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[NiToNi]

Is it possible to run different convolving filters for different zones?

I have an 8-channel USB DAC, the miniDSP U-DAC8. I also have two different stereo systems in two different rooms. Both of these systems are active 2-way systems with 4 channels of amplifications per system, i.e. 8 channels altogether.

I want to set up two zones, one for each room, and use 4 DAC output channels per room, i.e. 2 x 4ch = 8ch in total.

I want to use JRiver's built-in convolver for crossover duty for both zones, each convolving a different FIR filter (created by Audiolense, Acourate etc, as the case may be) that each has 4-channels out (tweeter left, tweeter right, woofer left, woofer right).

Is this possible, i.e. to run multiple instances of the convolver at the same time? Also, would it be tricky to get the channel allocation right? Let's say zone 1 uses DAC outputs 1-4, which is easy enough because when I then create a filter in say Audiolense I tell it that it should use channels 1-4 (and which driver is on which channel). But what would I do with zone 2 that uses DAC outputs 5-8? When I create the filter in Audiolense, should I tell it to use 1-4 and then JRiver bumps each channel with +4 or should I tell Audiolense to use 5-8? Bit paranoid about this because of the risk to fry the tweeters if channel allocations are incorrect.

[mattkhan]

IIRC you use the channel offset in the audio device, for the zone that wants channels 5-8, to shift the zone output channels 1-4 to the physical output channels 5-8. This setting is in the audio output options screen.

Bigger question is whether your audio device is reliably multichannel capable. Is it?

[NiToNi]

Thanks mattkhan.

Well yeah I would think so, with 8 channels out, that the u-DAC8 would be multi-channel capable. It's sort of made for the miniDSP crowd, which is all about active XO, so it would've tought that much. You sound sceptical though, do you have experience or sources telling you otherwise....?

[mattkhan]

I am referring to the asio driver being multi client capable, i.e. being able to accept multiple apps (or multiple instances of one application in this case) talking to it. It is why http://www.steinberg.net/forums/viewtopic.php?f=34&t=48 exists as asio is typically an exclusive protocol.

I believe true multi client support is the exception not the norm.

[NiToNi]

Hhmm... good point, I hadn't thought of that. I will need to check that with miniDSP.

But let's say it is, or that I switch to a sound card which is, is it possible to run two different convolver filters at the same time for each zone, even if they playback simtaneously?

[mattkhan]

Yes you can run two filter chains concurrently. I believe you will need to set both zones to resample everything to a common rate  BTW.

[NiToNi]

Excellent - thank you.

When I find out about the U-DAC8, I will post here for completion in case someone else is interested.