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Deciding what way to troubleshoot background hiss or grounding problem...

Discussion in 'Recording' started by patriiick02, Feb 12, 2013.

  1. patriiick02

    patriiick02 Active Member

    So, I have been working over the past couple of years intermittently trying to record both my guitar, and lately my voice, using my laptop and audio interfaces. I have always run into the same problem: background hiss and white noise. I have done this using Windows (XP, Vista, and now Windows 7 64-bit), as well as Cakewalk Music Creator and Reaper.

    I also have used two different audio interfaces. I just bought a Furman power conditioner and a Saffire 6 to try and mitigate the problems, and while they are not as bad, they are still there.

    First of all, I found I CANNOT record if my laptop is plugged in because of “blip/beep” noises it creates. So I run on battery. I also disable my Wifi card, turn off fluorescent lights, and turn my cell phone to airplane mode – I don’t know if maybe my speakers or internal audio card need to be disabled somehow also.

    Tonight I was using the Saffire as the only input and output, and that connects through the USB to my recently purchased Lenovo IdeaPad (laptop).

    So I've found a number of PARTIAL solutions so far, but not completely gotten rid of the issue. I'm running Windows 7 64-bit, running an Audix vocal mic with XLR on both ends into line 2 of the Saffire input. Reaper seems to be set up correctly to ASIO and recognizes the Saffire drivers. So with all that said, is there anything I’m missing?

    Do I need to create another ground and balance the signal like people on here who are having monitor issues, or do I need to look elsewhere?

    Thank you guys! I appreciate it.

    P.S. I am using a Monster Cable Standard 100 model XLR 25' cable - maybe I need a heavier duty (or shorter) one?
     
  2. hueseph

    hueseph Well-Known Member

    Hiss is more likely from improper gain staging. Don't crank your input level. Turn up your headphones. You don't need a whole lot of gain going in. You can always raise the volume after the fact.

    That being said, this is all just speculation. Can you post a sample of the hiss?
     
  3. DonnyThompson

    DonnyThompson Distinguished Member

    By and large, "hiss" or white noise is, as hueseph mentioned, more likely a gain issue. That's not to say that it would be entirely your fault as far as the staging... yes, it could be, but it could also be that you may have a bad/noisy preamp.

    Is this a new issue? Has it always been like this since you used the Sapphire, or did this just start happening?

    Check your gain staging. Make sure you don't have one output cranked while a corresponding input is too low... or vice versa.

    You mentioned using input #2 on the sapphire. Is this hiss evident on both inputs?

    As far as grounding issues, these generally present themselves more frequently as more "hum" or "buzz" than they do "hiss". If you are getting "hum" or "buzz", try to isolate the problem by changing power outlets, or removing each device (or cable) used from the path one at a time. Try another mic, if you have one. Switch cables... It may be something as simple as a bad XLR.

    And...while I don't think this has anything to do with the internal / built-in soundcard in your laptop, it's still a good idea to disable it when using an external USB audio I/O.
     
  4. Boswell

    Boswell Moderator Distinguished Member

    The fizz and bleeps from the computer when on mains power is pretty typical of most laptops and their poorly-designed power supplies these days. You are doing the right thing by switching to battery power during recording. It sounds as though you have everything set up and installed correctly.

    As far as white noise goes, the XLR cable is not going to be the source of the noise problem providing it's correctly wired. It's worth checking that the 10dB pad switch is not engaged for channel 2 on the Saffire 6 front panel.

    What is the "Audix vocal mic" you are using? There's a chance that has a fault that results in low output. Note that types like the OM7 are low-output anyway and may well give noise problems with some audio interfaces. An in-line booster like the Cloudlifter can help in these cases. If your mic is a normal-output condenser type like the VX5, check that you have phantom power enabled on the Saffire.

    Can you borrow a different (dynamic) mic such as a Shure SM58 for a quick test to see if it gives similar results in terms of noise?
     
  5. patriiick02

    patriiick02 Active Member

    Thanks for your help hueseph,
    So far I have been using a gain level of 7 or 8 - anything lower gives me below a -30 db level (which means my headphones are turned up all the way to barely hear it). Normalizing it then drastically worsens the overall quality. I will post a sample later tonight. (I had this problem even worse when I used to use the Lambda - had to crank it to 9.5 to get barely audible levels).

    What begins as background white noise, becomes a buzz if the gain is turned any higher. I will have to also check the Audix model - I am fairly sure it is an OM2 though.
     
  6. patriiick02

    patriiick02 Active Member

    Thank you guys for your thoughts! Much appreciated! I will definitely try out some of these ideas tonight.

    DonnyThompson
    ,
    Yes, this has always been a problem with every audio setup I've made during the past two years (not too much time devoted to it of course).

    I switched from input 1 to 2 because the manual recommended this for vocals - not sure if I could hear a difference though.

    Since I am running off of battery when I record, there are no power outlets connected to my setup. HOWEVER, I am wondering if there could be dirty power coming through the USB (acts as both power supply and data on the Saffire 6).

    Boswell,
    I do have a SM58 so I may try that. As DonnyThompson mentioned, I was also wondering if maybe my cable does not have thick enough insulation as it is the lower end version of Monster Cables offerings.
     
  7. Boswell

    Boswell Moderator Distinguished Member

    The two inputs on the Saffire 6 should have identical performance, with neither of them any more suited to vocals. Although the drawing on P7 of the manual shows a guitar plugged into input 1 and the mic plugged into input 2, I don't think that implies that it's better to use input 2 for microphones.

    The Audix OM2 has a sensitivity that is slightly less than a Shure SM58, but both of these would require about 6dB less gain on the interface than an Audix OM7.

    Your XLR mic cable plays no part in this white noise investigation (unless it's wrongly wired).

    USB noise is a possibility, but that would manifest itself as a pitched buzz or whine that changed when you performed various setup operations on the interface from the computer.
     
  8. patriiick02

    patriiick02 Active Member

    Well, I was going to upload files, but apparently MP3's are not allowed or there is something wrong with mine. Anyway, I recorded some samples (that I will get uploaded eventually) with all other sound devices onboard disabled, everything in the room that does draw power plugged into the Furman, and even went so far as to unplug my mouse and Wifi keyboard.

    Still getting noise - definitely a low buzzing sound, even with my gain at 3.5 on the Saffire input #2. I tried this with both the Shure SM57 (I do not have a 58) and the Audix OM2.

    If it is a buzz as opposed to white noise, does this mean I am looking at a different problem? The audio itself sounds very good, just has a background buzz which makes me wonder if I just don't have enough punch of a signal going in to start with.

    One other thought - could it be a specific setting in Reaper's Device or Buffering tabs (under Preferences in version 4.32)?
     
  9. patriiick02

    patriiick02 Active Member

    P.S. I uploaded the two files here, one with each microphone at gain level 3.5:
    OM2 FileSwap.com : saffire6_test_OM2.mp3 download free
    SM57 FileSwap.com : saffire6_test_SM57.mp3 download free
     
  10. hueseph

    hueseph Well-Known Member

    I have had a similar issue but it only cropped up when I used phantom power. Both of those mics are dynamic so, there's no reason you would have phantom power engaged right? I don't know. I'm just taking stabs in the dark now. It does sound like it may be some sort of grounding issue but since you have tried two separate interfaces, I'm at a loss.
     
  11. hueseph

    hueseph Well-Known Member

    If it's any consolation I was able to successfully minimize the noise with Audition's Restoration effects. Audition which I downloaded free of charge here: Adobe - CS2 Downloads
     
  12. patriiick02

    patriiick02 Active Member

    Yea, no phantom power. I might have to jerry-rig a ground somehow off the interface, or the laptop, or both.

    Oh, didn't see your second post - I will definitely try that!!! Thank you!!
     
  13. patriiick02

    patriiick02 Active Member

    Only other things that I could turn on/off or remove that I could think of are the video card could switch from the NVidia to onboard graphics, I am using the HDMI out to a separate LCD monitor with laptop screen off, and I have an SD card reader...
     
  14. Boswell

    Boswell Moderator Distinguished Member

    I think you have narrowed the problem down by re-classifying the noise as "buzz" rather than white noise. That makes it much more likely to be breakthrough from the USB, either from the cable/connector or be due to ground coupling. It could be worth trying a USB isolator such as this one, as long as there is a way of powering your interface other than via the USB cable.
     
  15. patriiick02

    patriiick02 Active Member

    Boswell: Yea, I am definitely going to investigate whether I can (safely) create a grounding setup on my own, or if I'll need to invest the money in some sort of isolator or ground-loop protector like you mentioned.
     
  16. patriiick02

    patriiick02 Active Member

    SOLVED!!!

    I *finally* figured out where it was coming from. I unplugged my HDMI out to my external monitor. Whenever it is plugged in there is buzzing, when I unplug it, the audio is completely clear! :redface: So maybe there's just not a good ground somewhere on my monitor? Who knows, but that was the offending hardware unit!!!
     

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