Polk SDA ACM - passive crossover - auto

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hoosier21
hoosier21 Posts: 4,408
The SDA ACM is a passive crossover unit that uses up to 3 amps for an SDA effect. Actually, only up to two amps are used for SDA, the third is for subwoofers. It uses the front two speakers for stereo, the rear speakers are dimensional, front to rear fader control is very important, as per the manual.

As far as home speaker potential, ??? Why not, that's what I was going to play around with and do, but never even tried it out.

Asking 75.00 plus shipping for this little piece of Polk history.

Comes with original box, manual and warranty card. I would rate it 8-9 of 10.
Dodd - Battery Preamp
Monarchy Audio SE100 Delux - mono power amps
Sony DVP-NS999ES - SACD player
ADS 1230 - Polk SDA 2B
DIY Stereo Subwoofer towers w/(4) 12 drivers each
Crown K1 - Subwoofer amp
Outlaw ICBM - crossover
Beringher BFD - sub eq

Where is the remote? Where is the $%#$% remote!

"I've always been mad, I know I've been mad, like the most of us have...very hard to explain why you're mad, even if you're not mad..."
Post edited by hoosier21 on

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  • F1nut
    F1nut Posts: 49,787
    edited February 2005
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    I've got one of those.........still haven't used it though. :(
    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

  • Tour2ma
    Tour2ma Posts: 10,177
    edited February 2005
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    Looks cool... I'll take it...

    PM sent...
    More later,
    Tour...
    Vox Copuli
    Better to remain silent and be thought a fool, than to open your mouth and remove all doubt. - Old English Proverb

    "Death doesn't come with a Uhaul." - Dennis Gardner

    "It's easy to get lost in price vs performance vs ego vs illusion." - doro
    "There is a certain entertainment value in ripping the occaisonal (sic) buttmunch..." - TroyD
  • hoosier21
    hoosier21 Posts: 4,408
    edited February 2005
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    Sold to Bruce, Thanks
    Dodd - Battery Preamp
    Monarchy Audio SE100 Delux - mono power amps
    Sony DVP-NS999ES - SACD player
    ADS 1230 - Polk SDA 2B
    DIY Stereo Subwoofer towers w/(4) 12 drivers each
    Crown K1 - Subwoofer amp
    Outlaw ICBM - crossover
    Beringher BFD - sub eq

    Where is the remote? Where is the $%#$% remote!

    "I've always been mad, I know I've been mad, like the most of us have...very hard to explain why you're mad, even if you're not mad..."
  • Airplay355
    Airplay355 Posts: 4,298
    edited February 2005
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    whats it do? give any set of speakers the sda effect?
  • hoosier21
    hoosier21 Posts: 4,408
    edited February 2005
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    It was for car audio. It is passive crossover (no power input), and yes any speaker. feed it 2 channels, it would output front stereo, and rear SDA channels, plus it would ad a subwoofer output if you wanted, all from the 2 channel input. you would use your car fader to balance the front stereo and rear SDA.
    Dodd - Battery Preamp
    Monarchy Audio SE100 Delux - mono power amps
    Sony DVP-NS999ES - SACD player
    ADS 1230 - Polk SDA 2B
    DIY Stereo Subwoofer towers w/(4) 12 drivers each
    Crown K1 - Subwoofer amp
    Outlaw ICBM - crossover
    Beringher BFD - sub eq

    Where is the remote? Where is the $%#$% remote!

    "I've always been mad, I know I've been mad, like the most of us have...very hard to explain why you're mad, even if you're not mad..."
  • twochannel
    twochannel Posts: 171
    edited February 2005
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    I also have a SDA ACM for sale. Asking $75 plus shipping. Box, packing materials, and manual included. 8/9 condition only because of marks from screws around mounting holes. This is serial # 709. These are getting rare. Please contact me if interested. Thanks
  • Airplay355
    Airplay355 Posts: 4,298
    edited February 2005
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    what happens if you used it on home theater speakers like rti70s?
  • HBombToo
    HBombToo Posts: 5,256
    edited February 2005
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    Originally posted by twochannel
    I also have a SDA ACM for sale. Asking $75 plus shipping. Box, packing materials, and manual included. 8/9 condition only because of marks from screws around mounting holes. This is serial # 709. These are getting rare. Please contact me if interested. Thanks

    I would like to have 1 also... How about shipping costs to Lee's Summit MO 64082.

    Henry
    ***WAREMTAE***
  • twochannel
    twochannel Posts: 171
    edited February 2005
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    Henry,
    "YOU HAVE MAIL"

    Kevin
  • twochannel
    twochannel Posts: 171
    edited February 2005
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    Sold to Henry.
  • nathanso
    nathanso Posts: 61
    edited February 2006
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    I just bought a NOS SDA ACM and am wondering whether I should re-cap it or try it as is. The date on the inside says 1986. The board sports four 260uF 50V NPEs.

    Anyone have any experience with these? Are those caps likely to be sound after 20-years of non-use?
    System: PS Audio HCA-2, PCA-2 + HCPS, Acoustat Model 2+2.
    Tweaks: Behringer DEQ2496, SRC2496, SU9920.
    Friends don't let friends drive cones
  • nathanso
    nathanso Posts: 61
    edited February 2006
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    Sorry to bump this thread again on the Flea Market but Google says this is the worldwide repository of written knowledge on the SDA ACM, so here goes one last time.

    The caps in my ACM seem fine (s/n high 900's).. it's playing without problems. I've got it hooked up in my office: Delphi XM Radio tuner feeding an Electrocompaniet Ampliwire IIa (75wpc) amp via an RS inline volume pad. Front speakers are KEF 60S, rears Dahlquist DQM-3. My office is 10ftx15ft with 10ft ceilings. The DQM-3s are on the floor in the corners behind my desk which backs near one of the 10ft walls. The DQM-3's are angled in at 45*. The KEF's are wall mounted about 10ft in front of me and up at door-top height, angled down and in at about 30*, i.e. all four speakers are roughly facing me.

    At home I've got SDA 2B's so I'm familiar with the effect. I've yet to have a head-swinging moment with my ACM but I'll add that I'm unable to balance the front/back fade as the manual suggests to balance the signal and enhance the sound field. Car stereos have faders; my vintage home systems don't. I'll probably stop playing with this setup as it does sound nice, albeit with too much sound coming from the closer/larger Dahlquists. Still, the sound out in front of me is rather expansive, appearing to come from no particular direction, i.e. everywhere. I don't have the equipment to A/B ACM vs non-ACM but I'm convinced it's better than it was as a 2-speaker system.
    System: PS Audio HCA-2, PCA-2 + HCPS, Acoustat Model 2+2.
    Tweaks: Behringer DEQ2496, SRC2496, SU9920.
    Friends don't let friends drive cones
  • Tour2ma
    Tour2ma Posts: 10,177
    edited February 2006
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    Yeah... we're the authorities all-right...

    I think you are the first person to actually report setting one up for a home/ office rig.

    Rest of us are locked in the "fixin' to" mode...
    More later,
    Tour...
    Vox Copuli
    Better to remain silent and be thought a fool, than to open your mouth and remove all doubt. - Old English Proverb

    "Death doesn't come with a Uhaul." - Dennis Gardner

    "It's easy to get lost in price vs performance vs ego vs illusion." - doro
    "There is a certain entertainment value in ripping the occaisonal (sic) buttmunch..." - TroyD
  • nathanso
    nathanso Posts: 61
    edited March 2006
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    Final bump here folks, I promise.

    Soon after making my last post I changed out the Dahlquists for some much smaller Boston HD5's that I had sitting around and the F/R sound balance immediately improved. The surround effect coming from the ACM is most impressive, I must say. I've been listening to a lot of Ambient music at work courtesy of XM Radio's Audio Visions channel and it sounds very cool through the ACM. If you have a chance at an ACM one day I recommend you grab it.

    I've got the original ACM owner's manual if anyone needs info on setup, etc. Btw, it's manadatory to open the unit up and set the jumpers prior to using the ACM as it supports options for 1, 2, or 3 amps.
    System: PS Audio HCA-2, PCA-2 + HCPS, Acoustat Model 2+2.
    Tweaks: Behringer DEQ2496, SRC2496, SU9920.
    Friends don't let friends drive cones
  • nathanso
    nathanso Posts: 61
    edited June 2006
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    Since posting here several people have contacted me for scans of the SDA ACM manual: This is the one that matters: http://www.n8software.com/Polk_SDA_ACM.JPG

    p.s. I solved my F/R balance problem with a Niles fader control. Now my home ACM setup is working quite well.
    System: PS Audio HCA-2, PCA-2 + HCPS, Acoustat Model 2+2.
    Tweaks: Behringer DEQ2496, SRC2496, SU9920.
    Friends don't let friends drive cones
  • honestaquarian
    honestaquarian Posts: 3,186
    edited June 2006
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    WARNING-The SDA-ACM for the car has the same common grounding issue as all of the home SDA loudspeakers!!!!!!!!!Which is why Polk did not make it for very long.I used to have one.I owned it for about fifteen years and never used it because of that issue.The only car stereo's that had common grounding back when this unit was being made in the eighties were factory systems.Common grounded car stereo's had ONLY ONE WIRE going to the speakers.The chassis was the ground for the speakers.
  • twochannel
    twochannel Posts: 171
    edited June 2006
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    I had my SDA-ACM hooked up with 3 Alpine Amps driving 14 speakers and had no trouble with the system in my demo car. I did installations for a Polk and Alpine dealer for several years and this is the first I've heard mention of a "common ground" issue with the unit. The SDA portion only effects the rear set of speakers. I hooked up at least 6 ACM's with Alpine and Adcom amps with no troubles.
  • honestaquarian
    honestaquarian Posts: 3,186
    edited June 2006
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    twochannel wrote:
    I had my SDA-ACM hooked up with 3 Alpine Amps driving 14 speakers and had no trouble with the system in my demo car. I did installations for a Polk and Alpine dealer for several years and this is the first I've heard mention of a "common ground" issue with the unit. The SDA portion only effects the rear set of speakers. I hooked up at least 6 ACM's with Alpine and Adcom amps with no troubles.
    The common grounding issue with the ACM is information that i got FROM POLK AUDIO.Another thing that they told me once was the fact that(and granted at the time they were talking about HOME SDA speakers when they told me the following)something could break immediately when using non common grounded amplification.OR two years could pass and then suddenly BOOM.