Vance Powell interview and statement on PT delay compensatio

Zero Grammys and zero delay compensation issues on HDX1 here 😁

The biggest failing of delay compensation in pro tools is the average user’s understanding (or rather, lack thereof)of how it works. Avid does themselves and many of you a disservice in its failure to clearly explain that functionality.

ADC in pt works well once you understand its architecture. It still has a few weaknesses and idiosyncratic behaviors (generally around side chains and some midi weirdness), but track order is not among them. Arrange your sessions however you choose. The big thing that matters (and what avid has done a piss poor job in explaining) is learning how to “terminate” signal paths for proper compensation. You need similar destinations for different outputs in order for latency to be correctly calculated session-wide. I didn’t watch the Vance thing but someone mentioned his use of aux tracks, and that’s what I’m getting at here. Ensuring that everything feeds an aux that eventually feeds a common destination will mitigate virtually all ADC woes.

And I was kinda joking about Vance telling tall tales. He is a funny guy but comes across as dead serious about all things audio to me. Now I obviously don’t know the guy but that’s the impression I get

Cheers,
Geoff

Vance reminds me of a bunch of guys I have worked with who are talented as hell but alway seam to interject enough humor to be interesting.

The trick with guys like this is usually about 4 well poured drinks.

I haven't watched, but I got the transcript and asked the questions y'all are asking to the o1-preview GPT model and here is the response (edit: added tonycamphd insights):

Vance Powell's Approach to Latency Compensation in Pro Tools:

Vance Powell, a renowned mixing engineer, discusses his methods for managing latency and phase alignment in Pro Tools, especially when using parallel processing. His practices might seem unconventional compared to common methods, but they are tailored to address specific challenges he encounters in his workflow.

Key Practices from Vance Powell:

1. Avoid Mixing Directly on Outputs:
- Powell advises against assigning all tracks directly to the main outputs (e.g., outputs 1 and 2).
- Instead, he creates a stereo auxiliary bus (aux) and routes all tracks through it, making this aux bus the main mix bus.
- This approach aims to keep all signal processing within Pro Tools' internal routing, which he believes helps maintain proper timing and phase alignment.

2. Use Auxes for Parallel Processing:
- By using auxes for sends and returns, he keeps all processing "inside the DSP window," which he suggests prevents latency and phase issues during parallel processing.

3. Session Organization:
- Powell places all his aux tracks at the beginning (left side) of the session.
- He believes that "time delay compensation is compensated from the left side of your session to your right," implying that track order affects how Pro Tools handles latency compensation.

4. Real-Time Printing:
- He prefers to print the mix in real-time while monitoring the recorded track instead of bouncing mixes offline.
- This practice ensures he hears exactly what is being printed, avoiding potential errors during offline bounces.

Does Vance Powell Have to Compensate Manually for Latency?

From his explanation, it appears that Powell structures his sessions to avoid the need for manual latency compensation. By carefully routing and organizing his session, he relies on Pro Tools' Automatic Delay Compensation (ADC) to handle latency issues. His methods aim to prevent phase problems that can occur during parallel processing, especially when using plugins or hardware that introduce significant latency.

Do His Assertions Have Basis on What's Known About Pro Tools, Especially Pro Tools HDX?

While Powell's methods are effective for his workflow, some of his assertions differ from the standard understanding of how Pro Tools handles latency compensation:

1. Automatic Delay Compensation (ADC):
- Pro Tools' ADC is designed to manage latency across all tracks and buses automatically, regardless of routing choices or track positions.
- ADC calculates the necessary delay compensation based on plugin latency, hardware inserts, and routing complexities.

2. Mixing on Outputs vs. Auxes:
- Assigning tracks directly to outputs should not inherently cause latency issues.
- Pro Tools compensates for delays introduced anywhere in the signal path, whether tracks are routed to outputs or auxes.

3. Track Order and Delay Compensation:
- The idea that ADC compensates from the left to the right of the session is not a standard concept in Pro Tools.
- Delay compensation is calculated based on the signal flow and plugin latency, not the physical position of tracks in the session.

Considering the Posts by tonycamphd:

The experiences shared by tonycamphd provide valuable insights into how Pro Tools handles latency compensation, especially when dealing with high-latency plugins.

Key Points from tonycamphd:

1. Pro Tools' ADC Limitations:
- Pro Tools has a maximum delay compensation limit of 16,383 samples per track.
- When using high-latency plugins (e.g., FabFilter Pro-Q3 in maximum linear phase mode), it's possible to exceed this limit on a single track.

2. Impact of Exceeding ADC Limits:
- If the latency on a track exceeds the ADC limit, Pro Tools cannot compensate correctly.
- Other tracks are offset to the maximum delay compensation, but the entire mix can go out of sync.
- This results in timing and phase issues that can affect the entire session.

3. Workaround Strategy:
- To mitigate this problem, tonycamphd places a high-latency plugin (Pro-Q3 in linear phase mode) on every track (excluding subs, auxes, and masters).
- This balances the latency across all tracks, effectively resetting delay compensation to zero because all tracks have the same latency.
- On tracks where the plugin isn't needed, he leaves it in bypass mode; however, the latency induced by the plugin remains, ensuring consistent delay compensation.

4. Latency Headroom:
- By uniformly adding latency across tracks, he avoids hitting the ADC ceiling.
- This method provides latency headroom, allowing him to use additional high-latency plugins without causing delay compensation issues.

Correlation with Vance Powell's Approach:

1. Managing High-Latency Plugins:
- Both Powell and tonycamphd are addressing the challenges posed by high-latency plugins and Pro Tools' ADC limitations.
- Powell's practice of using aux buses and carefully organizing the session may help prevent exceeding ADC limits by controlling the signal flow and plugin usage.

2. Avoiding Phase and Timing Issues:
- Both emphasize the importance of maintaining phase coherence and timing alignment.
- By ensuring consistent latency across tracks, they aim to prevent the phase issues that occur when ADC cannot compensate adequately.

3. Session Organization and Routing:
- Powell's method of placing aux tracks at the beginning of the session could indirectly help manage cumulative latency by structuring the session efficiently.
- While Pro Tools doesn't compensate based on track order, a well-organized session can make it easier to monitor and manage latency-inducing plugins.

Technical Clarifications:

1. ADC Calculation:
- Pro Tools calculates ADC based on the total latency in the signal path, including plugins and hardware inserts.
- The maximum ADC limit can be a significant constraint when using high-latency plugins.

2. Latency Induced by Plugins:
- Plugins operating in linear phase mode or with oversampling can introduce substantial latency.
- For example, FabFilter Pro-Q3 in maximum linear phase mode can introduce over 10,000 samples of latency.

3. Balancing Latency Across Tracks:
- By adding the same high-latency plugin to all tracks, the total latency is uniform, and Pro Tools can compensate effectively within its ADC limits.

Recommendations for Managing Latency in Pro Tools:

1. Monitor Plugin Latencies:
- Use Pro Tools' delay compensation view to monitor the latency introduced by each plugin.
- Be cautious when using plugins known to induce high latency.

2. Increase ADC Limits:
- In Pro Tools Ultimate, you can increase the ADC limit to Maximum (64,000 samples) in the Playback Engine settings.
- This provides more headroom for delay compensation.

3. Use Low-Latency Plugins:
- When possible, opt for zero-latency or low-latency processing modes in plugins.
- For linear phase EQ needs, consider using minimum phase mode if acceptable.

4. Uniform Latency Across Tracks:
- If high-latency plugins are necessary, consider applying them uniformly across tracks or using auxiliary buses to distribute the latency.

5. Auxiliary Buses for Processing:
- Use aux buses for parallel processing to centralize latency-inducing plugins.
- This can help manage cumulative latency and make ADC more effective.

6. Session Organization:
- While track order doesn't affect ADC, a well-organized session can help you keep track of latency and signal flow.
- Group high-latency tracks and monitor their impact on the session.

Conclusion:

Vance Powell's practices are rooted in practical solutions to real-world challenges in Pro Tools, particularly regarding latency compensation and maintaining phase alignment. While some of his assertions may not align precisely with Pro Tools' technical operations, his methods effectively address the issues caused by high-latency plugins and complex routing.

The experiences shared by tonycamphd underscore the limitations of Pro Tools' ADC and provide a strategy to manage sessions with significant latency. By adding a high-latency plugin uniformly across tracks, he ensures that the delay compensation remains effective, and the mix stays in sync.

He's really not using that many at all. 8 parallel busses on tracks 1-8 and those are: Drums Bus - 33609, Drum Crush - Fatso, Transient Designers 1&2 - SPL, Band Bus (no bass) - 33609, Vocals - 1176A, Bass -Fairchild 660, Sub Bass - Pro Subharmonic. Stereo bus is an API 2500. The rest of his template is pretty basic save for the vocal split to clean (1176a) and crush (fatso) busses. 

Same, brother, same.

It’s funny, I’ve been using Logic since I started recording again in 2011. I had left the music business for more than 20 years, but was encouraged to jump back in by my fiancé at the time. A friend referred me to someone A powerful apple laptop. When I contacted him to set up a meet to buy it, he had a whole bunch of plug-ins and said I could have them all for $100 extra. I had no idea what a plug-in was at that time, I only worked in analog decades before. I kind of figured it out, But basically didn’t know anything.

I bought the computer and he already had Logic and ProTools installed. I figured I would use ProTools because I knew most of the big studios used ProTools, but when I tried it, it wasn’t working. I had a 2 to 3 day deadline to create a song for my wedding.So I figured I better use logic and get on with it. It also came with one of those gigantic Plug-in packages with 150 plug-ins.

I managed to finish the song which was an amazing considering I had no clue three days earlier how to record digitally.  Logic wasn’t set up quite so logically.

Once I began to look around the Internet and learn anything about Logic and ProTools and Plug-ins, I realized all those plug-ins were cracked. I thought I was just buying some thing from the other guy. So I got rid of everything with the exception of one and two Plug-ins, bought Logic from Apple using Apple’s plug-ins, Some UAD  plugs and brought a few other plug-ins from third-party companies.

I used that little Apollo and logic set up for many years with no issues whatsoever. As I got more advanced I noticed that certain other systems sounded a little better, like the apogee. I considered getting them, but I really enjoyed the design of the Apollo interface. So I worked with that for many years.

Finally, I was able to get the Black Lion Audio full upgrade for the Apollo, and it’s worked out beautifully.

All the changes brought it up to a level I was finally satisfied with. The tone now resembles the Dangerous Music sound. It wasn’t as colored as say….. a Burl or the Symphony, But it was definitely high end now.

It’s such a powerful device, that I can do major production work and not feel like I’m missing something, even if I would prefer to have some of the original hardware pieces.

Hmmm…, My 2011 Mac Pro did it somewhat stressfully up to my 2022 MacBook M1 Max that does 240 instances without a cough

yeah, I was trying to respond re: running out of delay compensation (but someone else got in first).  

Oh not me, I don't run out of delay comp.  someone else here was...