Hi John C.
I added a KAS 200SM1 to my kn7000. This is available from Technote and at present on special price of £499.00(UK pounds).
This has made a terrific improvement in the sound of the KN and although it is expensive
can cope with a small/medium venue. It has the main bass booster plus two small monitors and is very light to carry. The main bass woofer is 120 watt and the two monitors can cope with up to 100 watt. Leads and cables are included. If you go on the technote site then you can read the info on them. With normal home use I have
set mine to a two thirds setting and then control the overall volume from the keyboard, which I have set at about one fifth.
Hope this is of some help.
Regards
Peter B