• From: Bangalore
  • Registered: 2012-08-13
  • Posts: 13

Topic: Noise on Mic input and Speaker out - Use DI?

Hi, I just got a Babyface, and I have issues with noise on my left speaker and mic input. From what I read on these forums (yes, I searched), it seems I have ground problems. Apparently, a DI will help. I would appreciate some input since I have never worked with DIs before.

- Will I be able to use the same DI unit for one speaker and the mic? I'm looking at the Behringer UltraDI 120, a two channel active DI. I don't have too many options; I'm in Bangalore, India, and there aren't too many shops here for studio gear. The other option is a 12-channel active DI from an Australian(?) company called 'Besteco', apparently. No presence on the web, and it's way cheaper than the Behringer, so I assume the B' will have better quality.

- Will an active DI unit interfere with phantom power supply to my mic? I.e., do I have to provide phantom power from a seperate preamp to DI in the input chain, in addition to phantom power from the Babyface to the DI? Or will the DI unit 'pass-along' the phantom power to the mic?

- One channel on my output is working fine (the right speaker has no noise). Is it okay if I use one speaker via DI, and the other directly to Babyface? Temporarily, of course. Ideally, I'd like all my outputs to be calibrated equally, so everything through the same signal chain, but I have a recording in a couple of days that I'd love to use the Babyface for.

  • isaac
  • isaac
  • S/Mux specialist
  • Offline
  • From: Auckland New Zealand
  • Registered: 2007-05-01
  • Posts: 339

Re: Noise on Mic input and Speaker out - Use DI?

mudeth wrote:

Hi, I just got a Babyface, and I have issues with noise on my left speaker and mic input. From what I read on these forums (yes, I searched), it seems I have ground problems. Apparently, a DI will help. I would appreciate some input since I have never worked with DIs before.

- Will I be able to use the same DI unit for one speaker and the mic? I'm looking at the Behringer UltraDI 120, a two channel active DI. I don't have too many options; I'm in Bangalore, India, and there aren't too many shops here for studio gear. The other option is a 12-channel active DI from an Australian(?) company called 'Besteco', apparently. No presence on the web, and it's way cheaper than the Behringer, so I assume the B' will have better quality.

- Will an active DI unit interfere with phantom power supply to my mic? I.e., do I have to provide phantom power from a seperate preamp to DI in the input chain, in addition to phantom power from the Babyface to the DI? Or will the DI unit 'pass-along' the phantom power to the mic?

- One channel on my output is working fine (the right speaker has no noise). Is it okay if I use one speaker via DI, and the other directly to Babyface? Temporarily, of course. Ideally, I'd like all my outputs to be calibrated equally, so everything through the same signal chain, but I have a recording in a couple of days that I'd love to use the Babyface for.

I think you are confused as to what your issue is here. I'm assuming you have the mic input you are getting the noise on panned to the left?  So therefore if you have noise on the mic pre, which is panned to the left, you will only have noise on your left speaker.

I would also try properly trouble shooting your gear. What happens if there is nothing plugged into the input of your babyface?

How about if you swap the output cables to your speakers?


Try some of this and let us know.

Isaac P

  • isaac
  • isaac
  • S/Mux specialist
  • Offline
  • From: Auckland New Zealand
  • Registered: 2007-05-01
  • Posts: 339

Re: Noise on Mic input and Speaker out - Use DI?

Also what are your speakers? And how do you have them connected etc?

Isaac P

4 Reply by mudeth (edited by mudeth 2012-08-13 09:45:49)

  • From: Bangalore
  • Registered: 2012-08-13
  • Posts: 13

Re: Noise on Mic input and Speaker out - Use DI?

Replying on phone, sorry I can't quote inline


Thanks for your reply, Isaac. I have spent a couple hours trying to troubleshoot this, so..

My speakers are KRK rokit 5s. My previous interface was a novation xio, which didn't give me any noise.

When I mute my mic input, noise still comes on the left speaker only. Even when I swap cables, noise continues on the same speaker. I have swapped power cables also, doesn't make a  difference.

Noise remains when the mic is unplugged from cable, but goes away when cable is unplugged from the babyface (not sure about this, can confirm when I head back to my studio). Noise wad there in 2 different mics, a sennheiser mk 4 (condenser with phantom power on) and a rode m1 (dynamic, phantom off).

I'm sure the speaker noise is independent from the mic noise, I have muted it and checked, like I said. FWIW, both my speakers are connected to the same power point on the wall through a spike buster, but I read on these forums that there can still be ground loop noise in such cases.

Edit: speakers are connected through xlr-xlr cables. I have tried swapping out cables and have tried xlr->trs to no avail.

  • From: Bangalore
  • Registered: 2012-08-13
  • Posts: 13

Re: Noise on Mic input and Speaker out - Use DI?

A sample recording I had made yesterday: http://www.mudeth.org/Babyface%20noise.mp3

6 Reply by mudeth (edited by mudeth 2012-08-13 11:13:41)

  • From: Bangalore
  • Registered: 2012-08-13
  • Posts: 13

Re: Noise on Mic input and Speaker out - Use DI?

Isaac, the problem seems to be with my speaker cable. I tried swapping the cable on the speaker end, and now the noise has shifted to the other channel. I suspect that the cable is effectively running unbalanced. Weird thing is that two different XLR-XLR cables of the same brand (G&BL, paid quite a bit for them) give me noise, and a locally made XLR-XLR cable is working fine. So I doubt that it's just a faulty cable. Any insights? I would like to get to the bottom of this.

  • From: Bangalore
  • Registered: 2012-08-13
  • Posts: 13

Re: Noise on Mic input and Speaker out - Use DI?

Update: I bought some no-name XLR cables to replace the G&BLs and everything sounds great. There have been a couple of times when the unit lost connection with the system (no audio out on meters and outputs, lagging/slow input meter), but I'll try to sort it out on my own first and start a new thread if it persists.

Thanks, Isaac.

  • isaac
  • isaac
  • S/Mux specialist
  • Offline
  • From: Auckland New Zealand
  • Registered: 2007-05-01
  • Posts: 339

Re: Noise on Mic input and Speaker out - Use DI?

mudeth wrote:

Isaac, the problem seems to be with my speaker cable. I tried swapping the cable on the speaker end, and now the noise has shifted to the other channel. I suspect that the cable is effectively running unbalanced. Weird thing is that two different XLR-XLR cables of the same brand (G&BL, paid quite a bit for them) give me noise, and a locally made XLR-XLR cable is working fine. So I doubt that it's just a faulty cable. Any insights? I would like to get to the bottom of this.

I'm glad you got it sorted. I would guess the G&BL cables have a link to the shield, or are just made incorrectly!

I had a great one a couple of years ago where we had all new mic leads made, the 5 and 20 metres were fine but the 20 metres hummed and buzzed. Metered them all, no issues. Getting confused at this point. Opened them up and pins one and two had been transposed on all of the cables!! Some soldering later no noise and a good story!!!

I guess the point is that you should take nothing for granted, check everything!


Isaac P