Karma-8 EOS-8 version

Discussion in 'DIY Speakers and Subwoofers' started by Matt Grant, Mar 16, 2013.

  1. I cooked up this design a few months ago and thought I would share it. Basically it is the Karma-8 but using the EOS-8 waveguide, I actually like this design more as I think the EOS-8 is a better performing waveguide. I think it sounds more detailed and cleaner in the midrange, overall sensitivity of this design is also a little higher at 93dB vs 91.5.


    The crossover for the DNA-150 on the EOS-8 is super simple, just a cap and two resistors though the woofer uses a few more parts, still not bad price wise though.

    *Don't forget to add the Celestion TF0818 at PE as well also the DNA-150, EOS-8 and adaptor plate here at DIY sound group should you want to build this design.


    On axis frequency response, reverse null and 0-60 degrees off axis:


  2. Love ALL the work you've put into these designs. Thank you! One Question:

    Would the crossover stand as-is if you subbed in an Eminence Alpha-8a or Beta-8a (I prefer the latter)?
  3. FR, sensitivity, acoustic center and impedance will all be different so the crossover designed for the TF0818 will not work perfect if the Alpha/Beta-8 is dropped in. Now it might do OK as they are all similar drivers but the crossover really won't be optimized for those woofers.

    I also forgot to note that the measurements were done with the enclosure sealed, if ported LF extension should drop about an octave.
  4. I attached transfer function on this design too just to show how the simple crossover works with the DNA-150 on the EOS-8.

    Attached Files:

  5. Really nice results for a simple crossover. Looks pretty cool too.
  6. This is such a cool budget design!
    mtg.......can both drivers be front-mounted on the baffle without issue? Is there a specific driver c2c distance? It looks like about 1/2 inch between driver edges.....
  7. Thanks,
    Yeah you should be able to surface mount both drivers no problem. The recess is close for both the woofer and waveguide so the z-offset will change very little. I would recommend keeping at most 1/4" to 1/2" between the drivers, larger distances will cause the forward lobe to narrow.
  8. So can i use the flatpacks for these?

  9. Yeah the 0.6cuft EOS-8 boxes.
    Erich should have these as a kit. He is trying to sell what he has left of the MTG-08 models before updating it though. I guess posting this does not help any ;D
  10. How would these compare to the Dayton Designer ones? I was interested in those but Erich said there was little interest in those so the flat packs aren't available any more.
  11. They are quite different from each other, the Dayton Designer ones are a decently efficient full range tower design where as this is a high efficiency bookshelf design that needs subs. The Designer's use the SEOS-12 waveguide and the DNA-350/360 where as this has the EOS-8 waveguide and DNA-150 CD.
  12. Which would you say is the better of the 2?
  13. That is a tricky question, better how?

    SQ, don't know, I have not heard the Designer's but the CD they use is nicer so the HF's should sound better. The designer's also use the SEOS-12 which is larger waveguide and has better directivity control.

    Output, I would say the Celestion may have the advantage over the Dayton Designer woofers in both output and sensitivity but not my much.

    The designer's would make better mains especially is your looking for more low end from them while the compact size makes the Karma-8 better for surround use.

    Any help?
  14. The Designer's strength is it could feasibly be used without a subwoofer (as opposed to the high-sensitivity systems which virtually always need a sub unless you build them in an ungodly huge ported box). But that said, a system using subs (note the plural!) will pretty much always be better than one without, if only because the subs can be located for best in-room bass, while subless speakers have to have the bass come from where the highs and mids work best (or vice-versa) which is never optimum.
  15. I'm looking to replace some ascend 340s. I do have 2 mfw15 subs that i built. This would be my first speaker build so I'm looking to stay on the lower side for money spent. Will eventually replace whole system. Any input would be greatly appreciated.
  16. I think this would make a great first build speaker. Very simple cross over. Nice sized speaker, so you can use it in multiple applications. Performs very well rounded.

    If you would like a little smaller and a little more bass there's a Designer 6" I did with the EOS6 waveguide and DNA-150. But it's less effecient. If you want bigger than this, you'll get a little more output. Consider the Kharma 10. Very cheap, but has all the goods. I really think this is a speaker fills a good sweet spot though. I like that it uses the DNA-150 over the DNA-205 because of the response hole the DNA-205 produces on the EOS8. So like I said, you can't go wrong with this one.
  17. Just about finished building these :D
    do you suggest using any stuffing?
  18. You want to line the inside walls with 1-2" of material, foam, poly batting, fiberglass, recycled denim, etc... anything that works well.
    Just leave the area around the port free so air can move in and out unrestricted.
  19. Great looking budget speaker.

    Would this design/crossover/waveguide etc work OK with the newer 205 CD?
  20. No unfortunately it would require a different crossover.
  21. H5tuu

    The DNA-150 is crazy good. It's sensitivity is really similar to the big boys. Once eq'ed flat it can tak some serious power. I think this is a stellar design and would be fine as is.
  22. Yeah DNA-150 is one of my favorites, not many know what a gem that is and the value is just unbeatable.

    I was listening to this design outside last week powered by a bridged Behringer A500 (375W RMS into 8 ohms) and it handled that power with ease. I have been on the lookout for a good deal on an amp that can push at least 1000W into an 8 ohm load to really test some of these speakers. If I blow up a DNA-150 I'll post it here. ;D
  23. Thanks guys.

    The problem I have is I live in the UK where buying the 150 CD is impossible but I can buy the B&C DE10 (which the 205 CD is a clone of?).

    Is the 150 a clone of another CD that is freely available worldwide that I could try?
  24. Where are you gonna get the EOS8 ? If you can get the EOS 8, then you can get everything you need for the Alpha 8 minion. That's a nice speaker.
  25. As far as I know the EOS8 is the same as the 18 Sound XT120?

    The minion is a great looking speaker but the driver is far more expensive.

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