Reverbs that are an intrinsic part of an instrument’s sound, such as a guitar amp’s built in ’verb, can be additionally included in a wider room simulation
Placing the instruments and voices of a mix into a consistent space does not preclude us from adding additional reverbs to specific parts and tracks. This is particularly true when a reverb is being used as enhancement rather than for simulation purposes.
For example, you may wish to add some spring reverb to a guitar track to help emulate a classic guitar amp sound. That reverb becomes an intrinsic component of the guitar performance, and would be present if performed in a live venue, and so it absolutely makes sense to also include it in the overall room reverb.
It is also not uncommon to apply more than one reverb to a single track when creating trackspecific enhancements and/or special effects. This is especially true of vocals and other lead lines; a good example being having both an up-front gated reverb and a more subtle, spacious reverb on the same part. In this case, however, we may not want to blend the ‘enhancement’ reverb with a shared room ’verb.
Ducking is a classic compressor-based effect that can be very useful when applied to reverb