perplexing 2.3TL issue

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knie0012
knie0012 Posts: 47
edited September 2023 in Vintage Speakers
Good day,

Come seeking guidance and suggestion(s).

In short, I'm nearing the end of rebuilding a pair of 2.3tl's that sat in rough shape for over 10 years. Bought them off CL back when things were cheap, for 200 bucks, they were bad to say the least.

This is my current progress list:
I had a set of gimpod boards (I bought a decade ago!) I used to rebuild crossovers and created new mounting board.
All new sonicaps and mills (removed polyswitch and replaced with jumper)
All new jantzens inductors to include the large 16.0mH – 2.6DCR (all values I found reading here)
All new tweeters rdo198s
Replaced any dead and mismatched drivers with all mw6510s.
Blackhole5 behind all the drivers
hurricane nuts on all mounting points.
made a new interconnect using speakeasy ends.
I'm paying local woodshop to re-veneer the tops and bottoms.
bought a set of brass spikes based on suggestions here.
Oh, all new speaker cloth on side panels and front grates.

To say the least....I've got a lot of money in this rebuild (~1500 bucks, if not more?!)

The list above is from my research and months of reading on this forum. I did not do any original research or new approaches besides how I mounted my boards and large inductor.

As I type this, my cabinets are laying on their side with plenty of weight and I'm waiting for liquid nails to cure.

To "test" my crossovers and speakon interconnect cable, I decided to connect the #1 tweeter, 1 of 2 drivers in the sda circuit and 2 of 4 in the other with the wiring harnesses (odd approach I know).

My interconnect cable works as expected, such a nice cable interface!. Both "speakers play" but I've noticed by audio reasoning, the one crossover (channel) is not nearly as bright as the other. When I mean crossover, I mean the entire thing, all the drivers are more dull than the other side and the tweeter is not near as bright.

I've tried switching drivers, and tweeters to no change. I've tried changing crossovers on different channels (L vs R and vice versa). Tried changing my audio source, I.E. preamp, amp (running all adcom, solid state gear), applicable cables (different rca cables, etc).

Any suggestions that I can try or test? I've read the SDA Handbook and the table 4.4 in the handbook I don't believe provides values for the 2.3TL? Does anybody have any values that I can test the crossovers? I've donwloaded the old gimpod website to help with my crossover parts and build and that documentation doesn't seem to yield any specific DCR values for the 2.3TL.

As I mentioned, I have a lot of effort, sweat and money into these things and I hate sitting here and having a sub optimal result.

Thanks for reading! I hope some of you have a few magic bullets that can help!
Jason
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Comments

  • nooshinjohn
    nooshinjohn Posts: 25,256
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    I am not certain I understand the methodology of your testing. In my experience with a 2.3Tl and 1.2TL, all drivers need to be connected in order to do an accurate test, because the signal comes through the crossovers differently due to SDA. Also without having back pressure, the drivers are going to respond differently than they would if they were installed in a sealed cabinet as they were designed. My suggestion is not worry about the little stuff right now until I get the speakers back together again and then give them a go.
    The Gear... Carver "Statement" Mono-blocks, Mcintosh C2300 Arcam AVR20, Oppo UDP-203 4K Blu-ray player, Sony XBR70x850B 4k, Polk Audio Legend L800 with height modules, L400 Center Channel Polk audio AB800 "in-wall" surrounds. Marantz MM7025 stereo amp. Simaudio Moon 680d DSD

    “When once a Republic is corrupted, there is no possibility of remedying any of the growing evils but by removing the corruption and restoring its lost principles; every other correction is either useless or a new evil.”— Thomas Jefferson
  • knie0012
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    Very valid point and critique. To be honest, I have no methodology besides only what my ear is hearing. And, I think I am/was searching for a methodology to get solidified numbers prior to installing everything.

    I figured if the same parts/pieces were hooked up the same way on both channels/crossovers, it would be a gauge to ensure everything is working as is.

    Again, you're probably right and not sweat it until my build is reconstructed and address it then. To take it a step further, I've read countless posts about burn in, and 100-300 hrs before any judging should be had, so there's that, too.

    Thanks for reading.

  • pitdogg2
    pitdogg2 Posts: 24,927
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    The dimensional side plays at a lesser volume, the tweeters are a progressive point source and only one plays full frequency and volume. The other two play at a lesser volume and frequency.
  • nooshinjohn
    nooshinjohn Posts: 25,256
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    As far as I know, the only thing you can test at this point is whether the individual drivers work as intended, and that the ohm reading for each driver is within specifications for its use. Other than that, it’s just a matter of placing them back in their proper locations, making sure you have no air leaks in the cabinet and listen to them play. I think he will be fine if everything that you’ve done was done correctly.
    The Gear... Carver "Statement" Mono-blocks, Mcintosh C2300 Arcam AVR20, Oppo UDP-203 4K Blu-ray player, Sony XBR70x850B 4k, Polk Audio Legend L800 with height modules, L400 Center Channel Polk audio AB800 "in-wall" surrounds. Marantz MM7025 stereo amp. Simaudio Moon 680d DSD

    “When once a Republic is corrupted, there is no possibility of remedying any of the growing evils but by removing the corruption and restoring its lost principles; every other correction is either useless or a new evil.”— Thomas Jefferson
  • knie0012
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    Absolutely, good reminder, thank you.

    As of now, I have the top tweeter (full freq and volume) plugged in. Both crossovers are setup identical, i.e. same drivers/tweeter installed currently.

    The main drivers are playing louder than the SDA drivers, as expected. The tweeter is playing the full frequency. It's just they are all playing noticeably softer than the other crossover.

    Could something cause that quieter output off the crossover rebuild, bad capacitor or inductor. I have pretty accurate fluke/voltmeter. Was scouring for some 2.3tl numbers - or am I talking nonsense.
  • knie0012
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    mljazptr12i6.jpg
    For visual on what I'm doing, SDA drivers is the single on top.

    wqre9pjc5pox.jpg
    My board with harnesses plugged in.
    n6q0t1okgtdm.jpg
    Crossover post rebuild.
  • treitz3
    treitz3 Posts: 18,657
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    Is the phase incorrect anywhere on the circuit?

    Tom
    ~ In search of accurate reproduction of music. Real sound is my reference and while perfection may not be attainable? If I chase it, I might just catch excellence. ~
  • Toolfan66
    Toolfan66 Posts: 17,051
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    Great looking crossover build..
  • VR3
    VR3 Posts: 28,310
    edited September 2023
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    The issue is how you are arranging the drivers on the floor. (lots of cancelations)

    Try it like this

    https://1drv.ms/v/s!AqNfgHBkow_9t6QrsKa0b9XRvr_ZHQ
    - Not Tom ::::::: Any system can play Diana Krall. Only the best can play Limp Bizkit.
  • Gardenstater
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    I guess if it was me I'd start by verifying that both crossovers are wired correctly and that all 5 inductors and 2 resistors have the same DCR values vs their comparable parts in the other crossover.
    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
  • VR3
    VR3 Posts: 28,310
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    If he is listening the way he showed that photo and came to the conclusion he has an issue... He really knows nothing about their operation.

    He needs to place them on the floor like my video and then he can start to run tests
    - Not Tom ::::::: Any system can play Diana Krall. Only the best can play Limp Bizkit.
  • knie0012
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    Definitely not listening as the photo depicts! I've spread the channels out nearly like your photo but didn't have them facing forward, rather sitting flat. I would cycle the balancing from L to R, with and without the interconnect plugged in. This is how I'm interpreting the one crossover is playing at a lower db.

    That said, I should be able to put all components back together tomorrow or the next. I'll circle back here with results!

    Thanks for the patience, all!
  • gmcman
    gmcman Posts: 1,789
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    Did you connect the stereo drivers the same way on both sides? The wiring is out of view, reason I ask is I believe the wiring is both series and parallel on different drivers to establish the final resistance, are you sure the loading is the same on both sides?

    Have you tried different songs to play or are you using the same track?

    As stated earlier, I don't know how you can accurately test without everything
    connected, even if what you have is even on both sides.

    What about amp loading? You could be dangerously low on resistance without all the drivers connected, but obviously without an ohm reading it's anyone's guess.
  • SeleniumFalcon
    SeleniumFalcon Posts: 3,585
    edited September 2023
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    Hello,
    Good looking job on those crossovers. Do you happen to have a signal generator, a volt/ohm meter and an 8 ohm resistor?
  • xschop
    xschop Posts: 4,837
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    If any of your drivers' spiders/suspension are sagging or setting where the voice coil is not centered in the base plate, Id highly suspect that too.
    6510's and 6511's are notorious for this issue.
    Don't take experimental gene therapies from known eugenicists.
  • knie0012
    knie0012 Posts: 47
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    After a long, long time, my rebuild is complete. Please don't judge me on my placement, it is temporary! ;)

    As for my perplexing sound issue that instantiated this post, that seems to have subsided as my crossovers are burning in. They are now coming into their own, sound and clarity wise. I bet I have 20-30 hrs on them since I completed my restore.

    That said, I was and still expecting more for sound stage. It seems to be a bit small for my effort and investment.

    97dgyvvp64x9.jpg

    I'm driving them with an Adcom 545 and pre amped with Schitt Saga. I did end up building a Dreadnought that I ordered directly from Avel Lindberg.

    I have moved on to my next project of rebuilding a pair of Altec 1570Bs that I have sitting around. I'm slowly gathering parts and pieces before I start the tear down - and still reading a lot!



    End goal is to refurbish them and do some pretty well documented mods to the amps that will make them sing! End goal is to mono block my 2.3tls with them?

    i6xnotz8ahqo.jpg

    In any sense, my journey continues.

    Thanks as always for the help in the forums!
    Jason

  • Toolfan66
    Toolfan66 Posts: 17,051
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    knie0012 wrote: »
    After a long, long time, my rebuild is complete. Please don't judge me on my placement, it is temporary! ;)

    As for my perplexing sound issue that instantiated this post, that seems to have subsided as my crossovers are burning in. They are now coming into their own, sound and clarity wise. I bet I have 20-30 hrs on them since I completed my restore.

    That said, I was and still expecting more for sound stage. It seems to be a bit small for my effort and investment.

    97dgyvvp64x9.jpg

    I'm driving them with an Adcom 545 and pre amped with Schitt Saga. I did end up building a Dreadnought that I ordered directly from Avel Lindberg.

    Don’t judge your placement? You were expecting more for sound stage? A bit small for your effort and investment?

    Don’t judge the speakers, or doubt your efforts, and investment till you get better placement, and better gear to power them with.

    I am judging, that set up is honestly horrible. Your crossover build is beautiful..
  • boston1450
    boston1450 Posts: 7,516
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    Just wondering if the Adcom has been upgraded or anything else. Being it's age. I have had the 545 & the 555 & enjoyed them with the 3 preamps I used. Great amplifiers & preamps imo. They seem to blend well with SDA's. Not so good with RTA's (8 & 15tl) imo.
    ..
  • VR3
    VR3 Posts: 28,310
    edited January 9
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    After reviewing your photos I think I know your issue.

    You are using metal bolts on Gimpod boards. You need you isolate the metal from the inner hole as there is no isolation between the copper traces around the mounting bolt holes and the inner edge so your bolts could be causing issues.

    The recommended mounting hardware was nylon encased screws or plastic stand offs
    - Not Tom ::::::: Any system can play Diana Krall. Only the best can play Limp Bizkit.
  • F1nut
    F1nut Posts: 50,086
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    Good eyes Trey
    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

  • Toolfan66
    Toolfan66 Posts: 17,051
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    Very good eye..
  • Gardenstater
    Gardenstater Posts: 4,281
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    You're saying a brass washer underneath could be shorting out traces, especially maybe the one with the arrow?

    i8drngi5j9vs.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
  • VR3
    VR3 Posts: 28,310
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    the main issue is the inner part of the hole has copper traces that can contact the bolt. So if he is using that same brass washer on the underside and it is touching a solder joint or broke the coating on the trace and made contact it could cause an intermittent short.

    I speak from experience here. I had a customer run into issues with Gimpod boards installing them with metal screws/bolts for this very reason.
    - Not Tom ::::::: Any system can play Diana Krall. Only the best can play Limp Bizkit.
  • knie0012
    knie0012 Posts: 47
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    VR3 wrote: »
    After reviewing your photos I think I know your issue.

    You are using metal bolts on Gimpod boards. You need you isolate the metal from the inner hole as there is no isolation between the copper traces around the mounting bolt holes and the inner edge so your bolts could be causing issues.

    The recommended mounting hardware was nylon encased screws or plastic stand offs

    I am using brass hardware - bolts, washers and nuts. I will replace with nylon and reassemble.

    I incorrectly thought the board coating was enough of an insulator, it seems

    You're suggesting and have experienced otherwise.

  • knie0012
    knie0012 Posts: 47
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    Just thinking as I re-read this, I want to keep my brass hardware for structure, but to eliminate the metal (brass) to board contact, I'll use a few silicone washers in place of the brass. That would isolate the metal off the board, retain structure, and stop any possible short.

  • Toolfan66
    Toolfan66 Posts: 17,051
    edited January 10
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    knie0012 wrote: »
    Just thinking as I re-read this, I want to keep my brass hardware for structure, but to eliminate the metal (brass) to board contact, I'll use a few silicone washers in place of the brass. That would isolate the metal off the board, retain structure, and stop any possible short.

    Just get these, they are stronger then you think, also don't use anything with silicone..


    crigkk90v0q4.jpeg
    hx4jd4bawg20.jpeg
    y5zlcny1auuy.jpeg



  • VR3
    VR3 Posts: 28,310
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    You can use a nylon washer and heat shrink the top portion of the bolt that goes thru the board and be ok
    - Not Tom ::::::: Any system can play Diana Krall. Only the best can play Limp Bizkit.
  • pitdogg2
    pitdogg2 Posts: 24,927
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    The nylon stand offs are amazingly strong. I'm perplexed as to why not use the same stand off that the old board used? When I did my 2.3tl's the new gimpod board went right back to where the old factory board was mounted with the same stand off matched right up to the new board.
  • knie0012
    knie0012 Posts: 47
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    Sorry, I misspoke when I said silicone - I meant nylon.

    As for the original standoffs, 3 were broke and the others were permanently bent (somewhat) from taking up the slack over the years. one of the speakers appeared to have fallen over at some point in its life as some of the internal bracing was lose, some of the magnets shifted on the drivers and the grill plugs were nearly all broke.
  • VR3
    VR3 Posts: 28,310
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    Just so we are on the same page.

    The issue is that bolts are making contact IN the mounting hole and in return energizing anything attached to it and touching it.

    It is not just a problem on the back of the board
    - Not Tom ::::::: Any system can play Diana Krall. Only the best can play Limp Bizkit.