[Outdated Mac User]

Hi, all:
I used a 3 channel Shure mixer, FP 33, for a couple of interviews. I
hooked the mixer to Canon XL1. Two wireless lavs were connected to the
mixer. During the test, I made sure that the level did not hit the
peaks; roll-off was on. While listening to the recording, it sounded a
little 'scratchy' so I reduced the camera's audio line in level. When
I looked at the waveform on the computer after the recording, it was
apparent that the waveform was clipped everywhere, both at the top and
at the bottom. I just don't understand why this happened if I ensured
that the master volume was set so that there would be no peaking. A
buddy told me with the Shure mixers, you have to set the master low
and adjust the individual channels if you want to increase the preamp
level.

What do you think could have caused this massive clipping? In the
headphones it did NOT sound as bad as it did on tape.

Thanks,
OMU

[Mike Rivers]

On Mar 28, 2:13 am, "Outdated Mac User"
wrote:

I used a 3 channel Shure mixer, FP 33, for a couple of interviews.
During the test, I made sure that the level did not hit the
peaks; roll-off was on. While listening to the recording, it sounded a
little 'scratchy' so I reduced the camera's audio line in level. When
I looked at the waveform on the computer after the recording, it was
apparent that the waveform was clipped everywhere

You probably connected a Line level output of the mixer to a Mic level
(or low line level) input on the camera. If that mixer has a mic level
output, try that next time. If not, reduce the output level of the
mixer. Set the level so that the VU meter reads 0 on peaks, then back
it down so that it's between -20 and -10, and don't look at the meter
again.

Best to experiment with this at home where you can check what's going
on. If the camera has a headphone output, if it's clipping at the
camera input, you should be able to hear what's happening by
connecting a set of phones there.

[Scott Dorsey]

Outdated Mac User wrote:
Hi, all:
I used a 3 channel Shure mixer, FP 33, for a couple of interviews. I
hooked the mixer to Canon XL1. Two wireless lavs were connected to the
mixer. During the test, I made sure that the level did not hit the
peaks; roll-off was on. While listening to the recording, it sounded a
little 'scratchy' so I reduced the camera's audio line in level. When
I looked at the waveform on the computer after the recording, it was
apparent that the waveform was clipped everywhere, both at the top and
at the bottom. I just don't understand why this happened if I ensured
that the master volume was set so that there would be no peaking. A
buddy told me with the Shure mixers, you have to set the master low
and adjust the individual channels if you want to increase the preamp
level.

What do you think could have caused this massive clipping? In the
headphones it did NOT sound as bad as it did on tape.

You were overloading the front end of the XL1. The meters on the XL1
are _after_ the front end, and the damn thing has hardly any headroom
to speak of so if you turn the gain on the XL1 down, it is very, very
easy to clip the mike preamp stage. (And yes, even with the thing set
to line input you're going through the preamps).

Next time reduce the _output_ of the mixer, and leave the camera input up.

Also, try the Sony MDR-V6 headphones, which exaggerate vocal clipping
problems so you have a better idea what is going on.
---scott

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

[Richard Kuschel]

Outdated Mac User wrote:
Hi, all:
I used a 3 channel Shure mixer, FP 33, for a couple of interviews. I
hooked the mixer to Canon XL1. Two wireless lavs were connected to the
mixer. During the test, I made sure that the level did not hit the
peaks; roll-off was on. While listening to the recording, it sounded a
little 'scratchy' so I reduced the camera's audio line in level. When
I looked at the waveform on the computer after the recording, it was
apparent that the waveform was clipped everywhere, both at the top and
at the bottom. I just don't understand why this happened if I ensured
that the master volume was set so that there would be no peaking. A
buddy told me with the Shure mixers, you have to set the master low
and adjust the individual channels if you want to increase the preamp
level.

What do you think could have caused this massive clipping? In the
headphones it did NOT sound as bad as it did on tape.

Thanks,
OMU
The FP33 has two levels for output Line level and Mic level.

I havr had the same problem you encountered every time I have used the
line level even into Professional cameras designed to take line level.
Sony BetaCams were particularly bad in this respect. I've never had
problems running line level into professional audio recorders. When
Sony was asked about this problem, the response was "We build
cameras".

So -- use the mic level output. Then, monitor from the camera and
listen for distortion. You can listen to the FP33 outputs all day long
and never have distortion. Even better, run a line from the headphone
outs from the camera back to the FP33 to listen for distortion. Camera
operators have enough to concentrate on without worrying about sound.
Besides, most of them are deaf anyway.G-- Running for cover.

Generally I keep the meters on the FP33 about in the middle of their
travel and don't push the inputs on the camera too hard. If the camera
needs to be set at at a level of 7 out of ten for correct levels in
the camera, you have things set up about right.

If the camera level is around 3 then you are probably distorting the
preamps in the camera. Turn the output of the FP33 down until you can
run 7 on the camera,

[Bruno Strapko]

The XL1 inputs are infamous among location audio folks. It's been a
while, but if recall correctly, the balanced XLR inputs are mic level
only, the RCA jacks are typical -10. The best way in on these cameras
is to use mic level. As noted by Richard, even "pro" cameras have
audio deficiencies; basically the input select switches are nothing
more than pads before an awful sounding mic preamp with a terrible
phantom power supply,

YMMV
Bruno