Parallel Compression and Latency?

[James Steele]

Let me admit that I'm primarily a tracker... not a mixer. To quote Clint Eastwood as Dirty Harry, "A man's got to know his limitations" and I do. That's why I have a friend mix my stuff for me. He's got more experience, better gear, better room and better ears.

Still, I like to experiment and after I bought the Steven Slate Drums EX at the blowout pricing recently, I decided to play around a bit with parallel compression.

The way my mind worked it made sense to me to send the output of Kontakt to a stereo bus. I named it "Drum Bus." (Are there two "s's" in Bus(s)? I forget.) I then created TWO Aux Tracks: "Drum Mix" and "Drum Mix Compressed." I fed both of them from "Drum Bus" and they output to my main audio output pair.

So in theory now, I could just strap a compressor on my "Compressed" Aux Track and mix the two to taste. That was the theory. I found that I got artifacts ranging from flamming to phasing with various compressors both powered like the UAD and AU. Only one that seemed to be okay was MW Limiter. (I didn't try that many.)

Ultimately, I decided to try a different way. I started over. I assigned my Kontakt (drum) track to my main output pair, then used a SEND to feed "Drum Bus" and then created just ONE Aux track fed by "Drum Bus" which output to may main output pair. I then strapped all sorts of compressor plugs on this single aux track and ADC did its job and no artifacts of any type... just dead on.

Is this the way it's always been? Was I wrong to think that I could just "mult" the drum VI by sending it to a buss and having that buss be the source for multiple aux tracks? Again, I know this is probably basic to many of you who have done this, but I was surprised. At least now I know the best method to use in DP when I want to parallel compress now.

[HCMarkus]

I've always used the letter method you describe, because it allows one to mix to the Compressor bus using sends. I've never had timing issues in DP.

[James Steele]

I've always used the letter method you describe, because it allows one to mix to the Compressor bus using sends. I've never had timing issues in DP.

I could see where that would make more sense anyway... especially if you had your drums laid out in a more conventional multi-track fashion with separate tracks for kick, snare, hihats, etc. like if you were micing and actual kit. I at first used the "mult" method because I was using the Slate EX drum and it was just a stereo out. I did indeed have timing issues doing the way I first did it. Don't understand why exactly but I did, but still using the sends seems better anyway.

[Dan Worley]

Let me admit that I'm primarily a tracker... not a mixer. To quote Clint Eastwood as Dirty Harry, "A man's got to know his limitations" and I do. That's why I have a friend mix my stuff for me. He's got more experience, better gear, better room and better ears.

Still, I like to experiment and after I bought the Steven Slate Drums EX at the blowout pricing recently, I decided to play around a bit with parallel compression.

The way my mind worked it made sense to me to send the output of Kontakt to a stereo bus. I named it "Drum Bus." (Are there two "s's" in Bus(s)? I forget.) I then created TWO Aux Tracks: "Drum Mix" and "Drum Mix Compressed." I fed both of them from "Drum Bus" and they output to my main audio output pair.

So in theory now, I could just strap a compressor on my "Compressed" Aux Track and mix the two to taste. That was the theory. I found that I got artifacts ranging from flamming to phasing with various compressors both powered like the UAD and AU. Only one that seemed to be okay was MW Limiter. (I didn't try that many.)

Ultimately, I decided to try a different way. I started over. I assigned my Kontakt (drum) track to my main output pair, then used a SEND to feed "Drum Bus" and then created just ONE Aux track fed by "Drum Bus" which output to may main output pair. I then strapped all sorts of compressor plugs on this single aux track and ADC did its job and no artifacts of any type... just dead on.

Is this the way it's always been? Was I wrong to think that I could just "mult" the drum VI by sending it to a buss and having that buss be the source for multiple aux tracks? Again, I know this is probably basic to many of you who have done this, but I was surprised. At least now I know the best method to use in DP when I want to parallel compress now.

I wonder if it's because of the UAD card, James. I can put four different AU compressors and some EQs on one of the Aux tracks and I don't hear any comb filtering or delay going on. I use parallel compression all the time exactly as you described (sans the UAD) and don't have any trouble.

c-ya,

Dan Worley

[newrigel]

I use UAD and SSL Duende cards and NEVER a problem... stop the sequence and let ADC do it's thing then hit play. Just bus to the auxillary channels because that's what parallel compression is... running two stereo stems, one with comp and one without... they are still going to be heard on the main out's in the end so might as well assign everything to those.

But I keep K assigned to the main outs (all my tracks are assigned to the main output pair) and just use a send (stereo or mono depending on the original content) to an auxillary with an SSL EQ and Bus Comp for a global compressed output and blend to taste. Sometimes I may go pre fader and do all my adjustments with the sends that way I can really get the panning focused in for each element. The sky is the limit here and it's all dependent on what you want as far as the placement is concerned with this technique. You could for example put a wide stereo focus to the overheads (I use the Panorama plug for this) to give them some spread and get them out of the way of the center to open up more room and keep the more powerful elements (bottom end) more centered for focus. Works great!

[Dan Worley]

I use UAD and SSL Duende cards and NEVER a problem... stop the sequence and let ADC do it's thing then hit play.

But I keep K assigned to the main outs (all my tracks are assigned to the main output pair) and just use a send (stereo or mono depending on the original content) to an auxillary with an SSL EQ and Bus Comp for a global compressed output and blend to taste. Sometimes I may go pre fader and do all my adjustments with the sends that way I can really get the panning focused in for each element. The sky is the limit here and it's all dependent on what you want as far as the placement is concerned with this technique. You could for example put a wide stereo focus to the overheads to give them some spread and get them out of the way of the center to open up more room and keep the powerful elements (bottom end) more centered for focus.

The basics of what you're describing is how he eventual got it to work, but I wonder why it acts up when routing a bus to two aux tracks. It shouldn't make a difference.

c-ya,

Dan Worley

[newrigel]

Could be the DSP cards having to process the signal TWICE. Without a signal flow chart (in which it would be really nice if MOTU had a flow matrix chart) your not going to know where the PCI bus grabs the signal if it's pre send or post send. This would be a nice spec to know.
I just take it for granted it's laid out like a console and that everything is summed to the main output pair and any mults are going to be summed externally... not within the MAS engine.

[James Steele]

Well when I used the first method I had issues with just about all plugs I tried except MW Limiter. You guys are all Intel. Perhaps it's a PPC issue or something? Using a send however fixed it. I did stop and start playback trying to coax ADC to "do its thing" and it didn't help. I will look into it more.

[newrigel]

Well when I used the first method I had issues with just about all plugs I tried except MW Limiter. You guys are all Intel. Perhaps it's a PPC issue or something? Using a send however fixed it. I did stop and start playback trying to coax ADC to "do its thing" and it didn't help. I will look into it more.

I would really like to see a signal flow matrix of the MAS engine in detail. It's something I've looked for in the manual, but haven't found... I may be looking in the wrong place who knows... but I haven't actually seen a nice diagram like a console manual has.

[Dan Worley]

You guys are all Intel. Perhaps it's a PPC issue or something?

That's an interesting thought.

I actually want to start using the method you guys have described using the sends. I never thought of doing it that way until bongo_x mentioned it the other day. It seems like it will be much more flexible.

c-ya,

Dan Worley

[James Steele]

You guys are all Intel. Perhaps it's a PPC issue or something?

That's an interesting thought.

I actually want to start using the method you guys have described using the sends. I never thought of doing it that way until bongo_x mentioned it the other day. It seems like it will be much more flexible.

c-ya,

Dan Worley

Yeah... I can really see the usefulness of that method. I was just doing a stereo mix of the Slate EX drums, but I could see how using sends, if you had individual kit elements on separate tracks, you could choose only which elements got compression. When I did my test with the stereo drum output, I made the send pre fader also, which is probably obvious, so as I'm pulling down the uncompressed stereo track, I'm not changing the way the compressed aux is sounding.

[James Steele]

I actually want to start using the method you guys have described using the sends. I never thought of doing it that way until bongo_x mentioned it the other day. It seems like it will be much more flexible.

P.S. These ARE EXACTLY the sorts of discussions that I always love to see on this board. I learned something new also, and that's much more rewarding than ripping on MOTU or DP.

BTW, gotta say I downloaded Amplidood's new "Sharp" GUI mod and between that and setting the Color scheme to "Pastel2" I'm really liking the way DP 7.1 is looking too.

[newrigel]

When I did my test with the stereo drum output, I made the send pre fader also, which is probably obvious, so as I'm pulling down the uncompressed stereo track, I'm not changing the way the compressed aux is sounding.

Exactly... there's where you get your positioning... albeit a different way but still, you can be very, very detailed in the amounts of compression to the mix. I like Amplidoods Night GUI in that on the sends, you can see where the levels are set @ in a quick glance (because they are in color) instead of having to focus in and look for the little line to see where it's levels are @... I have been opening up the meter bridge a lot lately making sure not to hit the busses too hard and my mixes have opened up tremendously! It's amazing how much open and clear the soundstage gets when your not heating up the busses in DP. I used to have a bad habit of slamming the bus and my mixes were a bit smeared.

[wheever]

James, I have the same problem on my Macpro. Sometimes I can fix it rebuilding bundles, sometimes not. Or sometimes I fix it and it breaks again when I reopen the project. I've asked about this on the board before. Magic Dave simply said "It works." But sometimes it doesn't.

On 6.03, though, basically the flamming/phasing often makes it impossible to buss things. I abandoned a huge project because of this problem. (When I opened the sequences after updating DP, the entire rhythm section fell apart. Nothing bussed synced up anymore. My collaborator and I were having problems anyway, so I just gave up.)

I think DP has a bug where the latency of plugs on aux busses doesn't properly report to host in some circumstances. I haven't been able to nail it down, though. But a lot of the time if I send a single source to 2 or more busses, it just turns into a smeary mess. I haven't been able to use parallel compression for just this reason.

Sorry I can't do anything but confirm your experience.

[newrigel]

James, I have the same problem on my Macpro. Sometimes I can fix it rebuilding bundles, sometimes not. Or sometimes I fix it and it breaks again when I reopen the project. I've asked about this on the board before. Magic Dave simply said "It works." But sometimes it doesn't.

On 6.03, though, basically the flamming/phasing often makes it impossible to buss things. I abandoned a huge project because of this problem. (When I opened the sequences after updating DP, the entire rhythm section fell apart. Nothing bussed synced up anymore. My collaborator and I were having problems anyway, so I just gave up.)

I think DP has a bug where the latency of plugs on aux busses doesn't properly report to host in some circumstances. I haven't been able to nail it down, though. But a lot of the time if I send a single source to 2 or more busses, it just turns into a smeary mess. I haven't been able to use parallel compression for just this reason.

Sorry I can't do anything but confirm your experience.

I haven't any issues here (5.13)... if I'm playing the sequence and insert a plug while it's playing I'll get the latency to the DSP cards but I stop the sequence and hit play and it's gone... some plugs won't publish their latency to DP and that's where the problems may be.