FD4 is a set of Four completely different, parallel compressors in a single rack, every one with a completely completely different character and saturation. Impressed by a well-known mixing method, it supplies a number of parallel compression, with pattern correct mixing between compressors and dry sign.
Compressor 1: Clean, even harmonics.
Compressor 2: Clear.
Compressor 3: Quick, odd harmonics.
Compressor 4: Brickwall limiter.
An elective multiband mode routes every compressor to a separate enter/output.