You need to play with it by feel.
I found that adding some delay to the NX3000D in the Behringer DSP GUI made my direct mount hybrid and BOSS platform made feel more closely matched/realistic/accurate to my nearfield sub, where the 18” driver isn’t as close in distance.
Keep in mind that adding “distance” in an AVR (Denon and Marantz and Onkyo) is actually increasing the speed the signal is processed... it’s opposite of what you might originally have thought. IE - If your speaker is 25’ away the receiver needs to process/output the sound more quickly to arrive in sync with a speaker that is 6’ away.
VS. on the Behringer amp DSP, adding delay is actually adding delay. Making the impact / impulse response slower in getting to you.
It plays out like this
Let’s say Audyssey puts my front sub bank at 12’
It puts my rear sub bank at 4.1 foot.
That all feels very much perfect
When I split off my sub 2 nearfield bank to the direct mount BOSS hybrid idea it didn’t feel quite right. Timing (impulse response) felt a bit off.
I turned off my nearfield 18” sub and manually fidgeted with the sub2 distance playing only the Boss direct mount hybrid until I felt like it felt good and accurate to the front sub 1 Bank of subwoofers. That distance setting for sub 2 was about 2.5’
Turn on the nearfield 18” again and boss hybrid both and now the nearfield 18” felt off because with the lesser distance in the AVR they are now firing too late. (In AVR more distance = < delay, less distance = > delay)
This is perceivable with kick drums of beat based music.
So I put my sub2 bank back at the original 4.1 feet which is ideal for the nearfield (but makes BOSS hybrid fire too fast, and in my NX3000D I added a slight ~ 2 foot delay. (Making it > delay for the BOSS Hybrid)
Since my butt is 6” from the direct mount and 2’ from the nearfield it l feels perfect now.
I used generic measurements through all this but you get the idea.
