The 1.2TL, Project Monolith

Options
1…67891012»

Comments

  • xschop
    xschop Posts: 5,875
    Options
    The semi-rings only need 2 taps per driver and 2 extra hurricane nuts.

    Easiest way to do the 2 taps is use a spring loaded auto-punch while the MW is mounted to the baffle. Remove MWs, drill and tap with a new tap drill combo.

    Easiest way to drill the 4 extra MW thru-holes is with a jig on a drill press. No need to tape off anything, just blow off with compressed air when done.

    I'll be glad to send you the one I built if you want to do this mod. It stiffens the baffle further and obviously couples the MWs completely.
    Don't take experimental gene therapies from known eugenicists.
    · Share on Facebook
  • ptrooper
    ptrooper Posts: 768
    edited October 20
    Options
    8azjz281fxmu.png
    phmm22texvba.png
    vb5siw1ui0nz.jpeg
    jzohj7hpnzk4.jpeg
    w83iymgi4tvk.jpeg
    t7wmvy2yzaj8.jpeg
    Ok,Back from my little Family adventure.
    @Gardenstater @xschop .
    A good template goes a long way, sure makes it less daunting. But I'm gonna pass on redrilling the original drivers. They are so hard to get these days that I want to keep them in factory condition. I actually have a future plan for another upgrade to the Monoliths down the road, and I might end up selling them later, so they need to stay completely stock as a rock.

    Extra bracing could never go astray, though. I appreciate all the ideas in this and other areas, and I'll incorporate something with the baffle brace install.
    Thanks again!

    Finally measured the Speakers!
    Front baffle thickness 20mmm
    Internally ront to Rear 273 mm
    Here are some pics,I removed one tweeter, there is bracing in view, I can move Xschops dowels into any position where we think they need to be on the day B) Exciting.I Removed a little glue laying on the top brace!

    VR3 SDA SRS 1.2TL Duelund Monoliths+VR31000va Dreadnaught +VR3 MM2 SDA cable, <3 ,Lumin u2x ,<-sfp fibre <-LHYas8 Pro+ Switch,Transparent Reference MM2 xlr,power and speaker cables.FTA Sinope SE usb.40 Amp power line for amp with earth stake&Faraday shield ,20 Amp power line for digital equipment ->shunyata 8 venom power board...Working on it!
    · Share on Facebook
  • xschop
    xschop Posts: 5,875
    Options
    Good deal. It's not vintage Polk unless you can remove a pound of goo lol.

    What is the round tube behind that tweeter cutout?
    Don't take experimental gene therapies from known eugenicists.
    · Share on Facebook
  • ptrooper
    ptrooper Posts: 768
    edited October 20
    Options
    Unsure about that rod to rear baffle Some sort of obsorbing resonating rod I thought ? It’s my first look into the top end of the monoliths.
    These next pics are from the beginning of this post taken by vr3
    7wzk1ps2db2z.png
    These pics clearly show braces between the tweeters
    One things for sure. The rear baffle certainly vibrates allot , I can’t wait to divert this energy where it’s suppose to be. ..forward !
    30rxbdggi5s4.png
    c0uajqaqh1xr.png

    Definately interested @Gardenstater idea of more bracing <3
    Thinking Corners leading out towards centre of MW’s. Etc. got the old brain clonking along :D
    VR3 SDA SRS 1.2TL Duelund Monoliths+VR31000va Dreadnaught +VR3 MM2 SDA cable, <3 ,Lumin u2x ,<-sfp fibre <-LHYas8 Pro+ Switch,Transparent Reference MM2 xlr,power and speaker cables.FTA Sinope SE usb.40 Amp power line for amp with earth stake&Faraday shield ,20 Amp power line for digital equipment ->shunyata 8 venom power board...Working on it!
    · Share on Facebook
  • xschop
    xschop Posts: 5,875
    Options
    Is there a bolt in the back baffle holding the tube?
    Don't take experimental gene therapies from known eugenicists.
    · Share on Facebook
  • Viking64
    Viking64 Posts: 7,820
    edited October 20
    Options
    It seems to me that the tube had something to do with the threaded rod that allowed the 1.2s and 2.3s to be attached to the wall. It allowed the rod to screw in and out without disturbing or getting caught in the fiber.
    · Share on Facebook
  • michaeljhsda2
    michaeljhsda2 Posts: 2,221
    Options
    Viking64 wrote: »
    It seems to me that the tube had something to do with the threaded rod that allowed the 1.2s and 2.3s to be attached to the wall. It allowed the rod to screw in and out without disturbing or getting caught in the fiber.
    That's correct.
    SDA SRS 2.3TL's
    Silk Audio MS-90-BT integrated tube amp
    Yaqin MS-20L integrated tube amp
    SDA 2B TL's
    · Share on Facebook
  • ptrooper
    ptrooper Posts: 768
    edited October 20
    Options
    Thank you , good to know. I didn’t think to look and I wonder how long the internal thread is ? Bolts a must , to be air tight ?i2yf7bdl1hfb.jpg
    VR3 SDA SRS 1.2TL Duelund Monoliths+VR31000va Dreadnaught +VR3 MM2 SDA cable, <3 ,Lumin u2x ,<-sfp fibre <-LHYas8 Pro+ Switch,Transparent Reference MM2 xlr,power and speaker cables.FTA Sinope SE usb.40 Amp power line for amp with earth stake&Faraday shield ,20 Amp power line for digital equipment ->shunyata 8 venom power board...Working on it!
    · Share on Facebook
  • michaeljhsda2
    michaeljhsda2 Posts: 2,221
    edited October 20
    Options
    The cardboard tube fell off of mine and since I was never going to use the bolt to attach it to the wall I threw the tube in the trash and used hot glue to seal it on the inside.
    SDA SRS 2.3TL's
    Silk Audio MS-90-BT integrated tube amp
    Yaqin MS-20L integrated tube amp
    SDA 2B TL's
    · Share on Facebook
  • michaeljhsda2
    michaeljhsda2 Posts: 2,221
    Options
    ptrooper wrote: »
    Thank you , good to know. I didn’t think to look and I wonder how long the internal thread is ? Bolts a must , to be air tight ?i2yf7bdl1hfb.jpg
    I can't recall exactly but I think the bolt that's shown in your picture is only the depth of the back of the cabinet with a nut on the inside and then the cardboard tube is glued on to the back of the cabinet.
    SDA SRS 2.3TL's
    Silk Audio MS-90-BT integrated tube amp
    Yaqin MS-20L integrated tube amp
    SDA 2B TL's
    · Share on Facebook
  • xschop
    xschop Posts: 5,875
    edited October 21
    Options
    Taking the design a little further....

    y9ezmy1qnepx.jpg
    x5bv1h7dr0bd.jpg

    os3zbygtuqo4.jpg

    Don't take experimental gene therapies from known eugenicists.
    · Share on Facebook
  • ptrooper
    ptrooper Posts: 768
    edited October 22
    Options

    Funny, I find that my guesstimate here is 3 mm off, I could have avoided taking that tweeter out!. Within 1/8th you said? My first wife still tells my children today(adults now) I am psychic :*
    luminu2x at 800 hrs and FTA Sinope SE at 400, Sounding like Liquid.<3 Thanks @xschop ,More of your heart and soul going into the Monoliths.
    I'll document the internal bracing when I install these, I do wonder how many different versions of 1.2tl bracing are actually out there if any at all?


    ptrooper wrote: »
    Good morning track to get you started

    Still pondering the bracing . Pump it up!

    For a 270mm front-to-rear brace with a temperature swing from 18°C to 32°C linear expansion average data to consider for baffle stress:

    Aluminum: 0.087 mm (Highest expansion; risk of pushing/straining baffle joints at 32°C; prone to ringing)

    Steel: 0.045 mm (Half the expansion of aluminum; 3x stiffer than aluminum; heavy and needs damping)

    Hardwood (Longitudinal): 0.015 mm (Most thermally stable; matches wood/MDF cabinet behavior; excellent internal damping)

    Bottom Line: Hardwood expands 6x less than aluminium and 3x less than steel , making it the safest choice to avoid putting mechanical pre-stress on your speaker baffles.

    I know the expansion is really only minimal with 11 braces per enclosure but, mentally , I'd like to keep to the natural organic textured signiture the Mono's have!


    Like @Gardenstater stated, " I like overkill " This is what I am told I do with everything all the time.

    This is the "Duelund Monoliths" Motto

    VR3 SDA SRS 1.2TL Duelund Monoliths+VR31000va Dreadnaught +VR3 MM2 SDA cable, <3 ,Lumin u2x ,<-sfp fibre <-LHYas8 Pro+ Switch,Transparent Reference MM2 xlr,power and speaker cables.FTA Sinope SE usb.40 Amp power line for amp with earth stake&Faraday shield ,20 Amp power line for digital equipment ->shunyata 8 venom power board...Working on it!
    · Share on Facebook
  • ptrooper
    ptrooper Posts: 768
    edited October 22
    Options
    Found an old pic ❤️
    lfld38wcm96e.jpeg

    VR3 SDA SRS 1.2TL Duelund Monoliths+VR31000va Dreadnaught +VR3 MM2 SDA cable, <3 ,Lumin u2x ,<-sfp fibre <-LHYas8 Pro+ Switch,Transparent Reference MM2 xlr,power and speaker cables.FTA Sinope SE usb.40 Amp power line for amp with earth stake&Faraday shield ,20 Amp power line for digital equipment ->shunyata 8 venom power board...Working on it!
    · Share on Facebook
  • xschop
    xschop Posts: 5,875
    edited October 22
    Options
    Those mortars even come rigged with 2 fuses. :D

    Seriously, 6061-T6 only expands (CTE) 0.023mm or 0.0009" / 3.3 linear ft.

    And 1.2TL rods only require a third of that, so 0.0003"

    I'd wager these large baffle Polks are a multitude higher travel than that just off low freq vibes when the volume knob is twisted clockwise lol.

    I'm also not going to use the locknuts on mine for simplicity sake. Blue Loctite is all that is needed and one less wrench to handle and turn while up in the cabinet. :)

    Don't take experimental gene therapies from known eugenicists.
    · Share on Facebook
  • ptrooper
    ptrooper Posts: 768
    edited October 22
    Options
    lol. Fire for effect.
    Good to know the correct specs!, Let me know how they go locknutless
    I was thinking locknuts might not have to be used!
    What’s the curing time on the blue loctite?
    VR3 SDA SRS 1.2TL Duelund Monoliths+VR31000va Dreadnaught +VR3 MM2 SDA cable, <3 ,Lumin u2x ,<-sfp fibre <-LHYas8 Pro+ Switch,Transparent Reference MM2 xlr,power and speaker cables.FTA Sinope SE usb.40 Amp power line for amp with earth stake&Faraday shield ,20 Amp power line for digital equipment ->shunyata 8 venom power board...Working on it!
    · Share on Facebook
  • xschop
    xschop Posts: 5,875
    edited October 22
    Options
    I'll post some pics this weekend of them in my 8TLs when I permanently glue the ends.

    Initially, just use a marker on threads near alloy so when you go back with glue, you only coat below that line with Blue Loctite. You'll have 10 minutes to adjust so a win/win there too.

    24 hrs full cure time will match Power Grab or Liquid nails.

    I adjusted the pointed spud base dimension for faster MDF penetration before full seating.
    Used the same Superglue I use on MW magnets to permanently attach the large washers last night. Already cured this morning rock solid. I'll do the same for your 1.2TL batch.
    I Should have built these long ago for my old Polks.

    Early bird gets the java...

    ltrywsdb3wv8.jpg
    Don't take experimental gene therapies from known eugenicists.
    · Share on Facebook
  • xschop
    xschop Posts: 5,875
    edited October 23
    Options
    These have been installed last couple days with off-on loud playing. Luckily clearanced the MW ring and tweeter magnet on these 8TLs. Semi-Rings are still glued SOLID to the MDF. Had to remove a 1.5 x 1.5 inch sq. Sound foam at back.
    Install just needed a 13/16" wrench to hold bolt hex while hand twisted rod to firm seat at front.

    t2sqj9efyria.jpg
    17011g0nfbs0.jpg
    yb3efn6v1h1a.jpg
    Don't take experimental gene therapies from known eugenicists.
    · Share on Facebook
  • ptrooper
    ptrooper Posts: 768
    edited October 23
    Options
    xschop wrote: »
    These have been installed last couple days with off-on loud playing. Luckily clearanced the MW ring and tweeter magnet on these 8TLs. Semi-Rings are still glued SOLID to the MDF. Had to remove a 1.5 x 1.5 inch sq. Sound foam at back.
    Install just needed a 13/16" wrench to hold bolt hex while hand twisted rod to firm seat at front.

    Awesome.How they sounding ? I don't see any glue that might have been squeezed out and wiped around washer!
    VR3 SDA SRS 1.2TL Duelund Monoliths+VR31000va Dreadnaught +VR3 MM2 SDA cable, <3 ,Lumin u2x ,<-sfp fibre <-LHYas8 Pro+ Switch,Transparent Reference MM2 xlr,power and speaker cables.FTA Sinope SE usb.40 Amp power line for amp with earth stake&Faraday shield ,20 Amp power line for digital equipment ->shunyata 8 venom power board...Working on it!
    · Share on Facebook
  • xschop
    xschop Posts: 5,875
    edited October 23
    Options
    Did those pics for install reference with washer/bolt/wrench combo. I just squeezed on some PowerGrab and reinstalled.

    Too many irons in the fire this week. Working on transformer housing and gaskets...

    uo9mgae81336.jpg
    Don't take experimental gene therapies from known eugenicists.
    · Share on Facebook
  • xschop
    xschop Posts: 5,875
    Options
    Here ya gooey go... B)

    After it dries, I'll cut a slit into the Dacron and pull it back up.

    odylfrbekdma.jpg


    Don't take experimental gene therapies from known eugenicists.
    · Share on Facebook
  • ptrooper
    ptrooper Posts: 768
    edited October 23
    Options
    xschop wrote: »
    Here ya gooey go... B)

    After it dries, I'll cut a slit into the Dacron and pull it back up.

    Nice, looks like the slippery goo self aligned perpendicular a bit better than the dry try or your centre punch point position end is slightly different than before.

    VR3 SDA SRS 1.2TL Duelund Monoliths+VR31000va Dreadnaught +VR3 MM2 SDA cable, <3 ,Lumin u2x ,<-sfp fibre <-LHYas8 Pro+ Switch,Transparent Reference MM2 xlr,power and speaker cables.FTA Sinope SE usb.40 Amp power line for amp with earth stake&Faraday shield ,20 Amp power line for digital equipment ->shunyata 8 venom power board...Working on it!
    · Share on Facebook
  • xschop
    xschop Posts: 5,875
    Options
    Pic is upside down, but I think the point was a little off from dry run. Indeed it lines up faster with some wet goo applied. :D
    Don't take experimental gene therapies from known eugenicists.
    · Share on Facebook
  • Butter
    Butter Posts: 65
    Options
    Everything lines up faster with wet Goo!
    · Share on Facebook
  • xschop
    xschop Posts: 5,875
    edited October 25
    Options
    Got to listen to them today for about an hour. ZERO baffle vibes now at high volume. Passes Cameo's "She's Strange" test lmao. Let them play loud while I worked on my amp in the garage shop too. Fun times.

    https://www.youtube.com/watch?v=jUgsmsvSYow
    Don't take experimental gene therapies from known eugenicists.
    · Share on Facebook