KVR Audio

BERFAB · Post by **BERFAB** » Mon Sep 24, 2007 1:00 am

OK, here's the deal:

After I finally returned the troublesome EMU-PM5 monitors, I picked up a pair of KRK RP6's. More power than I'll ever need, but to my ear, these things sound very clear. I'm picking up a lot of stuff in my mixes that I didn't know was there, which is a good thing.

The setup I use has a US-122 interface which only has a headphone jack and RCA line outs. So, I'm running the line out RCA's to the RCA inputs on the KRK RP6's (which also have XLR and Balanced inputs).

The problem is that when there's no music output, I can hear a faint high pitched whine coming from the monitors, and I'm wondering if the RCA's are causing this. (Unplugging the RCA ins eliminates the sound completely.) In other words, if I switch to an interface that has Balanced 1/4" TRS outs and ran them to the Balanced 1/4" TRS ins on the monitors, would that make a difference?

Or, is there anything I can do with my current set up that would help (run the RCA outs to the balanced TRS ins? run the headphone out to the TRS ins?, etc.).

Thanks
-B

thecontrolcentre · Post by **thecontrolcentre** » Mon Sep 24, 2007 1:14 am

I used to run the RCA outs of my US-122 into the 2-track input on my mixer, with my monitors hooked up to the control room output. I never had any noise problems with it ... are you using shielded/screened cables in your setup?

BERFAB · Post by **BERFAB** » Mon Sep 24, 2007 1:23 am

thecontrolcentre wrote:I used to run the RCA outs of my US-122 into the 2-track input on my mixer, with my monitors hooked up to the control room output. I never had any noise problems with it ... are you using shielded/screened cables in your setup?

I assume that my RCA cables are NOT shielded or screened. I assume this is a special feature you have to look for.

My old E-MU PM5's took the RCA's directly without a problem, but they weren't as powerful as the new KRK's.

-B

thecontrolcentre · Post by **thecontrolcentre** » Mon Sep 24, 2007 1:33 am

BERFAB wrote:I can hear a faint high pitched whine coming from the monitors

... another possibility is a ground loop. Are you using a laptop?
If so, try unplugging its power supply and see if the whine goes away.

BERFAB · Post by **BERFAB** » Mon Sep 24, 2007 1:39 am

Not a laptop.

BERFAB · Post by **BERFAB** » Mon Sep 24, 2007 3:03 am

OK, I just noticed that when my whole rig is turned on, (Monitors, Computer monitor, Computer, soundcard, etc.)the KRK's are quiet. But once I fire up Cubase 4, I get the high pitch sound. Is there something in the C4 engine that might be causing this? Something that I can (hopefully) turn off without too much effort?

-B

SledgeFist · Post by **SledgeFist** » Mon Sep 24, 2007 3:25 am

Have you tried tweaking the audio output samplerate/bitrate? I don't know if that will do anything... it probably won't. Is your Cubase running an Audio In and you're hearing mic noise?

C00kie · Post by **C00kie** » Mon Sep 24, 2007 6:21 am

What you're hearing is interference of RF emitted by components in your PC which is picked up by the soundcard. You'll get the same when using the TRS or XLR inputs on the monitors.

Does the KRK RP6 have a volume knob, at the back? Just turn that down and turn up the volume of your DAW. That will make it less noticable...

hibidy · Post by **hibidy** » Mon Sep 24, 2007 6:45 am

I am puzzled by the "turn on cubase" and then the problem starts thingy.

This seems to me there is something in the setup?

Do plugs in standalone do it? Is there another host you can run (even in demo like live 6)? That way you can start isolating the issue one variable at a time

hibidy · Post by **hibidy** » Mon Sep 24, 2007 6:46 am

C00kie wrote:What you're hearing is interference of RF emitted by components in your PC which is picked up by the soundcard. You'll get the same when using the TRS or XLR inputs on the monitors.

Does the KRK RP6 have a volume knob, at the back? Just turn that down and turn up the volume of your DAW. That will make it less noticable...

I forgot to add in the last post this can be a good solution. I have some bx5's I use as secondary monitors and if they are turned up all the way.......they WANK! Much better at half volume.

bluelife · Post by **bluelife** » Mon Sep 24, 2007 8:35 am

I changed from unbalanced to balanced cables which solved the problem for me. I think it would solve it here too, but you need the balanced output. Maybe worth buying a small mixer or different audio interface, blue

BERFAB · Post by **BERFAB** » Mon Sep 24, 2007 2:23 pm

Thanks all. I think C00kie and Hibidy may be closest to the mark, and I will try all ideas this evening when I'm back in the studio.

It also occurred to me as I was falling asleep last night that I didn't test it with standalone instruments. But I think the suggestions regarding adjustment of monitor and DAW volume are well taken. Currently, I've brought the DAW volume WAY down because of the power of the monitors.

As an aside, I have never been clear on the difference between balanced and unbalanced. Could someone enlighten me?

Thanks again.
Cheers
-B

bluelife · Post by **bluelife** » Mon Sep 24, 2007 3:24 pm

Well, a balanced connection involves three cable strands, an earth cable and two signal cables which are phased reversed, thus cancelling any noise picked up on the way. You could just borrow a mixer and two XLR cables (they are balnced) and try it. I almost can promise you that it will.

blue

Marc JX8P · Post by **Marc JX8P** » Mon Sep 24, 2007 3:28 pm

Does it still occur when you mute the recording channels in Cubase, or the master channel, or if you switch to a different ASIO setting?

BERFAB · Post by **BERFAB** » Mon Sep 24, 2007 4:10 pm

Marc JX8P wrote:Does it still occur when you mute the recording channels in Cubase, or the master channel, or if you switch to a different ASIO setting?

Doesn't matter. The noise begins as soon as C4 starts up, even without a project in the window.

I also tried some different ASIO settings.

Thanks though.

-B

Powered Monitors with Balanced vs. Unbalanced input