Tsi Driver dissection and Phase Plug

xschop
xschop Posts: 5,000
edited August 2022 in DIY, Mods & Tweaks
Had a driver sounding a little buzzy in my bookshelf TSi100's. Dust caps are a little stiffer than RTiA drivers. The cones are painted or thin laminate paper to my surprise. Looks like the thin paint gave way in an area under dust cap glue, so they're getting decapitated.

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Did an initial coat of the latex paint to lock in the old laminate to the paper. Then second thin layer because the gold is fugly...

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Looks like I'll have to shorten the bases of a set of RTiA phase plugs by about 0.07" and they'll fit perfect....

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These already have @Gardenstater foam frame mods. Looking forward to hear their new soundstage and imaging...





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Post edited by xschop on
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Comments

  • F1nut
    F1nut Posts: 50,496
    That driver is polycarbonate, which is very lightweight and very strong. I don't think adding a coating was a good idea.
    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

  • xschop
    xschop Posts: 5,000
    edited August 2022
    This driver is compressed cellulose paper, a polysaccharide of repeating D-glucose subunits. The small amount of latex paint when dried is probably 1/4 the weight of the dust cap and it's thick glue that started detaching.

    Now the RTiA's may be a type of polypropylene.

    Polycarbonate is a polymer of bis-phenol A subunits. Great for crackly water bottles my friend.

    And the frame foam mod cleans the mids up on these just like MW6500's.😉
    Don't take experimental gene therapies from known eugenicists.
  • F1nut
    F1nut Posts: 50,496
    zghaze4nikep.png
    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

  • xschop
    xschop Posts: 5,000
    They forgot to add "FAUX" before polycarbonate lol.
    Don't take experimental gene therapies from known eugenicists.
  • Gardenstater
    Gardenstater Posts: 4,458
    edited August 2022
    "The two-way TSi100 utilizes two Dynamic Balance drivers - a 1-inch silk-dome tweeter coupled to one 5.25-inch Bi-Laminate Organic Fiber cone woofer, crossed over at 2.5 kHz with a 2nd order (12db/octave) filter. Developed in conjunction with Johns Hopkins University, Dynamic Balance resulted from a laser interferometry research project that enables Polk to analyze the entire surface of a vibrating driver in real time, in order to determine the right composition of driver materials for the particular product." https://hometheaterreview.com/polk-tsi100-bookshelf-loudspeakers-reviewed/


    orx3c47moean.jpg
    George / NJ

    Polk 7B main speakers, std. mods+ (1979, orig owner)
    Martin Logan Dynamo sub w/6ft 14awg Power Cord
    Onkyo A-8017 integrated
    Logitech Squeezebox Touch Streamer w/EDO applet
    iFi nano iDSD DAC
    iPurifier3
    iDefender w/ iPower PS
    Custom Steve Wilson 1m UPOCC Interconnect
    iFi Mercury 0.5m OFHC continuous cast copper USB cable
    Custom Ribbon Speaker Cables, 5ft long, 4N Copper, 14awg, ultra low inductance
    Custom Vibration Isolation Speaker Stands and Sub Platform
  • xschop
    xschop Posts: 5,000
    JHU needs to develop a better dust cap glue. ;)
    Don't take experimental gene therapies from known eugenicists.
  • F1nut
    F1nut Posts: 50,496
    edited August 2022
    Polycarbonate cones are a blend of polyester film and carbon fiber hence the bi-laminate organic fiber cone woofer.
    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

  • Gardenstater
    Gardenstater Posts: 4,458
    First time I've seen carbon fiber referred to as an organic fiber. Organic fiber probably is a fancy schmanzy way of saying paper or cellulosic pulp of some formula.

    Polycarbonate is an amorphous high impact transparent thermoplastic. It is used for safety glasses among other things.
    George / NJ

    Polk 7B main speakers, std. mods+ (1979, orig owner)
    Martin Logan Dynamo sub w/6ft 14awg Power Cord
    Onkyo A-8017 integrated
    Logitech Squeezebox Touch Streamer w/EDO applet
    iFi nano iDSD DAC
    iPurifier3
    iDefender w/ iPower PS
    Custom Steve Wilson 1m UPOCC Interconnect
    iFi Mercury 0.5m OFHC continuous cast copper USB cable
    Custom Ribbon Speaker Cables, 5ft long, 4N Copper, 14awg, ultra low inductance
    Custom Vibration Isolation Speaker Stands and Sub Platform
  • xschop
    xschop Posts: 5,000
    edited August 2022
    Carbon fiber is synthetic. Cellulose fiber is organic/natural and main constituent of wood, bark, leaves etc.

    The gold layer on these drivers is only a few microns thick like it was sprayed on and does have a harder feel to it (may be polycarbonate polymer). But undoubtedly the main underlayer is paper pulp, with the same cross-hatch impression as MW65xx's have during their molding process.
    Don't take experimental gene therapies from known eugenicists.
  • F1nut
    F1nut Posts: 50,496
    About 90% of the carbon fibers produced are made from polyacrylonitrile (PAN). The remaining 10% are made from rayon or petroleum pitch. All of these materials are organic polymers, characterized by long strings of molecules bound together by carbon atoms.
    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

  • VR3
    VR3 Posts: 28,611
    Wouldn't it be funny if the tsi drivers are just the old mw woofers with gold poly coatings 😜
    - Not Tom ::::::: Any system can play Diana Krall. Only the best can play Limp Bizkit.
  • xschop
    xschop Posts: 5,000
    edited August 2022
    These are most definitely coated paper... They have that not so plastic sound signature I prefer.
    Anything derived through photosynthesis and contains carbon is organic...in org. chemistry terms.


    Polk should have went with black coating, the gold is wee bit "ghetto" de classe, as @mhardy would say. The dust cap glue didn't favor the gold coating either.

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    The only mod I did to the cabinets previously was add a 5/8" thick open-cell foam layer over the X-overs.

    I temp. have a plug set with blue tacky putty until I can get to shop and trim them down before setting them permanent with Loctite #271

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    Don't take experimental gene therapies from known eugenicists.
  • Gardenstater
    Gardenstater Posts: 4,458
    edited August 2022
    Organic chemistry vs Organic......I need to fill up my Honda. I feel better now knowing it is organic :)

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    Post edited by Gardenstater on
    George / NJ

    Polk 7B main speakers, std. mods+ (1979, orig owner)
    Martin Logan Dynamo sub w/6ft 14awg Power Cord
    Onkyo A-8017 integrated
    Logitech Squeezebox Touch Streamer w/EDO applet
    iFi nano iDSD DAC
    iPurifier3
    iDefender w/ iPower PS
    Custom Steve Wilson 1m UPOCC Interconnect
    iFi Mercury 0.5m OFHC continuous cast copper USB cable
    Custom Ribbon Speaker Cables, 5ft long, 4N Copper, 14awg, ultra low inductance
    Custom Vibration Isolation Speaker Stands and Sub Platform
  • xschop
    xschop Posts: 5,000
    Octane molecule, a tree-hugger's worst nightmare.
    Don't take experimental gene therapies from known eugenicists.
  • xschop
    xschop Posts: 5,000
    edited August 2022
    I listened for almost an hour last night to these set up in the living room rig where I listened to them before. Much improved imaging and vocals. These would be excellent with a complimentary sub as they lack in bass from factory specs, but the midrange is now incredible.

    On second one, I completely removed the gold layer by gently scoring the entire perimeter up to the butyl surround by scalpel. It almost peeled completely off in two sections...

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    The latex paint adheres extremely strong and semi-flexible....

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    @Gstater's foam mod pic. These only take 4ea 1/8" thick PVA squares 1.0" x 0.80"

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    Don't take experimental gene therapies from known eugenicists.
  • DaveHo
    DaveHo Posts: 3,501
    edited August 2022
    I have to question if any TSI series speakers are worth the effort. I don't give them a second thought when they pop up locally. Am I missing a gem in the rough?
  • xschop
    xschop Posts: 5,000
    I'd like to hear the Tsi-500's bass tonality. These are now great sounding PC rig monitors. All the hollowness of the mids are now gone and sound much more integrated with the tweeters. I took a look, and will back-fill the tweeter housings with high density Polyurethane and tighten them up. The cabinets are not the best that Polk has to offer. High density particle board about 5/8" thick.
    Don't take experimental gene therapies from known eugenicists.
  • xschop
    xschop Posts: 5,000
    Having done these, now I'm really curious how the LSi9 or LSi15 drivers are made.
    Don't take experimental gene therapies from known eugenicists.
  • skrol
    skrol Posts: 3,372
    DaveHo wrote: »
    I have to question if any TSI series speakers are worth the effort. I don't give them a second thought when they pop up locally. Am I missing a gem in the rough?

    I have to agree with you. I picked up a pair if TSI100 for next to nothing when Circuit City went under. Maybe I'll play with them and see if they are worth the effort one day.
    Stan

    Main 2ch:
    Polk LSi15 (DB840 upgrade), Parasound: P/LD-1100, HCA-1000A; Denon: DVD-2910, DRM-800A; Benchmark DAC1, Monster HTS3600-MKII, Grado SR-225i; Technics SL-J2, Parasound PPH-100.

    HT:
    Marantz SR7010, Polk: RTA11TL (RDO198-1, XO and Damping Upgrades), S4, CS250, PSW110 , Marantz UD5005, Pioneer PL-530, Panasonic TC-P42S60

    Other stuff:
    Denon: DRA-835R, AVR-888, DCD-660, DRM-700A, DRR-780; Polk: S8, Monitor 5A, 5B, TSi100, RM7, PSW10 (DXi104 upgrade); Pioneer: CT-6R; Onkyo CP-1046F; Ortofon OM5E, Marantz: PM5004, CD5004, CDR-615; Parasound C/PT-600, HCA-800ii, Sony CDP-650ESD, Technics SA 5070, B&W DM601
  • xschop
    xschop Posts: 5,000
    edited July 2023
    Decided to mod these further. The cabs are only 5/8" thick MDF and exhibit a hollow rasp on the left or right side panels. All other panels sound rock solid. This must be the weak spot in these series cabinets.

    To do a simple test, I put a set of wood clamps on the sides to preload and have a listen. Sure enough, the lower midrange/ upper mid-bass cleared up nicely.


    At 7" width, minus the side panel thicknesses, I made some quick tensioning rods out of 1/2" steel all-thread and serrated flange nuts, like I recently did on the 5B test mules....

    5.7" total length gives just enough clearange for side-to-side panel install...

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    Don't take experimental gene therapies from known eugenicists.
  • skipshot12
    skipshot12 Posts: 1,157
    ^ Damn nice solution.
    Want to hear your evaluation once you get them installed.
  • xschop
    xschop Posts: 5,000
    edited July 2023
    I used Power Grab to attach the flange nut and rod's 3/8" machined spud to the driver pole-piece on the 5B MWs. Here I'll use this construction adhesive to attach to the inside MDF....

    8dr7fw0fb9sd.jpg





    Don't take experimental gene therapies from known eugenicists.
  • xschop
    xschop Posts: 5,000
    edited July 2023
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    Tight space in these little jewel boxes...

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    Same stuff I filled in the plastic tweeter plates. I was going to make billet adapter plates but could not safely dislodge the factory tweeter without breaking it. So good for now until I fry one...

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    I tightened evenly till I heard a rap that sounds as tight as the other sides, then slathered on the adhesive to the nut and threads. Better bracing than what comes from any Polk I've owned...

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    Post edited by xschop on
    Don't take experimental gene therapies from known eugenicists.
  • xschop
    xschop Posts: 5,000
    Almost forgot to fill in the trim ring...

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    Don't take experimental gene therapies from known eugenicists.
  • Jazzhead
    Jazzhead Posts: 533
    You are a madman. The right kind of madness...
  • xschop
    xschop Posts: 5,000
    Anything for better sound out of these old Polk's is a worthwhile endeavor.
    Don't take experimental gene therapies from known eugenicists.
  • Jazzhead
    Jazzhead Posts: 533
    That puts ideas in my head.
  • xschop
    xschop Posts: 5,000
    edited July 2023
    Oh, do tell. Your RTA-12's need more bracing?

    Here's the TSi100 crossover. Already ordered some new film caps. That little maroon ceramic cap is labeled...

    224J
    100VJRD

    I dumped them on the CRS+ build and will do the same here...

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    Post edited by xschop on
    Don't take experimental gene therapies from known eugenicists.
  • Jazzhead
    Jazzhead Posts: 533
    If I drive them really hard with bass heavy tunes, I can feel some slight vibration on the middle of the sides. The 10/2 areas of the PR cut-out (you've recommended previously on 10's) seem like a good place to brace as well. The genius of threaded rod/flange nuts/epoxy is that it wouldn't displace as much internal volume as some methods (wood construction). What would you think, 1/2 inch rod? Would be a good winter project.
  • xschop
    xschop Posts: 5,000
    1/2-13 all thread will be good for up to 12 or 14" lengths as far as deflection under compression is concerned.

    BH5 may be great for some frequency damping, but is band-aid IMO for the lower mid-bass issues from loose cabinet structure.

    The absolute best midrange I got out all the builds were the phase-plugged, foam-framed, and solid billet baffle 5JRs that I built.

    The second best, and not too far behind are the highly braced 5Bs that I still have.
    Don't take experimental gene therapies from known eugenicists.