure Scott
Dorsey's analysis was correct. I was micing a PA with a narrow dispersal
pattern and simply did not have the access near the end of the soundcheck to
get up on a ladder and get my ears at the micing position. I was pointed very
slightly down and was probably off axis enough to have lost all the high end.
Never come across this before, but live and learn.

Tim


Geoff Wood wrote:

"tferrell" wrote in message
...
No...48k...if it were at 32k, I would expect no information at all above
14.

I'm used to getting unpredictable results doing this kind of work due to
the lack of control, but for the situation, this is very extreme. I'm

Are you comparing this wth how it actually sounded through the JBL PA (or
any PA ?!!!) to yourself, at the mic position, or how you expected it to
sound 'direct' ... ?

geoff

Geoff:

Did you look at the link I provided of the spectrum analysis? I'm not talking
subtle here. I'm talking about a drastic rolloff of something like 50dbs of
all upper mids and highs. It looks like a ski slope. And the sound at the
show was well balanced.

Based on experience, what I was hearing at the show and the decent results I
got the following night (which rule out a gear problem), I'm pretty sure Scott
Dorsey's analysis was correct. I was micing a PA with a narrow dispersal
pattern and simply did not have the access near the end of the soundcheck to
get up on a ladder and get my ears at the micing position. I was pointed very
slightly down and was probably off axis enough to have lost all the high end.
Never come across this before, but live and learn.

Tim


Geoff Wood wrote:

"tferrell" wrote in message
...
No...48k...if it were at 32k, I would expect no information at all above
14.

I'm used to getting unpredictable results doing this kind of work due to
the lack of control, but for the situation, this is very extreme. I'm

Are you comparing this wth how it actually sounded through the JBL PA (or
any PA ?!!!) to yourself, at the mic position, or how you expected it to
sound 'direct' ... ?

geoff