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ShakeWellProd

macrumors member
Original poster
Mar 4, 2008
76
0
Hello, I purchased a Sony HDR-A1U today and took it out for an interview. The video quality looks great.

My problem occurred when I hooked up two Sennheiser EW 100 G2 wireless lapel mics.

On the XLR part I set the settings to: Low Cut=Off on both

Rec CH to CH1 & CH2
Input level to MIC ATT on both
and the +48V to ON on both

I got this hissing and distorting noise when people talked. Now when I only hooked up one Wireless Lapel it worked fine. Where am I going wrong?

I'm thinking it is a setting in the Wireless Mic, but fooled around with it for hours and nothing.

Should the mics be on Pilot mode?

Danks for all your help.
 
Make sure each system (transmitter and receiver) are on their own frequency. Also, you do NOT need phantom power (+48v) for a wireless mic receiver.

-DH
 
My problem occurred when I hooked up two Sennheiser EW 100 G2 wireless lapel mics.]Just to make sure we are all on the same page, you did use the wireless transmitters and receivers, right? Or did you just connect the lapel mics directly to the camera (with an adapter cable)?

On the XLR part I set the settings to: Low Cut=Off on both
OK.

Rec CH to CH1 & CH2
That's confusing, but likely not the cause of your problem. Check if this setting means that the input on your first XLR is duplicated and recorded to both audio channels. It's not what you want with two mics. With two mics, you want XLR1 to go to channel 1, and XLR2 to channel 2.

Input level to MIC ATT on both
Nope. You should set the camera inputs to line level, because that's what your wireless receivers output.

and the +48V to ON on both
No. Your wireless receiver doesn't need phantom power. It's got its own power. Turn this off.

Should the mics be on Pilot mode?
It shouldn't make a difference for your case.

Does this help at all?

- Martin
 
Thanks

thank you to you both. I will try all of those things at my shoot in Berkeley today. thanks again.
 
Update

UPDATE:
I set the camera's XLR adapter to LINE. I import the footage to FCP and the audio doesn't seem to be very loud. I really have to crank up the speakers, which in turn makes the audio hiss.

On the Mic setting on the XLR adapter the audio on mic 1 sounds pretty good thou you can hear a lot of background noise. The audio on mic 2 seems over modulated. I have to be careful how loud I talk.

On the Mic ATT setting I get little to no background noise and decent audio from both mics. This seems to be the best choice when playing all the settings back in my headphones.

Any thought as to why LINE isn't getting me any decent sound?
 
UPDATE:
I set the camera's XLR adapter to LINE. I import the footage to FCP and the audio doesn't seem to be very loud. I really have to crank up the speakers, which in turn makes the audio hiss.
With your wireless setup, there are three different levels to adjust. You need to look at all of them to make it work:
  • The sensitivity of the wireless transmitter. As you speak into the wireless mic, you can see the level of the audio signal it picks up (labeled "AF" on the display). With the sensitivity setting, you can adjust this. With normal speech, the levels should reach somewhere between half and 2/3 of the maximum. More and you don't have enough headroom for the occasional louder-than-average sound; less and you don't have a strong enough signal for a clean recording. You make this change in the "SENSIT" menu of your transmitter.
  • Moving on to the receiver, you will need to adjust the output level. If your last experiment resulted in very low volume, use the "AF OUT" menu of the receiver to increase the audio level that it outputs.
  • Finally, your camera has controls to set the audio gain level for the recording, and a meter to see how strong the signal is. Again, you want the readout to be somewhere between half and 2/3 for speech at normal volume. Do not use automatic gain control (AGC) in the camera, it is almost always better to set the levels manually if you want to capture good sound.
Receiver output level and camera audio gain level go hand in hand, of course. You should be able to find a combination that works well where no single device is set to an extremely low or extremely high setting (in which case you'd end up with considerable hiss or noise).

Good luck!

- Martin
 
Nope. You should set the camera inputs to line level, because that's what your wireless receivers output.

Of the twelve wireless mic systems I own (3 Sony, 4 Telex, 4 Sennheiser and an old Vega), none of them output a line level signal. Each outputs mic level (balanced).

-DH
 
Of the twelve wireless mic systems I own (3 Sony, 4 Telex, 4 Sennheiser and an old Vega), none of them output a line level signal. Each outputs mic level (balanced).
OK, I wasn't careful when I wrote that. The Sennheiser G2 series receiver that the OP uses can be set to output mic or line level (see page 33 of the manual). For cameras that support a line level signal on the audio inputs, like his Sony A1, I would recommend to use this setting and have the audio gear send the "hotter" signal. That's because the audio pre-amps in practically all consumer and prosumer cameras are lower quality than what you find in good audio gear. Of course, if your camera will only take a mic level signal at its input, then you are stuck with that.

- Martin
 
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