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Alright guys and gals, I’m about to lose my freaking mind and I could really use some help. I run Logic on my top of the line Mac Pro (which I use solely for recording music). For the past year or so, I’ve been using two MOTU 8pres – one is a firewire interface, the other a USB. The USB (MOTU #2) is connected via optical cable to the firewire (MOTU #1). For over a year, the two have worked beautifully together. I’ve never had a single problem. Last week during a recording session, however, guitar tracks started cutting in and out as they were recorded, as well as when I played back previous recordings. I couldn’t figure out what the problem was, so I decided to uninstall/reinstall Logic, download the latest version of MOTU’s Audio Setup software, and update my Mac to the latest OS. The problem remains unsolved.

My next idea was to isolate each of the MOTUs, thinking that perhaps one of them was malfunctioning. I unplugged the optical connection between the two MOTUs and tested each MOTU separately. First, I tried plugging in MOTU #1 (firewire) and playing a song through iTunes. The playback through both of my monitors is crystal clear – no problems at all. When I open Logic and try listening to one of my songs, however, the playback coming from the left monitor has an absolutely horrendous fuzzy/squeeky/feedback sort of sound. It’s so bad that I literally can only barely hear the music playing under it. The right monitor, curiously, sounds absolutely fine.

I figured that I’d solved the problem, and that MOTU #1 was simply malfunctioning, so I decided to just plugin MOTU #2 (USB) and use it until I could get my MOTU #1 replaced/repaired. When I plugged in MOTU #2, however, an even weirder problem happened. Just like MOTU #1, MOTU #2 plays audio perfectly through iTunes. But when I open Logic, there’s no playback whatsoever from any of my projects. No fuzz, no hum, just total silence. Stranger still, after attempting to use Logic with MOTU #2, iTunes suddenly stops working. iTunes plays back fine BEFORE I try using Logic, but as soon as I open Logic, iTunes stops working.

I have no idea what’s going on and I desperately need some assistance. I find it nearly mathematically impossible that both of my MOTUs somehow crapped out at the exact same time. There’s gotta be something else going on that I can’t figure out. I believe the problem must be with Logic, because if it’s the MOTUs then songs probably wouldn’t be playing through iTunes at all. BUT, when I work on projects without my computer being connected to either MOTU, my Logic projects work fine. Please, PLEASE help!

Thank you in advance,


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Boswell Thu, 02/11/2016 - 10:52

I can't gather from your description whether box #2 is acting as an expander to box #1, that is, 16 channels of audio are going into the Mac via FireWire and the USB interface is used solely for setup on box #2.

If you are using (or the system thinks you are trying to use) audio input from both interfaces at the same time via the aggregate device mechanism in OSX, then this is where many problems can arise.

The other area to check is the clocking. When you have both interfaces interconnected by lightpipe and working correctly, I guess you must have had box #2 as the master clock and box #1 taking its clock from box #2 via the incoming ADAT data stream. Did you change the clock setup when using the two boxes independently? Have you altered the clock settings in any other way recently?

I hear it's snowy in Denver.

Will Young Thu, 02/11/2016 - 11:07

Thanks for the quick reply. MOTU #2 is indeed being used as an expander for MOTU #1 (or at least it was; as I said, I've been trying to use either of them independently, but they work neither together nor individually). And yes, I had MOTU #2 set up as the master clock and MOTU #1 taking its clock from MOTU #2 via ADAT. I've tried every clock configuration imaginable for both MOTUs, individually and when connected via ADAT. I only get playback from iTunes from either MOTU when their clock source is set to "Internal."

And yep, it is indeed snowy in Denver. Not as bad as last week, though. I was snowed in for 2 days haha

pcrecord Thu, 02/11/2016 - 14:05

So you got 2 motu 8pre, one usb, one firewire ?
If so, I'd choose the firewire as my master interface, make it the masterclock then plug the second one to the first via adat and place it in slave clock through the adat.
Make sure the clock is in sync and matching your project. 44 - 88 or 96

If all that doesn't make a difference, try another daw like band in a box.
Get back with the results, it's very intriguing ;)

Will Young Fri, 02/12/2016 - 09:24

That's exactly how I've had it setup (firewire 8 pre as master interface/master clock, USB 8pre plugged into the firewire 8pre via ADAT with its clock slaved). That configuration is no longer working. At this point, I'd be happy to just get one of my 8pres working independently. Neither the firewire nor the USB are working. I'm focusing on the USB at the moment, because it's the newer of the two (only about a year old). It's just very strange that when I hook up the USB and open iTunes, songs play perfectly through my monitors. But then when I open up Logic, none of my tracks play back, and iTunes suddenly stops working.

If anyone has any more ideas, I'm all ears. I really appreciate the help!

DonnyThompson Fri, 02/12/2016 - 10:35

Boy, Will... I dunno. I'm pretty good with this stuff, and I've been reading these posts, and the explanation is eluding me ( although I've been a little sick lately so my concentration level is lower than usual, like "basement" low. LOL)...

It almost sounds as if there's a sample rate conflict somewhere in your system.

You said you reinstalled the drivers for both MOTU's... did you happen to check and make sure that the drivers you installed are the latest from MOTU's support site?
Is there any firmware updates pertinent to these hardware devices?

Do you have ANY OTHER audio device installed, and either checked as enabled, ( or even disabled but still resident) anywhere on your system? An internal audio card that came stock in the computer from the factory perhaps?

Did you install any new software of any kind, just previous to the I/O's going flakey?

Have you swapped your older FW and USB cables for newer ones to make sure that it's not a bad connection?

I'm assuming you;'ve already checked the sync cable between your master and slave, and that if there was any termination required on the slave - either through software menu settings or internally within the device - that it is set to terminate...?

I'm not a Mac guy, Will, haven't been for years, and I can count the number of times I've worked in Logic on one hand... ( I'm a Samplitude guy) so take all the above with a very large grain of salt. I'm just tossing possibles out there in the hope that this is something simple that's being overlooked somehow. We all know what it's like to have our recording systems crash, and it truly does suck, especially when we rely on it as our living.
There's nothing worse than having to reschedule sessions or miss deadlines because our system is acting funky. I do feel your pain. ;)


Will Young Fri, 02/12/2016 - 11:14

Hey Donny, thanks for the input. Unfortunately, I've tried all of your suggestions and nothing seems to work. I don't have any other audio devices connected, and I haven't downloaded any new software lately (apart from MOTU Audio Setup). And unfortunately I don't have access to any other Macs at the moment, but I'll look around and see if I can find someone in the area to help me out.

If come up with any other ideas, please let me know. Thanks again.



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