Leakage into bass track

  • Hi all,


    I get leakage (i.e. bleed, background noise...) from other tracks into the bass track, particularly when reamping. That is, I can hear the drums in a mild background of my reamped bass track. No idea why this happens, and whether it has to do with the KPA to begin with, but it's really annoying. Things I've noticed related to this are:


    - The leak is already in the DI track (almost imperceptible), which I later reamp.

    - The leak is noticeable with specific profiles. Imperceptible with others. I would assume those with a specific frequency or impulse response let the noise through.

    - The more gain, the more noticeable the leak is

    - The leak is imperceptible with guitar profiles, as far as I can remember.

    - The leak is mostly cymbals and hihats. That's the noise that leaks through mostly into my reamped bass track.


    If anybody has any idea on how I could get rid of this for good, I would be eternally grateful.


    Stay well y'all :thumbup:

  • There’s no way leakage can bleed into a Kemper track through fault of the Kemper. There’s no mic to bleed into.
    IMO you need to look into either the original DI track (sounds like this was recorded during a live session with drums using traditional mic techniques with a cab?)

    Or if it was originally recorded with a Kemper, there’s something going on with your routing in the DAW. Check if there’s any send also from you drum tracks?

  • - The leak is already in the DI track (almost imperceptible), which I later reamp.

    This to me sounds like the pickup in the bass may be a bit microphonic and it picked those things up when you were tracking either live or from your monitors. It would be impossible to get bleed from one track to another in the digital world. This had to come in through a microphone or a pickup when the track was created. Once it is there, it is always going to be there. You would have to track it again and ensure it is not in a noisy environment.

  • I think Netheravon's thoughts about sends might be particularly useful for you to explore.


    Additionally, along the lines of sends, something that I still trip over from time to time when I'm not paying attention is reverb. I'll be going along my merry way and suddenly wondering why I can hear ghosted drums (or some other instrument) when the big, red M button clearly states that I've muted the bloody drums. If the reverb or any other send goes pre fader / mutes, then the track travels on its merry way to the reverb, and the reverb output ends up in the master bus. And because in my mind the drum have been muted, I've more than once thought, "how did the stupid drums get on my guitar track?" Actually the language is a bit more colorful, but you get the idea. Of course, if I mute the reverb, or disable the send on the drums, the ghost magically disappears. Ghosts are like that.


    Reverb is just an example, but it illustrates how routing mistakes can sometimes be less than intuitive. I'd go through all your tracks, busses and sends with a fine toothed comb. Also, I don't know what kind of audio interface you're using, but in my case it's a Yamaha TF5 mixer that connects via USB to the computer. Being a mixer, there's plenty of other opportunities for routing adventures. However, these days even simple two channel interfaces often come with powerful internal software that provides a lot of routing options, so that's another place to shine the flashlight.


    Anyway, hope this gives you a few ideas of things you can look into. Debugging is always such fun.

  • Additionally, along the lines of sends, something that I still trip over from time to time when I'm not paying attention is reverb. I'll be going along my merry way and suddenly wondering why I can hear ghosted drums (or some other instrument) when the big, red M button clearly states that I've muted the bloody drums. If the reverb or any other send goes pre fader / mutes, then the track travels on its merry way to the reverb, and the reverb output ends up in the master bus. And because in my mind the drum have been muted, I've more than once thought, "how did the stupid drums get on my guitar track?" Actually the language is a bit more colorful, but you get the idea. Of course, if I mute the reverb, or disable the send on the drums, the ghost magically disappears. Ghosts are like that.

    Very good point. This would be one way to make this happen in the digital world.

  • Very good point. This would be one way to make this happen in the digital world.

    If it's at all possible for someone to get wrapped around the axle with a computer, I've figured out how to do it. Pretty embarrassing given that I pay the bills as a programmer. But then, maybe that's the reason for it.

  • I'm pretty sure there were no send/routing oversights on my part, though I will triple check next time around.

    the pickup in the bass may be a bit microphonic and it picked those things up when you were tracking either live or from your monitors

    This sounds to me more like it. However I usually track with headphones. I don't recall how I did it this time around. I will carefully, obsessively check that no noise leaks in next time after tracking the bass. Hopefully I will get to the source of the issue.

    Thanks a bunch.

  • I'm pretty sure there were no send/routing oversights on my part, though I will triple check next time around.

    This sounds to me more like it. However I usually track with headphones. I don't recall how I did it this time around. I will carefully, obsessively check that no noise leaks in next time after tracking the bass. Hopefully I will get to the source of the issue.

    Thanks a bunch.

    You know, come to think of it, I've had that experience with my Strat when I was tracking with the studio monitors at a decent volume. After all, they're just little microphones, so I guess I shouldn't have been surprised.


    As for headphones, I've often had the vocal mic pick up headphone leakage when singing. I don't know how loud you have your headphones when you track, or how sensitive your pickups are, but it's probably within the realm of the possible.

  • Just thinking out loud here, but do you happen to hunch over the bass when you play? If the headphones are pretty loud, and they get very close to the pickups, you can actually get leakage via magnetic induction. Test this out - load up a click track or some drums, something obvious. Play that through headphones, then hold the headphones directly over the bass pickups, almost touching. Record the bass, moving the headphones slowly farther and closer from the pickup...you should hear the level of the leakage change dramatically.


    Might be a possible source of the problem!

  • Well they couldn’t pick up the sound from headphones surely? You must have open backs incredibly loud:)

    I have closed backs and open backs.

    Although unlikely, it could've happened that I used the open backs when I recorded the bass months ago. I don't recall.

    But the "incredibly loud" part doesn't quite fit into the story. I tend to treat my ears with care.

    Very strange.

    Thanks for your input.

  • If the headphones are pretty loud, and they get very close to the pickups, you can actually get leakage via magnetic induction. Test this out

    I'm definitely going to test this out and report here on my findings. I wouldn't say my headphones are ever "pretty loud", but it's still a great idea you came up with.

    You guys are great. :thumbup: