Here are the 4 SVS PB-13 Ultras, behind the Focal Utopias:
These SVS Ultras are pretty huge but when they are placed behind the Focal Utopias, they look quite small.
I moved the 2 x Paradigm Servo-15 subs to the back of the room while the 4 SVS subs were in the front. I have long wanted to do this but it's a pretty back-breaking effort so it's been delayed up to now. Placing the 2 subs at the back helps to flatten the frequency response of all the subs combined. This is based on theory, on the readings I took with the Audyssey Pro equipment and by ear as well.
The integration and calibration of the 6 subs together was not that difficult. The 2 subs in the rear act as one and the 4 subs in front act as one. All the individual subs were set at around 66 to 67 db at the main listening position, which provided a summed total of around 75 db. This meant that volume levels were balanced.
The distances of the front and the rear subs are not exactly the same to the main listening position but I have come to the conclusion that it doesn't matter that much. Given the long wavelengths of the bass frequencies, it seems that slight differences don't matter. This is also the view of many well-respected audio professionals.
My main objective in getting 2 more Ultras was to experience a similar "massage" effect as in the HT of Jazzy Jake. My initial report is that my HT still pales in comparison to Jake's, at least in the massage effect.
Nonetheless, there's been a massive improvement so maybe, I'm a bit closer now to the "massage" of Gaol and Pchin.
