Mic's input signal sounds doubled

[MikeDee]

Hi Bob -

SAC 2.2 on a Fujitsu LifeBook N6420, ADA8000, Layla24 PCMCIA (direct monitoring off) analog out 1 & 2 to Presonus HP4 headphone amp + V6s.

Audio setup (3 × 128):

ADA8000 1-8 I/O => ADAT (digital) 1-8 [Stereo Outputs 1-4]
Layla24 1-8 I/O => Analog 1-8 [Stereo Outputs 5-8]

My mic's signal (through either of the ADA8000's eight channels, mono [L or R only]) sounds doubled. No effects, no monitors...just FOH routed to Output 5. I don't see how the audio might be looping back and doubling itself.

I ran a keyboard's audio into one of the Layla's analog channels...no doubling there. (No, I didn't try running it into one of the ADA's channels. In hindsight, I guess I should have...I'll try that next chance I get.)

I figure it's user error...but I can't seem to find the root cause. I even checked the manual...no hidden gotchas revealed.

I don't have much more to offer here because the setup is very simple.

Your thoughts?

[Larry Burger]

Can you set your interface to 2 x 64 and see if that helps.
Also try headphones on your keyboard so if there is a small delay you can reference the original output.

[RBIngraham]

Running SAC at 3 x 128 is a pretty substantial amount of latency. I don't think that's going to work for listening on headphones. To use headphones you're likely going to need to get down to at least 2x64 for it not to unworkable for the artists.

Not sure if that is what is causing your issues, but I suspect that is what you are reacting to. The live mic sounds doubled because you hear the natural voice and the PA, but the keyboard doesn't because it doesn't make any sound of it's own. If the keyboard was hooked up to it's own instrument amplifier you would probably get the doubling effect on it as well. Just guessing....

[Larry Burger]

Richard,

The reason to use headphones on the synth was without reference from the direct sound to SAC sound would only be to touch not sound.

If you plugged phones into the synth then reference the output from the computer it may assist in trackng down the problem.

[RBIngraham]

Richard,

The reason to use headphones on the synth was without reference from the direct sound to SAC sound would only be to touch not sound.

If you plugged phones into the synth then reference the output from the computer it may assist in trackng down the problem.

Larry, we are saying the same things. :)


When I mentioned headphones I was talking about the fact that Mike mentioned he is using a Presonus Headphone amp with cans, I assumed for monitoring purposes, but maybe my assumption was wrong.

Anyway, we are saying the same thing or suspecting the same thing, which is that the reason the voice sounds doubled is because he is hearing the natural voice of the person as well as the PA or the sound in his headphones or whatever, and the latency is likely too large to make it work very well. While the keyboard you might not notice the latency if there is no amp or other noise emitting device of some kind hooked directly to the keyboard itself. Although most keyboard players I know would notice that amount of latency and would give me the "WTF? Look" :D

[MikeDee]

Thanks for replying, Larry and Richard! :)

I was thinking latency initially...but when I played the keyboard, I heard it pretty much instantaneously...I felt no lag. Then again, I did not try playing it through the ADA; it was connected directly to the Layla...so I need to retry.

Light bulb just turned on...I'll record what I'm hearing in SAC into SAWStudio via the link. If the playback of the vocal track sounds doubled, then I'll know I have some sort of loopback issue going on...if not, then I'll simply chalk it up to latency in SAC.

Funny, I never heard this when recording directly in SAWStudio at 3 ***215; 128...not even vocals at 3 ***215; 512!

Best regards,

[Bob L]

To hear if you have doubling... mute the output of SAC and see if you still hear some audio... there could be some monitor signal being passed directly thru the driver... you will need to find that and shut it off.

Bob L