building 5.1 system with line arrays etc. Need help on Xovers, and Powering ribbons

Discussion in 'Home Theater Projects' started by Wade$K, Dec 10, 2005.

  1. Wade$K

    Wade$K Auditioning

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    Before I buy everything I want to make sure this is all possible and will sound good.

    I'm planning on builing line arrays with 16 toal 7" Dayton Ref mids so 8 per tower. I also plan on using 1 Fountek neo5i ribbon with each tower. I plan to power all the mids with a behringer ep2500. What do I power the ribbons with? For the center channel I plan on using 4 5" Dayton Ref speakers with 1 LCY ribbon. I was hoping I could power the center channel and the rears with the receiver. As for the rears I was thinking maybe another dayton 7 and a tweeter. I'm getting custom 15" subs built for me so I've got all that taken care of. I still haven't found the receiver I'd like to use. Want to spend upwards of $500. I'd like a 7.1 so I could upgrade later. Also I know I need custom crossovers but I have no clue on how to make them. Is there anyone that could design some for me. I could build them just not for sure on how to design them is the problem.

    This is going to be used for Movies, and Music. This will be my first diy ht system so please let me know if something isn't right. I just don't want to spend all the money on everything and then find out it won't work or something won't sound right.

    I know this is my frist post so if this is in the wrong section I'm sorry and move it to where ever it needs to go. Thanks.
     
  2. Wade$K

    Wade$K Auditioning

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    is there anyone that can help me out? I want to get this started but what you guys to tell me if it would work, and help me figure out what I could use to power the ribbons in the towers
     
  3. Rory Buszka

    Rory Buszka Supporting Actor

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    Crossover design is where the real work of DIY is involved. I'm only now starting to figure out how to design crossovers that simulate well, but simulating well and sounding good can be two totally different things, and a crossover that looks great on your computer's simulating programs may sound dull and lifeless in real life.

    There's much, much more to it than asking someone if they will design a custom crossover for you. Download Audua's SpeakerWorkshop. Spend some time learning to use it. Learn about FRD and ZMA files, and the SPLTrace tool. Do some research and design work yourself, don't expect others to do it all for you, or to simply dump the knowledge into your brain. In the end it's more satisfying, and you learn a lot. But this is your project, and you need to be the one researching, learning, designing, and building this thing. (And, quite frankly, it becomes annoying to constantly hear "Yeah, I want these sweet speakers but I have no idea how to design a crossover...will you do it for me?" 99.9% of the time, the answer is no.)

    I'm also quite surprised that you're going to spend so much money if this is just your first project. I imagine you just looked at the cover of the most recent Parts Express catalog and said "I can afford that -- I want that." It could very conceivably turn out like crap and then you'll be mad at us for the rest of your life. DIY is much more than money - there is a certain level of skill involved, which is only developed through learning and practice. Where you need to be beginning on your DIY quest is to build a design from a more experienced designer who has measurement equipment. Go on the Parts Express board and ask about designs using the RS woofers. Finally, buy a book. Buy Vance Dickason's Loudspeaker Design Cookbook which will teach you much about what is involved in the design of speaker enclosures and crossovers. In addition, Koonce and Weems' Great Sound Stereo Speaker Manual will give you more in-depth information on crossover design, in addition to the usual information about box building. Designing the box is the easy part.

    DIY is an amazing, highly underappreciated hobby, but it does take real work. And no one else will do it for you. This is not me just being mean as an 'initiation' of sorts -- this is me telling you how it is.
     
  4. Wade$K

    Wade$K Auditioning

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    I guess it came out wrong. I didn't want someone to design the crossover for me but get me in the right track on doing it. Like you just did. Telling me where I can go to learn how to do it. What program you use, etc. Also no I didn't just look at the cover and say I want that. Thats not the reason I'm building this.
     
  5. ThomasW

    ThomasW Cinematographer

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    The primary issue with the design is that you'll have a line array of midwoofer (good vertical dispersion) matched a single leaf tweeter who's dispersion will only be a fraction of that provided by the midwoofers.

    The best way to do this is combine a line array of midwoofers with a line array of the leafs as well. That of course means big $$$ investment in tweeters.

    Given the increase in sensitivity with multiple drivers, the EP-2500 is complete overkill for the midwoofers.

    To properly design a crossover one must measure the drivers operating in the baffles where they will be used. Generally speaking one can't use the mfgr's plots. That data is them imported into the XO design program.

    If you're never done anything like this before, I suggest you have one of the companies that does LEAP modeling design the XO for you...
     
  6. Wade$K

    Wade$K Auditioning

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    would the ep1500 be better for the towers? Should I power the fountek ribbon with the same amp as all the 7's?
     
  7. Wade$K

    Wade$K Auditioning

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    also could I get a behringer xover and use that on the towers instead of using a passive xover?
     
  8. ThomasW

    ThomasW Cinematographer

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    Why you think you need a power house prosound amp to power the midwoofers is beyond me. With that many drivers 150 watts per channel would blow you out of the room.

    And no you shouldn't use a generic XO unless you plan on running without baffle step compensation (not recommended)

    It's obvious from your questions that you really don't have much knowledge regarding loudspeaker design and engineering. I strongly suggest you copy a proven design by a known designer, or better yet buy a kit.
     

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