Possible to recreate the sound of Magnepan speakers with DIY?

Discussion in 'Archived Threads 2001-2004' started by SteveEdwards, Mar 13, 2001.

  1. SteveEdwards

    SteveEdwards Agent

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    I've been exploring the idea of trying to recreate the full, detailed sound of Magnepan speakers without sacrificing the loud volumes, bass, and dynamics I'm accustomed to. Would it be unrealistic to think I could build a speaker that would have similar charactoristics to a Magnepan speaker if I used a vertical array of mid-woofers and small planar tweeters? Some mid woofers have excellent transient response and detail, yet still have dynamics and bass extention. Scan Speaks 7" Kevlar woofers come to mind; I own Avance speakers with these and think they are excellent. Still, I enjoy the incredible presense of Megnepan speakers, and was wondering if it was possible to recreate this without sacrificing the house-shaking party type volume I sometimes crave. Also, being a college student, the Magnepans look too fragile [​IMG]
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    -Stretch
    "I want good sound for cheap."
     
  2. SteveEdwards

    SteveEdwards Agent

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    ...or instead of the scan speak driver (which has an Fs of 22Hz I forgot to mention), I could use Vifa drivers. Right now Madisound has a 6 1/2" woofer on sale for $18! I could buy 8 per speaker at that price, and distribute them over 6' towers. That'd give a "big" sound, but do more mid-woofers bring more detail?
     
  3. JerryD

    JerryD Extra

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    I suggest you check out Newform Research. They have a ribbon technology speaker that many compare favorably to the Maggies and they do offer them as kits. They do have quite a backlog of orders though.
    http://www.newformresearch.com/
     
  4. Mark Hayenga

    Mark Hayenga Supporting Actor

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    You might try some RD75s crossed over to some 8-10" woofers at 2-300Hz. That would run you about $600 in drivers per speaker.
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    Mark Hayenga
    www.hayenga.com
    ----------------------
    "Saru mo ki kara ochiru"
     
  5. Alan Ross

    Alan Ross Agent

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    Newforms are monopolar, Maggies are dipolar. Your best bet are BG planar drivers. More information here http://f24.parsimony.net/forum54306/
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    Best regards,
    Alan
     
  6. SteveEdwards

    SteveEdwards Agent

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    Ouch, $600 for drivers per speaker is expensive! The scan-speak drivers were the upper end of my budget (as would be the Magnepan MMGs), at about $500-$600 total. Anything cheaper would be very warmly welcomed [​IMG]
    Again, I'm a college student! Money is very precious, but I also know good sound doesn't come cheap. Still, thanks for the suggestions, I at least like knowing what's out there, at any price.
     
  7. SteveEdwards

    SteveEdwards Agent

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    Also, monopolar speakers are probably the way to go with me, as speaker placement will not be very flexible. They'll probably have to go up against or close to a wall.
     
  8. Alan Ross

    Alan Ross Agent

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    Well Steve, a great deal of Maggie magic has to do with diporal radiation and subsequent lessening of side wall reflections. Since you stated that you are trying to recreate Magnepan sound, I feel dipolar is a must. A monopolar line source can sound excellent, but it would not sound like a Magnepan.
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    Best regards,
    Alan
     
  9. SteveEdwards

    SteveEdwards Agent

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    I was under the impression that the trademark sound of the Maggies was derived mostly from the sheer size and quickness of ribbon/planar drivers and not necessarily from it being dipole.
    I will assume then that I cannot build such a speaker within my budget. I cannot find the BG drivers for sale, but did find something about the DIY discount being over [​IMG]
    Any idea how the Hi-Vi planar drivers [1] [2] on sale at PartsExpress sound? They're very cheap, albeit only up to ~5" long or so. That's still much bigger than a regular dome, though. And while I'm sure they'll have a different sound than Maggies, but maybe share at least a few of the charactoristics I liked. Browing PartsExpress, I'm thinking I could design something with one of the above planar tweeters, dual Dayton 2" dome midranges, and dual Vifa 6.5" woofers-- mid tweeter mounted, 5' tall. It'd come to $342 for the drivers alone- cheap!
     
  10. ThomasW

    ThomasW Cinematographer

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    Sorry to be the spoiler but you can't create the sonic charateristics of a dipole planar with line array of cones. Also you can't use line arrays of dome tweeters. There are too many problems with comb filter effects due to the dome being a point source
    Nor can you get the SPL's to fill the neighborhood with Maggies or the B&G planars.
    So if you need high SPL's, go with a cone line array and use the Stryke leafs for the best value for the money. Use at least 8/side of the $25 model # RTW2
    [​IMG]
    If you want the best quality sound then get some Maggie MMG's and add a sub
     
  11. SteveEdwards

    SteveEdwards Agent

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    ThomasW: I was told you were the man to talk to [​IMG]
    I checked out your related posts on HTGuide. Thanks for the heads up on the Stryke drivers, those are a steal! I hope those preorder prices last a bit longer, as I haven't really made up my mind just yet. I'm leaning towards DIY rather than the MMGs just because that's more fun [​IMG]
    Thanks again! Any further advice appreciated, and good luck with your very impressive projects!
     
  12. Hank Frankenberg

    Hank Frankenberg Cinematographer

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    Steve, you're correct about your assumption of the Maggie sound quality being mostly from their quickness. Also line source. I hope folks don't dismiss the Newform Research monopoles - I'm considering them for a D-I-Y project. I believe their design will make for much less sensitive placement than dipoles, while retaining the benefits of: line source, wide soundstage, "quickness", narrow vertical dispersion, etc.
    ThomasW: any new projects in the works?
     
  13. ThomasW

    ThomasW Cinematographer

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    Hi guys
    The latest project under development is a clone of these
    [​IMG]
    Am using 8-8" Etons/side, combined with the B&G RD75's. Will be adding 12 leaf tweeters (or the Stryke planar tweeters) to augment the HF response. Prototype will be operational by mid April
     
  14. SteveEdwards

    SteveEdwards Agent

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    That brings up a few questions:
    1) Why 8 drivers? Is this because they have little verticle dispersion, or is this only to reach high SPL's?
    2) Could I make a line array of the Styke planars on top of just one or two woofers, similar to a Newform Research speaker? I noticed the Newform ribbons go down to 1khz, the Stryke's to 2khz. Could I make a budget Newform?
    3) In a line array, do the drivers have to be physically as close together as possible, or could they be spaced out slightly?
    Given what I've learned, I'm now considering keeping my Avance speakers for HT/parties and building new bedroom speakers instead, so SPL's will no longer be an issue.
     
  15. Hank Frankenberg

    Hank Frankenberg Cinematographer

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    ThomasW, I predicted a substantial project, and you haven't let me down. WOW! [​IMG] That's a project!! I know better than to ask this, but will it be your ultimate speaker?
     
  16. Bob Sorel

    Bob Sorel Stunt Coordinator

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    Whoa, ThomasW, that is one ambitious project! I assume that you are going to use these with your famous 12 dancing Shivas, right? The combined system just might be the very most awesome setup on the face of the Earth!!
    If you get a chance, or the inclination, could you share a few of the details of this project with us?
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    STOP DVI/HDCP/5C/DFAST!
     
  17. John E Janowitz

    John E Janowitz Second Unit

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    Steve writes:
    "That brings up a few questions:
    1) Why 8 drivers? Is this because they have little verticle dispersion, or is this only to reach high SPL's?"

    Well, I am actually using 12 of the SA071's in a similar project here. There are a few advantages to multiple midbass drivers. First, to eliminate most of the problems with vertical reflections you need to approximate an infinite line source. This means going floor to ceiling. A short line will not have the full advantages of controlling the vertical reflections. For information on this, see Roger Russell's patent.
    Secondly, is the issue with overall output capability. If you plan to use a subwoofer, this will be less of an issue. However with my lines using 12 7" drivers, many people will not need a subwoofer. A total of 24 7" drivers in the front will move about as much air as 3 good 12" woofers. The extra displacement of multiple drivers will allow you to EQ the bottom end if necessary. Even if used with a subwoofer, you will want to have multiple drivers to reduce distortion. For example 12 drivers moving 1mm each will have much less distortion than a single driver moving 12mm. If used as a dipole, or monopole, basically any situation where your baffle is not infinitely large, you will also be losing 6dB on the low end due to the baffle step as in any speaker. Multiple drivers will help to make up for this loss much easier.
    "2) Could I make a line array of the Styke planars on top of just one or twowoofers, similar to a Newform Research speaker? I noticed the Newform ribbons go down to 1khz, the Stryke's to 2khz. Could I make a budget Newform?"
    You could do something like this. I do have someone working on a similar project with 4 RTW2's and 2 7" drivers. This will not give the benefits of a true line array, but should still work very well. The only issue is that the 7" will have difficulty keeping up with the RTW2's. You can pad down the RTW2's if necessary.
    "3) In a line array, do the drivers have to be physically as close together as possible, or could they be spaced out slightly?"
    You will want to keep the drivers, especially the tweeters as close together as possible to eliminate problems with high frequency rolloff, and comb filtering. You can check out this post i did over on the HTGuide forum for info on calculating where these effects will begin:
    http://www.htguide.com/CFBoards/inde...estTimeout=500
    With the RTW2's you will not have problems with comb filtering and high end rolloff the same as you would with a point source tweeter. They are a much better option for this type of application.
    "Given what I've learned, I'm now considering keeping my Avance speakers for HT/parties and building new bedroom speakers instead, so SPL's will no longer be an issue."
    What is your listening position like? are you very close to these drivers, or farther away? If you are very close to the speakers, a short array would probably work well.
    John
     
  18. ThomasW

    ThomasW Cinematographer

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    Hi guys
    Well John J. did good job explaining the basics behind line arrays, also he's got some good info on them on the Stryke site.
    As for my particular project 8 drivers are being used because that's the number of drivers that will equal the height of the B&G RD75. Initially the 8"s will will be tried in a free-air/dipole configuration to mimic the dispersion of the B&G's. Now this may not work, so if there are problems then a sealed column willl be used.
    There should also be a tall array of the leaf/planar tweeter due to the limited vertical dispersion. Also I'll probably have a few rear firing tweeters for ambient fill.
    IMO leafs/planars should be crossover one octave above their rated lowest frequency. This is just a safety measure to prevent overdriving the unit.
    Hank
    Yes this will probably be the last big project for quite a while [​IMG]
    Bob Sorel
    Yes the idea is to definitely to use the big IB with these speakers. I do have 2 of the HE15's and 6 PR's on order if I need "portable" subs
    There is additional info HERE and HERE regarding this project
     
  19. SteveEdwards

    SteveEdwards Agent

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    John, the speakers will either go in a very small rectangular bedroom or in a small (17x15 optimistically) living room. However, my listening position will be all over- sitting, standing, or laying, on couches, floors, or chairs. Not only that, but every year I live in a different townhouse/apartment- that's college life.
    I think 6 Stryke Planars would do it, covering about 36" of 'space'. I'm not sure what I'll do about woofers just yet, but that'll be the easy part I'm sure.
    One last question (since you've all been so helpful): could I use a dome rear-firing? It'd have maximum dispersion for minimum cost, and comb filtering effects shouldn't be an issue for rear-firing. Right?
    Thanks for all the help guys!
     
  20. ThomasW

    ThomasW Cinematographer

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    Steve
    Yes you could use a dome tweeter as a ambient fill rear. But it would require a completely different XO design from the Stryke planars. It might be better to just use a couple more of the Strykes/side, then they could simply be included in the XO design for the front firing ones.
     

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