Trying to help out a friend here with a good recommendation. He is a big 60's/70's R&B and funk fan, so please keep that in mind. His basses are a Fender MIM P-Bass with flatwounds and a Schector Raiden Special 5 active 5 string. Its the 5 string I am concerned about this cab choice. In addition to the Ampeg PF-350 he just purchased used, he has a Peavey TKO115, that he runs with a Peavey Headliner 210 8ohm cab. The TKO115 has an internal 8ohm speaker and can take an 8ohm extension cab. He has run the Ampeg PF-350 with the Peavey Headliner 210, but is not super happy with the sound, so he is debating selling the 210 and getting a 4ohm 410 or just adding an 8ohm 115. I am advising him to go with 2 8ohm cabs for his ampeg and just add the 8ohm 115. With his current peavey 210, it does not have a spec on the effeciency and only goes down to 54Hz according to the spec of the cab. He has looked into the peavey headliner 115, but that only goes down to 45Hz and again does not list the sensitivity. I checked out the ampeg portaflex PF-115HE, which is an 8ohm cab, but again only goes down to 50Hz. My only other idea is a used Avatar B115 cab, but I don't know how easy those are to find used. His budget is $250.