DIY Synergy/Unity spreadsheet

Discussion in 'Waveguides and Horns' started by BillWaslo, Apr 29, 2012.

  1. I have a couple of questions on the dimensioning of this using the components originally specified, i.e. the Aura et al.

    First, I assume the dimensions are as if the piece were flat. It is NOT dimensioned as it sits angled back in space, correct?

    Second, what are the dimensions I circled in green referenced to? Or is the hole and slot different on the left side?

    Attached Files:

  2. Hi Tom,

    Yes, all dimensions are as if lying flat.
    The 1.250 is distance from center of midrange mounting position to vertical (as shown) centerline of the board.
    The 1.650 measurement is from the topmost (as shown) edge of the board to the centerpoint of the two midrange drivers' mounting positions.
    The 5.475 is from the topmost edge of the board to the center of the woofers' mounting positions.

    If you haven't cut wood yet, I have a more recent spreadsheet to more easily cut the pieces and assemble the horn. It can (and probably should) have the ports and drivers in the same positions as the original. Progress on writing that all up has been shoved to a back burner due to life in general getting out of hand, and because the first ones I made have their ports where I thought they would work better -- but they don't! I don't know why. But if you want it, I can give you the spreadsheet and incomplete writeup, it can make nicer looking horns with quite a bit less effort.

  3. The green-circled dimensions are for center points of the drivers, I get it now.

    No wood cutting yet. See your PM for my email -or- post info here?
  4. Tom,

    The docs, such as they are so far, are at . New boards #6, 7, 8, are for connecting the main panels when gluing-up (they also stiffen the panels), or for making the back mounting surface so the completed horn can be mounted onto a flat baffle or frame.

    I had hoped to get this all together a long time ago, but time and health haven't been cooperative enough for me yet. But it shouldn't be difficult to see how it goes together. I also have some more photographs I took during build of the pretty (but not so well functioning) woodgrain horns. I can dig those out if anything isn't clear enought

    Good Luck,
  5. Thanks, this explains where Synergy Calc V5.pdf is located, as referenced on V5 spread sheet, which I downloaded earlier in this thread!
  6. Hi Bill,

    Thanks for posting this terrific project and writing up all the documentations.
    I am new to diysoundgroup. After a long hiatus from hifi, I am ready to get some splinters in my hands and to try out your synergy horn project.

    In reviewing the spreadsheet, I am confused about boards 6,7,8. Can you give more details or photos on how you use those boards. I think this will be helpful to anyone who plans to build the speakers.
    Also when setting the saw blade angles for the cuts, did you just use the angle gauge on the saw or did you have to use a more accurate setup rig?

  7. Regarding the above sealed build, can anyone estimate the frequency at which a subwoofer would cross over at?
  8. I finally decided to work on this past weekend. I only did about half the horn to verify fitup prior to cutting the rest of the pieces. It fit together pretty well, however, please note a few things:

    1. I used 3/4" thick material. The slots for the drivers are obviously deeper. For the large Aura NS6 drivers I cut a .1 inch deep pocket for the cone travel. The small Gento drivers have a .05 pocket. Because of the thicker material, I took some liberty with chamfering the speaker holes deeper but, in the case of the NS6, used a 60 degree bit so as not to take away so much material the gasket cannot seal.

    2. There is interference of the side slots to the top panel. I do believe I have the dimensions correct. Some of the pictures of this build do show some interference. It seems the side panel must be filed some? However, my "prior to filing" interfecence seems excessive compared to some pics here. Bill, how did you know where to put the slots?

    Attached Files:

  9. I finally managed to complete the PDF instruction document to go with the spreadsheet. It can be found at, specifically at

    This one shows how to use the new odd pieces shown in the new spreadsheet, and how to dry fit and assemble using only wood screws (and not duct tape or hot melt!). Sadly, the original woofers I used are NLA except at high cost, but there are some others suggested in the document for those comfortable with designing crossovers or who use MiniDSP or the like.

    Sorry for taking so long on this.

    TomLang -- sorry, I just now saw your post from last year! (In my defense, I had major surgery the month before and wasn't all that alert due to all the pain meds I was still on!). Anyway-

    I wouldn't have gone with 3/4" MDF. There is no need for it, the horn is extremely rigid with the 1/2" due to the structure, and it changes the port depths and makes it harder to get the midrange drivers in close to the tweeter.

    Sorry about the slot dimensions, they were taken from the front of the horn and adjusted as for the back. I think I have them right, but there might be a math error? I don't want to take my CoSynes apart to measure from the back. I redid them in the document, hope they are correct this time).

    The positions were determined using HornResponse and the spreadsheet, but essentially came down to arranging so the midrange holes are as close to the tweeter as practical (probably a problem with 3/4" board) and keep them within about 2" (or closer) of each other so they act like one driver up near crossover. I think that's where I went wrong on the newer woodgrain horn, I shoved the mid ports into the corners which moved them too far from each other. I'm still listening to the black MDF horns as those worked out better than where I put the ports in the pretty oak woodgrain ones.

    The woofer holes were checked with HornResponse, but are less critical as the horn doesn't really do much for the woofers other than allow them to be close in and surrounding the tweeter and midranges.

    I've got a new scheme afoot for the next CoSyne horn, but it will take a while to make a spreadsheet for that version and build it. Bigger, unfortunately, but better vertical directivity and better extreme HF dispersion. And should look neater. I think.
  10. Sorry I made a mess of my post, somehow I deleted some of the photos. Anyway, I look forward to your next incarnation, Bill, as other priorities bumped this build off the schedule.

    Can you give us a hint as to which drivers you will use so we can be looking for them?
  11. Excellent, thanks for the extra effort!

    Oh, that sounds tasty. Can't wait!!
  12. I made a new, rather crazy complicated, crossover for the CoSyne horns I've been using. The old crossover had one inductor and one capacitor fo the tweeter crossover. This one.... well, there are now 8 inductors in the tweeter crossover on this one! Woofer and mid crossovers are still simple though. All the extra parts for the tweeter were for an all-pass filter and some curve shaping put in to flatten the phase response and keep it nearer to 0degrees.

    Not sure it made much sound difference, I just have one channel set up with it so far. Guess I'll have to do the other channel to see how it sounds in stereo.

    Here's an unsmoothed response plot:

    And the impulse response (these are all from about 4ft from the baffle):

    And lastly, a sweep (100Hz to 4kHz) of a square wave played through the CoSyne:

    If you want to check square wave response on speakers you have available, here's the file I used:
    It works pretty easy with OmniMic, or if you have a decent microphone and an oscilloscope.

    The nice thing about Synergy horns is that when you get it to look decent for phase and amplitude, it is pretty much good throughout the whole coverage range (because it's point source). Not many speakers can do that.
  13. Im glad to see you are still tweaking these Bill.

    Ive studied your new guide, have sourced some high end Baltic birch and my build will start any day now.

  14. Great work Bill!
    I have been reading these threads since the unity builds and am planning to pull the trigger. If the Visaton drivers you mentioned were used would a passive crossover be similar to your CoSyne? Would minidsp be a better option to get them dialed in? (I have a few power amps) Would a straight minidsp with advanced, (biquad) filters be adequate or would a MiniSHARC using FIR filters be more suitable?


  15. Steve,

    Unfortunately about anything you change will make a difference in the crossover need (if you're looking for best possible, anyway). If you have a way to measure frequency response, then miniDSP would be the best way to get there. If you aren't overly concerned with linear phase "transient perfect", then the biquad should be fine -- I ran on those for quite a while, worked fine. If you do want linear phase and flattest possible response, then FIR filters would be best, but I can't guide you much on setting those up since I haven't gotten any FIR hardware yet (maybe in the coming year...).

  16. This pretty much looks like the coolest DIY project I've ever seen. Going to need to digest this one a bit.
  17. Hello everyone. I'm a first time poster and first time builder. I've been lurking on this thread since the beginning and have finally started to build.
    I want to thank bwaslo for the outstanding work he has done on this. You can really appreciate it when you start cutting material!
    I've got everything cut and ready to assemble and am now putting together my order for crossover components. Here is where the confusion sets in. I've put my order together but have some questions.
    I am assembling the crossover in Synergy Calc V5, also posted in reply 71 of this thread.

    Q1. Regarding the inductors, is 500uH the same as .5mH?

    Q2. The crossover calls for a 6uF cap. Parts Express has only 6.2uF available. Is this ok?

    Q3. Does wattage on the resistor matter? In the pic on this thread it looks like 5w is printed on the 5ohm. PE has only 10W and 12W now.

    Q4. There is one iron core and three air core inductors. It looks like from the picture that the Icore is the 2.0 mH inductor. Is that correct and does it matter?

    Thanks in advance for any help you can lend.

  18. I can answer a few of these, someone else will chime in with the rest I'm sure.

    Q1) Yes, It is the metric system where 1000 u (micro) is 1 m (milli) unit

    Q2) I don't believe it should matter.

    Q3+Q4) Better to ask the crossover designer.
  19. Q2 - 6.2uF would be fine.
    Q3 - You can always use larger Watt resistors, but not smaller. Unless you're beating the speaker, 5W will usually be ok -- 5W average power into an efficient speaker is REALLY LOUD.
    Q4 - On the big inductors (in series to the woofer stuff) you'll want an iron core to keep the series resistance down. Air core could work, but the inductor would have to be low gauge and huge to get the same low Rs.

  20. Thanks bwaslo and Sully. It's fun cutting all these crazy angles and winding up with a horn. Pure magic!

  21. Hello everybody, just found this thread and I'm really interested in building. I have a pair of the original Unity horns designed by Tom Danley and built by Nick McKinley from Lambda Acoustics, ohhh...maybe 2001. I was one of the first one (maybe the very first one) to build a system with those horns and with Lambda's TD15H (or X? can't remember). Amazingly good, but 13 years have passed and I'm itching to build something new. Looks like to "new" drivers to be considered are FaitalPro; I like them a lot I'm building now a Mini Econowave with their 8FE200 and it seems very well built. I would be interested to try the 3" 3FE22 with neodymium magnet, so lighter. Is there a strong argument on why the 2" (or 3") drivers must be mounted in group of two on the wider side of the horns ? If they could be mounted one per side (ala Unity) their exit could be brought closer to the compression driver.

    Thanks, Alex
  22. The only reason for the top+bottom mounting is because on a lot of asymmetric horns with ~90degrees horizontal, there wouldn't be enough room on the sides. It also makes horn cutting and construction easier.

    You could make it with a square mouth and fit drivers on all surfaces. You would have to cut more angles on top/bottom board to give enough surface on left+right sides. Or cut each of the boards to have one overlapped (angled) edge and one overlapping (not angled) edge, giving more room for drivers to mount (off-centered).

    I don't think the 3E22 drivers would be generally better than the 4" drivers Danley used, though. I wanted to use 2" or 3" so I could move the drivers closer to the throat, allowing use of a smaller HF driver (the Celestion) or the B&C DE5. I'd use a sealed-back 3incher with those if I could find one that seemed practical. Having drivers on top+bottom only on the 90/60 horns also allows the mid driver ports to be closer to each other (though less in the corners).
  23. Hi Bill.
    Must have been around the net twice before finding this thread! EXCELLENT!!! This is just what I have been looking for; a nearby complete guide to making a Unity horn! You are hereby officially my Horn Speaker Guru"! RESPECT!
    As I aim for a small PA like system, do you have any suggestions to what I should change to get a higher SPL and what do I do to meet a 12" front loaded sub horn? Wood working skills are OK. Have been building speakers since childhood. Electrical capabilities are also fine. Been experimenting with D-class amps and Mini DSP for a while now.
    My thoughts are going for a 1" comp. 4 pcs 4" and 2 pcs 8" drivers, to get the low end and SPL needed. ANY suggestions before doing claculations and making saw dust?

    Again; perfect build, and excellent pics!
  24. Hi Peter,
    Thanks for the kind words.

    For higher SPL, you probably wantpro style woofs. Don't worry about the mids, and use a tweeter that can handle low like DNA360, not the little Celestion I used. Mine does plenty of spl for home listening room but maybe not for a club. I'd normally say to skip the 12" front load horn, but since you're going minidsp, you can easily handle the delay issue (provided you can measure responses). Dsp will also make the crossover easy, as long as you can get enough response overlap (basically, get the mid ports close enough to the tweeter throat and to eaxh other), you can basically fix anything else in dsp.

    Remember, big is better if you want it to act like a horn into the 100s oh Hz.

    And multi-amped active crossed over you should be able to get the people a few streets over calling the police.

    Good luck

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