Questions & Answers

Capture recording distorted despite clean monitor on headphone output on SL 16.4.2AI

0 votes
asked Feb 7, 2017 in Capture for StudioLive by drunkenrobot (170 points)
edited Feb 7, 2017 by drunkenrobot
Currently running SL16.4.2AI FW1.0.9194 AVB to RM16AI FW1.0.9244. SLAI is connected to a Windows 7 64bit PC via firewire. Sample rate is set to 48Khz.

Recording from the remote mixer via Capture so far has been fine, up until yesterday. I was recording, monitoring the mix through the headphone jack on the local SLAI. Feed was clean.

Today I open the WAV files from the capture session, and there's distortion, here's a sample:

I rebooted the mixers and the computer and now everything is fine, but I'm concerned that this will come back in a future session and I won't be able to tell because I can't directly monitor the recording in capture, only via the digital return on the mixer, which lied to me last time.

... Notes in response to Wahler's questions...

The chain is Neumann BCM104 > Mill Media HV3D > RM16 > AVB > SL16.4.2AI > Capture via Firewire

Both mixers are set to 48Khz, the recording is 48Khz. All tracks in the session have the same distortion on them.

The perplexing bit is that the audio was clean out of the headphone monitor on the SL16, just distorted on the Capture recording. I assume that the firewire driver just went south at some point and needed to be reset. I just want to know if there is a way to monitor the recording as it's happening to ensure that the recording is clean. Currently you seem to only be able to monitor via the digital return in the Mixer, which was clean during the recording, but the recording wasn't. If I use another audio card to monitor, I get nothing because capture will only let me monitor via the mixer. My temporary solution is to record a live backup with a separate deck just in case Capture goes south on me and I can't tell because there is no way to tell until after the session is finished.

3 Answers

–1 vote
answered Feb 7, 2017 by wahlerstudios (104,470 points)
edited Feb 7, 2017 by wahlerstudios
I can feel with you. It's not "nice" if equipment starts to get whacky, but it can happen any time to any equipment of any manufacturer and in any price category. What I hear is some kind of digital distortion, which reminds me of a dying battery in a wireless microphone. Several questions come to my mind: Is that noise on all tracks? How many tracks did you record? Was there a wireless microphone involved? Was there interference with mobile devices? Did you ceck all your cables (XLR and FireWire)? Are the option cards really fixed? Do you see any FW port pushed inside? Is your FireWire card (PC) ok and sitting tight in the slot? Did you try the second ports of FireWire? Did you also record at 48 kHz or are you using it for playback? Are both mixers set to 48 kHz? Did you compare the behaviour of the two mixers... (play the tracks back to the RM mixer)?

If all that is ok then the only thing you can do is watch the behaviour of your equipment. A factory reset (with the option card pulled out) mostly helps to cure "funny" symptoms, but first try to find out if there are "conventional" reasons for the crackling.
0 votes
answered Apr 23, 2018 by davidlorek (160 points)
Has anyone from PreSonus reached out t you? I have a similar issue with my 16.4.2s. I attempted to use one of the Safe modes and increased my packet size from 512 samples to 1024.  That helped me get a longer recording before noise crept in.  Still not long enough, though.  I suspect there is a firmware bug and am worried that PreSonus is ignoring it.  PreSonus, if you're out there and want another sample file, please contact me.
0 votes
answered Apr 23, 2018 by drunkenrobot (170 points)
I also emailed Presonus directly. I have not received a response either here or via email. I fought with it for over a year, and despite firmware upgrades improving the situation, I gave up and switched to Dante. I have had zero problems since then. My Dante network of three Presonus mixers and a Tascam DA6400 have been 100% solid for well over six months without a single reboot or audio distortion. I tried everything under the sun to solve the problem with AVB, but the noise always crept back in. I was using a MOTU AVB switch a 16.4.2AI, and a RM16. I had constant disconnects, audio distortion, and frequent reboots. Since swapping out the AVB cards for Dante cards, I've had zero problems.