lSi15 tweeter replacement

Is the Tymphany driver XT25TG30-04 1" the best replacement for the tweeter RD0517-2 (used in LSi15) after outer flange removal?

The XT25TG30-04 1 catalog specification shows 87.2 dB sensitivity at 1W/1M, and in reality, it seems sounding a little brighter then the original one after replacement.

Does anybody know the RD0517-2 specs?

Comments

  • F1nut
    F1nut Posts: 49,704
    Buy the real deal from Polk.
    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

  • The problem is $50 vs. $240 for a pair.
  • pitdogg2
    pitdogg2 Posts: 24,474
    Problem is Polk didn't buy off the shelf they sent design specifications to a company to build for their own design.
  • F1nut
    F1nut Posts: 49,704
    pitdogg2 wrote: »
    Problem is Polk didn't buy off the shelf they sent design specifications to a company to build for their own design.

    Ed Zachary
    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
    edited December 2016
    It is the exact same one, except for the Face Plate.

    It was verified by the Polk Marketing Guy (Paul DiComo) on another audio forum.
  • pitdogg2
    pitdogg2 Posts: 24,474
    edited December 2016
    K_M wrote: »
    It is the exact same one, except for the Face Plate.

    It was verified by the Polk Marketing Guy (Paul DiComo) on another audio forum.
    We've had this discussion on the older forum with the exception that one of the Polk engineers had said Polk tweaked it to their XO. So it can't be both ways. Will it work..Sure it will, will it sound the same well as the OP stated it sounds more in your face (brighter). So if he wants to go that way he will be replacing both
  • K_M
    K_M Posts: 1,627
    pitdogg2 wrote: »
    K_M wrote: »
    It is the exact same one, except for the Face Plate.

    It was verified by the Polk Marketing Guy (Paul DiComo) on another audio forum.
    We've had this discussion on the older forum with the exception that one of the Polk engineers had said Polk tweaked it to their XO. So it can't be both ways. Will it work..Sure it will, will it sound the same well as the OP stated it sounds more in your face (brighter). So if he wants to go that way he will be replacing both

    Wow, not sure now. Paul D. was asked by someone in another forum if it was that tweeter, and he said that is was an off the shelf regular XT25, and only the faceplate had been changed.
    I am pretty certain he said the only tweak was obviously making the faceplate flat on 2 sides, and possibly changing the shape where it meets the cone of the tweeter.

    Yes agree it can not be both ways.

  • tonyb
    tonyb Posts: 32,902
    edited December 2016
    FranzDolas wrote: »
    The problem is $50 vs. $240 for a pair.

    .....and that brightness your hearing is the price you pay for 190 buck difference. If that's worth it to you, then rock on, if not....buy the OE parts from Polk.

    You could also let them burn in for awhile and see if they warm up a bit, I doubt though it will be enough to be like the original. How did it get toasted to begin with ?
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  • pitdogg2
    pitdogg2 Posts: 24,474
    K_M wrote: »
    pitdogg2 wrote: »
    K_M wrote: »
    It is the exact same one, except for the Face Plate.

    It was verified by the Polk Marketing Guy (Paul DiComo) on another audio forum.
    We've had this discussion on the older forum with the exception that one of the Polk engineers had said Polk tweaked it to their XO. So it can't be both ways. Will it work..Sure it will, will it sound the same well as the OP stated it sounds more in your face (brighter). So if he wants to go that way he will be replacing both

    Wow, not sure now. Paul D. was asked by someone in another forum if it was that tweeter, and he said that is was an off the shelf regular XT25, and only the faceplate had been changed.
    I am pretty certain he said the only tweak was obviously making the faceplate flat on 2 sides, and possibly changing the shape where it meets the cone of the tweeter.

    Yes agree it can not be both ways.

    Well off the shelf is off the shelf stick it in. Your description is not exactly off the shelf. So now I wonder how well it fits? Anyway we here are wannabes so I wannabes out of this thread

    Peace out.
  • My main concern was a tonal balance around 2.4 - 4.0 kHz rather than high-frequency brightness. For me, the XT25TG30-04 1” sounds better in the HF range then the original one.

    Theoretically, the XT25TG30-04 1” has 90.84 dB sensitivity at 2.83 V. So, including - 4 dB drop caused by the 2 Ohm attenuation resistor in the tweeter circuit, the total HF section sensitivity should be about 87 dB which is 1 dB below the official (catalog) sensitivity of the whole loudspeaker.

    tonyb wrote: »
    FranzDolas wrote: »
    The problem is $50 vs. $240 for a pair.

    .....and that brightness your hearing is the price you pay for 190 buck difference. If that's worth it to you, then rock on, if not....buy the OE parts from Polk.

    You could also let them burn in for awhile and see if they warm up a bit, I doubt though it will be enough to be like the original. How did it get toasted to begin with ?

    I modified the LSi crossover networks in order to apply an active filtration idea for the subwoofer driver and other speaker sections with separate amplifiers. It has been working perfectly until the tweeters were overloaded by one of my family members.
  • K_M
    K_M Posts: 1,627
    edited December 2016
    pitdogg2 wrote: »
    K_M wrote: »
    pitdogg2 wrote: »
    K_M wrote: »
    It is the exact same one, except for the Face Plate.

    It was verified by the Polk Marketing Guy (Paul DiComo) on another audio forum.
    We've had this discussion on the older forum with the exception that one of the Polk engineers had said Polk tweaked it to their XO. So it can't be both ways. Will it work..Sure it will, will it sound the same well as the OP stated it sounds more in your face (brighter). So if he wants to go that way he will be replacing both

    Wow, not sure now. Paul D. was asked by someone in another forum if it was that tweeter, and he said that is was an off the shelf regular XT25, and only the faceplate had been changed.
    I am pretty certain he said the only tweak was obviously making the faceplate flat on 2 sides, and possibly changing the shape where it meets the cone of the tweeter.

    Yes agree it can not be both ways.

    Well off the shelf is off the shelf stick it in. Your description is not exactly off the shelf. So now I wonder how well it fits? Anyway we here are wannabes so I wannabes out of this thread

    Peace out.

    The driver is off the shelf. (supposedly from what I read, supposedly not quite from what you read) so not positive, who knows...lol
    The face plate, obviously mostly decorative can easily be changed over to the original Polk one.
    BTW, have successfully done this took all of maybe 10 minutes and it, in our circumstance sounded virtually identical.
    The OP noticed a slight difference though.
    Post edited by K_M on
  • F1nut
    F1nut Posts: 49,704
    Is that the extent of your husband's speaker engineering?
    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

  • ken brydson
    ken brydson Posts: 8,638
    F1nut wrote: »
    Is that the extent of your husband's speaker engineering?

    Married to X...
  • mikeyb128
    mikeyb128 Posts: 2,885
    F1nut wrote: »
    Is that the extent of your husband's speaker engineering?

    I didn't realize that the hello kitty boom box was considered speaker engineering :smiley:
    2 channel:
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  • tonyb
    tonyb Posts: 32,902
    FranzDolas wrote: »
    My main concern was a tonal balance around 2.4 - 4.0 kHz rather than high-frequency brightness. For me, the XT25TG30-04 1” sounds better in the HF range then the original one.

    Theoretically, the XT25TG30-04 1” has 90.84 dB sensitivity at 2.83 V. So, including - 4 dB drop caused by the 2 Ohm attenuation resistor in the tweeter circuit, the total HF section sensitivity should be about 87 dB which is 1 dB below the official (catalog) sensitivity of the whole loudspeaker.

    tonyb wrote: »
    FranzDolas wrote: »
    The problem is $50 vs. $240 for a pair.

    .....and that brightness your hearing is the price you pay for 190 buck difference. If that's worth it to you, then rock on, if not....buy the OE parts from Polk.

    You could also let them burn in for awhile and see if they warm up a bit, I doubt though it will be enough to be like the original. How did it get toasted to begin with ?

    I modified the LSi crossover networks in order to apply an active filtration idea for the subwoofer driver and other speaker sections with separate amplifiers. It has been working perfectly until the tweeters were overloaded by one of my family members.

    So your bi-amping them from what I gather ? Give the new tweet some play time, it will warm up some probably after 100 hours or so. Tweeters really need little power to perform their best, less than 20 watts in most cases. Throwing big power at them, and sticky fingers on the volume dial isn't going to work into longevity. See if you can place a limit on that volume dial....for those family members who had too much holiday eggnog. lol
    HT SYSTEM-
    Sony 850c 4k
    Pioneer elite vhx 21
    Sony 4k BRP
    SVS SB-2000
    Polk Sig. 20's
    Polk FX500 surrounds

    Cables-
    Acoustic zen Satori speaker cables
    Acoustic zen Matrix 2 IC's
    Wireworld eclipse 7 ic's
    Audio metallurgy ga-o digital cable

    Kitchen

    Sonos zp90
    Grant Fidelity tube dac
    B&k 1420
    lsi 9's
  • FranzDolas
    FranzDolas Posts: 5
    edited December 2016
    Not exactly the bi-amp. I changed the crossover networks in the following way:
    - The sub driver was connected directly to the bottom binding posts, and now, it’s being fed from a dedicated power amplifier, the fc <= 80 Hz, active filtration. All RLC elements are gone, so no extra inductor resistance resulting in a lover Qes value, likewise the LSi25 with a better sub amplifier.
    - The high-pass 130 uF capacitor in the 6.5” woofers circuit was removed too. This section along with the tweeter high-pass filter was hooked up to the upper binding posts, and fed from another amplifier, the fc = 80 Hz, active filtration.
    - Both power amps. are Emotiva A-300. Preamp. - Parasound 2100.
    - All remaining caps. and res. been replaced. Because the 2 Ohm/12 W (Mills) attenuation resistor in the tweeter section was still hot, even at a moderate volume, I decided to make a separate board with four parallel 8 Ohm/10 W (Dayton) resistors with a heat sink, and now, the temp. is OK.

    Pros and cons:
    - Boomy’ bass is gone, a quick, well-controlled one showed up. It was caused (as K_M mentioned, and I measured) by the overlapping 150-200 Hz range of the sub. and the both 6.5” woofers.
    - Another amplifier for the sub section is more cost effective than replacing those four 130 uF electrolytic capacitors in the crossover. The sub-woofer inductor and cap. should be even bigger (more expensive) in order to shift the fc down and avoid overlapping.
    - I can increase or decrease the bass amplitude without changing its phase.
  • K_M
    K_M Posts: 1,627
    Glad it all worked out!
    It takes the Lsi15 to another level for sure!
    Was a bit worried about overloading you with technical information, but it seems to have been put to good use.

    Enjoy!
  • K_M
    K_M Posts: 1,627
    edited March 2020
    K_M wrote: »
    pitdogg2 wrote: »
    K_M wrote: »
    pitdogg2 wrote: »
    K_M wrote: »
    It is the exact same one, except for the Face Plate.

    It was verified by the Polk Marketing Guy (Paul DiComo) on another audio forum.
    We've had this discussion on the older forum with the exception that one of the Polk engineers had said Polk tweaked it to their XO. So it can't be both ways. Will it work..Sure it will, will it sound the same well as the OP stated it sounds more in your face (brighter). So if he wants to go that way he will be replacing both

    Wow, not sure now. Paul D. was asked by someone in another forum if it was that tweeter, and he said that is was an off the shelf regular XT25, and only the faceplate had been changed.
    I am pretty certain he said the only tweak was obviously making the faceplate flat on 2 sides, and possibly changing the shape where it meets the cone of the tweeter.

    Yes agree it can not be both ways.

    Well off the shelf is off the shelf stick it in. Your description is not exactly off the shelf. So now I wonder how well it fits? Anyway we here are wannabes so I wannabes out of this thread

    Peace out.

    The driver is off the shelf. (supposedly from what I read, supposedly not quite from what you read) so not positive, who knows...lol
    The face plate, obviously mostly decorative can easily be changed over to the original Polk one.
    BTW, have successfully done this took all of maybe 10 minutes and it, in our circumstance sounded virtually identical.
    The OP noticed a slight difference though.

    https://www.audioasylum.com/audio/speakers/messages/8/82119.html


    "I'm with Polk Audio and can clear up some of the questions that have been raised in this thread.
    The tweeter is a Vifa XT25 (shielded version) and other than the faceplate is identical to all other shielded XT25s used by other companies. Some have wondered why we went out-of-house for a tweeter despite our long history of developing our own designs. The simple answer is that the Vifa is an outstanding tweeter and it would have taken us years to develop something as good or better and we wanted to get this line to market.
    The 5.25 inch mid driver was designed by Polk Audio but is not manufactured in our factory, again for reasons of time. The drivers are tested to the same standard of performance and consistency of all of our parts. The cone material is aerated (foamed) polypropylene that has better resonance damping characteristics than vacuum formed PP without adding mass.
    The enclosures are built by Polk in our factory."


    This is where Paul DiComo says they are identical.
    I have seen him also repeat that on another forum,...is it definitive...not sure.
    Someone here ask him personally (His Email is listed) if you need more reassurance I guess.