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

  • F1nutF1nut Posts: 44,826
    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.
  • pitdogg2pitdogg2 Posts: 16,774
    Problem is Polk didn't buy off the shelf they sent design specifications to a company to build for their own design.
  • F1nutF1nut Posts: 44,826
    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_MK_M Posts: 1,617
    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.
    Lsi15, Lsi9, LsiC,Rta11t,M5jr+,M4, SDA SRS 2.3TL, Rti6....Still listing stuff, a work in progress.
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  • pitdogg2pitdogg2 Posts: 16,774
    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_MK_M Posts: 1,617
    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.

    Lsi15, Lsi9, LsiC,Rta11t,M5jr+,M4, SDA SRS 2.3TL, Rti6....Still listing stuff, a work in progress.
    B+W-Sold
    Electro Voice EV-SIX
    Infinity-Sold
    Advent-Now gone
    Yamaha A-S801
    Yamaha RX-V377
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  • tonybtonyb Posts: 32,466
    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 ?
    HT SYSTEM-
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  • pitdogg2pitdogg2 Posts: 16,774
    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_MK_M Posts: 1,617
    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
    Lsi15, Lsi9, LsiC,Rta11t,M5jr+,M4, SDA SRS 2.3TL, Rti6....Still listing stuff, a work in progress.
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  • F1nutF1nut Posts: 44,826
    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 brydsonken brydson Posts: 7,791
    F1nut wrote: »
    Is that the extent of your husband's speaker engineering?

    Married to X...
    HT/Main- Panny 50" G10 Plasma, Pioneer SC-1222k AVR, Panny DMP-BD60 BDP, Polk LS90 mains, CS350LS center, LS/fx side surrounds, LS50 surround backs, SVS 25-31PC+ sub, Harmony One

    Office Rig- Marantz 2252B, Denon 2910, Kenwood KD2070 TT, Polk RTA 12B's/ RTA8t
  • mikeyb128mikeyb128 Posts: 2,887
    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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  • tonybtonyb Posts: 32,466
    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
  • FranzDolasFranzDolas 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_MK_M Posts: 1,617
    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!
    Lsi15, Lsi9, LsiC,Rta11t,M5jr+,M4, SDA SRS 2.3TL, Rti6....Still listing stuff, a work in progress.
    B+W-Sold
    Electro Voice EV-SIX
    Infinity-Sold
    Advent-Now gone
    Yamaha A-S801
    Yamaha RX-V377
    Yamaha RX-A860
    Yamaha RX-A3060
    Harman Kardon Hk-350i
    Harman Kardon Hk-........
    Harman Kardon PM-665
    Harman Kardon HK-775
    Pioneer.......Stereo Receiver

  • K_MK_M Posts: 1,617
    edited March 21
    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.
    Lsi15, Lsi9, LsiC,Rta11t,M5jr+,M4, SDA SRS 2.3TL, Rti6....Still listing stuff, a work in progress.
    B+W-Sold
    Electro Voice EV-SIX
    Infinity-Sold
    Advent-Now gone
    Yamaha A-S801
    Yamaha RX-V377
    Yamaha RX-A860
    Yamaha RX-A3060
    Harman Kardon Hk-350i
    Harman Kardon Hk-........
    Harman Kardon PM-665
    Harman Kardon HK-775
    Pioneer.......Stereo Receiver

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