RTA-15TL Tweeter

Are these tweeters available and if they are cost with shipping information would be greatly appreciated.

Thank you

Comments

  • F1nut
    F1nut Posts: 49,704
    CALL Polk customer service on Monday. Order two of the RD0198-1.
    Political Correctness'.........defined

    "A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."


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  • Nightfall
    Nightfall Posts: 10,042
    Apparently the RTA-15TL's have the tweeters crossed over too low, there's a mod someone here came up with to remedy that so you'll not kill tweeters as easy on those. Decato? Degato? I can't remember, just a sec.
    afterburnt wrote: »
    They didn't speak a word of English, they were from South Carolina.

    Village Idiot of Club Polk
  • Nightfall
    Nightfall Posts: 10,042
    afterburnt wrote: »
    They didn't speak a word of English, they were from South Carolina.

    Village Idiot of Club Polk
  • Ricardo
    Ricardo Posts: 10,636
    And that right there will bring your 15tls to a whole new level. Add Larry's rings and you'll have one of the best sounding speakers Polk ever made.

    Maybe I'm biased....
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  • K_M
    K_M Posts: 1,627
    edited January 2017
    Nightfall wrote: »
    Apparently the RTA-15TL's have the tweeters crossed over too low, there's a mod someone here came up with to remedy that so you'll not kill tweeters as easy on those. Decato? Degato? I can't remember, just a sec.

    This is an interesting idea and read, but got me thinking of a few things.

    1. Why were Polk's engineers not able to realize this "issue", but the forum member mentioned was able to?
    2. The issue noticed by the forum member, was using 15 or 16 year old caps, as his baseline. Any new cap could drastically change the "sound", as the original caps were most likely not good anymore.
    3. Why this issue was not noticed, on several other models, that use similar or the same crossovers, and tweeters.
    4. His modifications were not based on actual measured responses of the drivers in question, but simply based on assumed impedance values, not measured impedances.

    Still interesting though.
  • tomb57
    tomb57 Posts: 4
    K_M wrote: »
    Nightfall wrote: »
    Apparently the RTA-15TL's have the tweeters crossed over too low, there's a mod someone here came up with to remedy that so you'll not kill tweeters as easy on those. Decato? Degato? I can't remember, just a sec.

    This is an interesting idea and read, but got me thinking of a few things.

    1. Why were Polk's engineers not able to realize this "issue", but the forum member mentioned was able to?
    2. The issue noticed by the forum member, was using 15 or 16 year old caps, as his baseline. Any new cap could drastically change the "sound", as the original caps were most likely not good anymore.
    3. Why this issue was not noticed, on several other models, that use similar or the same crossovers, and tweeters.
    4. His modifications were not based on actual measured responses of the drivers in question, but simply based on assumed impedance values, not measured impedances.

    Still interesting though.

    My thoughts exactly

    Tom
  • F1nut
    F1nut Posts: 49,704
    1. Why were Polk's engineers not able to realize this "issue", but the forum member mentioned was able to?

    For the same reason the Polk engineers were not able to realize the issue of the SL2000's 5dB spike. Oh wait they did realize it, but decided to go with it anyway.
    Political Correctness'.........defined

    "A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."


    President of Club Polk

  • K_M
    K_M Posts: 1,627
    F1nut wrote: »
    1. Why were Polk's engineers not able to realize this "issue", but the forum member mentioned was able to?

    For the same reason the Polk engineers were not able to realize the issue of the SL2000's 5dB spike. Oh wait they did realize it, but decided to go with it anyway.

    You missed the sarcasm obviously. The guy that mentioned the mods to the Rta15, was making mods based on wrong information. That was the point.

    The Polk engineers did know what they were doing with the Rta15 tweeter and crossover. Member Decato was just guessing.
  • heiney9
    heiney9 Posts: 25,053
    K_M wrote: »
    Nightfall wrote: »
    Apparently the RTA-15TL's have the tweeters crossed over too low, there's a mod someone here came up with to remedy that so you'll not kill tweeters as easy on those. Decato? Degato? I can't remember, just a sec.

    This is an interesting idea and read, but got me thinking of a few things.

    1. Why were Polk's engineers not able to realize this "issue", but the forum member mentioned was able to?
    2. The issue noticed by the forum member, was using 15 or 16 year old caps, as his baseline. Any new cap could drastically change the "sound", as the original caps were most likely not good anymore.
    3. Why this issue was not noticed, on several other models, that use similar or the same crossovers, and tweeters.
    4. His modifications were not based on actual measured responses of the drivers in question, but simply based on assumed impedance values, not measured impedances.

    Still interesting though.

    Many, many things are re-engineered 20-30 years later by tinkerer's. Bean counters and lack of materials is usually the reason. All designs are compromises. 20-30 years later many times the compromises can be fixed or atleast updated.

    This is a very normal life cycle for a myriad of products that are older. As technology gets better, costs come down........it's natural to want to "improve" old things sometimes, even if they were cutting edge in their day.


    H9

    "Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass Pass Labs XA25 | EE Avant Pre | EE Mini Max Supreme DAC | MIT Shotgun S1 | Pangea AC14SE MKII | Legend L600 | BlueSound Node 3 - Tubes add soul!
  • K_M
    K_M Posts: 1,627
    edited April 2017
    heiney9 wrote: »
    K_M wrote: »
    Nightfall wrote: »
    Apparently the RTA-15TL's have the tweeters crossed over too low, there's a mod someone here came up with to remedy that so you'll not kill tweeters as easy on those. Decato? Degato? I can't remember, just a sec.

    This is an interesting idea and read, but got me thinking of a few things.

    1. Why were Polk's engineers not able to realize this "issue", but the forum member mentioned was able to?
    2. The issue noticed by the forum member, was using 15 or 16 year old caps, as his baseline. Any new cap could drastically change the "sound", as the original caps were most likely not good anymore.
    3. Why this issue was not noticed, on several other models, that use similar or the same crossovers, and tweeters.
    4. His modifications were not based on actual measured responses of the drivers in question, but simply based on assumed impedance values, not measured impedances.

    Still interesting though.

    Many, many things are re-engineered 20-30 years later by tinkerer's. Bean counters and lack of materials is usually the reason. All designs are compromises. 20-30 years later many times the compromises can be fixed or atleast updated.

    This is a very normal life cycle for a myriad of products that are older. As technology gets better, costs come down........it's natural to want to "improve" old things sometimes, even if they were cutting edge in their day.


    H9

    Uh no. The guy with that mod thread, based all his mods off of things he assumed were true. He even said he was only making assumptions. Simply guessing.

    He did not measure the impedance or frequency response of the speakers he was using, but guessed at what they might be......

    That alone is the reason it most likely was not done by Polk.

    Polk engineers for sure measured the response and impedance and designed a crossover taking all of those things into the calculation.
    His changes were made based on using very old caps that most likely were bad, and assumptions that were never verified.





  • F1nut
    F1nut Posts: 49,704
    Brian (Decato) did take measurements and posted charts in his thread.
    Political Correctness'.........defined

    "A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."


    President of Club Polk

  • K_M
    K_M Posts: 1,627
    F1nut wrote: »
    Brian (Decato) did take measurements and posted charts in his thread.

    I will go back and look again, when I have time. I remember reading him saying he was kinda guessing, and saying he did not measure impedance or response.

    Was it later in the thread? in the beginning he admitted he was kinda guessing.

    Im not bashing him or his work it seems reasonable, but perhaps not totally necessary for "sure" is all.
  • wolfie62
    wolfie62 Posts: 24
    Hmmm.

    "Polk engineers for sure measured the response and impedance and designed a crossover taking all of those things into the calculation.
    His changes were made based on using very old caps that most likely were bad, and assumptions that were never verified."

    There ya go....an assumption. You assume since the caps are "old", that they must be bad. I just measured the caps in my 1989 RTA 8Ts. All still good and within tolerance. Equivalent DC resistance still good. No mods have ever been done on these.

    I would like to see test results of the SL2000 tweeters' 5 kHz response spike. Can anyone provide a link?
    Invention is the mother of necessity.

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  • F1nut
    F1nut Posts: 49,704
    Those that don't know don't know that they don't know.
    Political Correctness'.........defined

    "A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."


    President of Club Polk

  • pkquat
    pkquat Posts: 742
    wolfie62 wrote: »
    I just measured the caps in my 1989 RTA 8Ts. All still good and within tolerance. Equivalent DC resistance still good. No mods have ever been done on these.

    You need to remove caps to properly measure them as I recall. How a cap behaves for different audio frequencies can vary. Electrolytic caps do age. There are plenty of electronics articles about this out on the web, and not just related to audio. Old caps can have effects on general electronic equipment and cause them to go out of spec because the cap does not behave the same at a certain frequency even though it may measure within tolerance at a specific measurement frequency.
    I would like to see test results of the SL2000 tweeters' 5 kHz response spike. Can anyone provide a link?

    Somewhere a while ago I saw a graph, but I have not been able to find it. Its been mentioned in a couple of magazine review articles from back in the day. They heard and measured the 12-13KHz spike / bump. I am not sure if graphs were provided. Many people including myself have heard it, and its been discussed at length.

  • K_M
    K_M Posts: 1,627
    pkquat wrote: »
    wolfie62 wrote: »
    I just measured the caps in my 1989 RTA 8Ts. All still good and within tolerance. Equivalent DC resistance still good. No mods have ever been done on these.

    You need to remove caps to properly measure them as I recall. How a cap behaves for different audio frequencies can vary. Electrolytic caps do age. There are plenty of electronics articles about this out on the web, and not just related to audio. Old caps can have effects on general electronic equipment and cause them to go out of spec because the cap does not behave the same at a certain frequency even though it may measure within tolerance at a specific measurement frequency.
    I would like to see test results of the SL2000 tweeters' 5 kHz response spike. Can anyone provide a link?

    Somewhere a while ago I saw a graph, but I have not been able to find it. Its been mentioned in a couple of magazine review articles from back in the day. They heard and measured the 12-13KHz spike / bump. I am not sure if graphs were provided. Many people including myself have heard it, and its been discussed at length.

    Its in the Stereophile review of the Rta11t speaker.