Dual mono with REL Subwoofer

[PeppaPig]

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So next thing I changed was speaker delay without effecting the pre out in the configurator. A big plus for the Devialet over almost any other amplification option. I ended on 3ms. I know that doesn’t sound a lot but it’s what changed me from regretting the sub purchase to loving it.
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By the way do you mind to share a screenshot of your Devialet configurator? how you set that 3m delay? Your G2 has a carbon cone, should be extremely fast in response. Surprise 3ms makes you feel the big differences.

The 3ms delay is there mainly (I assume) to compensate for the fact that the distance from the sub to the listener is further than from the main speakers to the listener, not to compensate for the sub itself being "slower" than the main speakers.  (Although having said that if there's signal processing going on the sub that might cause a delay in the sub output that can also be compensated for by adding delay to the mains.) 

Incidentally, a 3 ms delay is equivalent to about 1m difference in path length, because the speed of sound at normal temperature and pressure is about 340 m/sec.

Good thinking. It can be that reason too if Mart our his sub 1 meter behind the main speakers.