[nsa100]

Having had my G31 for 2 months now with the Bowers & Wilkins audio system, in my opinion if definately needs a little more bass to balance out the mids and highs.

So I decided to add 2No 8" Subwoofers. I wanted to maintain the factory look so decided to install them under the floor in luggage area.

I knew before I started it would be difficult to find a subwoofer thin enough with enough power handling to fit under the floor. Basically you have about 95mm to play with which must accommodate the depth of the speaker and cabinet. Because I didn't want to get into fibre glassing I decided to make it out of mdf sheets which I got CNC cut to my ACAD design.

Initially I wanted the speaker enclosure to sit on top of the under floor carpet liner but having designed it fit the contours of the carpet it was still about 5mm too thick so I had to remove the liner.

I designed the cabinet for 2No RETRO Sound 8" Slim Subwoofers which were rated at 250 WRMS each. These would be driven by an Alpine PDR-M65 Amp which puts out around 450WRMS at 4 ohm. Having wired the speakers up and tested them they just cannot handle the power so I returned them.
I ended up buying 2No Kicker 8" CompRT Slim Subwoofers. I wired these at 2 ohms so the amp would deliver 650WRMS. I had to modify the enclosure by inserting MDF rings as the mounting diameter was smaller.

I installed an Audiocontrol LC2i to take the speaker level to phono level and then passed it through a MiniDSP to compensate for the enclosure roll off and more importantly the time alignment.

I am now blown away by the sound. There is not window rattling bass, but the system sounds more balanced now especially at higher volumes when the system bass gets rolled off.