SP-2000s:
Take the backs off and spray some 'Dioxit' in the rotary switch in the back that controls the tone. Move switch back and forth about 50+ times. Doing that may clear everything up real nice. Guys have done this and said it fixed everything up and all the speakers fired up. You know, corrosion on the rotary tone control switch. Cleaning this corroded switch, the guys say, will fire up all the speakers real nice, if that was indeed what your problem was. It's an easy fix if that's all it is!
If that doesn't work, you need to check all your speakers and do a recap. In the AK Sansui section the guys explain exactly how to recap SP-2000s right down to everything required including the exact Daton caps required, numbers, and where to order them. One guy did this, think it was req50, and it really worked well so he told everyone how to do it, all the other guys copied him and achieved the same outstanding results. The only hard part is fitting all the newer larger caps on the smaller crossover board, but it can be done with a bit of jury rigging, tie straps, and a heat glue gun. There are photos to give you examples of what you should be doing. It's been done before, it can be done again! Right! It's a weekend job.
I have 2 pair. Both pair are untouched. One pair sounds 'really nice' and I'd give the cabinets a good 93+%. They sound so good that I wouldn't ever touch em for any reason. No need to..."yet". The other are 'Factory Fresh' in the boxes but sounds boomy. I'm guessing because the speakers have never been used and the capacitors have deteroriated. Never tried the 'dioxiting' of the tone controls yet but someday. I haven't done anything to them but keep em polished up, they are in the closet, and that's where they are going to stay for a later day. I'm pretty sure it's a cap job required, but who knows, it may just be the tone control switch. Just read up on recapping SP-2000s and you will find out all the info you need. And...they have Alnico speaker magnets which are really nice if your into that Alnico sound, which to me, is the best sound.
Everyone keeps knocking Sansui speakers. I, for one, really like the sound of mine. So does everyone else who hears em. And that's without a rebuild. They sound pretty darn nice to me.
SP-11000:
Now the big SP-11000s. Never heard them but have seen maybe 100 fotos of them and it sure is a wall of speakers!!!!!!!!! Biggest speakers Sansui ever made and they just look way-cool if you have the room for em! I'd give em a listen, if the cabs are fine, and all the 'connecting cables are there' (and that's super important!!!!!), and the individual speakers are in good shape, and if it sounds good, ya got a Sansui collectors item for sure. But I have heard that some people who have heard them say that they don't sound 'that' great. Got to hear them for yourself. *'Really concentrate on the sound of the woofers'*. I bet a good pair sound pretty darn good! I have seen em sell for $1000 and more for a beautiful pair...Plus shipping costs which is really expensive, and guys bought em. Very rare speakers indeed. And they look outrageously K O O L with the grills on.
'MAKE SURE' you get the orgional Sansui connection cables with the speakers!! I believe those had 'very special cables with special connections' for connecting the speakers to each other!!!!!!! No origional cables, no sale cause there is no resale value without em. Replacement speakers are probably darn near impossible to come by. Getting orgional cables would be like almost impossible.
That's all I know about them.
Good luck!