In Bedfordshire you got Autotronics Car Audio shop, 201 London road Bedford.
Hertfordshire you got Herts Car Audio it is on the road out of hitchen and towards Stevenage.
DNDservices (Car Audio) in Stevenage
www.dndservices.co.uk
These and other places are in the Yellow pages under Car Audio.
What do you need Black cloth for?
I am in Bedfordshire as well and am building a farly nice 5.1 system piece by piece I am about 1/2 way through and will be finished in the next month.
I currently have.
Lg3200e DVD player.
Denon 355 UK Amplfier.
Mission M73 Floostanding Mains.
21 inch 4:3 Television. (soon to be 28 inch widescreen)
Radio Shack Analog SPL meter.
I have just perchased a Denon 1802, I waiting for delivery of the amp. This will be matched to a M7c2 center and m7ds surrounds.
To crown the HC will be a DIY built IPL Acoustics SW2 subwoofer for the deep bass, I have still not chosen what finnish for the outside of the subwoofer.
Good Luck.