New SDA-1A owner needs opinions & spec

eeagle

As a brand new owner of a set of SDA-1A Polks I am enthused with their sound. I recall hearing these some years back but felt they were out of my price range. Then a fellow I work with put a pristine set with crossover cable and manual up for sale at work for $300 so I couldn't pass them up. Can you believe he had just thrown the original boxes out as this was planned to be his last move. He had won the speakers some time back and wasn't too familiar with them except for the fact that they sounded fantastic.

I am seeking opinions on the following:

1. I had not realized the SDA-1 or 1A series existed with the horizontally mounted tweeters. Reading a note from BobMcG in this forum I discovered they were the first in the series. The models I had seen and heard before were apparently the 1B or 1C as they had the vertical tweeter set. In your opinion was the vertical configuration superior and an improvement?

2. As with any set of new speakers I was doing an A/B comparison with my present AR-91 speakers. There are subtle differences between these systems and it becomes very subjective as to which is best. The thing I found interesting while hooked to my old 80 watt/channel KR-770 Kenwood receiver (same vintage as the ARs), I could not do an effective A/B with the SDA-1A crossover cable connected. Whenever I used the Kenwood's speaker switch to turn off the Polks, and turn on the ARs, the "dimensional array" in the Polks would still play. Any idea what is going on there?

3. Is there a schematic available anywhere for the SDA-1 speaker series. I am curious how they are wired and what their max power capacity is.


4. What is your favorite amplifier/receiver, or recommended min power, to drive the SDA-1 system?

wangotango68

as george allways says"get as much power as you can afford and then go one step higher" i have the sda 2b's and im running the carver m4.0t with them and they sound amazing.the forum unwritten rule is there is no subsitute for power.

scott:cool:

BobMcG

I don't have a bunch of answers for you but here goes:

I have the SDA-1 owner's manual but it doesn't give performance specs. (Only physical specs.) Polk used to have more complete spec papers available for them for a cost.

Not long after the first SDAs were made, Polk found out that it wasn't nessesary for the tweeters to be included in the SDA arrangement. (Due to the frequency range involved.) They better utilized the multiple tweeters by mounting them vertically and cascading the frequency range between them. (Each handling a certain portion of the high range.)

SDAs like power. Gobs of "QUALITY" power. IMO, I lean towards 200-250watts RMS per chan. into 8 ohms as a good minimum starting point.

I don't have a schematic for this model.

I don't have an answer for you as to the channel bleed-over you experience with the A/B recvr comparison, as I've never run a set of SDAs with a recvr before.

The 1's and the 1A's should NOT be biamped. Damage to amps and/or speakers could (likely) be done. Not even if you built or got your hands on a Polk AI-1 interface.

Power handling? My guess would be 350 watts.

eeagle

Looks like the SDA-1's can handle, and benefits from a good high power amp.

Hadn't realized the dimensional sub-system in the newer models didn't use the H.F. Units (tweeters). Great input!

I did finally find the text from an old Stereo Review (Dec 82) on the SDA-1 system out in the newsgroups. Would really appreciate any other details, pictures or specs that anyone else might have.

Thanks,
Rick

BobMcG

Check out my bother's and my site,

http://clubs.yahoo.com/clubs/mikespolkpage2

eeagle

Thanks for the pointer to the web site.

I was able to procure another good deal. This time it is an old Sansui G-9700, I almost didn't even look twice at it until I saw what these "Pure Power" 200W/ch units are going for on ebay. This thing is a real boat anchor for sure, but quite a nice well cared for piece of gear.

Doing some research I found these other Receivers listed with 150 watts per channel or more (prices in US dollars, the published US list) should anyone else have an interest in finding some 1980 vintage equipment to accompany their SDAs.

Hitachi SR-2004 ......... 200 watts per ch. ....... $1095
Kenwood KR-9050 ......... 200 watts per ch. ....... $1150
Marantz 2600 ......... 300 watts per ch. ....... $1600
Onkyo TX-8500MKII ......... 160 watts per ch. ....... $1000
Pioneer SX-1280 ......... 185 watts per ch. ....... $950
Pioneer SX-1980 ......... 270 watts per ch. ....... $1295
S.A.E. TWO R18 ......... 180 watts per ch. ....... $1350
Sansui G-9700 ......... 200 watts per ch. ....... $1100
Sansui G-22000 ......... 200 watts per ch. ....... $1400
Sansui G-33000 ......... 300 watts per ch. ....... $1900
Sanyo PLUS 200 ......... 200 watts per ch. ....... $1000
Technics SA-1000 ......... 330 watts per ch. ....... $1700
Toshiba SA-7150 ......... 150 watts per ch. ....... $1100
Yamaha CR-3020 ......... 160 watts per ch. ....... $1500


Anyway, I'm now treating myself to 200W/ch. I must admit though that I haven't noticed a great deal of improvement in the SDA-1A sound compared to my old 80W/ch. The Polks are quite efficient, and seem to get by very well even at low power.

I will try to attach the Stereo Review txt once again on the SDA-1.

madmax

Your A/B switch wont turn off the SDA's with the cable attached because it disconnects the grounds only. You will get the same effect if you remove the ground of both speakers while the positives are still connected. What you hear is the "difference" between the left and right channel. (makes a really cool rear channel if you want one really cheap!)
madmax

eeagle

For madmax001:

Hadn't considered the ground only would be switched on the receiver speaker switch, or had any insight into how SDA dimensional array was wired. Your explanation certainly explains the feedback I was getting.

For BobMcG:

Finally got Thanksgiving over with, and my Yahoo Password redone so I could actually see more of your site and join. Thanks for all the effort it is very informative. The pictures especially clarify many of the different models that I am just now becoming more familiar with. I encourage others with interest to check Bob's reference above!

I can certainly see why so many like these SDA's; they are really captivating, and I am revisiting lots of my old albums. Jazz and Classical are particularly great!