• Registered: 2008-05-08
  • Posts: 12

Topic: Two (2) Fireface 800's - Mac/Aggregate Device

Folks -

I have a FF-800 that I love. After trying to integrate a Mackie 1620i mixer over FireWire (I did it - don't ask), I decided to stick to a homogenous (RME) solution, so I ordered a second unit.

So - this question is for the Mac folks: will the both of the FF-800's appear at the Mac as one LARGE device, or will it present as two separate devices (I hope not!)

The reason I ask is that aggregating the two devices on the Mac may introduce additional delay, and may possibly cause the two interfaces to play with a time offset (msecs) between them. I had this experience when I first synced up the Mackie 1620i with the FireFace 800 - I could play music out of both, but there was a distinct delay in getting the music out of the Mackie. After further testing, I found that this delay was also apparent in the input/recording mode. I 'multed' (like a Y cable) a guitar to both the FF800 and the 1620i. The Mackie produced audio that was several (100's?) of milliseconds late.

So in short, does aggregating two FF800's on a Mac have delay/latency issues? Can these two units present themselves as one big interface?

Thanks!

Pete

  • Hugh
  • AD/DA expert
  • Offline
  • Registered: 2007-05-02
  • Posts: 84

Re: Two (2) Fireface 800's - Mac/Aggregate Device

Hello,

The two FF800s will show up in MacOS as two devices.  Aggregating them as a single device works, and you shouldn't have any delay offset issues.  The offset issues you described with your Mackie are due to the inherently different processing times at the same buffer settings.  The same model of device aggregates as it should, without offset delays.
However it will add slightly to your latency through the system.  I haven't measured the added delay but it's slight.

In the Aggregate Device dialog be sure you have the correct unit set as clock master and turn off "Resample" on the second unit which will probably be on by default.  Be sure to externally clock the second one correctly.

Hugh

  • Registered: 2008-05-08
  • Posts: 12

Re: Two (2) Fireface 800's - Mac/Aggregate Device

Thanks Hugh! By clocking, I'm guessing that you mean wordclock, right? I am surprised that there's no way to get them to sync up via firewire

In another post, I saw that it was recommended to connect the second unit via lightpipe into the first. This way there's no competition for firewire bandwidth. I would imagine if careful selection of channels/bandwidth was set in the FF control panel, supporting 2-3 units should be possible if say you were only passing analog channels 1-8.

In the event they were connected via lightpipe, I guess I could also clock the second unit from the lightpipe out of the first. This way I could avoid a long W/C cable, but of course I will still need long ADAT cables (have them on the way). I'm guessing that lightpipe sync may be the way to go, as the clock has less chance of getting distorted traveling via digital rather than analog (W/C).

Pete