SEOS12 with Designer12 woofer

Discussion in 'DIY Speakers and Subwoofers' started by BillWaslo, Mar 31, 2012.

  1. I have to say that this one so far sounds the best to me. That is probably because it has bass in the given configuration (sealed box, no sub playing). But it does have a nice richness to it even with stuff that doesn't have bass. It took a long time between changes, so it might be mind tricks. Or it might be the steeper slope on the crossover. Or it might be that it's not as sensitive and the amp gets worked harder. Who knows. Anyway, I like it a lot.

    For reasons I don't really follow, this one needed more delay on the woofer to match up. I didn't want to invert the tweeter to get there, since I want it to be able to play with the middle channel speaker Malcolm which has non-inverted tweeter (not sure it matters, but why not keep it the same?). So I added another two filter sections, which has the added benefit of rolling off the break-up region of the woofer even further. There are some slight changes to the tweeter section, too, to help with the match at crossover.

    edit 7/14/2012: The treble sounds a bit hot, depending on the environment, adding a 10 ohm resistor across the tweeter brings it down about 1.5dB if you need.

    edit 8/4/2012: I made some changes to the crossover to roll down the tweeter response some, and improve the load impedance. The v2 design files can be gotten at
    and the v2 schematic,with Parts Express part numbers is at

    Schematic (v1):

    I won't measure the horizontal pattern, since that's mostly just the waveguide and woofer diameter and it's the same. Vertical pattern is less touchy on this (the crossover is steeper). Here's the on-axis response just.... because:

    It is also the prettiest, I think. Cosmetically matches the SEOS12 nicely:
    Maybe that affects perceived sound, too.
  2. How would a vertical MTM with these work? That should bring up the sensitivity....... It would be a 4ohm load though..... Then it would have the bass and sensitivity!!!
  3. MTM doesn't work with large waveguides. With TM, the ctc distance is close enough to get decent vertical pattern extent, but with MTM, the ctc that limits things is the distance between the two midranges...which would have a big waveguide inbetween there. A TMM might do.

    But whats the big deal with efficiency, anyway, you can put together hundreds of watts of class d for cheap these days. Or biamp.
  4. This was confirmed to be bad / inaccurate measurements by the higher ups. LTD asked about it on the AVSforum thread.
    The woofer actually measures a lot better then the spec sheets lead you to believe.
  5. Is this device actually for sale? I can't complete a transaction on the diysoundgroup site.
  6. frankww -

    Which device? The plastic SEOS12 is on "pre-order" basis, shipment hopefully in a month or so. Shipping is a long process on these, I used some samples Erich got me.

    The Designer 12 is a Parts Express product, The crossover parts are from Parts Express. The cabinet was a one-off build, though Erich might be talked into making it a knock-down kit, maybe a full kit with parts, who know?.
  7. Hi, I meant the waveguide. I can't even place a pre-order. I get kicked out at shipping info. Then, I saw your post here and I thought, "He's got it. What gives? Etc."

    So, is there a procedure I'm missing for pre-ordering?

  8. Erich may have ended the preorders since the factory has sent the pallets. Plus there was a problem with one customer who didn't read the info about the preorder arrangement very well, which might have encouraged erich to stop taking preorders, too. But you'll still be able to get them when they arrive, just keep checking, they are worth it.
  9. Bill-
    Do you have a Z sweep of the DE250 with this XO in place?
    I am using this XO as a starting point for DS315+ DE250/QSC152 and I am measuring and modeling it dropping to about 2ohms at 1600hz.

    Attached Files:

  10. Sure Kim, here y'go. This was with one of Erich's CDs. Dips a little under 4 ohms
  11. Thanks Bill........back to the bread board
  12. Another great choice would be Beyma 12BR70, which is a rare animal from somewhere between pro and home audio. I've nor seen such set of parameters elswhere.
    Although in my opinion additional magnet would be beneficial.
  13. Erich and I are showing these speakers tomorrow at the MWAF at Parts Express. Threy are now in 3.5cu ft boxes tuned to 24Hz. Seemed a little bright so we pulled down the treble about a dB and a half by adding a 10 ohm resistor across the tweeter. Response was tuned flat before, but seems better balanced with the treble dropped slightly. Will see how it goes tomorrow (not too optimistic, as this isnt a crowd that has much fondness for horns)
  14. Grill cloth....hide the 'horn'.

  15. Well, since it's a DIY event, everyone is interested in what's in it. No, we didn't win anything, but it was a fun event. A lot of good sounding speakers this year, only a few that weren't listenable. Remarkable cabinetmaking on many that put mine to shame.

    Not much real listening can happen in 3min play per speaker set, and then it's not a room where waveguide advantages count for much -- side walls about 15' away from each speaker, so no near reflections to avoid. And a room packed full of people so that only maybe the main judges in front hear anything that might resemble an image. Quite a bit different from a medium or small living space with walls nearby and an intimate listening arrangement.

    It would be nice if there was a way to do a contest or demo like this in a situation that is more like home, but I think that wouldn't work for a large event. Guess the next best thing is to drop by each others' homes and hear what things sound like.
  16. Any thoughts on the impressions of the SEOS waveguide?

  17. I had no thoughts the speakers would place at all. My speaker cabinets were the only ones not painted or finished, and part of the grade is on appearance. :D But I was a bit disappointed with some things at the event. The music selection was not very good at all. 3 categories of speakers with a 3 minute sound clip (changed for each category).

    The category we were in had virtually no bass. One minute of 'classical', another 1 minute jazz clip, and then some lady singing with a bad voice. Not just that, but the listening volume for the last category was extremely low. The lowest of the bunch. They start by playing pink noise on each speaker to get the output to 85db. But then the CD they put in was recorded very low. And by the time the 2nd speaker has been played, they really can't go back and change volumes or they have to start the category over. I think those issues should be ironed out prior to the show.

    I also don't think they should allow 2-3 speakers per designer. Or allow them to enter the same speaker into multiple categories. It takes way to long. Pick your best speaker, and that's what you bring.

    8 hours with a 45 minute lunch break, two 10 minute breaks, and 30 minutes for Bill to talk about the Omnimic. We listened to some speakers at least twice.

    I also think they should have categories for skill levels. It's not as fun listening to novice speakers after or before some $3000 speakers done by guys in the field for 20 years. What's the point? There's zero chance to win anything and it just makes the new guys look funny. It's like taking your 8th grade science project to the national science expo.

    The event was nice, but with some small changes, it could be a lot better.

  18. Hi Bill, can you post the final XO schematic for this?

    I am looking to build a pair of these for outdoor duty (backyard cookouts, kids pool party, etc).

    I won't be using subs with them, so I think 3.5cf tuned to 24hz sounds about right.

    And what was the cab's dimension? Ports used?

  19. You could probably go a bit smaller and tune it a little higher. I think you would get a bit more kick tuning them up around 30hz or so. Especially for outdoor use.

    I can get you the enclosure dimensions later today if I get home. I'm dog and house sitting for a friend this week.
  20. Thanks Erich.

    If I can get it around 3cf, it wouldn't be even nicer. Easier to carry around, and probably a little easier to cut woods.

    I brought my OS speakers to my nephew's pool party yesterday and it was epic failure. :-[ Wasn't the right tool for the job.

    And we all agreed that I need to build some outdoor speakers. lol
  21. LOL!!! That's funny.
  22. Smokarz are you sure that you had the speakers aimed correctly? With the directivity that these speakers have they are able to be aimed at the listening position without bothering the neighbors too much.
  23. I think he brought his Overnight Sensations. I doubt the neighbours were the problem. I think the epic fail was that the poor little OS's couldn't party outside ;)

  24. Oops sorry I didn't catch the part about being the OS's. Must have been a case of not enough speaker for the application!

Share This Page