Almost all Surround processors have some way of doing this, don’t they, and always have as far as I remember?

Whether the OP, who specifically loves Trifield, will like them, though, is a complete unknown - they all have their own ways of doing this (and some may be better - who knows?) but they're not Trifield as Meridian were a sole licensee, as I recall, apart from a short-lived software version, which disappeared pretty quickly.