Tweeter Upgrade: To Do, or Not To Do?

wolfie62

I have been listening to and following Polk Audio products since 1980. The first Polks I ever listened to were the RTA 12s, listening to Billy Joel's "Glass Houses" LP, in the fall of 1980. I've been hooked ever since. I followed all the reviews and advertisements for the new lines developed until the present day. I have performed countless listening demonstrations over the years of the Polk line. But, with the family that came along, money for speakers wasn't a pressing concern.

In 1986, on a very limited budget, I purchased a pair of Monitor 4As, and still have them. They made many moves with me, and I raised 3 kids with them. Small, but they always satisfied me.

Until recently, when I decided to buy a near mint pair of 1989 RTA 8T speakers on eBay. I bought them and had them shipped. No problems. Everything stock, no upgrades. I have to say, I have really enjoyed listening to these over the past 3 months. I mostly listen to my collection of nearly 5000 vinyl LPs.

Now, the subject of tweeters. Polk started out using the ubiquitous Peerless silk dome tweeter. Through the years, Polk invested lots of R&D money to develop various tweeters, using laser interferometry, etc, to reduce distortion, increase power handling, etc. I see the SL 1000/2000/2500/3000 models used through the years.

Now....I see the RD-0194/0198 model tweeters being sold as "upgrades". Basically, after all these years, reverting back to the silk dome tweeter.

So.....my question is "why?" What are folks seeing as wrong with the SL line, and in my case, the 2000 model? Is it the inferior sound, or glue that is breaking down? What makes the RD line so much better? What are the opinions on sound quality of the old vs the new?

I see it as VERY IRONIC that Polk has come full circle after all these years; starting with the silk dome, and ending up with the silk dome tweeter. The more things change......

My RTA 8Ts:

michaeljhsda2

There's a spike that occurs in the SL2000 and it's a very irritating, shrill sound. The replacement RD0194-1 alleviates that issue.

The SL3000 didn't have that problem, however, not sure why Polk made the RD0198-1...cheaper perhaps? Somebody will comment soon I'm sure.

pitdogg2

the SL 2000 tweeter had a hump at about 13khz I believe and to most folks unbearable to listen to. The poly dome also gets brittle with age causing more problems.

The new RD-0194 and RD-0198 tweeters are leaps better that the older models.

audioluvr

I commonly see the perimeter glue separating and the poly dome warping with age. When I first got my SDA 1C's I bought New RDO 194's for them and did some serious A/B comparing because like you I'd always been happy with the SL2000's sound. First thing I noticed was certain vocal tracks, especially with female singers, "S" sounds were like fingernails on a chalkboard with the SL's where the RDO's reproduced it much more accurate. Violin tracks also were much more pleasant.

You should rebuild those crossovers first though then do your own A/B

F1nut

michaeljhsda2 wrote: »

There's a spike that occurs in the SL2000 and it's a very irritating, shrill sound. The replacement RD0194-1 alleviates that issue.

The SL3000 didn't have that problem, however, not sure why Polk made the RD0198-1...cheaper perhaps? Somebody will comment soon I'm sure.

Because the SL3000 was flawed as well. The RD0198 simply sounds better.

wolfie62

I haven’t noticed any shrill sounds on these. Just played the CD and LP version of Linda Ronstadt’s 1989 album, “Cry Like A Rainstorm, Howl Like The Wind.” Has the Aaron Neville duets. Linda can get shrill, but I never heard it.

F1nut

Then you can't hear above 11kHz.

Clipdat

Damn, we got an audiologist in the house, folks! Hearing tests now given over the Internet via Club Polk!

F1nut wrote: »

Then you can't hear above 11kHz.

wolfie62

A related question:

I scoured this site for info on replacement Peerless K010DT silk soft dome tweeters. There seem to be 2 sources of copies: M&K and MA Audio. I’m guessing from the specs that M&K makes the most exact copy. Any thoughts or experience?

wolfie62

MW Audio, not MA:

https://www.midwestspeakerrepair.com/shop/home-audio/tweeters/dome/mw-audio-mt-4115-1-inch-dome-tweeter/

Not M&K. But this seems to be a different sourced copy:

https://www.simplyspeakers.com/replacement-speaker-peerless-dome-tweeter-t-k010dt.html?gclid=EAIaIQobChMIqKvo8rzU2gIVEI5pCh1L4AAYEAQYAiABEgKGJPD_BwE

And this one:

https://picclick.com/MK-Miller-Kreisel-17050-Silk-Dome-Tweeter-332126648849.html

audioluvr

wolfie62 wrote: »

A related question:

Related to???

stainless0steel2

For a basically $100 you can have new tweeters that'll be much smoother.
I've upgrade a couple sets of Polk speakers to 194's and 198's. Each time there's a jump in quality.
It's definitely worth the investment if you plan on keeping these.

wolfie62

audioluvr: Related to tweeter upgrades. You have to read the posts. It helps.

Whether to go back to the Peerless K010DT or the RD-0194. I have seen and read that many prefer the sound of the silk soft dome Peerless over the 194/198 tweeters.

pkquat

The peerless tweeters / copies of them are completely different, and would require a different crossover. Their frequency response and impedance curves are different. Polk specifically designed the RD0 line of tweeters as a drop in replacements for the SL 2000/2500/3000 series of tweeters. Plus the mounting plate for the peerless is not the same. You would need a router, new mounting holes, and possibly some putty. The RD0's are the simplest option and are highly regarded.

The SL2000 can sound very detailed and crisp, but that is partly due the 12-13kHz bump people are talking about. I think part if it was the "sound" of the 80's. For short term listening they sound a little brighter and have a little WOW factor. For long term listening it can be what people call fatiguing. I would call it less pleasing for longer duration listening. Depending on the track, some stuff can even sound harsh.

I have a few sets of polks with SL2000's that will or have gotten upgrades. I only really listen to the ones I have upgraded now. I did listen to the SL2000's for a while, and I would say I got "used" to the sound so it was less noticeable. After switching to different speakers and then hearing the SL2000 I noticed the bump again.

What the source material is and what is driving the speakers can also make a difference. Since I have upgraded to separate amp / pre-amp, and even upgraded those, I have noticed much more in the music. I've heard things I never really noticed before. These have made the short comings of the SL2000 more noticeable as well.

westmassguy

RD0194s also replace the SL1000s

wolfie62

I still have yet to SEE the bump. Does any one have a link to lab tests or reviews showing this "bump?" Comparing these to my other speakers, specifically the Dynaudio pair, they sound smooth. Perhaps because my pair were warehoused (air conditioned) for 27 years?

I am very tempted to make some mods and upgrades. I'm just looking for a good reason, some real data, not just opinions and urban legends to go by.

I am going to build a totally new crossover, with an A/B switch that allows me to use the untouched original crossover, or the equal compromise design I have been using since 1982. I would like to be able to go between my design and the OEM Polk crossover.

michaeljhsda2

If they sound smooth to you, why do any upgrades?

RobbyKY

On the piano intro to "Beautiful Girl" off INXS's "Welcome to Wherever You Are" CD, my old ears could immediately tell the difference between the stock tweeters and after I upgraded to the RDO198-2's & modified the crossover. This just happened to be the CD I was using during my mods but it was a "Dang!" moment.

Never tried to compare just the stock SL to the 194 but the difference was night and day with the 198's. I originally ordered the 194's to replace a damaged tweeter but sent them back and decided to go TL mods after reading through past post on here. Now I have three engineering degrees, work with audio and love plots and graphs as much as the next guy but sometimes I just like to pause and listen. Only doctors should be looking at bumps....

Robby

codycatalist

wolfie62 wrote: »

I haven’t noticed any shrill sounds on these. Just played the CD and LP version of Linda Ronstadt’s 1989 album, “Cry Like A Rainstorm, Howl Like The Wind.” Has the Aaron Neville duets. Linda can get shrill, but I never heard it.

Linda with the SL2000s is lively but Linda with the Rd0s is smooth as butter. Her voice just melts with upgraded tweets.

pitdogg2

you can lead a horse to water......

K_M

.

K_M

wolfie62 wrote: »

I still have yet to SEE the bump. Does any one have a link to lab tests or reviews showing this "bump?" Comparing these to my other speakers, specifically the Dynaudio pair, they sound smooth. Perhaps because my pair were warehoused (air conditioned) for 27 years?

I am very tempted to make some mods and upgrades. I'm just looking for a good reason, some real data, not just opinions and urban legends to go by.

I am going to build a totally new crossover, with an A/B switch that allows me to use the untouched original crossover, or the equal compromise design I have been using since 1982. I would like to be able to go between my design and the OEM Polk crossover.

https://www.stereophile.com/content/polk-rta-11t-loudspeaker-measurements


Look at the FR graph....Figure #4......fairly big bump at 12khz.

Your tweeter caps are very likely bad also. That may be hiding the bump, possibly. We had one tweeter, that replacing the cap made the tweeter a decent bit louder and where it had seemed a bit dull before, it turned overly strident.
Turned out it was the SL 2000 age issue. It just did not sound good anymore.


With that being shown, it could also be some people who like that sound, and perhaps you simply do.

boston1450

Do it
.
Thank us later. Nice speakers btw

heiney9

This has been beaten to death. There are literally hundreds of threads on this exact topic, with in depth explanations as well as solid proof of the nasty spike in the sl2000 tweeter.

Don't mean to be a bore, but try searching the topic as you will get more information than you ever needed.

Yes, the RD0 tweeters are much better than the sl1000,2000,2500,3000. By far, well worth the cost of upgrade. But I'd also refresh the caps and resistors in the x-overs.

The transformation, as had been noted here 100's of times, is amazing.

H9

wolfie62

K_M wrote: »

wolfie62 wrote: »

I still have yet to SEE the bump. Does any one have a link to lab tests or reviews showing this "bump?" Comparing these to my other speakers, specifically the Dynaudio pair, they sound smooth. Perhaps because my pair were warehoused (air conditioned) for 27 years?

I am very tempted to make some mods and upgrades. I'm just looking for a good reason, some real data, not just opinions and urban legends to go by.

I am going to build a totally new crossover, with an A/B switch that allows me to use the untouched original crossover, or the equal compromise design I have been using since 1982. I would like to be able to go between my design and the OEM Polk crossover.

https://www.stereophile.com/content/polk-rta-11t-loudspeaker-measurements


Look at the FR graph....Figure #4......fairly big bump at 12khz.

Your tweeter caps are very likely bad also. That may be hiding the bump, possibly. We had one tweeter, that replacing the cap made the tweeter a decent bit louder and where it had seemed a bit dull before, it turned overly strident.
Turned out it was the SL 2000 age issue. It just did not sound good anymore.


With that being shown, it could also be some people who like that sound, and perhaps you simply do.

Thanks! That is the evidence I have been looking for.

No, I have never liked an abrasive, edgy sound. I always look for smoothness, and ACCURACY. As for smoothness, I have been doing a lot of work on that. Especially my cartridge/stylus combinations. My Dynaudio speakers are as smooth as silk, always have been. That is my comparison to the SL2000. I'm thinking my 2000s have aged much more gracefully than most. Sealed in plastic, original boxes and packaging, dessicant bags, air conditioned, for 27 years. Used for a 3 year period, military guy.

And why do you so readily say that my tweeter caps are likely bad? Mylar caps rarely go bad. (How they sound compared to polypropylene is a taste issue.) I already checked out the caps, all read within a very nice tolerance of rated value. Even the electrolytics are good, including DC equivalent resistance.

I see so many in here recommending at first sight to recap and re-tweet, that I had to investigate, and then ask why.

Since I'm not of fan of fixing something that aint broke, I'll put in my crossover mods first, then substitute the K010DT tweeters in (yes I have already made allowance for the differences in impedence and sensitivity) and perhaps eventually buy the RD-0194 tweeters.

polrbehr

Hey, it's your journey; follow your own roadmap but don't complain how much gas it took to get there... LOL - seriously, good luck with your project OK?

F1nut

The SL2000 when brand spanking new had the 5dB spike, it's got nothing to do with age.

In addition, the RD0194 is better than the Peerless.

K_M

wolfie62 wrote: »

K_M wrote: »

wolfie62 wrote: »

I still have yet to SEE the bump. Does any one have a link to lab tests or reviews showing this "bump?" Comparing these to my other speakers, specifically the Dynaudio pair, they sound smooth. Perhaps because my pair were warehoused (air conditioned) for 27 years?

I am very tempted to make some mods and upgrades. I'm just looking for a good reason, some real data, not just opinions and urban legends to go by.

I am going to build a totally new crossover, with an A/B switch that allows me to use the untouched original crossover, or the equal compromise design I have been using since 1982. I would like to be able to go between my design and the OEM Polk crossover.

https://www.stereophile.com/content/polk-rta-11t-loudspeaker-measurements


Look at the FR graph....Figure #4......fairly big bump at 12khz.

Your tweeter caps are very likely bad also. That may be hiding the bump, possibly. We had one tweeter, that replacing the cap made the tweeter a decent bit louder and where it had seemed a bit dull before, it turned overly strident.
Turned out it was the SL 2000 age issue. It just did not sound good anymore.


With that being shown, it could also be some people who like that sound, and perhaps you simply do.

Thanks! That is the evidence I have been looking for.

No, I have never liked an abrasive, edgy sound. I always look for smoothness, and ACCURACY. As for smoothness, I have been doing a lot of work on that. Especially my cartridge/stylus combinations. My Dynaudio speakers are as smooth as silk, always have been. That is my comparison to the SL2000. I'm thinking my 2000s have aged much more gracefully than most. Sealed in plastic, original boxes and packaging, dessicant bags, air conditioned, for 27 years. Used for a 3 year period, military guy.

And why do you so readily say that my tweeter caps are likely bad? Mylar caps rarely go bad. (How they sound compared to polypropylene is a taste issue.) I already checked out the caps, all read within a very nice tolerance of rated value. Even the electrolytics are good, including DC equivalent resistance.

I see so many in here recommending at first sight to recap and re-tweet, that I had to investigate, and then ask why.

Since I'm not of fan of fixing something that aint broke, I'll put in my crossover mods first, then substitute the K010DT tweeters in (yes I have already made allowance for the differences in impedence and sensitivity) and perhaps eventually buy the RD-0194 tweeters.

I might have agreed with you, until we took the plunge.
It is not so much "Broke", but simply not up to potential.

In our experience the caps did make a fairly noticeable change.
We also replaced the tweeter protection circuit.
Things still did not sound great, until we again replaced the SL-2000 Tweeters with the latest version replacement.
Quite better and smoother.

Clipdat

Do you have actual proof of these positive changes? I doubt you could identify the tweeters and caps in a blind a/b test.

K_M wrote: »

In our experience the caps did make a fairly noticeable change.
We also replaced the tweeter protection circuit.
Things still did not sound great, until we again replaced the SL-2000 Tweeters with the latest version replacement.
Quite better and smoother.

wolfie62

Any one have response curves, or know a link to get them, for the RD-0194/0198 tweeters?

My listening room is rather dead/absorbtive. Perhaps that's why I enjoy the "bump" in out put of the 2000 tweets. Perhaps getting analog equipment to sound more "digital" was what Polk was after when installing the SL2000 tweeters back in the 1980s.

OK. Since I have money for only 1 decision, guess I will go the way of the RD-0194 tweeters. I know what the Peerless tweets sound like and can do; The RD units will be a new experience.

K_M

Clipdat wrote: »

Do you have actual proof of these positive changes? I doubt you could identify the tweeters and caps in a blind a/b test.

K_M wrote: »

In our experience the caps did make a fairly noticeable change.
We also replaced the tweeter protection circuit.
Things still did not sound great, until we again replaced the SL-2000 Tweeters with the latest version replacement.
Quite better and smoother.

No....(but I see you are starting to get good at that humour thing!)