Troels Gravesen Illumina 66 Build Log

Discussion in 'Speakers' started by spwath, Jun 3, 2021.

  1. spwath

    spwath Hijinks master cum laudle

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    Moving halfway across the country to apartment, had to say goodbye to big JBLs, time for something a bit smaller.
    http://www.troelsgravesen.dk/Illumina-66.htm

    I had the tweeters laying around, so I figured I would go for these.
    I am using a simplified geometry to make build easier, but keeping angled parts to eliminate standing waves. I modeled it in Solidworks so I could calculate internal volume with all bracing in place (have not done bracing yet). Here is the basic geometry:
    upload_2021-6-4_0-38-43.png

    Next step, build a little scale model section to make sure everything is going together well, I dont have that much woodworking experience.
    [​IMG]

    So far so good, time to get the wood, got nice sheet of MDF
    [​IMG]


    A few other notes on the build

    I am using double thick front panel for rigidity.

    Also, these speakers are very very similar to YG acoustics Carmel 2.
    The tweeters all almost the same - YG uses scanspeak tweeters custom made for them, with I believe a slight difference.
    The woofers are also very similar: Same size, same basket and motor structure. Only difference I see is YG makes machined aluminum cones that they send to scanspeak to be used, while the regular scanspeak drivers use pressed aluminum cones.
    Other differences, the waveguide built into the YG speakers, crossover differences, YG have an internal resonation chamber instead of a port to outside, and of course, the YG cabinets are machined aluminum.

    Stay tuned for updates, need to finish cutting these and stuff before i move out at end of this month
     
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  2. spwath

    spwath Hijinks master cum laudle

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    Progress!

    Front baffle going well, tweeter flush mount looking all good. I was a bit concerned, never built speakers before, or did a flush mount, but it seems to all be going well.
    [​IMG] [​IMG] [​IMG]
     
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  3. spwath

    spwath Hijinks master cum laudle

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    And woofer hole cut as well, ordering woofers now to test fitment
    20210610_164747.jpg
     
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  4. spwath

    spwath Hijinks master cum laudle

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    Woofers arrived
    20210614_123516.jpg

    Sexy magnet structure
    20210614_123634.jpg

    Test mounted, starting to look like a speaker
    20210614_125412.jpg
     
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  5. Pancakes

    Pancakes Almost "Made"

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    Killer drivers! Do you have a mic and associated measurement equipment? Curious to see FR, CSD, dispersion, etc. when all is said and done.
     
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  6. spwath

    spwath Hijinks master cum laudle

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    Yeah I've got a minidsp mic that I use with rew. Not too informed on how to do CSD graphs and stuff but I'll look into it.
     
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  7. LetMeBeFrank

    LetMeBeFrank Won't tell anyone my name is actually Francis

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    These are awesome so far. Looking forward to the finished product!
     
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  8. spwath

    spwath Hijinks master cum laudle

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    People who know things about crossover design:

    I realized I accidentally bought the 8ohm woofers instead of 4 ohm. Is there anything I can do in the crossover (crossover plans here Illumina-66 (troelsgravesen.dk)) to fix it?

    Or maybe its a sign I should just go for an active DSP system?
     
  9. Pancakes

    Pancakes Almost "Made"

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    Hmmm that's a tough one. You can get an idea of how values for a generic crossover would change here https://www.diyaudioandvideo.com/Calculator/SpeakerCrossover/

    But the Illumina has a notch filter and bypass cap in addition to the basic 12db filter so you really need to be able to model it on a computer. And also you'd need to know Troels' design parameters so you can compare.

    Perhaps contact Troels for help?

    Or I suppose the easiest (if possible) thing to do is exchange the woofer.
     
  10. spwath

    spwath Hijinks master cum laudle

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    Unfortunatly Madisound, where I got the woofers, says they are out of stock of the 4 ohm, and the 8 ohm too. Maybe ill try contacting them.

    Or, I could just go with an active system, as the price quote for the crossover supplies, cabinet damping, wires, binding posts, etc was $1000, and I feel like I could get the parts I need cheaper, and do an active DSP system, as most listening will be from digital source anyway.
     

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