OK this seems to be a recurring theme recently, mic bleeds !
So setting up for some live recording/streaming and I am discovering my Hollow Body is bleeding into the vocal mic (SM58) and as I am monitoring direct from my Xenyx AI I can hear the gtr when not singing.
So the plan is to use a Noise Gate but I have two options.
The first is to use my Zoom MS 70CDRâs Noise Gate and add that to the Xenyxâs Aux send/return and apply the gate to the Micâs input channel only, which I have done in the past for isolated vocal FX - reverb etc. This should work fine when I find the power adapter or dig out some batteries !!
The second in to place a Noise Gate on the Audio Input Capture source in OBS itself. This may be more elegant as it is one less box on the desk or studio floor ! But my question is where do I place it in the OBS audio chain ?
As I am using GAIN to boost the overall OBS audio and a Limiter to keep me below the YouTube -2db TruePeak threshold, I assume it should be first in the chain as I have configured as above.
I think youâre right Toby, it would seem counter-intuitive to have a thing for removing noise after a thing for increasing noise. I put my noise gate in the same place.
Thanks for agreeing Ian, seems to be working like that and going with the OBS option.
I am now beginning to think its was more a perception of bleed, hearing the sound of the HB over the audio coming through the headphones. Time will tell when I get round to recording. But the Loudness Meter shows that nothing (unwanted) is coming through, so should be good.
I agree, Toby, and think as a general rule the noise gate would always be first in a chain.
Now I am wondering, maybe if setting up an electric guitar with dialed up fuzz and distortion pedals, maybe the signal in front would be so quiet that youâd still have the beast growling if the gate was first rather than after those pedals that boost the signal?
Just enough space on the card to note that is not your use case here, but the thought made me wonder if âalwaysâ should be âusuallyâ
A lot of high-gain pedals and amps are inherently a little noisy even without much of an input signal. In those cases, itâs not uncommon to put the noise gate after the gain pedal, or even in the FX loop of the amp.
Bear in mind, though, that distortion acts to compress the signal which makes differentiating between noise and signal more difficult (more on this later).
The thing to do is to turn the guitar volume down and see how noisy the setup is. If turning down the volume tames the noise then a noise suppressor in the front should work.
Now, as I said, differentiating noise versus signal is often challenging. And, one of the problems is, if you get this wrong it can result in an unnatural choking of the signal at lower levels.
An approach which goes a long way to solving this is to separate the noise suppression circuit from the signal detection. You can then put the signal detection at the beginning of your signal chain, and wrap your pedals (and, potentially, your amp) with the circuit which suppresses the noise, knowing that this should only get triggered when the input signal is very low.
This approach requires a particular type of noise suppressor, like the Boss NS-2, NS-1X, or similar. If you want to include your amp in the suppression loop, you also need to have an FX loop on your amp.
This approach uses a 4-cable wiring method. I constructed a pedalboard for a friend a few years ago, using existing pedals, including an NS-2 that he had previously had wired using the âsimple methodâ and which he often found didnât work well, as some of his pedals were generating noise after the guitar signal.
I rewired his board and, as well as being careful about the power and wiring (his old board had a mains power strip gaffer-taped to it with power supplies plugged in, within inches of his signal cables) I also wired his NS-2 with the 4-cable method and it eliminated most of his noise issues. He was very happy.
Of course, this doesnât always completely eliminate noise, as your guitar pickups (especially single coils) can generate noise which the noise suppressor cannot easily differentiate from signal, but this tends to be a lot lower level than the signal, so adjusting the noise detection levels can usually work here.
As usual a comprehensive explanation and guide Keith, Thank you for sharing, Iâll bank this for the future, happy in that fact I have a simpler problem to solve.
Placing the Noise Gate in the OBS Audio chain, as per the screenshot, seems to have solved the issue but as proof on concept, today Iâll -
Remove the OBS Noise Gate and record the guitar only, with the pup volume off, to see if it is actually bleeding into the vocal mic, on playback, or just my perception.
If it is, replace the Noise Gate and repeat the experiment, with current settings - Close Threshold -36db, Open Threshold -30db (I read an article saying -31db was a good starting point). Verify the guitar noise is removed.
Record the piece I am working on a see how much âunrecordedâ guitar noise is getting through to me while wearing headphones. Wash rinse repeat with the studio monitors and learn to live with it !
At which point I may try lowering the Close and Open levels but as long as there is no impact to the âampedâ vox and guitar, I am good to go !
The spoken audio either side of the short progression is still seen but no noise is bleeding when just the HB is being played. Evidence both in the Loudness Meter graphic but also on playback where there is no sign of bleeding on the videos audio track. Problem solved.
Obviously if this was a solid body electric bleeding in the vocal mic, the same approach could be used but the required Gate parameters could be set much lower.
Only down side on the amped up HB was a cut off in sustain but it rang on long enough to meet my requirements for this project.
