Back brace of SDA SRS 2.3

fredv
fredv Posts: 923
edited May 2005 in Vintage Speakers
I will be picking up my very first SDA (SRS 2.3) from a fellow Polkie here this weekend. However, the back braces were lost. Can one of the current SDA SRS 2.3 owners post a picture of the braces so that I can fabricate one myself.

TIA,

-fredv-

-fredv-
Post edited by fredv on

Comments

  • BobMcG
    BobMcG Posts: 1,585
    edited May 2005
    Hi Fred, congrats on the new 2.3s I'm sure you'll love them as much as I do mine.

    The base of the Bass-Brace is a small metal plate 2 1/4' wide x 1" tall by 1/4" thick. The center is drilled and tapped to accept standard 1/4" threaded rod as is the back of the speaker itself which should have a filler screw (air seal) in place. The plate is drilled out on either end for screws to mount it to a wall. Double sided mounting tape is also included in the original package from Polk incase you don't want to drill holes in your wall. At each end of the Bass Brace rod Polk supplied a washer and a wing nut for locking the ends in place. I also used a touch of silicon sealer on the speaker cabinet side to keep it air tight and bought and cut custom length rods for my Bass-Brace system.
    Good luck with the project.
  • fredv
    fredv Posts: 923
    edited May 2005
    Thanks for the picture. Will the performance of the SDA degrade if I don't have such brace installed? I am think about mounting the speaker to 2" thick wooden board (24" x 24" x 2"). That should help securing the tall speakers and separate it from the thick carpet below.

    Thanks,

    -fredv-

    -fredv-
  • BobMcG
    BobMcG Posts: 1,585
    edited May 2005
    I can't see where the SDA effect would be degraded but perhaps the bass might be. It works like floor spikes for reinforcing the bass response. Although Polk recommends using the Bass Brace OR the floor spikes I utilize both. I found out the reason they recommend one or the other is only due to the fact that with the spikes on the bottom (which have to be put on first obviously) and the weight of the speaker to contend with and the possible damage that could occure to the floor, getting them in place to use the brace would be a duanting task. And it is indeed but do-able none the less if you're up to the task and determined. I did it myself but it would be much easier with help. You have to lift the speaker, there is no sliding it. At least not without floor damage and perhaps even ripping the spikes right out of their sockets!

    AND: The speakers are tall without being all that deep in proportion and the Brace prevents any movement that might otherwise occur due to high volume levels. (Very excited drivers mounted fairly high!) Combine this with their hefty weight and say a less than rock solid floor and Polk figured you could get movement. I can see their point. If you were to find the balancing point of one of these speakers I think you'd find them a bit top heavy.

    You might have a decent platform with the base you're thinking of using though. You'll find out. :)
  • fredv
    fredv Posts: 923
    edited May 2005
    Thanks again for the info. It is going to be quite a challenge to work on the speakers that are only 1 foot shorter than me :D

    I have purchased a preowned common ground Mac (Mc-2002, Direct Couple not Autoformer) for the SDA SRS 2.3. [The Mc-2120 that I mentioned before will continue to hook up to the Dahlquist.] It is rated at 200wpc @8ohm and 300wpc @4 ohm. Since I don't play really loud, I hope this "new" amp will provide all the juice the 2.3 wants, stay tuned ;)

    -fredv-

    -fredv-
  • madmax
    madmax Posts: 12,434
    edited May 2005
    Vinyl, the final frontier...

    Avantgarde horns, 300b tubes, thats the kinda crap I want... :D
  • fredv
    fredv Posts: 923
    edited May 2005
    Originally posted by madmax
    Here is a pic of some home made braces I made.
    http://clubpolk.polkaudio.com/forum/showthread.php?s=&threadid=20087&highlight=madmax+bass+brace
    madmax

    Many thanks for the link to this thread. Now I know what to look for in my next trip to Home Depot!!

    -fredv-

    -fredv-
  • F1nut
    F1nut Posts: 49,707
    edited May 2005
    I would encourage you to forget the platform idea, make the bass braces or get carpet spikes instead.
    Political Correctness'.........defined

    "A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."


    President of Club Polk

  • fredv
    fredv Posts: 923
    edited May 2005
    I would encourage you to forget the platform idea, make the bass braces or get carpet spikes instead.

    You are absolutely right. After I saw the real speakers in person, I very much concluded that making a pair of bass braces was the prefer solution. I am glad that a long weekend is coming up :)

    -fredv-

    -fredv-