SDA 2 + The SDA Effect

jimmydep
jimmydep Posts: 1,305
edited October 2010 in Vintage Speakers
Awhile back at a Local NJ. Polkie get together at Sal's house, I was introduced to the 1.2TL's and the SDA effect. I marveled at the wide sound stage and pin point placement of the instruments.......so I began to look for SDA's in my area, hoping to find a pair of 1C's with no luck.

As luck would have it at this years Polk Fest Hawkeye generously donated a beautiful pair of SDA 2A's to be raffled off, and I got to take them home (with the help of Devani).

I finally hooked them up this weekend, and I must say they are very impressive. I noticed that small changes in speakers placement can have a big affect on the SDA effect.

I'm curious about a few things I've noticed, for one some of the vocals seem to emanate from the floor, and the sound stage seems to be centered at the height of the passive radiator.

Is it common to shim the front of the speaker to tilt it back slightly?


Jimmy
Post edited by jimmydep on
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Comments

  • sda2mike
    sda2mike Posts: 3,131
    edited October 2010
    doesn't sound right...there is a sticky on the forum that has the wiring diagram for your speakers...i would start there...also, make sure all drivers are functioning...do a search for 'sda test'...that might help..btw, you don't need to shim your spkrs


    mike
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  • chandler9a
    chandler9a Posts: 878
    edited October 2010
    I would say its your room if nothing is actually wrong with the speakers. I have the same SDA's and moving them an inch can change where sounds are coming from in certain rooms.
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  • Conradicles
    Conradicles Posts: 6,082
    edited October 2010
    My center stage is about ear level or slightly above when seated; kind of near the top of the speaker. I have owned a few pair of SDA's and never heard vocals low like you are describing. Sounds kind of odd.
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  • headrott
    headrott Posts: 5,496
    edited October 2010
    Check to see if they are 90 degrees perpendicular to the floor. You should not have them tilted forward or back (or left and right for that matter). They should be perfectly level.

    Greg
    Relayer-Big-O-Poster.jpg
    Taken from a recent Audioholics reply regarding "Club Polk" and Polk speakers:
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    My response is: If you need 60 seconds to respond in one sentence, you probably should't be evaluating Polk speakers.....

    "Green leaves reveal the heart spoken Khatru"- Jon Anderson

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  • cnh
    cnh Posts: 13,284
    edited October 2010
    The general rule of thumb is to put SDAs least a half foot from the back wall or a bit more. Space them about 8' apart (if you can, this is dependent on room size and listening area....as little as 4 feet is possible). Make sure they are EXACTLY on the same front line and that there is NOTHING between them; that they are furthest out from the wall with nothing farther out than them--even though they are not that far from the wall.

    They should also be at least 3 feet away from any side walls on either side. And you should sit or find the sweet spot. As for tilting SDAs, no. Straight up...in the same plane, close to the back wall and FAR from the side walls.

    Make sure the SDA I/C is firmly connected, and remember that NOT all recordings will give you the full SDA effect and you must find your 'listening' spot.

    And congrats on the speakers. I have some kind of SDA 2A/B transitional model so much like yours and the ONLY room in the house I can use is the basement room where they take up far too much space and have to be placed in front of the HT floorstanders I have in a BUILT-IN unit down there. NOT ideal..but the only free wall that is more than 14' long?

    Good Luck...

    cnh
    Currently orbiting Bowie's Blackstar.!

    Polk Lsi-7s, Def Tech 8" sub, HK 3490, HK HD 990 (CDP/DAC), AKG Q701s
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  • jimmydep
    jimmydep Posts: 1,305
    edited October 2010
    Thanks for all the responses.....I see I must take a more calculating approach to placing these speakers, so I've got my tape measure, carpenters square and a level at hand. I've already determined that the speaker are in fact tilting forward so moving them 7" from the back wall and standing them up straight has made a substantial difference, but some tracks still sound like they are 6" above the floor.

    Jimmy
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  • Face
    Face Posts: 14,340
    edited October 2010
    Something is either out of phase or you're experiencing some funky room reflections.
    "He who fights with monsters should look to it that he himself does not become a monster. And when you gaze long into an abyss the abyss also gazes into you." Friedrich Nietzsche
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  • sda2mike
    sda2mike Posts: 3,131
    edited October 2010
    jimmydep wrote: »
    Thanks for all the responses.....I see I must take a more calculating approach to placing these speakers, so I've got my tape measure, carpenters square and a level at hand. I've already determined that the speaker are in fact tilting forward so moving them 7" from the back wall and standing them up straight has made a substantial difference, but some tracks still sound like they are 6" above the floor.

    Jimmy

    good to hear you got some improvement! i'll bet the sounds you're getting from the floor are your brain playing with you, based on the old config of your spkrs...get some long listening sessions in! that should work
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