SDA2 Vs SDA-1C

[Marty913]

I have SDA2's (5 driver) from 1986 and have a possible opportunity to pick up a pair of SDA 1C's. I'm going to rebuild the xovers on the 2's but was wondering about the value of maybe picking up the 1C's and keeping the 2's as surrounds or selling them to a friend. Or just skipping the purchase and sticking with the 2's.

I guess what I'm looking for is opinions on which set (sound-wise) would be the better "keepers". I haven't even researched 1C's so I'm not even sure of their benefits (or not). Do they have two dimensional drivers, two xovers, etc.

Thanks everybody.

[heiney9]

1C's all the way. They are newer have better cabinets, drivers and a more refined SDA soundstage. Each generation of SDA used better materials and the concept was furthered each time by a lot.

IMO, the 1C's are the gem of the entire line for many reasons. The big SDA's are nice but the 1C's are about perfect for many situations.

If you 2's have the dimensional tweeter you owe it to yourself to hear/own a later gen pair of SDA's.

my .02c

H9

[Joe08867]

I have original series SDA2's and once I disconnected the dimensional tweeter they started sounding almost identical to the 2A's.

IMHO I would go with the 1c's. They have a little bit of everything going for them.

You could use the sda2's for surround but you would need to change the tweeters to match the 1c's.

[avguytx]

1C's are the ones to get. I've had them and loved them but I also have a pair of SRS II's and it didn't make sense for those great 1C's to do "closet time". If I wouldn't have gotten the SRS II's, the 1C's would have been the main speakers.

[F1nut]

I agree with my esteemed colleagues, get the 1C's.

[george daniel]

1C's,, take it from one who learned the hard way,,good luck.:)

[danger boy]

1C's and they'll put a nice smile on your face :D

[ben62670]

I concur with post above. Get the 1C's.

[Marty913]

I have original series SDA2's and once I disconnected the dimensional tweeter they started sounding almost identical to the 2A's.

IMHO I would go with the 1c's. They have a little bit of everything going for them.

You could use the sda2's for surround but you would need to change the tweeters to match the 1c's.

Thanks so much everyone, you confirmed my "gut feel" but that has gotten me into a lot of trouble so I figured "ask the experts".

Joe08867, I have disconnected the dimensional tweeter on the 2's and they sound better (to me) that way. I believe it was your suggestion that got me to do that. You mentioned changing the SDA2 tweeters to match the 1C's. Don't the 1C's have the SL2000 which would be the same as my SDA2's (don't believe I mentioned that). Are either of the 1C tweeters dimensional?

[heiney9]

Thanks so much everyone, you confirmed my "gut feel" but that has gotten me into a lot of trouble so I figured "ask the experts".

Joe08867, I have disconnected the dimensional tweeter on the 2's and they sound better (to me) that way. I believe it was your suggestion that got me to do that. You mentioned changing the SDA2 tweeters to match the 1C's. Don't the 1C's have the SL2000 which would be the same as my SDA2's (don't believe I mentioned that). Are either of the 1C tweeters dimensional?

The 1C's use the sl2000 for an original tweeter. They are hooked up in what is called a "Taper array". Polk did away with using a dimensional tweeter after the 2nd generation because it was found to be unnecessary and actually detracted from the overall effect.

Furthur testing/tweaking helped them discover only the mid-bass driver(s) needed to be dimensional drivers and then only between a certain band of frequencies. For all Polks with the sl2000 tweeter a new Polk designed "silk" dome tweeter is avail (part # RD0194-1) which is much smoother and gets rid of an inherent +5dB spike at around 12.5kHz in the original sl2000. Which causes some fatigue and some nasty resonance at certain freq.

Those are drop in replacements that can be added after you purchase the 1C's and IMO are a great upgrade and are needed if you plan to freshen up the x-overs.

H9

[Marty913]

Thanks heiney9, I know the SL2000's in my SDA2's sound a little weird (disjointed, perhaps a little harsh) but assumed it was probably my x-overs needing replacement. Disconnecting the dimensional one helped. I had planned on replacing them with the 194's.

So if I understand all this, the 1C's have the same tweeters as the SDA2's (later models like mine) but the dimensional has been dropped (so I pick up another "real" tweeter, and in addition, the x-over has been reworked to provide better control of the dimensional mid-woofer. The 1C use a single dimensional mid-woofer and 3 normal mid-woofers. Is that all correct?

Edit: Well I may have answered some of my own stupid questions (should have checked first). From the schematics it seems the 1C's still have a dimensional tweeter but add another dimensional mid-bass (although of a different model).

Thanks.

[heiney9]

Thanks heiney9, I know the SL2000's in my SDA2's sound a little weird (disjointed, perhaps a little harsh) but assumed it was probably my x-overs needing replacement. Disconnecting the dimensional one helped. I had planned on replacing them with the 194's.

So if I understand all this, the 1C's have the same tweeters as the SDA2's (later models like mine) but the dimensional has been dropped (so I pick up another "real" tweeter, and in addition, the x-over has been reworked to provide better control of the dimensional mid-woofer. The 1C use a single dimensional mid-woofer and 3 normal mid-woofers. Is that all correct?

Edit: Well I may have answered some of my own stupid questions (should have checked first). From the schematics it seems the 1C's still have a dimensional tweeter but add another dimensional mid-bass (although of a different model).

Thanks.

The 1C's and any subsequents SDA speaker built after the 2nd generation does NOT have a dimensional tweeter.

The 1C's have 2-dimensional mids and 2-stereo mids. The 2-tweeters are arranged in a taper array and both tweeters play different freq and have slightly different output from one another. The idea is to use multiple tweeters to create a single point source. It works quite well.

IMO, when you freshen the x-overs in any speaker with the sl2000 tweeter the flaws become even more apparent and that's why I said the RD0 replacement tweeter(s) are a must if you are spending the $$$ and time on the x-overs.

The RD0 is so much better that all my sl2000 tweeters have been replaced and it's a night and day difference.

H9

[MillerLiteScott]

1C's have two cascaded tweeters to eliminate phase shift, IIRC, 2 stereo drivers and 2 dimensional drivers. Also IIRC all the 6.5" drivers work together below 150hz to produce bass and to reinforce the fluid coupling to the passive radiator.

I have a pair of hot rodded 2B's and stock 1C's.

Scott

Edit see above

[heiney9]

Check out this link:

http://www.polksda.com/sda1creview.shtml

For more info. It's a scanned copy of the 1986 Stereo Review-review of the 1C's. It has some good info that might help you understand a bit better what the differences are.

H9

[I-SIG]

I'm gonna be the lone nay-sayer here and say that while you should certainly jump on the 1C's, the difference in clarity and scale from the 1C's to the original SRS's was very noticeable and for the price of the original SRS's is worth it. To go from 1C's to SRS 1.2TL's, probably not worth the price since they can go from $500 to $1000 more than the original SRS's.

Wes

[Marty913]

Check out this link:

http://www.polksda.com/sda1creview.shtml

For more info. It's a scanned copy of the 1986 Stereo Review-review of the 1C's. It has some good info that might help you understand a bit better what the differences are.

H9

Thanks you MillerLiteScott and H9 for hanging in there with my 1C ignorance. You've been extremely helpful and IF I can work the deal I will pick up the 1C's (not a done deal yet but close). I-Sig, you're certainly not being a nay-sayer to me as I have no comparison basis. I owned 2.3tl's back in the day and maybe will again when the price drops (a lot). Until then, it sounds like the 1C's will be bring me closer to the goal (sound-wise) than the SDA2's I currently have. At least it moves me in the Line-Source-Array direction.

The link to the Stereo Review article was very, very helpful.

[genocidedeath]

newbie here ! any one have a pic of a sda-2 ? thx you

[nms]

newbie here ! any one have a pic of a sda-2 ? thx you

Dude, google is your friend.

http://images.google.com/images?hl=e...-8&sa=N&tab=wi

[genocidedeath]

google has not my type of speakers

[nms]

google has not my type of speakers

Sorry, thought you were looking for SDA 2A. Try this.

http://cgim.audiogon.com/i/rv/s/f/1033318612.jpg

[Marty913]

newbie here ! any one have a pic of a sda-2 ? thx you

Here's an SDA2 with SL2000 tweeters

[Marty913]

Thanks you MillerLiteScott and H9 for hanging in there with my 1C ignorance. You've been extremely helpful and IF I can work the deal I will pick up the 1C's (not a done deal yet but close). I-Sig, you're certainly not being a nay-sayer to me as I have no comparison basis. I owned 2.3tl's back in the day and maybe will again when the price drops (a lot). Until then, it sounds like the 1C's will be bring me closer to the goal (sound-wise) than the SDA2's I currently have. At least it moves me in the Line-Source-Array direction.

The link to the Stereo Review article was very, very helpful.

Just to close out the thread I started, I closed the deal on the SDA-1C's. I'm buying them from the original owner with manual & cable. Just spoke with the owner and he assures me they are "perfect". He seems to be a true Polk fan but was unaware of the Club. I will be sending him the link so hopefully we will have a new member.

I pick them up Saturday (5 hour drive one way) so as to avoid any shipping damage as I experienced with my SDA2's. Yes, I'm excited.

I wanted to thank all of you again. Perhaps some of you with hundreds or thousands of post don't realize (or have forgotten) what a valuable resource you are. I've been in and out of this stuff for 40 years but there is no expertise that can approach "collective expertise".

Just wanted to say thanks to all of you that participated in this thread. It has truly helped. I plan on abusing you often.

[heiney9]

Cool and congrats...............you will one happy camper. Perfect cond. 1 owner SDA's are hard to come by. :)

[MillerLiteScott]

Congrat's. You will enjoy them.

Scott

[Mike Reeter]

These must be the ones,congrats,you made a good buy...and they are also the Studio version.

http://cgi.ebay.com/ws/eBayISAPI.dll...MEWA:IT&ih=011

Always liked the "look" of that style.

Happy listening.

[Joe08867]

Congrats on the purchase.

BTW I didn't realize the original series SDA2's ever came equipped with the SL2000 tweeter. I thought they all came with the SL1000 like mine.

So it's all bubbles no troubles matching up the sound of the 1C's to the 2's.

[Marty913]

These must be the ones,congrats,you made a good buy...and they are also the Studio version.

http://cgi.ebay.com/ws/eBayISAPI.dll...MEWA:IT&ih=011

Always liked the "look" of that style.

Happy listening.

Congrats on the purchase.

BTW I didn't realize the original series SDA2's ever came equipped with the SL2000 tweeter. I thought they all came with the SL1000 like mine.

So it's all bubbles no troubles matching up the sound of the 1C's to the 2's.

Yes Mike, those are the ones. I've been looking for a pair that was in driving distance. I think it's a fair price given the one-owner thing. He assured me they are extremely we-cared for with not a mark on them. He's driving them with Carvers so they should feel right at home when they get here. The black will match everything else but I do like the regular stained look a little better. I'm not complaining.

Joe, I was a little surprised at the SL2000's also but from what others mentioned on here I guess it's not all that strange. The mid-bass drivers are all dated March or April of 1986. No dates on the tweets. Unfortunately they have x-over issues (dropped in shipment, I think) so that's a project after the first of the year.

[PW47]

I agree with my esteemed colleagues, get the 1C's.

IALREADY SEND IMAIL TO SUPORT TO FIND OUT ABOUT THE CABLE INTERCONNECTION TO SDA 2 WE ARE IN THE FORUM NOBOBY CAN GIVE LITLLE HELP ? MODEL R SDA 2 ONE ROUND PIN AND BELLOW AN HORIZONTAL . WITHOUTH THOSES CABLES SDA2 WORKS RIGHT? CAN I BUY ONE CABLE ? THANKS PWILSON

[NJPOLKER]

PW47
Welcome
Try doing a forum search on pin/blade innerconnect. You can easily make one yourself and if that does not work for you try posting in the "wanted" section in this forum.

[cnh]

Considering the fact that Polk must have done a lot of R&D on the SDA series? How could 'they' have possibly missed a +5 decibel bump in their SL2000--wouldn't it have been EASY to spot something like that in their own testing and fixed it!

I am still very puzzled as to how a silk treated RDO replacement does not radically alter the sound of an original SDA with an SL2000 tweeter. Am I just dense or am I missing something. I thought the whole idea of the SL2000 plus series was that they are, in fact, superior tweeters to silk/domes currently used by Polk? So why replace them with silk? And if the SL2000 sounds so 'bad' why did so many so equipped SDAs sell so 'well'?

thanks,
cnh