LSi7's on the chopping block

2

Comments

  • ALL212
    ALL212 Posts: 1,553
    edited March 2019
    This is just a note - not gospel. The woofer looks a lot like the MCM Audio 55-1862 or something in that series. MCM is now Newark and obviously things have changed since 2011.

    That the label on the woofer starts with 55 (5534-2). Maybe...
    Aaron
    Enabler Extraordinaire
  • VR3
    VR3 Posts: 27,967
    The tweeter is the XT32...

    Woofer is made for Polk with their super aerated poly cones. To my knowledge this cant be sourced anywhere else and Polk no longer makes it
    - Not Tom ::::::: Any system can play Diana Krall. Only the best can play Limp Bizkit.
  • ALL212
    ALL212 Posts: 1,553
    Well, then I can quit looking!

    I like to figure out the crossover logic and without the cone specs it's not easy. The crossover is really very basic. The 16.5 uf and .5 ohm in the woofer crossover are a Zobel network so the basic woofer crossover is just an inductor. I'm guessing the 2.5 ohm is just to knock the tweeter down a notch or two (padding) and then it's a simple second order setup.

    that 1.3mH inductor is what's weirding me out. It just seems too big but those dual ports are also messing with simple calculations.

    I'll stop with the "figuring it out" aspect and tonight, with a little luck, may get these done.
    Aaron
    Enabler Extraordinaire
  • VR3
    VR3 Posts: 27,967
    Yeah my understanding (redundant) is that the small port (ARC) which is intended to minimize the effect of an internal standing-wave resonance by vibrating at the same frequency as the standing wave, but out of phase with it.

    - Not Tom ::::::: Any system can play Diana Krall. Only the best can play Limp Bizkit.
  • pitdogg2
    pitdogg2 Posts: 24,477
    Opus D art....
    Nice Aaron
  • VR3
    VR3 Posts: 27,967
    lookin good!
    - Not Tom ::::::: Any system can play Diana Krall. Only the best can play Limp Bizkit.
  • halo
    halo Posts: 5,616
    Very nic Aaron!
    Audio: Polk S15 * Polk S35 * Polk S10 * SVS SB-1000 Pro
    HT: Samsung QN90B * Marantz NR1510 * Panasonic DMP-BDT220 * Roku Ultra LT * APC H10
  • K_M
    K_M Posts: 1,627
    edited March 2019
    VR3 wrote: »
    The tweeter is the XT32...

    Woofer is made for Polk with their super aerated poly cones. To my knowledge this cant be sourced anywhere else and Polk no longer makes it

    Tweeter is the Vifa XT-25TG30-04
    https://www.parts-express.com/peerless-by-tymphany-xt25tg30-04-1-dual-ring-radiator-tweeter--264-1016

    Woofer is a Peerless unit (From several years back now) that is very similar to one in production still.
    (minus magnetic shielding etc.)
    https://www.parts-express.com/peerless-by-tymphany-830860-5-1-4-ppb-cone-hds-woofer--264-1080
  • msg
    msg Posts: 9,308
    Nice work, Aaron. Curious to hear your thoughts as you get more time on them.
    I disabled signatures.
  • VR3
    VR3 Posts: 27,967
    Would be curious to see if Polk would recommend that woofer as a replacement. It looks similar but different
    - Not Tom ::::::: Any system can play Diana Krall. Only the best can play Limp Bizkit.
  • dromunds
    dromunds Posts: 9,969
    Some time ago, I bought what Polk told me were the last two LSi woofers in Polk’s inventory and I was told there would never be anymore. They told me there were no replacements and once their inventory was gone a person would have to scab one out of another speaker or elsewhere find a used one. That’s all I know.
  • ALL212
    ALL212 Posts: 1,553
    Shielding isn’t really needed.

    Find another pair of these and I’ll hack up another. Also update the tweeter...?
    Aaron
    Enabler Extraordinaire
  • ALL212
    ALL212 Posts: 1,553
    24 hours of continuous play have gone by. I don't expect to call these broken in yet but its' a start. I'm streaming from a dedicated Roon server through a wired Roon bridge thin client PC to a Schiit Bifrost Multibit DAC. From DAC to the Odyssey Tempest and down to the Stratos dual mono amp. IC's are the Groneberg with WBT ends and speaker cables are newly minted Furez 2x10g wire with Furez silver ends. Speaker cables are new enough that more break in is probably required also. I have approximately 150 to 180 watts available per channel.

    One of my "got to haves" is sound stage. I want the speakers to disappear. I'm not fussy about hearing things outside of the speaker physical plain but if that happens it's nice. Mid and Treble are what I'm watching on these as I don't expect bass to come booming out. They just aren't designed for that. My concern is that with the slight variance in component value and the much lower DCR in the inductors I might have affected the freq response, crossover point or caused overall oddness.

    I haven't had these long. Didn't listen for hours to get a baseline so there will be no comparison to what they were before the operation.

    Sound stage is where I want it. The speakers are gone. Even with lights on and eyes open they are just gone. Normally I listen with the lights down and with these it matters not. I do have some soundstage outside of the speakers. These are not in an optimal listening position so I wonder what would happen should they go front and center.

    I'm not hearing any "holes" in the frequency spectrum. I don't have an analyzer but so far I've not heard anything deficient. The only slight complaint might be a very slight mid-range hump, a bit of bloat, but that could be because the components aren't broken in yet (had the same issue with the Yggy DAC and it did eventually even out). Also see above about listening position.

    These are very pleasant to listen to. I think the word that comes to mind is "smooth". No harsh edges. The treble is wonderful. Crips, clear and precise. Mid range and voices are also very good. Possibly a bit forward...(see the "hump" comment from above)? Just a thought - it's possible these are a bit over engineered for bookshelves with the dual porting going on and the bi-amp feature from pre-mod.

    So...is the forwardness of the mid...upper mid from the room, not being broken in, new speaker cables, something in the chain? It's not offensive and my thought is that I'm overloading the room acoustics in the position they are in as bringing the volume down tames it considerably.

    Bass is unchanged - there were no miracles. If you want the bottom basement boom these will need a sub. Again, I'm not looking for these to do that so no complaints.

    Ultimately my goal was to provide a speaker that I can use to compare the changing of components with. This rig is open and far enough from the wall that I can get to all the cables without becoming a contortionist.

    As time goes on I'll voice in here again.
    Aaron
    Enabler Extraordinaire
  • K_M
    K_M Posts: 1,627
    VR3 wrote: »
    Would be curious to see if Polk would recommend that woofer as a replacement. It looks similar but different

    Yes it fits exactly the cone is "different", but not all "that different".
    Have not tried them personally, but what we heard from a friend, he said he thought they were extremely close, but was not "Sure" if identical, but live too far to hear what he made.

    He bought them for a DIY project, and said they were excellent, and maybe a bit better than the LSI specific woofer, for whatever that is worth, so doubt they are a downgrade anyways.
  • K_M
    K_M Posts: 1,627
    edited March 2019
    dromunds wrote: »
    Some time ago, I bought what Polk told me were the last two LSi woofers in Polk’s inventory and I was told there would never be anymore. They told me there were no replacements and once their inventory was gone a person would have to scab one out of another speaker or elsewhere find a used one. That’s all I know.

    Yeah we thought about parting out one of our Lsi15's pairs so that would make 4 available, but have a nostalgic liking to them, so still have not done it.
  • K_M
    K_M Posts: 1,627
    VR3 wrote: »
    Yeah my understanding (redundant) is that the small port (ARC) which is intended to minimize the effect of an internal standing-wave resonance by vibrating at the same frequency as the standing wave, but out of phase with it.

    That is what I have heard also, but not really sure of its effectiveness.
    Stereophile measured oddities in the response that are at the same frequencies, that the ARC port has oddities.....
  • VR3
    VR3 Posts: 27,967
    In my experience, the shape and depth of a cone can alter just about everything from a speaker
    - Not Tom ::::::: Any system can play Diana Krall. Only the best can play Limp Bizkit.
  • dromunds
    dromunds Posts: 9,969
    K_M wrote: »
    dromunds wrote: »
    Some time ago, I bought what Polk told me were the last two LSi woofers in Polk’s inventory and I was told there would never be anymore. They told me there were no replacements and once their inventory was gone a person would have to scab one out of another speaker or elsewhere find a used one. That’s all I know.

    Yeah we thought about parting out one of our Lsi15's pairs so that would make 4 available, but have a nostalgic liking to them, so still have not done it.

    It would be unfortunate to part out a good pair of 15’s. Enough things happen so that speakers get parted out from time to time anyway
  • ALL212
    ALL212 Posts: 1,553
    48 hours in:

    Bass is beginning to fill in. Not the lower 48 type of bass but a nice warm bottom (oh good grief - that's gonna get some remarks!), so again, no miracles.

    That mid range flair has settled down. I still think it's got a lot to do with overloading this room/position at volume.

    No listening fatigue at all. I've been buried in the basement (my option) all day trying to figure out a DAC that won't DAC and putting some nifty cables together for Victor. No desire to put the main rig on.

    The treble is mesmerizing and almost holographic. Bullseye on that.
    Midrange is no slouch at all.

    So what I have here is a nice smooth but detailed top, good mid presence and a nice warm bottom.

    :p
    Aaron
    Enabler Extraordinaire
  • msg
    msg Posts: 9,308
    Niiiice, Aaron. Stuff like this inspires me to try crossover mods. I'm not brave enough to invert binding posts though. That's just sheer lunacy!
    I disabled signatures.
  • ALL212
    ALL212 Posts: 1,553
    999...

    Turn the speaker upside down...?!
    Aaron
    Enabler Extraordinaire
  • pitdogg2
    pitdogg2 Posts: 24,477
    msg wrote: »
    Niiiice, Aaron. Stuff like this inspires me to try crossover mods. I'm not brave enough to invert binding posts though. That's just sheer lunacy!

    You should step out of that comfort zone Scott
  • heiney9
    heiney9 Posts: 25,053
    LSi 7's stock have a very non-fatiguing and listen all day type presentation, but it sounds like you upped the ante on these. I always preferred the 7's to the 9's stock. Keep us posted.

    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!
  • VR3
    VR3 Posts: 27,967
    Excellent! Glad to hear they are meeting/exceeding expectations! Im sure in 200 hours they will sound a little more of everything you are already hearing!
    - Not Tom ::::::: Any system can play Diana Krall. Only the best can play Limp Bizkit.
  • ALL212
    ALL212 Posts: 1,553
    Over 200 hours one 'em (last notes unless something changes).

    Better bass presence and just an overall smoother listen. Things appear to be settled in. The holographic, 3 dimensional effect is more pronounced.

    The room overload still occurs. Volume at about 9 - 9:30 is good. Anything past 10 makes listening uncomfortable (then again I'm getting over some disease that I've had since Thursday so my head might still be on crooked.) I don't think padding the tweeter down further would help, it's not that far into the upper ranges. Upper mid maybe... The last 2 notes in the 3 note piano lead in on Norah Jones, "Don't know why" is overload. Bring the volume down to 9ish and it's fine.

    As an experiment I covered the front ports with some high density foam held down by packing tape. Just gets screechy so unless you like screechy don't do that!

    OH! and no corrosion on the binding posts.

    Aaron
    Enabler Extraordinaire
  • pitdogg2
    pitdogg2 Posts: 24,477
    edited March 2019
    A little corrosion on the binding post will help pad the tweeter..... just sayin :#
  • ALL212
    ALL212 Posts: 1,553
    edited March 2019
    Many little rubber baby buggy bumpers underneath the speakers
    4axs636vb6oc.jpeg

    Listening right to left. Note the cabinet behind the chair hence my suspicion of room overload.
    6uomg8r02qs9.jpeg
    Aaron
    Enabler Extraordinaire