I was wondering what the depth knob on the ott compressor actually does i want to use another multi band compressor to achieve the same effect but i dont get what is actually happening. Can someone tell me what it is doing to the sound like why it sounds flat and also how it does it thanks.

The OTT plugin from Xfer is modeled off of the OTT preset for the Ableton Multiband Dynamics effect. It's an Upwards/Downwards Multiband Compressor and Expander, pushing everything Over The Top (hence the acronym OTT) so that the frequency response of the sound is essentially equal in level - all the quiet parts of the sound are brought up to be the same volume as the loud parts of the sound, which are being pushed down to fit within the same range.

Since low frequency sounds require a lot more energy than high frequency sounds, this ends up pushing down the bass and increasing the treble, as all that HF content is now at equal power (which is actually perceived as louder).

The depth knob on OTT is IIRC somewhat like a dry/wet knob, in that it changes how strong the effect is on the sound. The knobs that say Upwards and Downwards also do similar effects, but on the Expander and Compressor, respectively.

An expander does the opposite of what a compressor does - instead of reducing the distance between the loudest point and the quietest point, it increases them. It has the same (or similar) controls to a Compressor, and many compressors have an expander option. You can think of it like this: "Below Threshold = Off, Above Threshold = On (and maybe LOUD)"

A noise gate is a good example of an expander - If the signal doesn't go over the threshold you set, it's cut off completely.

No problem! Happy to help.