Page 1 of 5 1 2 3 ... LastLast
Results 1 to 10 of 47

Thread: How do i get rid of electrical hum in my recording set-up?

  1. #1
    Join Date
    Nov 2018
    Posts
    6
    Thanks
    0
    Thanked 0 Times in 0 Posts
    Rep Power
    0

    Question How do i get rid of electrical hum in my recording set-up?

    Sign in to disable this ad
    So i put together a little home recording set up with the following gear:

    15' Macbook pro (2016)
    M-audio profire 2626 audio interface
    Yamaha HS8 studio monitors

    Everything is working as it should but i just can't seem to get rid of this electrical hum thats on my speakers at all times. First i tried simply using balanced cables for the connection from my interface to the speakers and it didn't do anything, then i bought a ground loop isolator (ART DTI) and that lowered the intensity of the hum quite a bit but it's still there, very quiet but still noticeable.

    The ART DTI ground loop isolater has this pin for connecting a ground wire to it but i am wondering how that works exactly? Do you just take any old metal wire, and then what do you connect it to?

    To be clear the ground loop isolater is located in between the output of the interface and the input of the monitors. I also need to point out that when connecting the power adapter of the macbook the hum gets a lot more quit but even with the adapter plugged in the hum is still there.

    So if any of you have any knowledge of electricity and sound and can help me out with this i would greatly appreciate it!

    (attached image shows the ART DTI ground loop isolator, on the far left of the device is a piece of metal which i believe is used for attaching a grounding cable)is505495-01-02-big-jpg
    Last edited by Sikes; 11-26-2018 at 13:38.

  2. #2
    Join Date
    Apr 2005
    Location
    Lowell Street Studio, New England
    Posts
    12,100
    Thanks
    19
    Thanked 559 Times in 532 Posts
    Rep Power
    18632360
    When you run the laptop on battery is there still a hum? Does the hum get louder when you turn up the volume on the monitors? The hum is not recorded, correct?
    Mike B My new album on CD Baby: Fact and Fiction
    My Bandcamp site: http://mikebirchmusic.bandcamp.com

  3. #3
    Join Date
    Sep 2013
    Location
    Tampa, Fl.
    Posts
    1,224
    Thanks
    309
    Thanked 170 Times in 162 Posts
    Rep Power
    733383
    I'm sure you'll get more specific suggestions, but here's one along the lines of the path you've already set upon :

    (This is not a ground lift)

    Ebtech Hum X Ground Loop Hum Exterminator | Sweetwater
    Failure - - the path of least persistence
    And, uh, oh - hire a decorator to come in here quick, 'cause... DAMN.

  4. #4
    Join Date
    Aug 2017
    Location
    Texas USA
    Posts
    1,994
    Thanks
    165
    Thanked 371 Times in 338 Posts
    Rep Power
    2178943
    Are you saying the hum is louder when the MacBook is running on battery and quieter when it is running on AC? That is odd.

    How about when the computer is disconnected from the interface? (Always connect/disconnect the Firewire device with the MacBook powered down!)

    If the hum reduces when the MacBook is plugged in, I'm suspecting a problem with that interface (or possibly its power supply?), honestly, which is why I'd like to get the computer out of the picture. Did you buy it used? Is it the correct power supply for it? Any way for you to test another interface?
    "... I know in the mornin' that it's gonna be good
    when I stick out my elbows and they don't bump wood." - Bill Kirchen

  5. #5
    Join Date
    Aug 2017
    Location
    Texas USA
    Posts
    1,994
    Thanks
    165
    Thanked 371 Times in 338 Posts
    Rep Power
    2178943
    Quote Originally Posted by spantini View Post
    I'm sure you'll get more specific suggestions, but here's one along the lines of the path you've already set upon :

    (This is not a ground lift)

    Ebtech Hum X Ground Loop Hum Exterminator | Sweetwater
    The speakers are the only ones with a 3-prong plug, if I understand this setup. Seems like they'd hum just all by themselves if they were at fault, and probably not both.

    I'd invest in one of those cheap AC outlet testers too.

    (I've used a FireWire interface with a MacBook and powered monitors for years and never had any hum issues. Different interface manufacturer, but still...)
    "... I know in the mornin' that it's gonna be good
    when I stick out my elbows and they don't bump wood." - Bill Kirchen

  6. #6
    Join Date
    Jan 2013
    Location
    Niagara Region Canada
    Age
    53
    Posts
    143
    Thanks
    0
    Thanked 11 Times in 11 Posts
    Rep Power
    37538

  7. #7
    Join Date
    Oct 2012
    Location
    Hampshire, UK
    Posts
    147
    Thanks
    1
    Thanked 16 Times in 16 Posts
    Rep Power
    7
    Have you checked that your balanced cables are wired correctly? This sounds like a ground issue but properly balanced connections shouldn't have these issues which is why I'm suspicious of the cables.
    JRP Music - Audio Mastering and Restoration
    http://www.jrpmusic.co.uk

  8. #8
    Join Date
    Jan 2006
    Location
    Fremantle, Australia
    Age
    62
    Posts
    5,885
    Thanks
    0
    Thanked 211 Times in 193 Posts
    Rep Power
    11804435
    Is the power point properly earthed, or has it got a bad resistive earth?

    Have you tried lifting (unsoldering) the shield on the balanced cables to the monitors, lift at the monitor end of the cable.

    Alan.

  9. #9
    Join Date
    Nov 2018
    Posts
    6
    Thanks
    0
    Thanked 0 Times in 0 Posts
    Rep Power
    0
    Thanks for all the reply's guys! Finally i found a forum where people actually reply to question, i love this place already

    To clarify: The hum gets a lot more quiet when the power adapter is plugged in compared to when it's running on the battery.

    Also, the hum does indeed get louder as i turn up the volume of the speakers so all of the issues are indeed pointing to the audio interface. I have also tried a different interface (focusrite saffire 6), this interface gives less hum on it's own but as soon as i plug in for instance a synth or an instrument thats connected to a power outlet the hum gets really bad. So maybe there is just an issue with the electrical circuit where i live? I live in Europe (Belgium), and all sockets have three pins here so i didn't think that would be the issue.

    I will check the balanced cables to see if the ground wire is connected if so i will disconnect it on one side (that should help right?)

    In the meantime i will also start reading some of the pdf's posted here, i need to brush up on my knowledge of electricity anyway.

    Edit: Disconnecting the lift pin (at the end of the connector which connects to the monitor) on the balanced cables didn't work
    Last edited by Sikes; 11-27-2018 at 01:50.

  10. #10
    Join Date
    Feb 2009
    Location
    northampton uk home of Dr Who and Blackstar Amps!
    Posts
    9,799
    Thanks
    1
    Thanked 654 Times in 618 Posts
    Rep Power
    9266934
    'Ow do Sikes. First of all I DO NOT LIKE those Ebtech hum "eliminators"! They fook about with the earth path and that might be acceptable in 110V land (but I wouldn't) but not with "proper" 230V nominal. The "Earth" safety system was designed by people who KNEW WTF they were at, never mess with it.

    Rant over. The Hum: Can be a trial tracking this down. Your first attempts do indicate a hum (aka ground/earth) loop but you might have a residual hum from a completely different source.

    First stop, the monitors. Diss all audio cables and fire them up, set volume pots to min' and with ear close to speaker is there a hum? There will be a bit of hiss but I would expect NO hum. Now advance the VCs and IMO there still should be no hum but there might be a tiny bit at the top end of the pot. N.B. It is very possible for active speakers to produce a mechanical hum, i.e. not from the cone, from the power transformer.

    If the speakers seem blameless rig the system with the Art isolator box in line. Play out a track at a decent level* and then stop it and check the hum. If audible at the mixing position you have a problem. Now unplug the computer from the AI (FireWire?). Still hum? That would actually be good news because it eliminates a FWire hum loop. Rare but vitually incurable if it happens.

    You could post a "silent" recording? Turn all the pots to zero on the interface then make a 30 second recording of "nothing" (44.1kHz and 24 bits) For me it is best attached as a 320k MP3 clip. I can then look at it and possibly help with other suggestions.

    Dave.

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. Replies: 6
    Last Post: 12-13-2016, 17:37
  2. Electrical interference when recording
    By Fishybob in forum Digital Recording & Computers
    Replies: 20
    Last Post: 03-08-2007, 10:44
  3. Electrical Hum
    By Cheeky Monkey in forum Studio Building & Acoustic Treatment
    Replies: 6
    Last Post: 11-13-2005, 02:48
  4. electrical noise killing my recording!
    By doughulin in forum Fostex Forum
    Replies: 4
    Last Post: 08-15-2004, 15:50
  5. ...electrical ?s...
    By fonts in forum Studio Building & Acoustic Treatment
    Replies: 8
    Last Post: 02-07-2004, 08:53

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •