could You recommend a good compressor pedal?
My bassman has a 15" speaker, can I still achieve a decent sound?would a boss compressor and flanger be sufficient?

a boss compressor and flanger is a good buy but if you can get a hartke 4x10 cab to add to the 15 or just use the 4x10 you will be blown away by the difference. bass is the one thing you don't have to worry about being heard the trick is to keep it clear and not muddy. if you were playing an arena then 15" speaker combined with the 10's would be great but for clubs and rehearsal rooms it's overkill. in the studio we always use 10" speakers because the incredible clarity they give.

also check out
http://www.ehx.com/ehx2/Default.asp?...Black%5FFinger and
http://www.ehx.com/ehx2/Default.asp?...Flanger%5FHoax

I'd like to thank You for Your help, You seem quite knowledgeable on the subject.:)

no problem. let me know how it works out. :)