Modular Mixing

[w_ellis]

Oh, I totally hadn't noticed that the phase fix buttons had been removed. Also loving the modular mixer anyway. I can't see myself going back to the STMs now.

[spacef]

You can add that most stems and master bus direct outputs, as well as the Rec Channels, have a feedback module, ie a constant latency of 1 sample. It is a constant so it is "nullified" in terms of phasing issues in a mixing network, whatever is the input (channel or grouper/router). But there would probably be a 1 or 2 samples latency compared to an asio signal connected directly to the outputs for example. So, if you look for it, it is possible that some construction cause sample-scale phasing, but in that case, you know perfectly which section of the mixer is affected, and can be corrected by loading modules of feedback to add 1 sample to the connections that require it (for ex, something connected directly to a stem, while other sources have channels in between: variation=1 sample). but in most mixers, it will be perfectly aligned. Mix outputs don't have this feedback module, only direct outs and buss out (interconnections).

POST EDITED DUE TO INEXACT INFO: PLEASE SEE 3rd post below for accurate info. Thanks.


but even if you create voluntarily a phasing of 1 sample, it takes a bit more than 1 sample to cause true phasing, but if you look for technical precision, you now have all the details.
sorry it completely escaped my attention, but might be important for your calculations (nice pics btw ! )

ok now, I really need to finish mixing those tracks of mine...
have fun !

[tgstgs]

just for fun:

how much samples would it need to cause true phasing?

good vibes

[spacef]

just for fun
at what sampling rate ?

[spacef]

Hi there, sorry again to insist, but I went to look inside the Modular Mixer circuit to check I was not giving wrong info...
I went to check which outputs have a feedback module, as it changed a lot during the building (which was last year, so ...)
, and so here are the result

- Rec Channels: they all have a feedback module whatever is the device. It is a feature of the rec channel for looping back
- MB7: there is a feedback module on each external Aux outputs (s1/s2/s3 otherwise you cannot send back effect 1 to aux 1 for example), not on any direct outputs (there is no feedback modules anywhere on Mix5 / Mix 7)
- Routers/Groupers/Stem: feedback module on the buss/group outputs

As a result:
- In a modular mixing network, you have a maximum sample latency of 1 sample due to the feedback on groupers/routers/stems.
- Through the Rec channels, you get 1 sample by rec module in your Rec chains; as you usually use two rec channels to record everything in the project (eg, 1 for channels, 1 one the master bus), you are likely to get 2 sample latency typically

If I'd removed the Feedback from stems and groupers, then the entire modular mixer would give a latency of 0 sample whetever the mixer you build with it. It might be a good idea for a future version for xite. It is ok to remove those feedback module because they are not very useful here eventhough they do allow to create an aux send to an effect that is sent back to the main mixers channels, ie, before those stems/routers/groupers, so you can mix its levels and additional effects on the same board as other channels (asio, inputs etc). more confortable in a vu-meter point of view. If I do so, I will have to rename some groupers that need to have feedback on them (the small groupers such as G82 and G62 are perfect for adding an aux circuit to an effect for a few channels especially in a loopback circuit where you don't need all channels to be sent to this or that effect, so those ones would have a feedbacked version of them (by the way, groupers are cool to add 2 aux sends+effects to any mixing network that's how you can go well beyong the number of buss offered on the stems and routers.).

But for the moment, it is 1 sample latency for all groupers/routers/stem and 0 latency for any other module except the Rec channels.
Also, remember that new modules such as the M12Rec has specific outputs to record mono signals to asio. With this module, you should be able to bypass some of the latencies induced by dsp communication as there is a direct connection from the channels rec outs to the asio inputs, without needing to go through rec channels or other modules. So if you record a drummer or lots of mono stuff at the same time, it might be something you want to use.
All the above is accurate info that you can use for your calculations.... sorry for any previous mistatement due to fading memory due to grand age and also because i am mixing stuff while installing w7x64 on a new hard drive and it's difficult to do all this at the same time ...

better vibes from Paris

[tjsound]

If we imagine that there are no other problems with the "dsp assigment" is my dream now would be a modular mixer 2.0.
8 stereo bus
6 stereo aux (or 1 bus + 13 aux)
new 16 and 24 routers.

[spacef]

nice project...
There are bigger modules in my modular mixer's builds, but for the moment, i think they are too big so i didn't continue their development...
later may be if i can try on xite what is good and not good...
but thanks for the pic, that's how I evaluate device panels too, before making them

What you want might be possible with a future G86 modules (8 ins, 6 outs, connected like that: 8SL used as master bus --> G86 --> 6 aux module (Mix 7 for example). )Ok I have to do the G86 then

give me a few time, this week-end is gonna be install of win7x64 and plenty of drivers and some apps (scope is one of them)....still very unsure to go full 64bits or 32bits cubase in 64bit OS (because that way, cubase would use 4GB of memory...may be...). also scope 32 or 64? i don't know, my very old board needs a primitive asio driver or it will not work.... it's gonna be an awful week end i am sure

[tjsound]

I can do everything from the fact that there are, lacking only a router.
May be 32 x 14 router? universally, not need merger...

[dawman]

Anyone who doesn't enjoy these mixers obviously doesn't need the extra options.
Those who have hardware and software to mix down to simultaneously know it's benfits.
Guys like me who need to send to monitors, mains, software recording app., and hardware recording like the Alesis 24/96 just piss people off with the options provided.
The Logic " only " FOH at the House Of Blues trys to expalin to me the Logic Enviroment and how excellent it is, I agreed. Then we compared the qaulity of the recordings and while Logic is a phenominal host, its summing pales in comparison to ProTools, Pyramix, SAW Studio, Samplitude or Scope.........
Once Scope gets Mac Drivers the Logic guys are going to jump in on the XITE-1 Juniors once they make an appearance....if they choose to break down and buy the XITE-1 they will spend a tad more but be ahead of the hybrid ITB guys that can barely move their massive ProTools rigs to a gig.
I just don't think most of the chaps using their XITE-1's have even begun to touch on it's capabilities.
I am excited that the new SDK is in the works.
Even if it takes until next summer to get it stable, thats fine by me.
I shall enjoy the party even more when that day comes.

Thanks Again So Much 2ZANI....................

[Andy_F]

Do these have a way to lock the L+R phase with stereo devices in the insert path?

Im mostly happy with the standard STM mixers except for stereo insert devices loading across DSPs and making mono compatibility problems

[spacef]

unfortunately, it won't fix what device makers chose not to implement to load onsame dsp or if the effect is too big to load on one dsp... then it's too big to load on the same dsp. on Scope-pci there are solutions like try a reload of the project (might help for a session time), use a micro delay in scope to compensate, or to record quickly and align the tracks by cutting samples. and may also be by assigning the effect to a particular dsps in xite.

[tjsound]

I really want a convenient way to send to an external analog mixer, 8 stereo bus and a separate effects. Client wants to analog bus summing and analog bus compression. And control for returns on consols...
I need a new router for 14 stereo pairs outs (8 groups switch and 6 faders for the auxs per channel)
who can make it especially for me and how much can cost buying?

[spacef]

a dynamic router takes a bit more dsp than the classic aux send that i use on Modular Mixer, and which is the smallest possible router in scope.
A dynamic router is an aux send + a switch. A ModMixer bus send is just the aux send without the switch.
A router with 14 lines would take less dsp than 6 aux + 8 routing switches.
But I have an 8 dest switch for bussing (from the 36/12/8 i tried to make 3 years ago, but couldn't load it
You didn't say for how many input channels...
I personnally don't know if it is worth the effort of trying when it is possible that it does not work in xite :-/

[tjsound]

I thought that the switch easier for DSP than the router ("classic" send)
Perhaps it is hard to do - 64 (32 stereo) INs, 28 (14 stereo) OUTs.
In any case, not less than 24 stereo input would be helpful.

[spacef]

it would take approximately the same dsp as 2 Stem 247 in a single device.
I have no idea wether this is possible for xite (even on scope-pci it is the kind of dev that put a lot of pressure on the pci channels, may be unusueable on scope-pci due to the pci overflows, not the dsp).0...
but it wouldn't be very hard to do, just long in terms of hours in front of the computer.

[tjsound]

6 BUS 4 AUX. client will be pleased.

Edited: router 16x10 definitely will not be hard for XITE.

[jksuperstar]

I've been playing more & more with the modular mixer, and had my "aha!" moment in DSP assignments last night. Some of it is due to just realizing the tips that Ralph had sent out over a year ago, some of it was just some other experience...

#1 - Like tjsound does, place your INPUTS on DSPs 7-10. These DSPs have more communication with DSP#1 and DSP#2, which control the Hardware and Software I/O. Placing your channels or inputs here means FAR less likely chance of SAT errors.

#2 - If you don't place the initial module, it will start piling things up on DSP#18...which has low latency between other DSPs, but has less SAT connections too. This will turn into a cascade of issues later in the project development. Don't let SCOPE do this first assignment for you, if you start placing mixers first thing. Once the first module is placed, SCOPE is smart enough to start placing overflow modules along 7-10.

#3 - Right-click/"Assign to DSP" works. But then the module you place next, will automatically get placed to the same DSP you just assigned. This can actually lead to DSP or SAT overflows, just during the assignment. Sometimes, you have to place/assign modules in empty DSPs, then re-assign them once you can see where the large connection buses are. Keeping large buses inside the same DSP means NO SAT errors.

#4 - Have your inputs in 7-10, then build the modular mixer toward DSP15. This leaves DSPs 10/14/18 to be the home of your effects (not as inserts, but wired in the project). These are low latency, so you won't add phase issues when layering effects on your dry signals (the round trip DSP-DSP to that last slot is about 4-8 cycles, and the DSP-DSP latency on other chips is...7-11 cycles. Minimal phase issues is nice.


Using this technique, I've built a 32-channel stereo mixer, with VCAs (for Compress/Gate/Expansion with Modulation) on EACH channel, 7 stereo AUX sends, 7 stereo buses, 1 Mix7, and 1 MB7 (this is a sub-mixer for my Aux effects, so effects can be chained here). ALL IN 2 DSPs. For those with Modular Mixer, that's:
(2) Side Chain 16
(2) Router 167
(2) Stem 167
(2) Merger Y16-16
(1) Mix7
(1) MB7

I'll play with this more, and probably add a channel in front of the SideChainers for EQ, Compression, etc. Until I played by the rules I listed, I was hitting SAT errors constantly. Once that happened, SCOPE would crash often (the application, not just DSP overloads). Last night I did a 5 hour jam, and had absolute stability. It seems that saturating DSP communications has a direct effect on XITE-1 stability. So get this part right, and the rest will be better.

Oh, if you start seeing "SAT Error, no more communication available between DSP 9 and DSP e", where the second DSP is listed as a letter instead of number...you know a crash is coming soon. SAVE YOUR PROJECT NOW.

I think similar rules apply to the MasterVerb, or any device that requires communication with the Host for processing: Place them in DSP 10 if possible...this is lowest latency, and also shares the high-count of SAT connections to DSP#2, where the communication to the Host PC happens. This will place a lesser burden on the resources of the system, so you can do more elsewhere in the project.

[RP_001]

Excellent stuff!

Ive been searching for a stable modular mixing environment for some time now. My "default" project is quite stable in the beginning, but once I add more fx/filters/inserts or new synths, at later times I get these annoying "no more sat connections from.." errors. Sometimes it needs a lot of time to recover to the last properly working project.

I will try some of your findings this weekend and check if it works, and "convert" some of my templates. Thanks for sharing!

[spacef]

you guys kick ass
you actually make me more impatient to upgrade my scope (i cannot stand its constant pci overflows anymore (as i am still on cubase and haven( changed to studio one yet).
i always knew i would never upgrade if Mod Mixer does not work, but as I follow this thread and follow your progress, I am more and more confident and thankful to you. I can see now that an upgrade is possible (i don't have the moeny yet).
I wonder where the sat connection comes from... is it the many inserts slots, is it the "in project connections" between all the modules..?
I don't know, but you make me want to find out.
I must thank you
Here is a lousy video of a fast music with something I cheated scope with (DSI Tetra)
http://www.youtube.com/watch?v=7xSJGD3m ... ture=share
It uses scope, Mod Mixer, Fat inserts and Aux Delay.
I hope to bring a tetra module for Mod Mixer when I updgrade I can control it more easily with the midi from Scope than the, Zero SL MKII, for some reason....
So for example a "3 LFO" followed by a CC2x2 seems to work ok with tetra, much better than Zero SL MKII at least (it causes artifacts, while scope midi does not cause artifacts but sometimes jumps, even with high lag settings)..... I don't know why it is like that, but I am happy that Scope's midi works fine with such gear.
See you

[jksuperstar]

I'm almost 100% sure that SAT are the inter-dsp communications that are mostly eaten up by the "in project connections" (or any other communication, such as a device's need to talk to the Host in order to use memory, or MIDI signals).

It's me that wants to thank you Two years ago a friend and I almost started to hack our two mixers in order to add VCAs and resonant filter w/ modulation for each channel...much like a "modular synth" extension into the mixer world. But your mixer has done a lot of the work for us! Yahoo!

So I am also eager for you to get an XITE, because I think then there would likely be a OpenScope Mod Mixer X edition. As there's probably a lot more that is possible, particularly with Interface consolidation / optimization. Maybe an extension into Parseq would be the ultimate

Anyways, once this mixer is done and set in stone, I'm off to building my large touch interface to work with it It would be more upright than this website shows, so the audience can see what's happening too...
http://www.maximumpc.com/article/featur ... e_computer

NOTE: I left a message on the spacef user forum...the Post/Pre buttons don't seem to work on the STEM 247 in Mod Mix v1.10 Post is the only signal that gets through?

Also, the SideChainers have some delay when enabling any 1 channel...is there a way to "play" the bypass/enable button in real time without the DSP recalculation? I'd like to send a MIDI signal to Gate channels with a sequence, but would also like to "play" which channels are getting sliced by the gate, rather than have it all setup & pre-programmed. Maybe I just need to set groups of channels with an ADSR in Sustain mode by default (so the VCA is on), then change up the sequence when needed.

I don't have any suggestions for the Tetra, but LFOs and modulation over MIDI is ugly anyway you try I have a DSI Evolver, and the audio ins can be used into an envelope follower (built in), and used to modulate settings...does the tetra have the same possibility? Then you could use 1 or two signals for realtime control (like CV), and MIDI for the rest.