Audio inputs - Popping / Clicking noise buildup at DVinfo.net

pathways · February 15th, 2003, 04:38 AM

I covered this problem a while ago regarding clicking on my audio, thought the problem was a cable, turns out not to be. I will be taking my XL1s in for servicing, but wanted to check and see if anyone else has had a similar problem.

Problem description:

When using only the on board XL1s mic, and Stereo1 16bit, no problems result (audio is clear).

When using external analog inputs for audio (either from a deck or mic) *the first half an hour* of recording (as timed after the camera has been powered off for an hour plus, usually overnight) is clear, clean audio. Then small pops/clicks are gradually introduced into the recording. These seem to be occuring at audio peaks, though an accurate correlation has not been established yet.

The clicking increases and usually plateaus at a point, resulting in the recorded audio being understandable but still plagued by this clicking.

Note: this is not distortion due to levels being set to high. No clipping of audio peaks is occurring.

My feeling is that a charge is building up somewhere. Possible? Is my XL1s audio circuitry bad?

Again, the problem occurs when using an external mic or when recording off of, for example, a deck (vhs, umatic, etc.).

For reference, in the case of using an external mic, I am using a Sennheiser K6+Shotgun combo (powered) cabled via XLR connectors into the MA200 unit. Of course the fact that this occurs with any analog audio input (on both the audio 1 and audio 2 rca jack inputs) suggests that the mic isn't to blame.

Don Palomaki · February 15th, 2003, 06:49 AM

Just a couple quesitons to help better understand.

Is the clickling present when the same section of tape is played back later? Played on a different machine? And it goes away after the cancorder sits off for a while

Has anyone opened the audio in a wave efitor such as SoundForge or Cool Edit to look at the precise waveform near the clicks?

Might be a leaking capacitor (or similar effect) that gradually pulls-up an analog signallevls with a DC bias to the point of generating a click when the audio level would go into clipping.

pathways · February 15th, 2003, 01:02 PM

don, answers to your questions:

clicking is consistent and specific to the tape and region of tape. i.e. it is present in the recorded audio signal.

i've looked at the audio in soundforge and the clicks are very, very short in duration. i can post a waveform capture on a website to review if helpful, along with a sample audio file.

Don Palomaki · February 16th, 2003, 08:25 AM

A post would be interesting to look at. and hear.

February 15th, 2003, 04:38 AM	#1
pathways New Boot Join Date: Jan 2002 Location: Hong Kong Posts: 14	Audio inputs - Popping / Clicking noise buildup I covered this problem a while ago regarding clicking on my audio, thought the problem was a cable, turns out not to be. I will be taking my XL1s in for servicing, but wanted to check and see if anyone else has had a similar problem. Problem description: When using only the on board XL1s mic, and Stereo1 16bit, no problems result (audio is clear). When using external analog inputs for audio (either from a deck or mic) the first half an hour of recording (as timed after the camera has been powered off for an hour plus, usually overnight) is clear, clean audio. Then small pops/clicks are gradually introduced into the recording. These seem to be occuring at audio peaks, though an accurate correlation has not been established yet. The clicking increases and usually plateaus at a point, resulting in the recorded audio being understandable but still plagued by this clicking. Note: this is not distortion due to levels being set to high. No clipping of audio peaks is occurring. My feeling is that a charge is building up somewhere. Possible? Is my XL1s audio circuitry bad? Again, the problem occurs when using an external mic or when recording off of, for example, a deck (vhs, umatic, etc.). For reference, in the case of using an external mic, I am using a Sennheiser K6+Shotgun combo (powered) cabled via XLR connectors into the MA200 unit. Of course the fact that this occurs with any analog audio input (on both the audio 1 and audio 2 rca jack inputs) suggests that the mic isn't to blame.

February 15th, 2003, 06:49 AM	#2
Don Palomaki Wrangler Join Date: Sep 2001 Location: Northern VA Posts: 4,488	Just a couple quesitons to help better understand. Is the clickling present when the same section of tape is played back later? Played on a different machine? And it goes away after the cancorder sits off for a while Has anyone opened the audio in a wave efitor such as SoundForge or Cool Edit to look at the precise waveform near the clicks? Might be a leaking capacitor (or similar effect) that gradually pulls-up an analog signallevls with a DC bias to the point of generating a click when the audio level would go into clipping.

February 15th, 2003, 01:02 PM	#3
pathways New Boot Join Date: Jan 2002 Location: Hong Kong Posts: 14	don, answers to your questions: clicking is consistent and specific to the tape and region of tape. i.e. it is present in the recorded audio signal. i've looked at the audio in soundforge and the clicks are very, very short in duration. i can post a waveform capture on a website to review if helpful, along with a sample audio file.

February 16th, 2003, 08:25 AM	#4
Don Palomaki Wrangler Join Date: Sep 2001 Location: Northern VA Posts: 4,488	A post would be interesting to look at. and hear.