Polk SDA-2B or 1C, which is better?

PolksTillIDie

Though somewhat pointless, I thought I'd canvass users here and ask a delicate question: which is the better speaker? I've had a pair of 2B's for about 25 years and have had them on 1 amp and 2 different receivers, but they were looking worn and checking on eBay to make sure I didn't overpay for their re-covering and upgrade, I found a pair of 1C's in good condition for $375 and got them. I'm just blown away by how much better they are than the 2B's, at least on my system (Yamaha RX-a1080, 120 wpc).

I've bragged about the sound quality of the 2B's for years, but always thought the SDA dimensional qualities were a little lacking compared to the other SDA's. With the Yamaha and 1C's I get a wrap-around soundstage with bolder, tight bass. If I use the Yamaha Ai surround mode, I get an even bigger soundstage (+50% bigger), though flattened out in front of me. And I think the Ai mode is pushing more power to the speakers than straight mode because I'm only using 2 out of 7+ channels.

Anyway, those are the parameters. Anybody have a preference?

polrbehr

That's tough for me to answer, as I don't think I've ever heard the 1Cs. But I do own a modded pair of 2Btl, I have heard other SDAs (more than one pair of 1.2tl, a modded pair of SRS2, and several other pairs of 2Bs), and I still think I can't beat the $200 speakers I have. So honestly, I have no desire to explore other options at this point.
But I do think you got a deal on those 1Cs, enjoy them.

pitdogg2

After 4.1tl mod I've found the SDA 2b a better speaker. I've heard both sets modded and have preferred the SDA 2b.

Navy_Goat

I have both. Finding a set of 2B's on FB marketplace for next to nothing got me started down this rabbit hole. I did a down and dirty TL mod first. Eventually I replaced the rest of the caps and resistors on the original board. Finally I moved all the components to a Gimpod board, and did the rest of the standard mods. They sound great. At this point I had a great sounding pair of speakers that were rough around the edges appearance wise.

A pair of 1 owner 1Cs came up for sale near by and I was out the door. Many here warned me the that I was about to throw some money away, but being the stubborn SOB that I am I made the drive and brought home a really nice pair of 1C SDAs. I rushed home and set them up. They looked great, basically new. I really was proud of myself for pulling the trigger and getting a great set of speakers. For sure they are a great pair of speakers. I listened to them for a few weeks before I put my 2Bs back in the living room to see how much better my new larger SDAs were. Well, long story short it didn't take me long to figure out the smaller 2Bs were better. At this point the 2Bs were tl'd but I had not swapped to the gimpod boards.

I ordered the components GIMPOD boards for both speakers (2 sets) and all the components I would need to swap caps and resistors on both. I also ordered everything else I would need to completely mod both speakers. I completed the both speakers around the same time and A/B'd them on and off for a few weeks.

To be sure the 1Cs improved significantly with the crossover refresh and the RD0194 tweeters were an improvement, but I just kept coming back to the unavoidable conclusion that the 2Btl SDAs just sounded better.

Your results may vary, and I don't really regret purchasing the 1Cs, but when I was heading out to purchase them I was warned that the 2Bs would sound better and I should have listened. I will keep the 1C and there may even be a situation (room size maybe?) where the 1C are better. I know the set I have is in much better condition that the 2Bs that I have.

Let me know if you have any questions, and do whatever you want. Its your money and time and both speakers are really good. The SDA 2Bs are just a more balanced sound. Also the SL3000 (or RD0198) really is a superior tweeter. Its not even close. I think this alone accounts for a lot of the difference.

PolksTillIDie

Thanks for the comments. Maybe its my Yamaha (RX-A1080) or the room. Or since I don't know their history, maybe the 1C's have been superiorly modded. The 2B's have remained stock. Bought 'em in the 90's. Anyway, speaking for the two sets in my living room right now, the 1C's are better.

What, in your opinion, is the optimal amp power (6 ohms of course) for these? My documentation never said. Online documentation doesn't say. I've read in forums the were rated up to 500w (I assume into 6 ohms).

For my education, what does the "tl" designate?

Navy_Goat

the TL stands for Tri-Laminate.

"The dome of the SL3000 has a shiny metallic appearance due to its vapor deposited metal layers. The SL3000 dome is composed of a triple layered (Tri-laminate, or "TL") construction with a top layer of stainless steel, second layer of aluminum, and third layer of clear polyamide. The SL2500 has a dull appearance and has a black polymer coating on the front and rear sides. It is not clear to me at this time if the SL2500's dome has a triple layer (Tri-laminate) structure similar to the SL3000's."

Source: The Tale Of 5 Tweeters - SDA Tweeter Replacement Guide


Long story short its a better tweeter.

The most important thing is what sounds better to you. The reason I typed the post above is if you had asked me which speaker sounded best after I had the 1C in my living room for a little while I would have said the 1C without hesitation. RIght up to the point where I put the 2Bs back in the mix. I pulled the 2B out of the closet and they just sounded better all the way around.

At the end of the day its a great problem you have. We are all fortunate to have gthe time and means to pursue this hobby.....

invalid

I have a pair of sda2A's with the TL mod. I've used everything from cheap receivers to top notch amps on mine, and everytime I upgraded my amplification the speakers have performed better. I'm using a krell ksa 300s amp with them and it's rated at 600 watts into 4ohms, the speakers are 4 ohms. You can use more than 500 watt amps with the 2b's it's the quality of the amp that counts.

pitdogg2

It's not all about watts per say, it's more about high current and the ability to control the drivers. The SDA 2a above start at 4ohms and drop to low 3ohms which can be very unforgiving to many amps and most all receivers. Receivers just do not have the power supply to be able to keep up with them. The Krell on the other hand is able to double down into very low ohms and provide all the power/current they need without breaking a sweat.

invalid

pitdogg2 wrote: »

It's not all about watts per say, it's more about high current and the ability to control the drivers. The SDA 2a above start at 4ohms and drop to low 3ohms which can be very unforgiving to many amps and most all receivers. Receivers just do not have the power supply to be able to keep up with them. The Krell on the other hand is able to double down into very low ohms and provide all the power/current they need without breaking a sweat.

You are correct about the current of an amp with the sda speakers. I even put lower dcr inductors in the sub bass drive circuit so they are even lower than 4ohm now, the krell doesn't have a problem with them and sounds much better than my adcom gfa555 did.

audioluvr

I have modded 1C' s and love them. It's all about what sounds best to you, not us.
As for amp upgrades. Tell us where you live. We love spending other peoples money.

Something like this would do:
https://www.usaudiomart.com/details/649645685-pass-labs-1508-power-amplifier/

invalid

audioluvr wrote: »

I have modded 1C' s and love them. It's all about what sounds best to you, not us.
As for amp upgrades. Tell us where you live. We love spending other peoples money.

Something like this would do:
https://www.usaudiomart.com/details/649645685-pass-labs-1508-power-amplifier/

That amp would certainly do the job well.

pitdogg2

invalid wrote: »

pitdogg2 wrote: »

It's not all about watts per say, it's more about high current and the ability to control the drivers. The SDA 2a above start at 4ohms and drop to low 3ohms which can be very unforgiving to many amps and most all receivers. Receivers just do not have the power supply to be able to keep up with them. The Krell on the other hand is able to double down into very low ohms and provide all the power/current they need without breaking a sweat.

You are correct about the current of an amp with the sda speakers. I even put lower dcr inductors in the sub bass drive circuit so they are even lower than 4ohm now, the krell doesn't have a problem with them and sounds much better than my adcom gfa555 did.

I wouldn't be surprised if those hover around the higher 3 ohm and drop to 2 ohm then. that would just kill most receivers and make them go into protection mode.

invalid

I run them on my HT system most of the time with a marantz sr7007 it doesn't trip the protection if you keep the volume down, but I've tripped it several times with music. The krell doesn't have any problem with it. The krell does have a problem with the apogee duetta 2's I have because they are so inefficient it takes a lot of power to get it to realistic volumes.

PolksTillIDie

Well, as for the upgrades, I've heard Polk has offered upgraded tweeters and I think crossovers over the intervening years. I asked my local speaker guy in Austin and he actually said upgrades could be "open ended" cost-wise. Of course, you spend as much as you want, but I had the impression that there were some "stock" upgraded components that Polk offered that were fairly reasonable.

F1nut

Polk never offered upgrades other than in more recent years with the RDxxxx tweeters.

So, when are you going to investigate what is wrong with your 2B's because something definitely isn't kosher.

Our favorite crossover upgrade components are Sonicap Gen I or Clarity CSA caps and Vishay/Mills resistors.

PolksTillIDie

So.... for the 1C's, I see the RD0194-1 tweeters available at Midwest Speaker in October. For an easy upgrade, any reason not to start there? I should mention, I'm not interested in making this a life-project, I just thought that if the 1C's are stock and an upgrade tweeter is available fairly cheap ($60 x 4), I should jump on that. The 2B's are going to a friend, so it's his baby to deal with. As far as amplification goes, my Yamaha RX-A1080 sounds great with them, but I've already had one instance where it went into system protection, so I think I'm gonna add a Yamaha M-80 or -85. I don't think a mostly stock pair of 1C's will out-run those two, at least at listening levels I'll use.

pitdogg2

Tweeters are a very good first investment.

txcoastal1

Good start, but you may also want to consider removing polyswitches

https://forum.polkaudio.com/discussion/128258/resistor-replacement-for-the-sda-srs-1-2tl-polyswitch

https://forum.polkaudio.com/discussion/73796/sda-polyswitches-are-nasty

muncybob

For sure, the 1st upgrade I would do to the 2B is the tweeter. Big difference there, no listening fatigue any more. Mine never sounded their best with an AVR or low powered amp. You don't have to spend big $$ for an amp, a Parasound HCA1500 does the job nicely for me. But it is def worth upgrading the crossover and all the other tweaks you will find on this forum.

polrbehr

muncybob wrote: »

For sure, the 1st upgrade I would do to the 2B is the tweeter. Big difference there, no listening fatigue any more. Mine never sounded their best with an AVR or low powered amp. You don't have to spend big $$ for an amp, a Parasound HCA1500 does the job nicely for me. But it is def worth upgrading the crossover and all the other tweaks you will find on this forum.

@muncybob I think that ship has sailed, but I agree with you 100%. Maybe his friend will read this thread and upgrade the 2Bs himself? I wish I had a friend that gave me a pair of speakers like that to "deal with" LOL... but he's going in the right direction with the 1Cs so let's see what he thinks after the new tweets are in.

JayCee

PolksTillIDie wrote: »

...I think I'm gonna add a Yamaha M-80 or -85. I don't think a mostly stock pair of 1C's will out-run those two, at least at listening levels I'll use.

Starting in 2009...First amp I ran w/my 1C's was an M80. No complaints and worked well, however, I'd have it cap refreshed if you do. You could do allot worse...or better.

muncybob wrote: »

You don't have to spend big $$ for an amp, a Parasound HCA1500 does the job nicely for me. But it is def worth upgrading the crossover and all the other tweaks you will find on this forum.

Replaced the M-80 with an HCA-1500A. Liked it so much I picked up a second at a killer price for my other SDA's. Spent some quality $$ updating the 1500's and they are still with me. One's on my home theater and the other in reserve. After the upgrades they outperformed similar for more $$. I've moved on, considerably, but will keep the 1500's until they, gulp, die.

Back to the M-80. The cool factor of the vertical meters is pretty sweet. I miss it, at the very least, for that.

As other's have recommended, tweeter is a no brainer and XO upgrade(s) will move things along nicely. Good luck.

Gardenstater

PolksTillIDie wrote: »

Thanks for the comments. Maybe its my Yamaha (RX-A1080) or the room. Or since I don't know their history, maybe the 1C's have been superiorly modded. The 2B's have remained stock. Bought 'em in the 90's. Anyway, speaking for the two sets in my living room right now, the 1C's are better.

Perhaps it might be time to take a look inside at the crossovers and see what was done, as far as XO mods and internal wiring.

PolksTillIDie

Thanks for all the comments. Just need October to get here so I can get the tweeters. The M-80/85 will be completely refurbished. Waiting on a quote on them to see which way I'll go.

engie490

PolksTillIDie wrote: »

Just need October to get here so I can get the tweeters.

Speaker Exchange has the RDO-194 in stock. Just ordered 4 for my SDA-1Cs.