Solving the audio noise problem on the Edirol UA-1X

by Volker Weber

Last year I bought a USB audio interface from Edirol. The UA-1X has stereo inputs and outputs and headphones output. You want this kind of interface if you need to add more channels to an iBook, for instance to have two output channels to the amplifiers and two for the headphones. This enables you to queue up songs in a DJ software. You will also get a much better sound quality than going out through the headphones jack.

After I used this device a couple of months, it suddenly started producing a crackling and hissing noise that was very noticeable, especially if you set the sound output to 100% and the iTunes output to something like 10%. I reported the problem to Edirol, and they eventually replaced the device with a new one. Unfortunately it had the same problem. On both my iMac and my iBook.

I tested this with my friend Thomas' PowerBook and he did not have a problem. So I swapped the Edirol with his M-Audio Transit. Eventually I was having problems with the Transit and swapped back to the Edirol. The noise issues I was having seemed to be gone by now. Why? I was not sure. I had since installed a new operating system (Tiger replaced Panther), Quicktime and Core Audio were revved. I did not really care.

Until yesterday. The noise was back.

Today I dug around trying to find a driver for the Edirol. But it does not need one, since it uses the Core Audio driver supplied with the OS. I also found some references on the Roland site, talking about noise issues that had been resolved in OS 10.3.3. But here I was running 10.4.3 and still having problems. Then I found an interesting article explaining how to resolve issues with the M-Audio Transit. The author was advising to take a look at the Audio MIDI Setup in the Utilities folder.

And there I found it.

Look in the lower right hand corner under Audio Output. This should not be 2ch 8-bit. Set it to 2ch 16-bit with 48000 or 44100 Hz. The noise was gone. So simple, once you know where to look.



Karsten W. Rohrbach, 2005-11-27

I have a terrible soundtrack in iMovie with crackling noises (produced by a faulty mic). Tried in vain with everything I know, can anybody here help me with it? Up until now I tried different methods in iMovie as well as spin doctor to no avail: the speeech data gets worse, the crackling stays... Is there a way that springs to mind in this community?


Armin Roth, 2005-11-27

What about a programm like Sound Laundry or Sound Rescue™ to clean a sound file.
They are made for sound restoration. I am not familiar with it but have it installed with one of my audio devices,
i guess it was my TerraTec DMX Fire as this has a phono input...

Hubertus Amann, 2005-11-27

Volker, use 44,1 kHz/16-bit for consumer gear and CD quality - 48 kHz is normaly combined with 24-bit and can cause troubles with wrong sampling rate for your kids CDs. I run the on board audio device as standard with 44,1/16-bit and the other devices only inside my audio tools with 48/24-bit or 96/24-bit. Wrong sampling rates convert the speech to Mickey Mouse...

Hubertus Amann, 2005-11-27

CoreAudio should convert sample rates neutrally to the time base.
Volker triggered a very strange bug there which — IMHO — should be reported to Apple for further investigation.

Karsten W. Rohrbach, 2005-12-01

I had the exact same problem and this fixed it. Thanks so much for posting it - I never would have worked that out!

Bill Trikojus, 2006-05-16

I don't know if you can solve this one for me...

I'm getting some unwanted background noises in Logic Pro 7 when recording audio. There is a noticable hiss on recorded audio and a constant high-speed beeping sound in the background which also shows up on recorded audio. I'm at my wit's end!

My setup is as follows...

Keyboards into Mackie CR1604VLZ
Mackie CR1604VLZ into Edirol UA-1X
Edirol UA-1X into Apple G5 PPC

I also have an Edirol UM-1X which is connecting my Mac to my keyboards via midi.

Any ideas?

Mitch Thompson, 2006-08-07

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