New SDA-1C's sounding dark...Polk house sound?

jmitchnh

Greetings all,
Just took delivery of a pair of fairly minty SDA-1C's. I have always absolutely loved the imposing look of this speaker and thought it would be the perfect speaker for my vintage set-up. The only aniexity I felt about the purchase is would they sound the same as the newer Polks?
I've owned a pair of LSi 9 (so sexy looking) and LSiM 703's (again sexy looking), only to be dissaponted in the sound. They sound very "back of the house" to me meaning the vocals seemed recessed in the mix and the highs sounded a bit muted and dark. I was hoping these older Polks would not have the same sound signature but after playing a few different tracks, I hear the similar sound. Rather lifeless and dark high end and vocals.
I guess my question is so you think there may be something amiss with these or are all Polks voiced the same?
All the drivers seems to be working ( I do hear something from each one) and I am using the factory interconnect cable. As far as upstream, I'm using a Yamaha M-60 amp with a Nackamichi CA 5 preamp. The room is rather smallish but also sonically bright. This system has always sounded a bit on the bright side so I don't think its the source.
On the upside, the bass and mid-base sound fantastic.
I don't have a problem with doing some simple mods to try and upgrade what I'm hearing from them but I'f they "sound how they sound", I won't throw good money after bad. I know we all have seperate tastes in what "sounds good" to us and don't mean to insult anyone who loves the Polk sound. I'm just trying to determine my next step with these beauties.

F1nut

What you are hearing is the sound signature of the 1C, which sound different than any other SDA I've heard and I've heard most.

jdjohn

Have you played around with placement (e.g., proximity to the wall)?

The newer RD0194 tweeters should help, along with some of the typical mods. IME, the mods help to tighten-up the bass, which then allows more HF detail to be heard. Having said that, if you have the studio version cabinets, there is a lot to be desired, which creates limitations.

jmitchnh

I have them about a foot from both the rear and side walls. I know that’s not optimal placement but my room is rather small ( 12 x 19) so placement options are somewhat limited.
The previous owner mentioned they haven’t been used in a few years so I’m hoping part of what I’m hearing can be attributed to that. I’m letting them play at low volume to see if it has any effect on how they sound.
They do throw an image and a sound stage like no small speaker can. I’m hoping I can get them dialed-in because there’s certain aspects of them I love!

F1nut

They should be on the 19 foot wall, 5 to 6 inches from the back wall, no toe in and 3 feet from the side walls. Sitting unused isn't going to change their sound.

engie490

I would not characterize the SL-2000 as "dark". It's definitely (and measurably) bright.

I had 1Cs and the sound dramatically improved by upgrading the tweeters to the RD-0194. They changed the entire balance of the speaker. HIGHLY recommended!!!!

F1nut

I agree the SL2000 is a bright nasty tweeter, but the 1C has an overall dark flavor to it. The only time I heard them sound halfway decent was at Ted's PF powered by a Manley tube integrated. The smaller 2B easily outperforms them.

nooshinjohn

The Yamaha is not the best amp to pair with the Polks… I would see if you can find a Nak PA7 to go with them.

audioluvr

Having the crossovers refreshed with good components will help also.

heiney9

My 1C's are anything but dark. I owned the CA5 for a long time and it's titled to the bright side, not overly bright, just lively. The Yammy is a weak link for sure, never heard a Yammy amp that sounded all that great. Very closed in and slightly dark and muddy.

Also note all your gear is 25-30+ years old and getting very long in the tooth....that could be part of the issue as well. Parts start to slowly degrade over time. You don't mention if the amp/pre-amp have ever been refreshed.

Upgrade your amp, caps in the crossover and get the RD0-194 upgraded tweeters and you will have a completely different speaker on your hands.

Nothing wrong with the 1C's. IMO, they are not "dark" sounding. They are just like the rest of the SDA line. Very little difference between similar 1B's and 1C's, except the 1C's hit a bit deeper and have a slightly more expansive sound stage.

Here's a review of the day talking about how good they sound. No mention of them sounding "dark"

https://polksda.com/sda1creview.shtml

H9

xschop

New caps and resistors or you'll remain in the dark.

VR3

Sda in general is a warmer speaker but if you are running the original crossovers chances are they are out of spec

jmitchnh

Thanks to everyone for your feedback, it's definately given me some things to look into.
I've swapped out the M-60 for a Parasound HCA 1000 amp with some higher quality speaker cables. The sound is slightly better, esp in terms of air and detail. The overall sound is still similar. Reading the Julian Hirsch review , I see he describes the sound of the speakers as "slightly soft" with a "laid back" soundstage. I'd have to agree that's what I'm hearing as well.
I can also see where after 30+ years, that caps have aged and my well be out of spec. I have a line on a Nakamichi PA5 amplifier which is considered a high-curent amp which should be a better match. I may just give it a try to see how it sounds. I'll def look into replacing the tweeters as well. It will be fun to see what changes these make.

heiney9

IMO, slightly soft doesn't mean dark. So perhaps there is some misinterpretation of terms or we each have our own idea what certain terms mean.

But cap refresh, new RDO tweets and some "fresher" gear will do wonders.

H9

F1nut

I find the original SDA SRS dark sounding as well.

audioluvr

F1nut wrote: »

I find the original SDA SRS dark sounding as well.

Were they in your crypt at the time?

F1nut

audioluvr wrote: »

F1nut wrote: »

I find the original SDA SRS dark sounding as well.

Were they in your crypt at the time?

Not in mine.

DarqueKnight

Bad polyswitches are one of the main culprits in diminished high frequency performance. One of the first things I recommend trying is replacing the polyswitches with wire jumpers or a small value resistor.

There are lots of good discussions here on the topic. Here is a thread for reference:

https://forum.polkaudio.com/discussion/73796/sda-polyswitches-are-nasty/p1

jmitchnh

I'm assuming there's one polyswitch per tweeter or just one per speaker? Are they accessable through the PR opening or does the crossover have to be removed from the cabinet? Thanks )

F1nut

One per crossover. You have to remove the PR to access the crossover. The polyswitch should be replaced with a new one or better yet, a 0.5 ohm 10 or 12 watt Vishay Mills resistor.

jmitchnh

Well, thanks to all your feedback I'm happy to report I'm now in audio nirvania with my 1C's!!!!!!!!

I switched out the M-60 for a Parasound HCA-1000A. Slight improvement , a bit more detail but still rather dull sounding. Ending up swapping both for my Yamaha A-S1100 integrated. Heard a bit more high end and even more detail. Trending in the right direction!

Decided to go the next step and eliminate the polyswitches to see what difference it might make...
VOILA ! The vocals are now front and center, no longer recesssed in the mix. I can hear cymbals and piano so clearly. Tons of air and detail. They sound so perfectly balanced now!

Just for reference, I had the RDE 050A polyswitches which are rated at .5 -.77 and post trip at 1.17. I measured the resistance and found one was at 1.9/2.0 and the other at 3.1 ohms. I guess I can see why they sounded so dark and lifeless.

As dissapointed and bummed as I was when I first brought them home, I am now on cloud 9!!! My next step I believe will be replacing the tweets with RD0194's. What kind of improvement should I expect to hear? Eventhough, I'm so excited at how good they sound now, I'm, afraid to mess with them. Will adding spikes add any benefit?

Thanks to all for your advice and knowledge!!!!

michaeljhsda2

Major improvements will be achieved with the RD0-194's and spikes.

Navy_Goat

RD0194 will make a big difference. Spikes will also improve the sound a little or a lot depending on what the speakers are sitting on.

What did you replace the polyswitches with out of curiosity?

jmitchnh

I just clipped off the switch itself and soldered the two legs together. They are currently sitting on hard rubber feet (disks) on a concrete floor. I do like the idea of adding spikes but not sure how much it will ultimately improve the sound.

Navy_Goat

Ah, okay. RD0's and a resistor as recommended by F1nut above will calm the tweeters down a bunch. The original SL2000's can be a bit harsh to some ears, and that is with the polyswitch providing some attenuation (0.5 ohms +/- a little).

I am not sure how much of a difference spike will make on concrete. I use them with good results on carpet, but I have no experience with concrete floors and audio.

invalid

I have my SDA 2a's on carpet over concrete, they make a positive difference, I bought mine here.



https://meniscusaudio.com/product/long-mirror-image-pts-gold/

DarqueKnight

jmitchnh wrote: »

Well, thanks to all your feedback I'm happy to report I'm now in audio nirvania with my 1C's!!!!!!!!!

Congrats!! Your 1C's are on the path to reaching their full potential. If you decide on further improvements, do them in stages so you can access the benefit of each modification. As you have heard, the polyswitch is a good place to start. Next is the RD0194 tweeter replacement. After that soaks for a while, look into refreshing the crossovers with modern resistors, film capacitors, and perfect lay inductors. Good luck with everything.

Regarding your question about spikes, I have owed two pairs of 1C's and the results with spikes varied, depending on the floor.

K_M

jmitchnh wrote: »

Greetings all,
Just took delivery of a pair of fairly minty SDA-1C's. I have always absolutely loved the imposing look of this speaker and thought it would be the perfect speaker for my vintage set-up. The only aniexity I felt about the purchase is would they sound the same as the newer Polks?
I've owned a pair of LSi 9 (so sexy looking) and LSiM 703's (again sexy looking), only to be dissaponted in the sound. They sound very "back of the house" to me meaning the vocals seemed recessed in the mix and the highs sounded a bit muted and dark. I was hoping these older Polks would not have the same sound signature but after playing a few different tracks, I hear the similar sound. Rather lifeless and dark high end and vocals.
I guess my question is so you think there may be something amiss with these or are all Polks voiced the same?
All the drivers seems to be working ( I do hear something from each one) and I am using the factory interconnect cable. As far as upstream, I'm using a Yamaha M-60 amp with a Nackamichi CA 5 preamp. The room is rather smallish but also sonically bright. This system has always sounded a bit on the bright side so I don't think its the source.
On the upside, the bass and mid-base sound fantastic.
I don't have a problem with doing some simple mods to try and upgrade what I'm hearing from them but I'f they "sound how they sound", I won't throw good money after bad. I know we all have seperate tastes in what "sounds good" to us and don't mean to insult anyone who loves the Polk sound. I'm just trying to determine my next step with these beauties.

No one mentioned this, but if the OP finds the LSim Muted and dark sounding, it may be his preference in sound is a much more forward or treble tilted up sound.

nooshinjohn

...

pitdogg2

K_M wrote: »

jmitchnh wrote: »

Greetings all,
Just took delivery of a pair of fairly minty SDA-1C's. I have always absolutely loved the imposing look of this speaker and thought it would be the perfect speaker for my vintage set-up. The only aniexity I felt about the purchase is would they sound the same as the newer Polks?
I've owned a pair of LSi 9 (so sexy looking) and LSiM 703's (again sexy looking), only to be dissaponted in the sound. They sound very "back of the house" to me meaning the vocals seemed recessed in the mix and the highs sounded a bit muted and dark. I was hoping these older Polks would not have the same sound signature but after playing a few different tracks, I hear the similar sound. Rather lifeless and dark high end and vocals.
I guess my question is so you think there may be something amiss with these or are all Polks voiced the same?
All the drivers seems to be working ( I do hear something from each one) and I am using the factory interconnect cable. As far as upstream, I'm using a Yamaha M-60 amp with a Nackamichi CA 5 preamp. The room is rather smallish but also sonically bright. This system has always sounded a bit on the bright side so I don't think its the source.
On the upside, the bass and mid-base sound fantastic.
I don't have a problem with doing some simple mods to try and upgrade what I'm hearing from them but I'f they "sound how they sound", I won't throw good money after bad. I know we all have seperate tastes in what "sounds good" to us and don't mean to insult anyone who loves the Polk sound. I'm just trying to determine my next step with these beauties.

No one mentioned this, but if the OP finds the LSim Muted and dark sounding, it may be his preference in sound is a much more forward or treble tilted up sound.

One word
Klipsch

jmitchnh

Funny you should mention that Pitdogg2. I believe I do prefer a forward, brighter sonding speaker. May be due to the fact my high frequency hearing has started to wane with age or maybe just what sounds good to my ear.
I own many pairs of klipsch speakers as a matter of fact (Forte, KG4, RF7, RF5, RP600M) and they are all on the sidelines. I find I just cant get into the sound of those horns. I, like you, thought Klipsch would be my panacea but not to be. I do tend to like brighter speakers (Focal, Infinity RS/Kappa, JBL) but right now I'm tranfixed with my SDA's. Their frequency response, soundstage and dynamics are just what I'm looking for in a loudspeaker.
I'm thinking I'll be upgrading to the RD0 194's next to get that next level of detail out of them and the x-overs. I don't mean to be negative towards Polk, I'm just happy I've found a pair I can really, truly enjoy !