Definitive Technology Speakers BP 7006 built in Subwoofer/Amp Question


I purchased these speakers without testing them.
I only paid $ 80.00 for the pair.
When I hooked them up  they sounded good even though it became evident that
both built in Subwoofer/Amps are not functioning.
Just Tweeter and Mid range are working.
It has LFE Inputs in back of speakers.
My question:
Should I add an external subwoofer or leave the speakers as is ?
I have a Sansui AU 607MR Integrated Amp. How would I hook up external subwoofer to this amp?
Does anyone own these speakers...I would like to hear your input.
Thank you
rocky1313
I believe these amps are a very common problem. Do a google search,and you will see what I’m talking about. Still a decent speaker for $80. I run def tech subs in my HT,and they have a history of bad plate amps. 
Thank you for your reply.
Are the subwoofers in your home theater ...are they external subwoofers?
Thanks
Yes they are. For some reason,def tech had some issues with what seems like most of their sub amps. It didn’t seem to matter if they were powered subs in the speakers,or separate subs.   I do like the way their subs sound,but when they die again,I will look elsewhere. 

Hey rocky1313, don’t listen to stereo5, he doesn’t know what he is talking about.   Your amps have gone bad, because they have design flaws. They could have not been absurd in the least bit and the amps will still go out.  Also, running the speakers without the sub causes ZERO problems with impedance. They are not wired together, so feel free to run them without the subs as much as you like.  If you still have them, I do repair these amps if you’re interested.  If not interested in having them repaired, I would be interested in buying the bad amps off of you.  Just lmk, thanks!

Just came across this. I've got 4 BP 7006's. All 4 are blown. What do you charge to repair? Would you be interested in repairing 2 of them in exchange for 1 set? Also, what would you buy them for blown as individual amps and as whole speaker? I actually am embarking on building my own cabinets for them as soon as I can locate or fix 2 of the amps. The only reason I have 4 total was because the second set I bought had fully functional amps that went bad within a month of purchase.