Background Noise

logantoo · Post by **logantoo** » Sun May 14, 2006 8:26 pm

In VS9 is there anyway in which I can remove the background "hum" leaving only the recorded voices. I have tried the various filters but this does not appear to help or have I done something wrong when actually recorded a scene.
Many thanks,

PeterMilliken · Post by **PeterMilliken** » Sun May 14, 2006 10:31 pm

Filtering unwanted sound will always be tricky and often provides less than satifying results i.e. I had wind noise when recording an out door wedding with wind instruments playing the wedding music - any wind noise filter invariably reduced some of the music from the instruments, I found it better to leave in the wind noise than attempt to filter it.

You can try something like audacity (http://audacity.sourceforge.net/) to edit the sound. But the best was of reducing noise is at the source i.e. don't record it to begin with.

Peter

bobcwilson · Post by **bobcwilson** » Mon May 15, 2006 1:03 am

I have found a program called Goldwave (www.goldwave.com) that does a better job at reducing the hum than Audacity. Most people recommend that you use the noise reduction filter to eliminate the hum. I have not had a good experience using this type of filter. The sound becomes tinny and to me it is worse than the hum.

Hum is usually in the 50-60HZ range. Goldwave offers and equalizer (which Audacity does not have) that can reduce this sound range. You won't get rid of all of the hum but you can reduce it by more than half without losing to much of the sound. While Goldwave is not free (it costs $49), they do offer a free trial version.

Peter is correct in that it is better to make your recording without the hum. I have a satellite dish hooked up to my capture device. I was getting this 50-60HZ hum on everything I recorded. I found out that most hum within the home is caused by a ground loop. You can read more about ground loops and how to get rid of them here:

http://www.epanorama.net/documents/groundloop/

Gound loops are hard to find and get rid of. An easier method is to buy a Ground Loop Isolator. You can get one at Radio Shack or you can buy one from Ebay. After I hooked up the device to my capture card, no more hum!

bob

logantoo · Post by **logantoo** » Mon May 15, 2006 6:52 am

Many thanks, but it may be of interest as I tried the same clips using the limited programme I got with the Sony camera and also Windows Movie Maker and neither had the background noise and the recorded spoken word of the subject came over crystal clear. Have I perhaps done something wrong with setting up VS 9 or in editing?

logantoo · Post by **logantoo** » Mon May 15, 2006 12:03 pm

Further information is that the camcorder audio recording is 12 bit stereo, voice playback on the camcorder is clear without "hum" and transfer from camcorder to PC is via USB 2 cable. Could it be that the programme is picking up the "hum" of the PC during the transfer? I hope you can help as it is a recording of an important event that cannot be repeated.
Many thanks,

maddrummer3301 · Post by **maddrummer3301** » Mon May 15, 2006 12:05 pm

logantoo · Post by **logantoo** » Mon May 15, 2006 2:29 pm

Please forgive the beginner, but what are notch filters?

logantoo · Post by **logantoo** » Mon May 15, 2006 3:16 pm

Wow!! Just looked up notch filters, sorry much too complicated for me but thanks for trying to help.

logantoo · Post by **logantoo** » Mon May 15, 2006 8:32 pm

If any one is still interested I got rid of most of the backgroung noise by duplicating the audio channel - not perfect but a lot better. Anyway thanks to all for trying to help me.

Mike-Mat · Post by **Mike-Mat** » Mon May 15, 2006 8:46 pm

For your sound card inputs, you should turn off inputs that your NOT using. Double click on the little speaker in the lower right of your Windows screen and Mute everything (except maybe Wave & Video). Also make sure all your devices are well grounded.

Mike