What wears out in an SDA SRS??

gij801

I am the original owner of a pair of 1985 SDA SRS's. Believe it or not I stuffed both of them in the back of my VW Rabbit GTI and drove 90 miles home - but that's another story. They are cosmetically in perfect condition, barely different from new, and have never been moded or even disassembled. Always in a living room environment and never abused. I have a couple of questions. Are there any components in this model that typically deteriorate over time? Is there any way to check for this? Is there anything that should be done to refurbish these 20 year old electronics, connectors, etc. Could/would Polk examine the crossovers to see if they were in tolerance to the original specs? Can the SRS effect be tested to see if it is operating properly?
My concern is that after living with these speakers for 20+ years my ears may have become accustomed to a slowly deteriorating sound quality. Then again, maybe my 47 year old ears are just the right match for 20 year old speakers.
Thanks,

heiney9

LOL, I put my brand new RTA-11t's in the back of my GTI as well right around that same year. Damn cars will swallow anything.

I would say to just visually inspect the drivers to make sure there is no damage. Typically if they aren't abused and haven't been moved from palce to place too many times they are probably just fine.

One suggestion is to purchase the NEW silk dome replacement tweeters as they sound much smoother than the original sl2000. If you are not hearing any odd sounds then I'm sure things are fine.

My RTA11t's of the same era are still like new almost 20 years later.

H9

Tour2ma

gij801 wrote:

I am the original owner of a pair of 1985 SDA SRS's. Believe it or not I stuffed both of them in the back of my VW Rabbit GTI and drove 90 miles home - but that's another story.

I'd like to see a picture of that... Welcome to the Club.

The cross-over polyswitch that protect the tweeters is the most likely candidate. After years of passing current, their "value" changes and they will tend to do their duty sooner and sooner, earlier than necessary to protect. If you've ever noticed one speaker of the other going "dull" for a bit on you, this is what is occuring. Ken Swaugger of Polk CS will mail you replacements gratis along with replacement instructions.

The SL2000 tweeters are the next most likely to go, but not very likely at that. The later SL3000's were far more prone to failure.

Stew

The electrolytic capacitors in the crossover deteriorate and change value over time. It would probably be easier and cheaper to just replace the capacitors than to find someone to test the old ones. At 20 years old, it's a safe bet they're out of tolerance anyway. Try a search for "crossover upgrade" and you'll find lots of good discussions. The tweeters are unlikely to fail but the replacements sound much better to many on this site including myself.

reeltrouble1

Great speaker, love mine, changed the tweets for the silk domes, that was nice.

No problems with my poly's yet, several here have done the capacitor upgrade with varying results.

How do they sound to you? Since your asking you might need to just go do the crossovers for peace of mind or it might bother you to no end. Check your cabinets for any air leaks, guess that can happen. Ken will also get you some spikes if you want.

We like pics even though we have seen them many times, lets see them naked!!

RT1

twochannel

This year is my SDA-SRS's 20th birthday and they still sound amazing! They will remain all original untill I try the RD0194 Peerless tweeters.

gij801

My inital concern was that they sounded different than they used to. Of course I made a "couple" of changes recently.
1)moved them to a large home theater room (19'x30') in our new house after previously having them in much smaller location.
2)Changed the cd player from a Denon DCD-1100 to an Apex DVD player.
3)Changed preamp from Adcom to Pioneer A/V VSX-1015.
4)Used receiver to auto-calibrate 7.1 speaker system (the SRS's are my 2 fronts)
5)Ears not what they used to be.

After I accounted for these I'm back to being amazed at the sound. One thing that wasn't appearant to me was when I set up the SRS's as my 7.1 fronts I used the speaker auto-calibrate function of the A/V receiver. It's pretty cool in that you connect a mic to the receiver and hit the auto-calibrate button. The receiver sends out a bunch of hisses, chirps, booms, pops etc. out of all speakers over a 5-10 minute test. The receiver is looking at the capabilities, speaker placement, room dynamics, etc and adjusting the speaker settings (delay, distance, equailization) specific to your setup. I was running the CD signal through these changes to just the two fronts. There is an option on the receiver to bypass all the changes and just present the CD signal to the amp in it's raw form - for playing CD's, duh! Once I did this and turned the volume up a bit to handle the large room, I'm all smiles. I wonder if others who have moved vintage speakers to home theater use have made the same mistake of over processing the CD source?

Tour2ma

Over procesing may be it all, but the larger room is a big factor. What amp are you using to drive the SRS's?

gij801

Amp is Adcom 555. I love the Pioneer/Adcom match. As soon as I switched from the processed signal to "stereo/direct" it was like night and day. I figured out that in the default stereo mode the receiver only uses the two fronts but still applies the processing that the auto-calibrator configured. I also complicated things a bit by not yet installing a sub woofer or center - so both of those signals were run through the fronts and considered by the auto-calibrator. I'm waiting for someone to ask why I am using an Apex player though :eek: .

heiney9

No trying to be to critical, but the Apex DVD player has to go if you are using it for cd's. A nice dedicated cdp will do wonders for those SRS's. Again not trying to be critical, just trying to help. A poor source can ruin the listening experience. Perhaps the lesser quality of the Apex is what you are noticing,

FWIW
H9

joeparaski

Has anyone ever disconnected the passive crossover in the SRS (or other Polks) and went with an external electronic crossover? Anything wrong with doing that? (other than not being "all original")?

gij801

Excuse me! The Apex isn't of lesser quality, it's of the lowest quality.

Tour2ma

I thought Apex, although tempermental, were one of those little "giant killers"... Maybe that's for video only, but "FWIW" since gij did not come here adding for source advice, I would not offer any.

gij,
Stick around long enough and someone or another will have you change out everthing but your socks... which are actually kind of ugly.

Although you can never have too much, power is not an issue. Enjoy your rig...

heiney9

gij801 wrote:

Excuse me! The Apex isn't of lesser quality, it's of the lowest quality.

Well I was trying to be PC when I wrote that. But seeing as you are fully aware I'll leave it alone . You know what has to be done.........get a good source and your smile will be even bigger .

Joeparski wrote:

Has anyone ever disconnected the passive crossover in the SRS (or other Polks) and went with an external electronic crossover? Anything wrong with doing that? (other than not being "all original")?

The x-over is the main ingredient in the SDA process. So unless the active x-over is designed to do EXACTLY the same thing, I'd say big NO. Not even sure if it's possible to create the SDA process with an active x-over.

H9

heiney9

Tour2ma wrote:

"FWIW" since gij did not come here adding for source advice, I would not offer any.

Umm..... he asked why they might sound different and looking at his list of changes I rec. accordingly, that's all.

gij801 wrote:

My inital concern was that they sounded different than they used to. Of course I made a "couple" of changes recently.
1)moved them to a large home theater room (19'x30') in our new house after previously having them in much smaller location.
2)Changed the cd player from a Denon DCD-1100 to an Apex DVD player.
3)Changed preamp from Adcom to Pioneer A/V VSX-1015.
4)Used receiver to auto-calibrate 7.1 speaker system (the SRS's are my 2 fronts)
5)Ears not what they used to be.

H9

heiney9

Also, not to sound snobby, but the Apex was never a "giant" killer. It was known to be region free and would play essentially any thing thrown at it. Why? because it's nothing more than a modified (word used loosely) computer DVD drive. Again this may come off the wrong way I'm trying to slam anyone or anything, just trying to set the record straight.

***keeping my flame suit near by***

H9

Tour2ma

No flaming... at least not into addition to the singe I posted above. Not like I have never commented on an item uninvited (depending on the amp answer, I might have here), but all too often a newbie comes in and we have him changing everything.

Some here did have the Apex "way up there" if not Giant status once upon a a time. Then I think they all quit working...

The x-over question is an interesting one... Certainly it could be done with the primary HF/LF split at the external and the LF/MF SDA split internal.

danger boy

heiney9 wrote:

No trying to be to critical, but the Apex DVD player has to go if you are using it for cd's. A nice dedicated cdp will do wonders for those SRS's. Again not trying to be critical, just trying to help. A poor source can ruin the listening experience. Perhaps the lesser quality of the Apex is what you are noticing,

FWIW
H9

Bingo! thanks heiney9.. when i read that it jumped out and smacked me in the face.. go back to your Denon CD player or another. but that Apex DVD is killing your sound quality now. and not to mention the soundstage. I've been there.. i know a low end DVD player will kill the sound quality.

Larry Chanin

joeparaski wrote:

Has anyone ever disconnected the passive crossover in the SRS (or other Polks) and went with an external electronic crossover? Anything wrong with doing that? (other than not being "all original")?

Hi Joe,

Is this suggestion meant as a workaround for the possible deterioration of components in the passive crossover circuits by substituting adjustable external electronic crossovers for each speaker?

Pardon my overall ignorance regarding crossovers, but aren't we really dealing with multiple crossovers in a speaker, i.e. different crossovers for different drivers, including cascaded crossovers for multiple tweeters, etc? If so, wouldn't it require many external crossovers to correct each internal crossover?

Larry

Tour2ma

Larry,
I'd think the first goal of the external x-over is the basic HF/ LF split for "pure" bi-amping.

Good point about the progressive point source tweeters (F1 will be proud of me for that).

dorokusai

Crossover upgrades are overrated....unless you have a failure, stick with the stock caps.

I digress....I may do it to play around and have fun, but it's certainly not neccesary.

jcmccorm

What deteriorates over time with the SDA SRS's?

My back.

Cary

dorokusai

That's definetly a fact

madmax

joeparaski wrote:

Has anyone ever disconnected the passive crossover in the SRS (or other Polks) and went with an external electronic crossover? Anything wrong with doing that? (other than not being "all original")?

The only reasonable way to go with an external xover is covered in the manual. Two amp channels to each speaker using an active xover feeding the internal crossover with quite a bit of overlap between the highs and lows. I did this and it didn't work out very well for me because my crossover didn't allow any overlap. This sounded a little clinical and on my system and I could hear the results of putting an extra electronic stage in line. Had I had a little overlap it would have been ok, still, extra stages of electronics detracts from the overall quality.
madmax

gij801

That's it! I'm keeping the Apex. All you guys will be after it in the Apex Vintage forum in 20 years.

heiney9

gij801 wrote:

That's it! I'm keeping the Apex. All you guys will be after it in the Apex Vintage forum in 20 years.

LOL! Hopefully you have another retirement plan . Enjoy your SDA's they are great speakers. Glad to see a new member able to have some fun as well as us established members.

H9

reeltrouble1

I could not agree more with my fine friend. The limiting factor within the many "ordinary" rigs I have previously put together or heard elsewhere had little to do with speaker crossover modifications. Poor power supply's, inferior circuit design and room acoustics have been far more the culprit. It was not until I paid some serious attention to source, amplification circuits and power that my rigs began to transform to something more special. High end audio exsits because it sounds better. I am now in the process of building a totally new listening room. I look forward to getting to hear what the Hardcore/Guru's round here come up with.

If you want to do the crossover mods its not going to hurt anything and may give you some piece of mind, but I would not expect anything like a new level. Its not a slam mind you, its very much about the music for me.

RT1

RuSsMaN

What wears out in an SDA SRS??

One's interest in listening to them?

:eek:

Cheers,
Russ

madmax

RuSsMaN wrote:

One's interest in listening to them?

:eek:

Cheers,
Russ

You are blaspheming, I don't have to listen to a blasphemer...
From: Mad Max
madmax

The main thing that wears out is the seat in the sweet spot.

F1nut

Stew hit the nail on the head, the electrolytic and mylar capacitors have a life span of maybe 10 years after which they deteriorate. Besides that, they aren't that good to begin with. Changing to film capacitors can and will make a nice difference in the sound quality of your speakers.

dorokusai

That's if you believe what you read.