Quantcast
Help understanding M/S stereo collapse anomaly - Gearspace.com
The No.1 Website for Pro Audio
Help understanding M/S stereo collapse anomaly
Old 27th January 2013
  #1
Gear Maniac
 
john john's Avatar
 
🎧 10 years
Help understanding M/S stereo collapse anomaly

Just for the record, I don't currently consider myself to be a mastering engineer or advertise myself as such, but I do want to be able to provide a competitive product for budget projects and personal one offs. That said, I did work for a popular mastering engineer and do have practical knowledge and experience on the subject. I'm just getting started on my own so my current (meager) chain is all ITB within ProTools 10HD.

To the point: I have a manually routed M/S chain with a pre and post master prior to my loading tracks. I always place the same plugins in the same positions on both the mid and side tracks to prevent phase issues. I've never noticed anything weird with this setup until using the Wave Arts Multidynamics5 on the M/S tracks... BUT everything is initially fine... it doesn't get weird until I change a crossover or add an additional band on the side track. Once I do one of those, the stereo field kind of collapses and shifts, or maybe better said, the L and R channels seem to blend oddly.

Example: a friend sent me a mix with an out of control highhat panned pretty far to the left, so I go to my Multidynamics5 on my side track and add a band to target the hats... before making any adjustments to the new band the hats immediately moved from the dominate left to kind of ambiguously stereo... it also seemed to kind of shift the entire stereo image slightly to the right. I get the same effect when changing the crossover point of a default band.

Any ideas what's happening here? Any help understanding the problem would be MUCH appreciated. I'm also open to any information or suggestions to manual mid/side processing.

Thank you!!!

John
Old 28th January 2013
  #2
Gear Addict
 
🎧 10 years
Any dynamic effect on the S channel, even if it the M channel has the same effect with the same settings, can add phase issues - unless the processing is a stereo effect in linked mode.

That's because as a difference signal, the S channel contains lots of phase information, and because an unlinked (e.g) compressor is likely to raise the lower level channel (S) more than the M channel.
Old 28th January 2013 | Show parent
  #3
Gear Maniac
 
john john's Avatar
 
🎧 10 years
Quote:
Originally Posted by haberdasher ➑️
Any dynamic effect on the S channel, even if it the M channel has the same effect with the same settings, can add phase issues - unless the processing is a stereo effect in linked mode.

That's because as a difference signal, the S channel contains lots of phase information, and because an unlinked (e.g) compressor is likely to raise the lower level channel (S) more than the M channel.
Thanks for chiming in! BUT, independent gain changes or compression on one or both of the M/S channels is definitely not what's causing what I described above. TC's MD3 (TDM) and MD5 (S6000) work GREAT in M/S... unfortunately, I don't have the scratch for either of those right now. What I'm experiencing seems directly linked to the crossovers on the Multidynamics5 plugin. I can process as much as I want without this anomaly as long as I don't change the default crossover points.

I don't have another multiband compressor to test this on right now, but I'm planning on at least demoing another to see if I can duplicate the problem. Regardless of those results, I'd still like to get to the bottom of what's going on here... if for nothing else, simply a better understanding of what's going on.

I'm super bummed about this because the Multidynamics5 is a little different than your standard multiband compressor... it has functionality comparable to a dynamic EQ that I find super useful... especially on my budget.
Old 28th January 2013
  #4
Lives for gear
 
🎧 5 years
You need to use the same crossover for both M and S. When the gain is reduced in a band, it will cause a phase anomaly because the crossover becomes asymmetric. Linear phase crossovers minimize this.
Old 28th January 2013 | Show parent
  #5
Gear Maniac
 
john john's Avatar
 
🎧 10 years
Quote:
Originally Posted by OpusOfTrolls ➑️
You need to use the same crossover for both M and S. When the gain is reduced in a band, it will cause a phase anomaly because the crossover becomes asymmetric. Linear phase crossovers minimize this.
Aaaaahhhh, now that makes sense to me! Thank you!!!

Hmmm... assuming that's the case, it definitely limits the flexibility of the Multidynamics5 plugin... at least the way I intended to use it. Guess I should be in the market for a linear phase multiband compressor and dynamic EQ, or of course versions that have internal M/S processing! Like I mentioned above, I'd be happy to use the TC MD3 for a multiband, but can't really afford that at the moment (nor do I really want to drop that kind of dough on legacy ONLY technology at this point). Any budget minded suggestions?
Old 28th January 2013
  #6
Lives for gear
 
🎧 5 years
LinComp by DDMF
Old 28th January 2013 | Show parent
  #7
Gear Maniac
 
john john's Avatar
 
🎧 10 years
Quote:
Originally Posted by OpusOfTrolls ➑️
LinComp by DDMF
Many thanks!
πŸ“ Reply

Similar Threads

Thread / Thread Starter Replies / Views Last Post
replies: 15929 views: 1528516
Avatar for Ragan
Ragan 11th January 2019
replies: 992 views: 105793
Avatar for funkyman
funkyman 1 week ago
replies: 22 views: 2780
Avatar for arnoldorodeo
arnoldorodeo 25th April 2021
Topic:
Post Reply

Welcome to the Gearspace Pro Audio Community!

Registration benefits include:
  • The ability to reply to and create new discussions
  • Access to members-only giveaways & competitions
  • Interact with VIP industry experts in our guest Q&As
  • Access to members-only sub forum discussions
  • Access to members-only Chat Room
  • Get INSTANT ACCESS to the world's best private pro audio Classifieds for only USD $20/year
  • Promote your eBay auctions and Reverb.com listings for free
  • Remove this message!
You need an account to post a reply. Create a username and password below and an account will be created and your post entered.


 
 
Slide to join now Processing…

Forum Jump
Forum Jump