Audio trim setting on the PMW-EX1 at DVinfo.net

Kevin Walsh · October 10th, 2008, 02:53 PM

I'm not sure if this post should be in the All Things Audio or in the EX1 threads, but I figured I'd try it here. Could somebody explain how I go about choosing the correct audio trim settings on my EX1 when I'm using the Sony PCM-673 mic. I looked in the manual and I've searched the forums and I haven't found any information on what setting to use. Do I simply match the trim setting to the spec'd sensitivity for the mic (-36dB) or do I set it to a setting that would give me desired output at a given audio/level setting? I'm really surprised that the manual doesn't even mention this.

Steve House · October 10th, 2008, 04:18 PM

I haven't been able to locate an online copy of the manual to look up just what trim settings and adjustments you're talking about. Are you talking about an input sensitivity or attenuator setting of some sort or are you asking about the audio recording input gain (or recording level) setting? Meanwhile here are some general guidelines that might help.

You should use the setting that gives normal recording levels as indicated on the camera's meters. Output levels are irrelevant while recording as they are as much a function of the playback or headphone volume settings as they are of the recording settings, you've got to use the meters. Your actual output levels for the final program are set in post production, not in the camera original - your aim in the original recording is to provide the best raw material possible to work with later. For the best signal/noise ratio you want to record at the hottest levels you can without going so hot that you approach clipping on peaks. The exact settings that will accomplish that depend on many factors, including the volume of the original sounds you're capturing, so there's no 'magic number' on the dials that you should use. You need to monitor the meters for levels as you shoot. Assuming the camera has peak reading meters as is the norm in digital equipment, you want to make sure the average levels are as high as possible without peaks ever going over about -3dBFS. (0dBFS is the true digital 'never exceed' level but it's possible for peaks causing audible clipping distortion to be so brief that they don't register on the meter, hence -3 to provide a safety margin.) If there are both input level and input trim controls. you should use the trim setting that gives you this when the level dial is about 2/3 of the way up. You also need to listen while recording through good quality, isolating, headphones set to a comfortable volume level in order to judge subjective quality, catch interfering noises, etc.

Kevin Walsh · October 10th, 2008, 05:21 PM

Quote:

Originally Posted by Steve House

If there are both input level and input trim controls. you should use the trim setting that gives you this when the level dial is about 2/3 of the way .

Steve, I was talking about microphone input sensitivity. You've answered my question. Thank you!

October 10th, 2008, 02:53 PM	#1
Kevin Walsh Major Player Join Date: Feb 2008 Location: Phoenixville, PA Posts: 225	Audio trim setting on the PMW-EX1 I'm not sure if this post should be in the All Things Audio or in the EX1 threads, but I figured I'd try it here. Could somebody explain how I go about choosing the correct audio trim settings on my EX1 when I'm using the Sony PCM-673 mic. I looked in the manual and I've searched the forums and I haven't found any information on what setting to use. Do I simply match the trim setting to the spec'd sensitivity for the mic (-36dB) or do I set it to a setting that would give me desired output at a given audio/level setting? I'm really surprised that the manual doesn't even mention this.

October 10th, 2008, 04:18 PM	#2
Steve House Inner Circle Join Date: Mar 2005 Location: Hamilton, Ontario, Canada Posts: 5,742	I haven't been able to locate an online copy of the manual to look up just what trim settings and adjustments you're talking about. Are you talking about an input sensitivity or attenuator setting of some sort or are you asking about the audio recording input gain (or recording level) setting? Meanwhile here are some general guidelines that might help. You should use the setting that gives normal recording levels as indicated on the camera's meters. Output levels are irrelevant while recording as they are as much a function of the playback or headphone volume settings as they are of the recording settings, you've got to use the meters. Your actual output levels for the final program are set in post production, not in the camera original - your aim in the original recording is to provide the best raw material possible to work with later. For the best signal/noise ratio you want to record at the hottest levels you can without going so hot that you approach clipping on peaks. The exact settings that will accomplish that depend on many factors, including the volume of the original sounds you're capturing, so there's no 'magic number' on the dials that you should use. You need to monitor the meters for levels as you shoot. Assuming the camera has peak reading meters as is the norm in digital equipment, you want to make sure the average levels are as high as possible without peaks ever going over about -3dBFS. (0dBFS is the true digital 'never exceed' level but it's possible for peaks causing audible clipping distortion to be so brief that they don't register on the meter, hence -3 to provide a safety margin.) If there are both input level and input trim controls. you should use the trim setting that gives you this when the level dial is about 2/3 of the way up. You also need to listen while recording through good quality, isolating, headphones set to a comfortable volume level in order to judge subjective quality, catch interfering noises, etc. __________________ Good news, Cousins! This week's chocolate ration is 15 grams!