Topic: RME / Ableton massive droputs on OSX 10.7
Hello!
I have a big problem with audio dropouts in my current liveset. But first, here´s my setup:
-Macbook Pro 15" (early 2011), 2,2GHz, i7, 4GB 1333MHz DDR3
-OS 10.7.3
-Ableton 8.2.6 / 8.3.4 (same problems)
-RME Fireface 800 v2.77, driver v3.10
-Behringer ADA8000 Ultragain Pro 8 Digital, connected (and synced) via Adat to get more Outs out of the RME
Before the RME I had an old Motu and never experienced problems like this, but I never did livesets like this before. Before I had mostly just a few playback channels and a lot if Input and live processing. Now I have about 100 Audio channels plus Midi, one Midi track that "listens" all the time and gives the midi from the keyboard via oldschool Midi (no USB) to the Virus Ti. Never more than 6 channels + 1 Midi play at once. I use the session view and start master scenes for each song including tempo changes….. I use 24bit wav files for playbacks.
First I had the buffer size of ableton set to 512 like I always had but I experienced heavy dropouts in the whole audio. So I used the test tone and cpu simulation to 80% and found that in most cases brizzel dropouts appear. When I set the buffer to around 200-220 it´s ok, when I use less it bruzzels and stops again when I go really really small buffer size. So I thought 220 would be ok. - Dropouts! Sometimes every few seconds, then randomly some per hour, very randomly.
First I used to sync the Behringer with wordclock. I pulled the cable off and set the sync to "adat". - Dropouts!
Then I switched the whole Behringer off. - Dropouts!
Then I updated my Live to 8.3.4 - Dropouts! So I went on, trying to reproduce the mistakes to get closer to the core of it….
Then I generated low sine tones of 60 minutes and played them from 1. A fresh ableton set, then iTunes and recorded the Outs of the RME with another computer. - No failures. (I didn´t check all the 1h long waveforms visually but I checked with Wavelabs 3d analysis and there´s only the one frequency of the sine wave to see over the whole time)
Then I played 6 channels from a fresh Ableton set plus Midi, and the same from inside my current liveset. No failures. (Checked with Wavelab analysis again)
Then I thought, when a dropout of the whole audio driver, caused for example by a problem between RME driver and the OS-X, there should be a hard cut of the waveforms which should be hearable in a high (and low) frequent click, and also should appear visually in the Wavelab 3d-freq-analysis. So I routed all outs in my liveset via Abletons sends to the main out and put a high-cut on it and played back songs of the liveset. I recorded that signal with the second computer. - Dropouts appear… and: they do not contain any high frequencies. They sound as low as the filtered music. So I think, I now found out that the problem appears inside Ableton and not after the audio has passed Abletons output.
Questions:
1. Do you think I am right?
2. Does anyone have the same problems or have any ideas where it could come from?
My next ideas are:
-to change all playback files from 24bit into 16bit (but I checked the cpu (it´s at max 7-8%) and I checked the hard disk activity by OSXs Acivity monitor (it´s just reading from time to time and doesnt seem to be stressed))
-to setup the whole liveset in Cubase and see what happens
-or to setup the whole liveset again in a fresh set
I hope, someone has an idea or we can exchange some information.
Manu