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
First, I would check to see if the internal subwoofers in the speakers are blown.  You do have the speakers plugged into the wall socket, correct?  From there if the subwoofers check out okay, I would call Definitive and find out the price on 2 plate amps for the subs. If the amps or subs are blown, it tells me the speakers were really abused and should probably go into the trash.  Running the speakers without the woofers can really screw up the speakers impedance. 
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