Room Correction: Should I disconnect my REL Subwoofers before running room correction?


I have a NAD C 658 Streamer / Dac with Dirac room correction.  I have a pair of REL Subwoofers R 528 connected/ integrated to the mains.  I’m wondering if it would be best to run room correction with the subs connected or to run without and then tune the RELS after.  
Equipment:
Modwright150SE
Dali Euphonia ms-4
NAD C 658
REL R528 x2 
puffbojie
@George. To clarify : So when running the RC, I would set the sub volume at 50% and the frequency at 100%? If I am understanding that, would I then leave the sub at those levels when playing music?
Yes make sure you say yes to having a sub, volume at 50% and xover at max hz, if your auto setup room correction program is done using a microphone, the the program should do it all for you, even the sub phasing. I know Audyssey does, and it’s very good at it hardly had to manually tweak it all in my HT room.

Cheers George
Hello puffbojie,

If the R528 subwoofers are connected via RCA to the sub outs on the C-658 streamer then you can leave them connected while the room correction program runs. If they are connected using the high level input to the speaker output terminals on the power amplifier, then we have found that it is best to run the software with the high level cables disconnected from the back of the subwoofers. In some cases when you have subwoofers connected using the high level input the room correction software will "see" the output of the subwoofers as being too much bass output coming from your main loudspeakers, and as a result the software will turn down the bass frequencies being sent to your left and right speaker channels. This can make it so that you're system lacks low-frequencies no matter how high you turn up the level on the subwoofers.

In our experience it is best to run the room correction with just the main loudspeakers connected and set to large or full-range within the NAD streamer, and after the program has finished you can reconnect the subwoofers and tune their level and crossover controls by ear to blend with the loudspeakers. 

We have an article on our website which could be worth checking out, that goes into detail regarding using room correction with REL subs:  https://rel.net/how-to-use/
Room correction primarily addresses lower frequencies so they have to be on. That's the whole purpose.