Ahem - DIY Sound Group HTM12 and Volt 10LX kits

Discussion in 'Hardware Lounge' started by Dustin B, Feb 15, 2017.

  1. Dustin B

    Dustin B Well-Known Member War Zone Member

    Well I finally pulled the trigger and put my money where my mouth was recommending DIY Sound Group speakers.

    3x HTM12 kits and 4x Volt 10LX kits have been ordered. Parents are in the US until end of March and will be bringing them back for me. Could be quite a while before they get built though. Will depend how quickly the theater rebuild happens.

    The larger is an HTM12 and the smaller is a HTM10. 12" vs 10" driver and 15" vs 12" waveguide.

    Last edited: Feb 16, 2017
    CJ likes this.
  2. CJ

    CJ Well-Known Member Admin War Zone Member

    Cool. I prefer the matte waveguide. What did you go with?
  3. Dustin B

    Dustin B Well-Known Member War Zone Member

    Matte. Don't want shiny things to reflect light at the front of my room. Although it really won't matter as I'm intending for my screen wall to completely hide them.

    I'm planning to just use 300 thread count cotton for my screen. So I'll likely order the same fabric in black and use that to hide the left and right main. Then all 3 will be going through the same fabric. The HTM12 has a crossover option to tame the high end slightly (1.5db). Being behind the fabric will hopefully make that unnecessary and result in a great in room response.
  4. CJ

    CJ Well-Known Member Admin War Zone Member

    Its an interesting design. Is the goal really the high efficiency aspect? It doesn't seam that they go super low given the woofer sizes but they're not "high excursion" I guess.
  5. Carl V

    Carl V Well-Known Member Donor War Zone Member Top Poster

    Not for really deep freq. Mostly efficiency, SPL & Directivity.
    PSA has similar offerings.

    Sounds like a fun project & a Killer HT
  6. Dustin B

    Dustin B Well-Known Member War Zone Member

    They're quite similar Geddes speakers just a fraction of the cost in kit form. Goals of the design are constant directivity, high sensitivity and flat response.


    The high efficiency and power handling mean they'll do reference level in my room with ease with receiver power. You tow them in so that directly on axis to the right speaker is a bit to the left of the main listening position and the left speakers on axis is to your right. This way as you move left you're getting further away from the right speaker but getting more on axis with it. And you're getting closer to the left and getting more off axis with it. Given how even and consistent the drop off is off axis this means the right speaker gets a bit louder being more on axis while the right speaker gets a bit quieter going more off axis. The end result is great imaging over a wider range of listening positions. Then the waveguide also limits sound to the front and side wall for each speaker reducing same wall first reflections without room treatments.

    Geddes waveguides are round while these opted for a oval shape which narrows their vertical coverage limiting floor and ceiling first reflections. They both use an oblate spheroid profile which eliminates the harshness you get from typical horns. Geddes takes this a step further and fills his waveguides with open cell foam which he says reduces HOMs (higher order modes) in the waveguide further helping this.

    The larger mid is to get the polar response to match up to the waveguide better. They have a few other designs that use a pair of 8" drivers side by side to get the same effect. The HTM series are definitely intended to be used with subs. I'm planning to change my dual FiCar Audio SSD 18" IB into a ported monster (1600L tuned to 16hz with a massive slot port). I'll continue to run dual AE C12.2 subs I have sealed. They'll get a new enclosure though. And I'll take back a Dayton DVC12 from my parents to build a higher tuned ported sub for my third sub. They'll be spread out through the room and integrated into the system with a MiniDSP.

    So they play very loudly, cleanly and accurately with small amounts of power while interacting with the room as little as possible in a negative way. If they come even close to the Summas I heard in Geddes room I'm going to be quite happy. Helping that to happen I'm copying as much of his room design as I can.
    Last edited: Feb 16, 2017
  7. Dustin B

    Dustin B Well-Known Member War Zone Member

    Forgot to mention I'll likely build mine sealed to help protect the drivers more as I intend to run them full range but still copy their content over to the subs in the receiver settings. So they'll be -3db in the 70s instead of the 40s.
  8. Mike B

    Mike B Well-Known Member Donor War Zone Member Top Poster

    I would go vented. You can always set the XO to 40 Hz.
  9. Dustin B

    Dustin B Well-Known Member War Zone Member

    If I can confirm that the receiver I get handles the crossovers properly I will. But if it's still done the way it was I last looked into it I don't want too. That being if you set surrounds at a higher frequency than mains. Say 80 and 40. It takes the signals from the mains and surrounds, sums them, and then low passes them at 40hz leaving a 40-80hz hole in your surrounds.

    I'd definitely go ported if I had minidsp style control over the routing and crossovers between all the channels and the subs.
  10. Dustin B

    Dustin B Well-Known Member War Zone Member

    All the parts have arrived safely. Eric did quite the packing job. Almost nothing was in the box I expected it to be. He did a pretty efficient job though. Only thing that I found a bit surprising was how light the Eminence 12 inch Deltalite drivers are and how heavy the 1 inch Denovo DNA325 compression drivers are. The 15" SEOS waveguides are quite impressive too. Especially for the $36 price tag. And the 12 and 10 are even cheaper.

    IMG_20170416_165126123.jpg IMG_20170416_165207852.jpg
  11. Andrew Pratt

    Andrew Pratt Well-Known Member Top Poster

    Cool stuff. I've got an itch to build something again...luckily my neighbour is rebuilding his basement with me as the consultant so that'll tide me over for awhile.
  12. Dustin B

    Dustin B Well-Known Member War Zone Member

    It's quite anti-climatic right now since I have a bunch of parts, but won't build them until I have the new room finished and I don't have any real time line on when that will be yet.
  13. CJ

    CJ Well-Known Member Admin War Zone Member

    Yeah, need more pics!
  14. Denton

    Denton Well-Known Member Donor War Zone Member Top Poster

    I came very close to buying some Cornscalas that looked very much like those. Should be good fun.
  15. Dustin B

    Dustin B Well-Known Member War Zone Member

    Here's all the pictures. First is all the boxes that were in the 3 big ones. Next two are the 10" coax drivers. Then crossover parts and 3/4" compression drivers for the Volt10 followed by their baffles. Then the HTM12 kit parts. 12" driver, 1" compression drivers, crossover parts, baffle and ports I may or may not use. 6a4871d0a7c2062d8c7c600a21c275e2.jpg 88c6d09443266644969fa27671fee461.jpg 946398ba519c3477810ea7ec4ebd7aa2.jpg 753a3c06534005defc4e1bc3de36892c.jpg 90ec1efab7fc3d69431abd1764bee90d.jpg 21b28022e6180fbcba61d120ced94f7b.jpg 906a0dea92af82346c7073d7914c9201.jpg a44c3a4fc952930c54c34960f7f8f165.jpg b45853aaebd18a9b9321826cc786a11c.jpg 6d711cb65aca99631b50589aa8b7b4c8.jpg 8a604f973bfa024f9f01f6c7f8895754.jpg 4cbfe5036b8339eaa1b25ae2f49ebdf3.jpg
  16. Carl V

    Carl V Well-Known Member Donor War Zone Member Top Poster

    Cool Mike B and I have those coincident 10" setups.....
    Nice sound.
    Keep us in the loop
  17. Mike B

    Mike B Well-Known Member Donor War Zone Member Top Poster

    Looks like you'll be having big fun and making lots of dust!

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