How many subs?

I got my room analysed by an acoustic engineer.

3 subs - 2 with delays.

Maybe I did not have the gain set right for each sub?

The pressure in the room was overwhelming.  Opening the door was a relief.

One sub - front left - the one with no delay in the design seemed really good.

But I got hungry for more - so I tried 2 subs.

Does anyone have experience with using a multi-sub setup using delays?