Feature Request: A/B Loudness Matching for channels, busses, and plugin chains

This is a new post for the current version of Cubase. Referencing previous posts:

Understanding the actual effect of plugins on a signal chain, without perception being colored by loudness changes, is crucial.

Use case: User is evaluating the effect of an EQ, compressor, and limiter on a bass track. The user wants to listen to the exact change to the signal without being steered by an increase/decrease in overall volume (which, due to Fletcher-Munson and the effect of loudness itself) can unduly influence perception of the changes being made.

Cubase does currently provide some built-in plugins which individually offer automatic level matching, and there are complicated routing schemes that can approximate the desired matching, but many users would like simple, built-in loudness/level matching functionality that can be applied ad-hoc at any points in signal processing chains.

Current workarounds:

  1. The user can buy specialized plugins for this task, such as:
  • HoRNet CLMS
  • LetiMix GainMatch
  • Melda MCompare
  • MeterPlugs Perception AB
  • TB Pro Audio ABLM
    These plugins work pretty well, but they’re a hassle to set up (two instances per channel /bus- a feeder instance at the top of the chain and an evaluator instance at the end of the chain) and several are expensive relative to their functionality. The plugins’ advantage is in continuously integrating loudness matching for precision.
  1. More imprecisely, the user can utilize loudness meters to roughly match loudness manually. This is also a bit of a hassle because the user has to set up metering correctly and make manual level compensation changes every time a change is made to the chain.

  2. Also imprecise, the user can “eyeball” it with their ears. This avoids the hassle and expense of setting up meters or specialized plugins, but it will likely be the most frustrating, time-consuming approach.

Feature Request: Include optional loudness compensation as an integrated part of the plugin system in Cubase (similar to Smart Bypass in Steinberg WaveLab, but using a continuously integrating algorithm like the plugins mentioned above).

The user could:

  • turn on overall loudness compensation for each track (keeping levels consistent regardless of plugins used); or
  • set numbered “in and out” points for each loudness compensation thread. For example, the user could set the source (starting “in” point) before a specific plugin on a bass track, and set the compensation (adjustment “out” point) after a specific plugin on the master buss. (For lateral-thinking examples of this sort of numbered matching scheme, see Blue Cat Audio ’s metering plugins, where tracks can be assigned numbers and all represented within one plugin instance. Not a direct analogy, but the numbering idea is similar.)

In response to previous posts, users mentioned:

This sounds like it would be a good addition to the channel strip as another mini-plug. You could enable/disable, have one knob to set how much level matching, and a few meters to check differences. - @omniphonix

Personally, I would like to see the option to have a small meter that measures the difference between the input and output volume of each plug-in effect. In addition, a small trim slider that you could easily adjust to properly gain stage your chain. There could also be an option button to auto adjust the gain to match the input and output levels for the entire chain if that is what you prefer.

The extra metering may use quite a bit of extra CPU so it should be optional for those who have older computers. However, if it were coded to only meter the chain on the selected channel, it shouldn’t be too heavy. - @Quinn3k3

If the infrastructure to provide this feature is built (tapping the input signal at two locations), it might not be a huge stretch to extend that capability to provide a differences output - flip the phase on the “after” signal (that signal having been first level-adjusted) and mix that with the “before” signal. The result would be just that which is different between the signal at the “before” tap and at the signal at the “after” tap. - @dmbaer