Eliminating background noise with SF6 & NR2.0? -Sound Forge - PC

Subject:Eliminating background noise with SF6 & NR2.0? Posted by: orca Date:3/7/2003 7:37:01 PM Does anyone here know how to effectively reduce if not eliminate the background noise from a mixer using Sound Forge 6.0 or with the help of Noise Reduction if needed? Since I'm new to SF 6.0, I just used EQ to knock off 450 Hz noise which helps, but not that much. I'd appreciate if you could give me a tip or pointers how to fix this problem. Here's the sample of the background noise: http://www.bxglassus.com/noise.ram or http://www.bxglassus.com/noise.rm I'd greatly appreciate any help I could get from this forum. Thanks, Marty
Subject:RE: Eliminating background noise with SF6 & NR2.0? Reply by: philsayer Date:3/8/2003 7:32:01 AM I had a listen - sounds like mains-driven hum, maybe some kind of earth-loop? (As you'll see from recent posts, I'm no electronics expert.) What listening to your posted sound file doesn't tell us is how loud the hum is, relative to the wanted signal, nor the nature of the wanted signal - is it speech or music? If it's speech, and the unwanted noise is at a low level (let's say peaking the speech at -4dB or thereabouts, and the noise is below -40dB) use SF's Noise Gate. Set it with short attack and release times (1 attack and maybe 150 release) at -32dB. That way, you'll get silent pauses without removing any of the speech. I record at home all the time, and although my mic is in a quiet room, ambient noise shows up at around -45dB - this is mainly the computer itself, heating boiler and pump, noise from outside and so on. But it is so quiet that it's inaudible while I'm actually speaking. Noise Gate works by detecting (and removing) ALL the sound quieter than the threshold you set it to, but it's a one-way process, (apart from un-doing last action) so be sure to keep the original while you're experimenting with settings! If the hum is really so intrusive (i.e. loud relative to the recording) that Noise Gate isn't appropriate, then it'll need to be filtered out with one of the EQ routines, as you suggest. 60Hz sounds likely as a start point, but I'm sure there are harmonics in there too! Finally, is this a one-off recording that you're trying to improve, or are you making lots of recordings that suffer the same problem? If the latter, you really have to eliminate the source of the noise.
Subject:RE: Eliminating background noise with SF6 & NR2.0? Reply by: drbam Date:3/8/2003 8:37:11 AM Yes this definitely sounds like a ground issue or perhaps an audio cable crossing a power cable, that kind of thing. Make sure your cables are run correctly. It also might be a bad connector or a plug that's not seated all the way, or a noisy efx unit or stomp box inserted in the signal chain somewhere. Or, or course, it could be a problem within the mixer (you didn't mention what type of mixer you are using). I would try to sort this out before recording more noise and then trying to eliminate it afterwards. Good luck, drbam
Subject:RE: Eliminating background noise with SF6 & NR2.0? Reply by: stusy Date:3/8/2003 2:19:39 PM What does the wall socket look like that you're pluggin into...? if it's a 2-er, and you're pluggin in a 3-er with an adaptor, well, that can be probs also...or maybe even a light if it's on the same strip, etc...
Subject:RE: Eliminating background noise with SF6 & NR2.0? Reply by: orca Date:3/8/2003 5:33:50 PM Sorry I didn't give too much details. Yes, the noise level is relatively loud compared to the speech. And this is just one of the recording that has this problem. The reason was the sound operator forgot to turn down / mute all other channels from musical instrument when the speech was recorded. We figured this out afterwards and didn't have the problem ever since, but yeah I just need to restore this one recording as much as possible. Thanks for the tips.

Subject:Eliminating background noise with SF6 & NR2.0?

Posted by: orca

Date:3/7/2003 7:37:01 PM

Does anyone here know how to effectively reduce if not eliminate the background noise from a mixer using Sound Forge 6.0 or with the help of Noise Reduction if needed?

Since I'm new to SF 6.0, I just used EQ to knock off 450 Hz noise which helps, but not that much. I'd appreciate if you could give me a tip or pointers how to fix this problem.

Here's the sample of the background noise:
http://www.bxglassus.com/noise.ram
or
http://www.bxglassus.com/noise.rm

I'd greatly appreciate any help I could get from this forum.

Thanks,
Marty

Subject:RE: Eliminating background noise with SF6 & NR2.0?

Reply by: philsayer

Date:3/8/2003 7:32:01 AM

I had a listen - sounds like mains-driven hum, maybe some kind of earth-loop? (As you'll see from recent posts, I'm no electronics expert.)

What listening to your posted sound file doesn't tell us is how loud the hum is, relative to the wanted signal, nor the nature of the wanted signal - is it speech or music?

If it's speech, and the unwanted noise is at a low level (let's say peaking the speech at -4dB or thereabouts, and the noise is below -40dB) use SF's Noise Gate. Set it with short attack and release times (1 attack and maybe 150 release) at -32dB. That way, you'll get silent pauses without removing any of the speech.

I record at home all the time, and although my mic is in a quiet room, ambient noise shows up at around -45dB - this is mainly the computer itself, heating boiler and pump, noise from outside and so on. But it is so quiet that it's inaudible while I'm actually speaking.

Noise Gate works by detecting (and removing) ALL the sound quieter than the threshold you set it to, but it's a one-way process, (apart from un-doing last action) so be sure to keep the original while you're experimenting with settings!

If the hum is really so intrusive (i.e. loud relative to the recording) that Noise Gate isn't appropriate, then it'll need to be filtered out with one of the EQ routines, as you suggest. 60Hz sounds likely as a start point, but I'm sure there are harmonics in there too!

Finally, is this a one-off recording that you're trying to improve, or are you making lots of recordings that suffer the same problem? If the latter, you really have to eliminate the source of the noise.

Subject:RE: Eliminating background noise with SF6 & NR2.0?

Reply by: drbam

Date:3/8/2003 8:37:11 AM

Yes this definitely sounds like a ground issue or perhaps an audio cable crossing a power cable, that kind of thing. Make sure your cables are run correctly. It also might be a bad connector or a plug that's not seated all the way, or a noisy efx unit or stomp box inserted in the signal chain somewhere. Or, or course, it could be a problem within the mixer (you didn't mention what type of mixer you are using). I would try to sort this out before recording more noise and then trying to eliminate it afterwards.

Good luck,

drbam

Subject:RE: Eliminating background noise with SF6 & NR2.0?

Reply by: stusy

Date:3/8/2003 2:19:39 PM

What does the wall socket look like that you're pluggin into...? if it's a 2-er, and you're pluggin in a 3-er with an adaptor, well, that can be probs also...or maybe even a light if it's on the same strip, etc...

Subject:RE: Eliminating background noise with SF6 & NR2.0?

Reply by: orca

Date:3/8/2003 5:33:50 PM

Sorry I didn't give too much details. Yes, the noise level is relatively loud compared to the speech. And this is just one of the recording that has this problem. The reason was the sound operator forgot to turn down / mute all other channels from musical instrument when the speech was recorded. We figured this out afterwards and didn't have the problem ever since, but yeah I just need to restore this one recording as much as possible. Thanks for the tips.