Q: Should I use Noise Gate?

Grazie wrote on 2/27/2013, 12:07 AM
Specifically here to mop-up and sweep away an annoying PC -50db noise floor that's got my a-nally retentive nature twitching......

Here's the Online Vegas Helpfile on it:

"Noise Gate - The Noise Gate effect is the most basic of all dynamics-processing effects. For years, engineers have been using noise gates to eliminate subtle noise, tape hiss, and low-level electrical hum from recordings.]

And yes, I've spent hours and months trying to "naturally" eradicate this issue, but apart from adding iZo Denoiser - which works well, but AFTER the event, just applying NF is a quicky that I kinda like.

Anybody doing this? With NG? How about the further SONY recommendation of "Graphic Dynamics"?

TIA

Grazie

Comments

farss wrote on 2/27/2013, 12:33 AM
Forget NG, Graphic Dynamics is much better.
That said neither are exactly brilliant as they're not frequency sensitive or shaping.
The gate in Rx is very good and avoids the obvious nature of basic gates as they open, a sort of woosh sound.

Aside from doing some very serious NR in Rx the only time I've used a gate is with old 1/4" tape that was going to be compressed as mp3. With most moden recordings I've not seen the need for them outside of location recordings destined for cinema playback. The average listening environments noise floor will mask the noise anyway unless the amp is at 11.

The Maths:
If you've got a S/N of 60dB then for the noise to compete in the average loungeroom the peaks SPL in the room would be 120dBA.
The Exception:
If you've recorded 96 tracks each with 60dB S/N and theyr're going to be summed by the mixer then you think about using gates.

One of the most most important lesson I've learned about audio, don't try to fix a problem that isn't.

Bob.
Grazie wrote on 2/27/2013, 1:50 AM
Eh, I'm speaking of the PC noise floor, and do others use a gate to hammer that noise, specifically as I record my dulcet tones to Timeline.

G
farss wrote on 2/27/2013, 4:42 AM
"I'm speaking of the PC noise floor, and do others use a gate to hammer that noise, specifically as I record my dulcet tones to Timeline."

A noise floor is a noise floor. It can come from the room, the preamps, the mic.

You can insert an FX into an Input Bus, never done it myself, looks complicated and it means the FX is baked into the recording. I've always recorded clean and then added any FXs as needed, at least then I can undo it.

Bob.
VidMus wrote on 2/27/2013, 4:43 AM
A noise gate wil remove the noise during quiet parts but when there is sound again the noise will be heard.

So if a person is talking quietly and they pause for a second or two then there will be total silence and no noise. But when they talk quietly again the noise will be heard again. I find that solution to be poor at best.

I just tried the noise removal effect in Audacity using the default settings and got the best results I ever had.

I found a quiet portion of audio where the noise (furnace blower) is, selected a second of it, used 'Get Noise Profile' so it knows what to use, closed that then did CTRL+A to select the entire audio, back to noise removal and click OK for the default. Cleanest audio I ever heard! I am using my memory to explain this so I may have missed a step or two.

Of course the default may not always work but it turned out to be a good place to start. At least on the audio's I am working with.

The one thing I liked best is there was not any of that goofy sounding artifacted audio in the background that other software's leave.

I tried the Sound Forge Pro 10 trial version and the results I got with it were the poorest ever! Maybe I do not understand it enough but since the free Audacity's results were superior why would I spend money on Sound Forge?

Anyway, I hope this helps.

Danny Fye
www.dannyfye.com/ccm
rraud wrote on 2/27/2013, 10:56 AM
Noise Gates are often audible if there's little BG sound to mask it. An 'expander' can be more gentle.. Normally an expander will have adjustable parameters for; threshold, attenuation level, look-ahead, attach, release, hold, and trigger bandwidth.
Neither VP, SF or Acid have one.. however, as 'farss' stated, the Graphic Dynamics processor can be used as a simple expander. Just draw a curve opposite of compression, though this takes experimentation until one 'gets-the-hang-of-it'.
Example:
Arthur.S wrote on 2/27/2013, 4:06 PM
Another vote for Audacity. I used the Beta version which has a little more control over noise removal. This was on some audio from a DSLR (YUK!) Worked brilliantly.
larry-peter wrote on 2/27/2013, 5:10 PM
Grazie,
Is your noise of the white/pink variety (a mix of a lot or all frequencies) or is there a good deal of hum from external interfaces? If you have Sound Forge and can sample the noise to see what it's made up of, you might find an easier and better way to get rid of it.
On some audio that's been brought to me from noisy PC workstations, vinyl restoration tools worked well in getting rid of the noise. I can't remember if Sony's tools include a notch/comb filter for 50/60Hz hum, but Waves' do. I've used a combination of hum removal and hiss removal and got better results than a gate or MB dynamics will give you, especially if the audio is voice only. But if your PC noise includes the low-level chirping from drives being accessed, it obviously won't help much with that.