Not enough DSP memory

[Mr Arkadin]

Dear Lord, makes my projects seem quite minimalist. Holy cow, do you have a six-screen monitor to view all this on?

[borg]

look at the scroll bars, Mr T

[blazesboylan]

I set out to automate everything via MIDI. It has turned out to be mildly challenging! Fun though. That monstrosity is a 32 x 8 x 2 mixer with 3 auxes, nothing more. *Sigh*.

I'll talk to the folks at CW and see if they have any advice on DSP memory conservation...

Johann

[Ricardo]

Double WOW!!
The only thing I can think of is bouncing down to reduce the need for all those mixers.

[blazesboylan]

Thanks for the suggestion Ricardo. I would reduce the # of mixers in a heartbeat if I could figure out how to automate the busing.

The problem is that I can only have 1 MIDI channel controlling each mixer. And with 32 audio channels and several parameters per channel, MIDI ccs get eaten up really quickly.

The components are:

• 4 16/32 mixers provide gain control and dynamics for the 32 channels. Each 16/32 only passes 8 mono signals, and the DIs go to the various buses. Each 16/32 takes up a full MIDI channel of ccs: 1 gain, 4 EQ, 5 expander, 5 compressor, times 8 channels = 120 ccs.
  
  There might be a way around using 16/32 mixers, but after assigning 480 MIDI controls (twice), this is the section I don't want to touch.
• The top 48/96 mixer is used to pan and sum the 32 input channels onto the L/R mix bus. Level and pan x 32 = 64 MIDI ccs.
• The middle 48/S mixer is to send each channel to 1 of 8 buses. Each of the 8 surround outputs is treated as a bus. The only way I could get 32 x 8 to work with MIDI ccs (potentially 256 controllers) was to use the 48/S and assign only 64 MIDI ccs for the bus selectors, as well as 32 for send level on each channel.
• The bottom 48/S mixer is for the auxes. Same idea as the bus mixer, but there is no send level control -- only a continuous pan between aux outs. The 8 buses from the previous section are also routed to the aux buses. 40 x 2 = 80 MIDI ccs.
  
  Unfortunately I ended up with only 3 auxes, all sent to external gear. I'd really like to have 3 more with DSP effects, but...
• The rightmost 16/32 mixer sums the mix L/R, 8 buses, and 3 auxes into 1 final L/R mix. Level and balance controls are assigned here.
  
  The MIDI channel on the master bus section is shared with a bunch of DSP dynamics (bus and master inserts) throughout the project. Between the mixer and the other devices on the same MIDI channel I think about 90 ccs were used. The mixer itself uses only 30 or so ccs.

I would be very curious to hear others' views on approaching some of the MIDI control issues I've run into.

Also any tips on optimizing mixer efficiency?

Has anyone tried the automated 8 bus approach -- is there another way to achieve it without the surround mixer?

(I'm limited to routing each channel to 1 bus only. In the aux section, each channel's send has only 32 degrees of level control.)

Ricardo, can you think of any wild ideas on how to combine mixers without losing control over channel parameters?

I know it's a weird project. But any advice, especially from left field! , would be much appreciated.

Thanks for your time all,

Johann


<font size=-1>[ This Message was edited by: blazesboylan on 2004-07-15 13:16 ]</font>

[blazesboylan]

I suspect I'll be carrying out a conversation with myself here for a while. But what the heck. Maybe some other wacko will benefit down the line...

I removed the right-most 16/32 mixer (the "master" section) and ran all the 8 buses and 6 auxes into the topmost 48/96 mixer. Now the 32 input channels, 8 buses, and 6 auxes are all summed in a single master section.

Each of the 32 channels has 1 level control and 1 pan; the 8 buses each have 1 level and 1 pan; and the 6 auxes each have 1 level and 1 balance. Plus the master mix level. That makes 101 MIDI ccs for the master module (same as before, but with 1 less mixer plug taking up valuable resources.)

Thanks for the suggestion Ricardo -- it worked!

The 6 auxes now include 3 outboard effects devices and 3 new DSP ones.

I was able to add 2 delays and 1 chorus as the 3 DSP effects.

I was not able to add 1 delay and 2 choruses as the 3 DSP effects. This approach led to the same "out of DSP memory" error that I mentioned in the earlier post.

My suspicion is that those 32MB of onboard memory are used for delay effects. Whereas each "DSP memory" is used as a buffer for "shorter" processing.

One strange thing: the 3 external effects returns produce signals in the Aux return channels of the 48/96 mixer, as they should.

But the 3 internal DSP effects do NOT produce any signal!

Maybe this relates to the thread which Rogurt started? Ralf, if you happen to read this, I suspect that Rogurt's problem is only for internal DSP effects inserts -- not for hardware audio inputs into the return channels. (I haven't gone through all the steps to test this hypothesis though.)

I've also had trouble getting the Aux returns to keep their MIDI ccs. When I assign via the "Channels" window they're lost immediately. When assigned via the "Channel Strip" window they seem to be kept. I *think* it's just a cosmetic thing but haven't fully tested yet.

Cheers,

Johann