It's nothing to do with sub integration - I could integrate a sub into this system perfectly from any frequency from 150Hz down.

I have the skill to do it seamlessly and that would normally be my preferred option and has been my setup method for years.

However I am talking about the difference between Direct and Stereo with the system as it is now - purely stereo speakers and set to large.

861v4 LPSU, HD621, Bryston 9BSST
KEF Reference 3 and 2c, 2 X SVS SB13 ULTRA
Audio PC: JPLay, LPSU, JCAT, PPA Studio
Cables XLO Limited, Unlimited Edition and Signature
Sony VW500 Isotek Titan, DIY Mains and Clean Signal Earth Solution