SDA 2B Studios: powered by monoblocks and no isolation transformer!

I'm kind of embarrassed to admit this but I need some advice. Please excuse the long post as I wanted to describe my issue in detail.

Back in 2013 I bought a set of SDA 2B Studios. They were in excellent condition cosmetically. But when I put these speakers in my system I remember being underwhelmed by them. They have the pin-blade connectors and the guy I bought them from had spliced the interconnect cable to make it longer. He used regular speaker wire to make the extension.

When I hooked them up they just didn't sound very good. Nothing really stood out that something wrong but the highs were harsh and there wasn't much bass. I also remember not really noticing what all the hype was regarding the SDA effect, either. If I recall correctly they were only in my system about a month or two.

Well, to get to the point... at the time I was powering my SDA 2B's with a pair of W4S SX-1000 class-D monoblock amps. The SDA's and monoblocks are both out of my system and have been for several years now. I'm just using an Onkyo receiver with a set of Pioneer SP-FS52 speakers at the moment.

I recently decided I want to try putting my SDA's back in my system and after doing some reading and research I decided my speakers probably need some upgrading. So I ordered a pair of Larry's rings with the plan to seal the cabs, redo the crossovers, add new binding posts, etc. All good so far, except...

After getting my rings I seen these cases Larry's selling... Dreadnought cases. I'm like wtf are these things and why would I need one? After doing some more research now I know, and now I see that powering my SDA speakers with my monoblock amps was a big mistake. Hence my embarrassment.

So now I'm wondering if I've done some serious damage to my speakers or amps. So before I start the rebuild process and go through the effort, I'd like to ask if anyone can weigh in and give me some advice on what to do first to see if I need more than just a standard upgrade.

I ordered a dreadnought case from Larry to build an isolation transformer so I don't make the same mistake again. But I'm worried, so before I do anything else, what would be advisable to check regarding the way I had these speakers powered before?

I appreciate any help, thanks

Comments

  • polrbehr
    polrbehr Posts: 2,825
    You may well have damaged the speakers. But, I would try hooking up your AVR to them anyway, I think most if not all AVRs are common ground so you'd be OK doing that.
    Use just left and right to start, keep the volume down, and listen to them. Then, shut down and try connecting the SDA cable and do the same thing.

    If the Xovers and tweeters are OK, there could be something wrong with the SDA cable; especially if you feel there's no SDA effect and the bass is thin. No matter, even if you did irreparable damage, they can (and should) be restored to working condition. They will be eye-opening once you've done that.
    So, are you willing to put forth a little effort or are you happy sitting in your skeptical poo pile?


    http://audiomilitia.proboards.com/
  • Checked out my speakers over the weekend and they're toast.

    No bass, highs are null, no SDA effect. Looks like I really F'd up.
  • Pull the passives and take a look at the crossovers for damage.
    Yamaha RXA1030, Yamaha CD-S2100, Yamaha AS-2200, Bluesound node 2i
    Polk SDA2btl highly modded
    Polk SDA 1C modded
    Polk CS350 LS x2
    Kimber 8TC
    Sony 55" Bravia
    Wish list SVS sub

  • Thanks for the help. Lots of folks have viewed my issue here but not a lot of comments, so I appreciate the advice.


    Wasn't real sure how I should proceed but I can certainly pull the passives and take a look at the crossovers. What should I be looking for, specifically? Burnt parts or something else?
  • By the way, from just a visual inspection the drivers and tweets seem fine.
  • pitdogg2
    pitdogg2 Posts: 24,474
    edited February 2017
    you'll know it when you see it most likely the case.

    Post pictures of them we'll be able to offer more help.