how to remove audio noise ?

[jneill0752]

What is the best way to remove camcorder noise from captured home video files. I am capturing to Mjpeg avi files with PCM audio. I use a Pinnacle DC10plus card to capture.

The noise is worse on the captued file than the original tape when played.

I shot this video over the last 12 years with the camcorder microphone. The camcorder noise is especially bad when I used a tripod.

Should I reduce the record sound level when I do the capture, or will this reduce all the sound volume so that when I increase the playback volume the background noise is still bad.

Any suggestions welcome.

Henderson, TX

[setarip]

I would suggest that you demultiplex the file and load the sound file into aprogram such as GoldWave or CoolEdit, both of which include filters for eliminating extraneous "noise".

Let us know of your success ;>}

[Carlos Menem]

I would suggest that you demultiplex the file and load the sound file into aprogram such as GoldWave or CoolEdit, both of which include filters for eliminating extraneous "noise".

Let us know of your success ;>}

I have this exact problem but the tape is on a VCR... I would like not to multiplex the file I've like to correct this problem starting from the VCR any ideas?

[GeorgeInRaleigh]

Reducing microphone hum noise

I'm trying to clarify how to reduce or remove "hum" from a microphone used with a digital camcorder
I've read a number of articles, but not being a technician, I'm struggling to understand most of the articles.
I CAN get rid of the hum when:
o holding both camcorder & mike in bare hands
o using Panasonic mike, supplied w/camcorder & "talk" pressed
o using inexpensive microphone with 4 foot cord & a mono mini jack

Microphone specs:
http://www.audio-technica.com/cms/wi...64a/index.html -
Camcorder info:

http://www.camcorderinfo.com/content/Panasonic-PV-GS250-Camcorder-Review.htm

Is audio-technics microphone too strong?

Mike specs:
-59 dBm +/- 3dB, 1 kHz at 1 PA
PV-GS250 Mic input:
-50 dB (0dB=1V/Pa, 1kHz)(stereo mini jack)

Microphone specs:
http://www.audio-technica.com/cms/wi...64a/index.html -
Camcorder info:

http://www.camcorderinfo.com/content/Panasonic-PV-GS250-Camcorder-Review.htm

Thanks.

[RFBurns]

There are several methods to remove noise from audio. The fast way is using what was suggested above, putting the file through demuxing and run the audio portion through GoldWave or CoolEdit, both are excellent and have a ton of filters to play with.

A more complex method, and allowing to remove the noise from the source rather than capturing and demuxing is to use what is called "mix-minus".

If you scope the audio as it plays, and adjust the oscilliscope sweep rate to only display the noise waveform, a passive filter can be made to "bandpass" the noise frequency so that only the noise signal will pass through the filter, then feed that to a mixer with a negative channel. With this method, you can "null" out the noise signal quite effectively without degrading the audio signal you want.

Hum noise can be of any frequency. However as with any signal, RF or Audio, there are harmoics. Sometimes the harmonics are very low in amplitude compared to the primary signal we want, and can simply be ignored. But sometimes it can wreak havoc if it is of a certian frequency and either the primary frequency or one of its harmonics happens to fall within the frequency range of the main signal we do want. At that point, running the audio signal through one of the above mentioned programs can assist with great accuracy, since both programs are capable of focusing in on the entire waveform or specific point where noise is located.

Depending on the frequency of the "hum" noise from the camcorder, which could be capstan motor noise, video drum servo noise, or even noise from the microphone amplifier circuits, it might just be easier and time saving to capture the video/audio and demux it, clean up the audio and then remux it for final assembly.