DM4800 - ad/da conversion and effect latency

[OrangeMan]

Sorry, I couldn't find an answer yet.

Ad/da Conversion:
I assume the signal from a microphone goes through the pregain and is then converted a/d.
When it is send to the DAW through a firewire interface in the slot, it is therefore not converted again, because from the beginning it stays digital?
And when we bring it back from the DAW there's also no conversion happening? So therefor there's also never any conversion happening at the input and output-points of the internal effect units like the compressor?
The signal only gets converted to analog right before it leaves the outputs for the speakers and headphones?
So a firewire card in one of the slots is never working as an ad/da converter?
An internal ad/da converter is doing this?

Latency:
Does it cause less latency to use the internal compressor for the headphone mix of a musician than using a simple stock-plugin-compressor in logic?
If so: why, just because the mixer effect works more quickly by itself? Or because the processor of the mixer is more "dedicated"?

 

[Arjan P]

Hi @OrangeMan, To start with AD/DA, the mixer indeed converts analog to digital with the sample rate you assigned and a bit depth internal to the mixer that I don't know. When the signal is sent through the IFFW, it becomes a 24-bit signal which the DAW receives. The DAW usually works at an internal bit depth of 64 bits float (or 32 bits float) IF you 'work' the signal. That means EQ, compression and other processing (but even a simple level change) means the signal is expressed in the higher bit depth. When you send it out again to the mixer it becomes 24-bits again. So to conclude with your question: Conversion is not really happening but the bit depth changes a few times along the way.

And the mixer latency (from AD > processing > DA) will always beat the times you can get with the detour of a DAW in the chain. AFAIK, the DM's latency is around 1-2 ms, while a super latency for a DAW starts around 5-10 ms, which you always ADD to the mixer latency. So yes, feeding your artists only a signal from the mixer (direct monitoring) is the most direct way.

 

[OrangeMan]

Thanks, very interesting concerning the bit depth. Great to see there's not so much ad/da happening - I didnt get this at first because i looked at the firewire card as some sort of normal soundcard.

But the latency question was about something slightly different. I agree: direct monitoring could be a good solution, but let's say we are told to use the post-tape signal for the headphone mix (because that's what really has been recorded) - which means: the latency of the daw is happening anyway. In that case: do we know if adding the mixers compressor is adding less latency than adding a compressor in logic?

 

[Arjan P]

Yes, ofcourse there comes a time when the artist plays or sings along with what's already recorded. The DAW compensates for its own latency, so newly recorded signals will line up with what's playing back. If you monitor the artist from the DAW while recording, the artist will have to deal with the DAW latency, since his/her signal takes the detour I mentioned. Ofcourse, a compressor on the playback tracks will simply be taken into account with the DAW's latency (which might increase a little bit).

Personally, I never monitor recording signals from the DAW - always direct. And why not? The DM's are perfectly capable of creating a great monitor mix with any type of proccessing you might need (within reason ofcourse).