"MTG-08" 8" Celestion + DNA-150/DW-774s bookshelf/surround design

Discussion in 'Legacy Speaker Designs' started by Matt Grant, Jul 16, 2012.

  1. Re: DW-774S/DNA150 + Celestion TF0818 design/build

    I am listening to it right now with just the resistor change and that brings down the brightness, sounds better now that it is more balanced.

    Using the low DCR solid core 1mH inductor should also bring up the bass a little compaired the the 20awg air core I have in it now.

    Again all that changed is the 2.2 ohm parallel resistor, now a 1.8 ohm resistor.
    Here is the updated parts list:
    [​IMG]
     
  2. Re: DW-774S/DNA150 + Celestion TF0818 design/build

    How come your resistors are only $0.64? I can only find them for $1.25 on PE... Which is pretty expensive for a resistor.
     
  3. Re: DW-774S/DNA150 + Celestion TF0818 design/build

    Go to electronic components and in resistors they have 5/10/20 watt wirewound by Xicon, inductance is negligible and test no different then the Dayton non inductive ones. They used to be $0.39. :'(
     
  4. Re: DW-774S/DNA150 + Celestion TF0818 design/build

    The prototype box was cut for these yesterday along with the one from tuxedocivic. I'll get pictures up and figure pricing for the kits.

    There will be something added to these designs for each designer. I haven't figured out how it will all work out just yet, but I think it will be better than relying on the donation buttons from here on out.

    By the way, I also got prototype boxes made up for one of these woofers to go under the SEOS-12. The 8" woofers still look okay under the 12" waveguide, and the cabinet is only 8" deep. I also bought the 8" Dayton Designer Series (which looks really nice), 8" B&C, and an 8" Eminence.


    Once the word gets out on these smaller speaker designs being able to reach high levels in a home theater environment, I do believe they will sell pretty good, which will allow the designer to make some money.
     
  5. Re: DW-774S/DNA150 + Celestion TF0818 design/build

    Cool, did you end up using a round port/s or did you go with the slot port?

    Edit: I guess I can wiat for the pictures and find out for myself.
     
  6. Re: DW-774S/DNA150 + Celestion TF0818 design/build

    I already had some ports that I bought for another kit, so I figured those could be tried out. But they can be changed easily.

    There are two 1.5" diameter ports on the front. They are flared quite a bit so I'm hoping they work okay.
     
  7. Re: DW-774S/DNA150 + Celestion TF0818 design/build

    Hmm, the air velocity reaches 60 m/s (200ft/s) with 100 watts input, there is going to be lots of chuffing/port compression.
    Is there a reason you did not go with the slot port? More cuts = more cost and/or don't like the look of them?
    The minimum I would go with is the single 3", You could make the enclosure shorter 16" internal (vs 18") and a bit deeper 10" internal (vs 9") then throw a 3" out the back.
     
  8. Re: DW-774S/DNA150 + Celestion TF0818 design/build

    Where does the high velocity occure? If its below the subwoofer cutoff (80hz), which I suspect, then it shouldn't be a problem...?
     
  9. Re: DW-774S/DNA150 + Celestion TF0818 design/build

    Velocity max is at 65hz (70hz tune) putting a 2nd order high pass at 80hz does limit it to 30m/s which might be ok but I still think that is a little high.
    These don't do to bad when run fullrange especialy if you need a compact speaker for backyard parties and such. The bass output from this little thing was pretty impressive outdoors and I only had the one, I can't imagine what it will be like with the both of them. WinISD predicts 110dB+ from 65hz on up per driver (100w /1m).

    I need to hurry up and finish up the other one so I can listen to them in stereo.
     
  10. Re: DW-774S/DNA150 + Celestion TF0818 design/build

    The reason I put the ports on the front was because that's where you had them, and that would work good if anyone used them for surrounds against the wall. I haven't tried designing any slot ports yet, so I wasn't sure how that would work or how hard it would be for someone to assemble in a flat pack form.

    My mistake on the smaller ports. I put two 2" ports on the Designer Series 12" woofer and I can't heard anything bad even when it's really moving, so I figured going to 1.5" would be okay for the 8". But those are ported on the back and the high volume would probably hide any chuffing there anyway.

    I'll see if I can find some 2" ports. Two of those would work like a 3" and still make things look okay and symmetrical on the front. If that doesn't work, then I'll try to figure out the slot port method.


    I have a feeling these will be popular so getting the enclosure nailed down will be great. I also made a box with the Celestion under the SEOS and it looks okay. But with some interesting waveguides coming, a narrower EOS-10 model might be just the thing to experiment with as well.


    I'm anxious to try out this design and the WAF model that tuxedocivic made. By the way, do you have a name for this one mtg90? Maybe it could be called the MTG-90! :D
     
  11. Re: DW-774S/DNA150 + Celestion TF0818 design/build

    The advantage to slot ports is that you can get them to fit where the round ones don't. I think they should be on the front with this one, in general I do not like rear ports like you said it keeps the speakers from being positioned against a wall. The only reason I suggested the rear port is because that is where one could fit. Two 2" ports should work ok.

    Another advantage to slot ports is that they add to the bracing of the enclosure, and really it is only two extra pieces that would go in like just like the bracing would. My second one is still without a baffle mounted so I could take a picture just to give you an idea of what the slot port looks like on the inside.

    I knew you would bring up the naming sometime soon, I spent the earlier part of this day trying to come up with some name for these, if you like MTG-90 use it, its as good as any name I might think of.
    EOS-10, ooh, I like the sound of that. ;D
     
  12. Re: DW-774S/DNA150 + Celestion TF0818 design/build

    While going back through this thread I found something I didn't see because it was hiding in one of the posts.


    How did I miss this???

    http://www.youtube.com/watch?v=jkDki019l4U


    That is awesome!
     
  13. Re: DW-774S/DNA150 + Celestion TF0818 design/build

    I had time to tape up the prototype box. I noticed that you made your sides from .5" mdf. This prototype box went with .75" all around with increased dimensions to keep the same internal volume.

    Let me know if this is okay because I don't want to mess up your work: 9.5" wide x 19.5" tall x 10.5" deep. I did put a 1/2" roundover on the front, but if the .25" on each side will mess up the BSC, I will see about getting 1/2" mdf used. It would be good to keep all the panels the same thickness so everything can be cut from the same sheet. So if 1/2" is used, it might make sense to double up the front for 1" versus using the .75 material.




    Right now the braces were spaced out evenly in the box. But for the final product, it would make sense for me to move one horizontal brace directly between the woofer and waveguide to stiffen that up. Then I guess I'll move the lower brace down a couple inches. And of course, maybe a slot port could be figured out as well. I just wanted to show you what I was working on.





    [​IMG]
     
  14. Re: DW-774S/DNA150 + Celestion TF0818 design/build

    This is a great size and looks to be a good performer, especially for surrounds or heights, etc. slot ports would be great to reduce the height.
     
  15. Re: DW-774S/DNA150 + Celestion TF0818 design/build

    No doubt they would make for some sweet surrounds. I also had a box made for the same Celestion 8" and the SEOS-12. I'm hoping he can possibly use the same type setup with a little bit of a crossover change for the added width.


    The original with the slot port was 19". The one above is 19.5". But I made it 19.5" only because it used .75" mdf versus .5".

    The only way to reduce the height would be to make them 17" tall with the ports on the back. But doing that would mean the box would have to be wider and deeper to get the same volume.

    I really......really like the width of this cabinet and how everything is tight as can be on the front.
     
  16. Re: DW-774S/DNA150 + Celestion TF0818 design/build

    That looks great :)

    Those are the cutouts for the 1.5" ports right?

    3/4" is fine, I kind of knew you would use that anyway, the added 1/2" should not cause any issues with the BSC. The horizontal brace between the woofer and waveguide is a much better spot, here is a picture of what my second one looks like currently.

    [​IMG]
     
  17. Re: DW-774S/DNA150 + Celestion TF0818 design/build

    classy looking setup.
     
  18. Re: DW-774S/DNA150 + Celestion TF0818 design/build

    This kit is now ready to go.

    http://www.diysoundgroup.com/speaker-kits/mtg-kit.html

    I might be able to tweak the price once I get a better grip on the shipping supplies and get the price under $150. I might just start them at $145 and see if it works out because I do have some left over shipping boxes from past things. Matter of fact, that's what I'm going to do.


    The $5 donation per speaker for the designer has been added in. That could increase as demand goes up. I'm wondering if I should put the price at $145 and make an option where the person buying must select the amount. I could put a few different amounts there to pick from, but make it to where they have to pick at least one. Any suggestions? The $5 amounts will likely increase depending on the speaker and other things. Doesn't sound like much, but it's a good starting point to see how things go.

    MTG, if you have stuff to add to the page, please let me know and I'll make all the changes. I just gave it a real quick write up to get it started.
     
  19. Re: DW-774S/DNA150 + Celestion TF0818 design/build

    If I think of something to add or change with the page I'll be sure to let you know. Only thing I don't see on the page is the crossover schematic, which would be unneeded if you have a printout that you throw in with the kit. Otherwise looks good.

    $5 is plenty for me, but I think a $10 and $20 donation would be good choices for the other amounts. Just make sure you are not losing $$ with every kit sold, I think your entitled to just as much/more then the designer with all the time and effort you have put into everything.

    Edit: looks like the schematic has the 2.2 ohm resistor I'll change it to the 1.8 ohm just so there is no confusion.
    Here is new schematic:

    [​IMG]
     
  20. Re: DW-774S/DNA150 + Celestion TF0818 design/build

    I know $5 doesn't sound like much, but it could change later. Had $5 been added to Paul Carmody's Overnight Sensations, it would have been a really nice amount of extra money for him. We'll see how this goes.

    I'll also add the crossover schematic to the page.
     
  21. Re: DW-774S/DNA150 + Celestion TF0818 design/build

    I'm looking for a reasonably high dynamic setup on as tight of a budget as possible for a friend. Do you think these would fit the bill? They look pretty impressive to me.
    Would you recommend running 3 of them across the front, or doing something different for the center channel?
    Thanks in advance. I love what you all are doing for the audio world.
     
  22. Re: DW-774S/DNA150 + Celestion TF0818 design/build

    I think these will fit your goals rather well. How do you plan on using it for the center? If you plan on using it sitting horizontal you will be limited to a small listening area of about 10-15 degrees to each side, but sitting upright in its normal position it will work great.

    You just wait, it is going to get even better. ;)
     
  23. Re: DW-774S/DNA150 + Celestion TF0818 design/build

    I think he would have it upright. At first he was thinking HTIB....maybe I shouldn't have said anything. I'll probably give him the bug too.
    I'm pretty limited on funds and time, but if there's anything small I can help with, just let me know.
     
  24. Re: DW-774S/DNA150 + Celestion TF0818 design/build

    These will blow any HTIB speakers away, a huge step up. I think most* of the new designs will be larger and upwards in price from this one, but Tuxedocivic has a few smaller designs (due out sometime soon) which should come in under this one.
     
  25. Re: DW-774S/DNA150 + Celestion TF0818 design/build

    Will these speakers work well with a $300-400 receiver? I'm sure he's not wanting to get needing mini dsp or anything extra.
     

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