Difference between SDA 1b and 1c

McLoki
McLoki Posts: 5,231
edited January 2005 in Vintage Speakers
Subject says it all. I have a pair of SDA speakers in my basement (purchased new in the late 80's). I think they are SDA 1b's but am not sure. Is there a way that I can tell from looking at something on the speaker? (SDA cable is the double blade type, not blade/pin if that helps.)

Also, I have read in a few places that there is a tweeter upgrade available for these speakers. Is that true and what is the difference between the factory tweeter that I have and the new one.

Final question. Would they mate ok with the LSiC that I have now, or should I just run phantom center (they are SDA's after all) and run the 7's rears with the LSiC as a rear center for 6 channel sound?

Thanks,

Michael
Mains.............Polk LSi15 (Cherry)
Center............Polk LSiC (Crossover upgraded)
Surrounds.......Polk LSi7 (Gloss Black - wood sides removed and crossovers upgraded)
Subwoofers.....SVS 25-31 CS+ and PC+ (both 20hz tune)
Pre\Pro...........NAD T163 (Modded with LM4562 opamps)
Amplifier.........Cinepro 3k6 (6-channel, 500wpc@4ohms)
Post edited by McLoki on

Comments

  • Tour2ma
    Tour2ma Posts: 10,177
    edited January 2005
    Easy difference to spot here... cabinet style. The C's have the SRS style end caps. The B's are boxes with what looks to be a built in base (ala the larger Monitor series, e.g., the 12's).

    Mid-woofer driver complement does differ, but both have the SL2000 tweeter. There is a replacement for the 2000 that many prefer and some think sounds good with the LSi tweeter in HT.

    Since you have them, try them and then decide whether or not you need to upgrade, which will run around $200, less any fundage from sale of your old 2000's.
    More later,
    Tour...
    Vox Copuli
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    "Death doesn't come with a Uhaul." - Dennis Gardner

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  • jdhdiggs
    jdhdiggs Posts: 4,305
    edited January 2005
    I have the 1B and LSi's and they mate OK (Not for super critical listening, but for HT they're fine)

    Still stock 2000's, not the upgrades...
    There is no genuine justice in any scheme of feeding and coddling the loafer whose only ponderable energies are devoted wholly to reproduction. Nine-tenths of the rights he bellows for are really privileges and he does nothing to deserve them. We not only acquired a vast population of morons, we have inculcated all morons, old or young, with the doctrine that the decent and industrious people of the country are bound to support them for all time.-Menkin
  • McLoki
    McLoki Posts: 5,231
    edited January 2005
    Originally posted by Tour2ma
    Easy difference to spot here... cabinet style. The C's have the SRS style end caps. The B's are boxes with what looks to be a built in base (ala the larger Monitor series, e.g., the 12's).

    That settles it. I have the SDA 1b's. I have always liked the sound of them. (played through a Yamaha M-85 amp) They can get a little bright when played loudly, but have a great soundstage and were VERY realistic for Home Theater duty. (back when HT consisted of stereo speakers hooked up to a VCR).

    If I end up moving my HT out of the family room I will repost and let you all know what I think of them in a 5.1 system.

    Has anyone just run 4 of them (fronts and rears) for HT? I really don't see the need for centers with SDA's. I have always wanted to get a set of SRS's (fronts) and run the 1B's as rear channels. I can't imagine HT getting much better than that.

    Michael
    Mains.............Polk LSi15 (Cherry)
    Center............Polk LSiC (Crossover upgraded)
    Surrounds.......Polk LSi7 (Gloss Black - wood sides removed and crossovers upgraded)
    Subwoofers.....SVS 25-31 CS+ and PC+ (both 20hz tune)
    Pre\Pro...........NAD T163 (Modded with LM4562 opamps)
    Amplifier.........Cinepro 3k6 (6-channel, 500wpc@4ohms)
  • jdhdiggs
    jdhdiggs Posts: 4,305
    edited January 2005
    When I added the tube CDP, the brightness went away on mine. If you want to stick with SS gear, you may look at changing out the tweets.
    There is no genuine justice in any scheme of feeding and coddling the loafer whose only ponderable energies are devoted wholly to reproduction. Nine-tenths of the rights he bellows for are really privileges and he does nothing to deserve them. We not only acquired a vast population of morons, we have inculcated all morons, old or young, with the doctrine that the decent and industrious people of the country are bound to support them for all time.-Menkin
  • VR3
    VR3 Posts: 28,666
    edited January 2005
    Old yammer gear is bright, OUCH -

    However, I wouldnt get to hyper on the no center thing, try it first, unless you watch movies alone 100%, i wouldnt even think about it. However, if you do, WHY NOT! the best center is no center.
    - Not Tom ::::::: Any system can play Diana Krall. Only the best can play Limp Bizkit.
  • Larry Chanin
    Larry Chanin Posts: 601
    edited January 2005
    Hi,

    For home theater if everyone were sitting on axis perhaps a center channel wouldn't be needed. However, as the name suggests, home theater frequently involves a group of people where its not always feasible for everyone to be sitting in the center.

    In movie soundtracks the center channel is used to anchor the dialog in the middle of the sound stage. Without it folks sitting off axis would hear the dialog collapsing into the nearest speaker, and the soundstage would be skewed to the right or left depending on where the listener was sitting.

    I have a dedicated home theater with SDA-1Cs as mains. I use a pair of stacked SDA CRS+ as centers. They are perfectly timbre matched centers for the 1Cs.

    Larry
  • McLoki
    McLoki Posts: 5,231
    edited January 2005
    Originally posted by Larry Chanin
    Hi,

    For home theater if everyone were sitting on axis perhaps a center channel wouldn't be needed. However, as the name suggests, home theater frequently involves a group of people where its not always feasible for everyone to be sitting in the center.

    In movie soundtracks the center channel is used to anchor the dialog in the middle of the sound stage. Without it folks sitting off axis would hear the dialog collapsing into the nearest speaker, and the soundstage would be skewed to the right or left depending on where the listener was sitting.

    I have a dedicated home theater with SDA-1Cs as mains. I use a pair of stacked SDA CRS+ as centers. They are perfectly timbre matched centers for the 1Cs.

    Larry

    Thanks for your comments. Do you find the SDA effect of these speakers makes the problem better or worse? I was wondering if the SDA would compensate for the lack of a center channel.

    Do you notice a large difference in your setup if your 1c's have the interconnect cable connected and you set your preamp or avr for center channel = "none"?

    If you have not tried it, please do and report back if you notice a large change in the soundstage from where you are sitting. I thought the SDA's had a very large sweet spot, but that is from memory. (I have not run my 1b's for quite a while (years)) due to placement issues (read WAF issues) and lack of proper amplification. (They just sounded really bad when run from my onkyo - no bass at all. They do ROCK with my new amp though :) )
    Mains.............Polk LSi15 (Cherry)
    Center............Polk LSiC (Crossover upgraded)
    Surrounds.......Polk LSi7 (Gloss Black - wood sides removed and crossovers upgraded)
    Subwoofers.....SVS 25-31 CS+ and PC+ (both 20hz tune)
    Pre\Pro...........NAD T163 (Modded with LM4562 opamps)
    Amplifier.........Cinepro 3k6 (6-channel, 500wpc@4ohms)
  • Larry Chanin
    Larry Chanin Posts: 601
    edited January 2005
    Originally posted by McLoki
    Thanks for your comments. Do you find the SDA effect of these speakers makes the problem better or worse? I was wondering if the SDA would compensate for the lack of a center channel.

    Do you notice a large difference in your setup if your 1c's have the interconnect cable connected and you set your preamp or avr for center channel = "none"?

    If you have not tried it, please do and report back if you notice a large change in the soundstage from where you are sitting. I thought the SDA's had a very large sweet spot, but that is from memory. (I have not run my 1b's for quite a while (years)) due to placement issues (read WAF issues) and lack of proper amplification. (They just sounded really bad when run from my onkyo - no bass at all. They do ROCK with my new amp though :) )

    Hi Michael,

    You're welcome.

    The "SDA effect" is interaural crosstalk cancellation. It has nothing to do with reproducing a separate discrete center channel in a multi-channel movie sound track.

    In real life sounds from an audio source is heard in each ear. The brain interprets the delay in the two sounds reaching each ear to determine distance and location. In reproduced sound, especially stereo, there are two main speakers and sounds are heard in both ears coming from two sources rather than an actual single audio source. This additional artificial sound is called interaural crosstalk and it deminishes our ability to localize sounds, that is, it hurts stereo imaging. By introducing a cancelling signal the SDAs attempt to recreate the sonic image of the original sources thereby improving stereo imaging.

    The center channel is a discrete channel separate and apart from the main channels. There is no relationship between it and the SDA effect. Based on the action on the film the director and sound engineer put different, but appropriate sounds in the center channel (just as they do for all the other channels, LFE, surrounds, etc.) The purpose of multichannel sound is to rely on physical speakers distributed throughout the room to more accurately throw sonic images than can be achieved with two main speakers and a phantom center image.

    Removing the interconnect cable turns off interaural crosstalk cancelation and hurts stereo imaging. The cancelation effect is highly dependent on the sound track, therefore the degree that imaging will be hurt also depends on the sound track.

    The SDA effect requires that the listener be seating on axis, as do other electronic versions of crosstalk cancellation. People who have used both types of cancellation methods have expressed the opionion that size of the SDA sweet spot (the amount of distance a listener can be off axis and still hear the effect) is larger.

    As I mentioned, if you turn off the center channel, in a multichannel system, people sitting off axis will no longer accurately hear where the sound should be coming from. People sitting on axis would not be affected.

    Larry
  • McLoki
    McLoki Posts: 5,231
    edited January 2005
    Are you running your crs+ as mono (without the sda cable.) or are you only running one speaker?

    Michael
    Mains.............Polk LSi15 (Cherry)
    Center............Polk LSiC (Crossover upgraded)
    Surrounds.......Polk LSi7 (Gloss Black - wood sides removed and crossovers upgraded)
    Subwoofers.....SVS 25-31 CS+ and PC+ (both 20hz tune)
    Pre\Pro...........NAD T163 (Modded with LM4562 opamps)
    Amplifier.........Cinepro 3k6 (6-channel, 500wpc@4ohms)
  • Larry Chanin
    Larry Chanin Posts: 601
    edited January 2005
    Originally posted by McLoki
    Are you running your crs+ as mono (without the sda cable.) or are you only running one speaker?

    Michael

    Hi Michael,

    I'm running both speakers as mono without the interface cable. As you are probably aware the SDA effect requires a stereo signal.

    Larry
  • BobMcG
    BobMcG Posts: 1,585
    edited January 2005
    Here is a better list.