Noise removal

Finishing up a song this week, and I found noise on two of the drum tracks. The lead in on both is clean and quiet, but as soon as the drumming starts, there's a motorboat like sound, louder at the beginning of the tracks, fading towards the end. I had not heard it previously, but as I'm mastering and EQing the songs, it really stuck out to me. I'm told there are ways to eliminate, but I'm not sure how to go about it, or what plug in I might use. Anyone have any suggestions to try to eliminate the noise?

metz
Isotopes denoise plugin is awesome. I've stopped using all others. https://www.izotope.com/e...t/rx-plug-in-pack.html

+ 1,000

Are they MIDI or audio tracks?  I know you've been using AD lately, right?  Check your buffers and latency because you can turn them up while mixing or mastering.

there are quite a few good noise reduction plugins, and unless your wallet will allow the entire CEDAR suite I think you are going to need a couple to cover all contingencies.
 
My tool chest has too many, the few I use include:
Izotope RX - probably the top of the heap today, and it is fairly intuitive, meaning you can get good results without a lot of artifacts without too much tweaking.
 
Accusonus ERA-D - this was distributed by Plugin Alliance, but is now available directly from the developer. It works really well on all sorts of noise, but it requires a bit of effort to get the best results. Other than ease of use I'd call it a tie with RX. The strange thing is one will work better on a track, and the next track the other will win. Very strange.

Sony/Sound Forge/Magix/whoever??? - There was a noise reduction plugin developed for Sound Forge, I'm pretty sure at some point they just bundled it with the editor, and I don't know if it can still be purchased separately. Which is too bad. Like Sound Forge it is FAST, and relatively easy to use, and for broadband noise, especially things like HVAC, I think it is probably still the best bet out there. In fairness, it was my only tool for a number of years (big number) so I pretty much know what settings to start from. If you are just getting started with noise reduction it might not be easy. I have no way to judge<G>!
 
I've used the demo versions of the Waves noise reduction plugins a couple times, always hoping that they'll knock it out of the park. Thus far I've been impressed with the results, but they offer me nothing new, no better noise reduction, no better workflow... might be a good starting point, but I've found no compelling reason to add them to the tools I already have.
 
Two things to keep in mind:
1) two or more passes with very gentle noise reduction will usually sound better than one pass with extreme settings. This applies to steady state and impulse noises.
2) it is all about the settings, and even almost 20 years later I have to listen carefully and make small adjustments to get rid of the noise without causing other problems. It is slow, tedious work.
 
Depending on the noise - and this does not apply to your case as described - my first pass is always to mute the noise at the heads and tails of the tracks, and sometimes even between phrases. Muting between notes can work, but often sounds unnatural.
 
For motorboating I would be inclined to start with a gate, a drum kit can cover a multitude of sins, unless of course it doesn't. In the bad old days I had a MIDI controlled gate from Drawmer that let me program in where the gate opened and closed... pretty remarkable at the time. I can now do the same thing more quickly, and more accurately with automated volume or mutes.

Good luck!

Speaking of gates.. Check out the demo of Expurgate. Exceptional gate!

I agree Slartabartfast. I'm stumped as to what caused it. I initially thought it was only on one track and thought maybe a cable or mic issue, but that does not make sense on two tracks and only when there is signal present. I would like to figure out what the cause was.
Jackson

No matter how good  I don't think a noise reduction plug in will help much. 
 
My approach would be to open the tracks Wave file in a wave editor as that would rule out all other interference. 
If the noise goes away you are saved because now all you need to do is find the cause from with in Sonar.
 
If the noise is still there. My first move would be to open a back up of the original recording. 
If the noise was there from the beginning and you just missed it, my next move would be to replace this track using one of many tools we now have on hand. 

You made me curious as to what caused the issue, perhaps this was a Tube Guitar Amp? 
 
 
In electronics, motorboating is low frequency parasitic oscillation (unwanted cyclic variation of the output voltage) that occurs in audio and radio equipment and often manifests itself as a sound similar to an idling motorboat engine, a "put-put-put", in audio output from speakers or earphones.[1][2][3][4] It is a problem encountered particularly in radio transceivers and older vacuum tube audio systems, guitar amplifiers, PA systems and is caused by some type of unwanted feedback in the circuit. The amplifying devices in audio and radio equipment are vulnerable to a variety of feedback problems, which can cause distinctive noise in the output. The term motorboating is applied to oscillations whose frequency is below the range of hearing, from 1 to 10 hertz,[3] so the individual oscillations are heard as pulses. Sometimes the oscillations can even be seen visually as the woofer cones in speakers slowly moving in and out.[2]
Besides sounding annoying, motorboating can cause clipping of the audio output waveform, and thus distortion in the output.

https://www.youtube.com/watch?v=sctKIMAunhk
 
This is me trying to remove some noise.