Background hiss/hum with Apple Logic Pro X

Discussion in 'Recording Studio' started by Dadou, Jun 3, 2015.

  1. Dadou

    Dadou Well-Known Member

    Joined:
    Jan 8, 2013
    Messages:
    594
    Likes Received:
    351
    Location:
    Paris, France
    Hi all, this morning I tried to record some sounds with my dad's iMac and the Logic Pro X software.
    My signal chain was as follows:
    Stratocaster-> cheap audio interface -> iMac.

    It was very hard to tame the background him which only occurs when I'm playing; in fact, the guitar is dead silent if the strings are not vibrating. It's not like a ground problem or whatever, it literally is only when the strings are oscillating. I am still trying to learn how to use the software so I did find a noise gate feature, but it seemed useless.

    I noticed that "creating" a new amp and removing the cab reduces the noise, as if Logic was emulating a real amp hissing a little bit at high volumes.
    But this hiss does bother me quite a bit.

    At least with Audacity on my PC I could get rid of the background noise (sacrificing lots of frequencies but still), I can believe a 200€ program doesn't let me edit that. What could the problem be?
     
  2. Rain

    Rain Well-Known Member

    Joined:
    Dec 3, 2013
    Messages:
    350
    Likes Received:
    470
    Location:
    Las Vegas, NV
    Stratocasters are typically equipped with single coils, which can be a pain when using any sort of gain. They tend to be very noisy, as opposed to humbuckers which are quieter.

    Also, what's relatively tolerable when playing can be unacceptable in the context of a recording, and sometimes we don't realize just how noisy real amps can be until we record them. So when you couple that with single coil, you are bound to face some issues.

    Logic's Amp Designer - and other software amp sims - behave similarly to regular amps, as you've figured. I haven't worked w/ Amp Designer all that much, and not in a quite a while, but I know that some amp sims have basic Noise Gating - meaning that you won't hear any hissing until you start playing and cross the noise gate's threshold.

    There are varieties of possible options and partial solutions - stuff that you could try using Logic's own plug-ins, but Logic itself isn't primarily intended as a tool for deep audio editing and intense forensics. There are 3rd party solutions as well.


    Companies like Izotope sell specialized applications that cost a fortune to fix all kind of noise problems, such as
    https://www.izotope.com/en/products/audio-repair/rx/

    Because restoring audio w/o generating artefacts and losing definition is a challenge.

    But in the end, unless you invest in some kind of fancy noise cancelling pick ups or something, single coils + gain will induce noise.
     
  3. Dadou

    Dadou Well-Known Member

    Joined:
    Jan 8, 2013
    Messages:
    594
    Likes Received:
    351
    Location:
    Paris, France
    Thank you for your reply;

    I am aware that single coils are likely to produce hum, especially when put in front of such devices as a computer screen.
    However, I noticed the same phenomenon with my humbucker-equipped Gibson SG.

    I need to get more into the noise gating features of Logic, but all in all I agree with what you said about the program.
     
  4. dcwave

    dcwave Well-Known Member

    Joined:
    Feb 21, 2014
    Messages:
    318
    Likes Received:
    372
    You're going direct into a cheap POS interface. Which POS interface? There is more than likely all kinds of RF interference with the interface itself. Does this cheap interface actually have a properly loaded instrument input? Or are you just going into a line in?
     
  5. Dadou

    Dadou Well-Known Member

    Joined:
    Jan 8, 2013
    Messages:
    594
    Likes Received:
    351
    Location:
    Paris, France
    The interface is a Behringer UCA 222
     
  6. Crazy_8

    Crazy_8 Well-Known Member

    Joined:
    Nov 6, 2014
    Messages:
    791
    Likes Received:
    583
    Location:
    Chicago
    Yeah, the entire problem is the interface. Those are line level inputs so there is both an impedance and gain mismatch. You'll need an appropriate instrument preamp to make it do the job you intend it for. Do you happen to have an guitar amp with a effects loop or line out? That would work a champ.

    Good luck !
     
    Dadou likes this.
  7. Dadou

    Dadou Well-Known Member

    Joined:
    Jan 8, 2013
    Messages:
    594
    Likes Received:
    351
    Location:
    Paris, France
    Yes. I have a tube Blackstar that's got both the fx loop and an emulate output (which is what I assume you intended with "line out ")

    Will it work if I plug the amp straight into the mac? I mean I bought the cheap interface because my pc couldn't handle the signal directly from the amp.
     
  8. Crazy_8

    Crazy_8 Well-Known Member

    Joined:
    Nov 6, 2014
    Messages:
    791
    Likes Received:
    583
    Location:
    Chicago
    No, amp line out to interface into Mac

    The amp line out will match the impedance and voltage, and the interface will convert the analog to digital. Unless your Mac has both line in and mic in.... if it does use the line in without the interface.
     
    Rain and Dadou like this.

Share This Page