Speaker Building Questions.

Discussion in 'Archived Threads 2001-2004' started by Jason Bosch, Dec 14, 2002.

  1. Jason Bosch

    Jason Bosch Agent

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    Hi everyone. I'm new to this kind of thing so I had a few questions. I apologize if they are asked all the time and I didn't find them when I searched.
    1. I'm curious if guys think it would be possible to make a speaker system similar to the old Polk SRT system. here's a link. Polk SRT System I'm sure I could build cabinets similar to them. The 2 problems I would have is finding drivers and actually designing the box to make them sound great. And getting the crossovers to mate perfectly with them. The originals had kind of a cascading crossover in that certain drivers would reproduce only certain frequencies. Anyways I know this one is alittle far fetched... I just wanted to get some of your opinions.
    2. I was wondering if it were possible to build something as good as say a Vienna Acoustics speaker like the Beethoven or Bach. From what i've seen most people here make thier speakers out of MDF. Can you use true wood like Oak or Cherry? This same question I have in regards to the subwoofer. I'd like to make something similar to a REL. I love the look of real furniture grade wood. Also do any of you know where to find great silk dome tweeters? I love the smooth, warm non fatiguing sound of silk vs. metal domes. Are there any other dealers for great equipment for building speakers besides Parts Expess?
    Thanks in advance for replies.
     
  2. Greg Monfort

    Greg Monfort Supporting Actor

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    >1. I'm curious if guys think it would be possible to make a speaker system similar to the old Polk SRT system.
    ====
    With enough experience and the proper measuring tools you could do it and have it sound good, but you can probably buy them used for less than the cost of Lspcad pro and a TEF machine (or equal). Then there's the steep learning curve and component prices..... The XOs alone would set you back hundreds.
    Best to tackle an easier project unless you're willing to get way serious about learning all aspects of speaker design.
    ====
    >2. I was wondering if it were possible to build something as good as say a Vienna Acoustics speaker like the Beethoven or Bach.
    ====
    A Bach 'clone' looks like a good beginner's project assuming it's just a two way, though obviously whatever you should build won't have the same sonic signature unless you build an exact copy.
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    > From what i've seen most people here make thier speakers out of MDF.
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    Yeah, but mechanically, void free plywood such as Baltic Birch is far superior for a given thickness.
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    > Can you use true wood like Oak or Cherry? This same question I have in regards to the subwoofer. I'd like to make something similar to a REL. I love the look of real furniture grade wood.
    ====
    Small cabs are fine, and certain hardwoods can be used in larger cabs, but building a proper cab and using real wood or veneer is best left to a cosmetic covering, especially a sub.
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    > Also do any of you know where to find great silk dome tweeters? I love the smooth, warm non fatiguing sound of silk vs. metal domes.
    ====
    I don't keep up with the consumer/DIY components for the most part so I'll let others make recommendations.
    ====
    >Are there any other dealers for great equipment for building speakers besides Parts Expess?
    ====
    Well, I don't know that any of what any of them sells qualifies as truly 'great', but in the same vein there's Madisound, Sound Clearing House, Speaker City, Adire, Martin Sound Products. There's probably others, but none come to mind at the moment.
    E-Speakers sells 'great' components IMO, but are for the most part much more expensive.
    I've never bought from them, but since you're ~local, there's Audio Lab of Ga. ~just up the street from me. http://www.mindspring.com/~audiolab/
    GM
     
  3. Dave Milne

    Dave Milne Supporting Actor

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  4. Jason Bosch

    Jason Bosch Agent

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    Hey thanks for the replies. I'm new at this so I didn't know you could do that for the furniture grade look. I have a bunch of ideas rolling around my head right now. Still researching to see if any of them are feasible for me to do. Has anyone built a powered tower? I was thinking that it wouldn't be too hard to make one. I'm probably way off however. What I was thinking is building a cabinet which has a completly sealed top section like the size of a good bookshelf speaker. In it i'd put 2 5.5" Mids and a 1" tweeter in the D'appolito configuration. And on the lower section using 2 7" woofers and mounting a 120 watt amp on each towers side. Do you think this would be as easy as it sounds? Wouldn't you just need to figure out the nessesary airspace for both chambers, get a 2 way crossover at like 3000 hz (depending on drivers of course) to seperate the top end wire them series-parallel-series. To get an 8 ohm load from 3 8 ohm drivers. Then on the bottom just hook those up in series for a 4ohm load for the sub amp. I'd probably go sealed for bass tightness and simplicity. Drivers i'm thinking of from what research i've done are Scan- Speak 7" Mids cuz from the specs and look of em the can go to the 30 hz range. Mids would probably also be Scan Speak unless i thought something cheaper like from Vifa would blend well. Not sure on the tweeter either since what I really want is a nice smooth, warm and detailed sounding silk tweeter. Only one i've found is Vifa and it's 6 ohm which i think wouldn't work well. Another think i was thinking is with a 3 way crossover it might be possible to use those drivers in a unpowered speaker. I'd imagine it would be very power hungry though. Then it would kind of be like the Beethoven. Anyways i'm sorry about the long post. Any opinions on this would be great.
     
  5. Brian Fellmeth

    Brian Fellmeth Supporting Actor

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    Do not choose a group of crossovers and try to design a crossover for them. Find a tweaked design and copy it. Scanspeak also makes outstanding silk dome tweeters- the 9000 series. In my opinion, the best silk dome tweeter in the world is the Hiquiphon. These links have some designs you might want to consider :
    Dillon
    Dave Ellis
    Dennis Murphy
    There are many, many others. Most are 2 ways since a good sounding 3 way is immensely more difficult to pull off. Your best bet is to make 2 way bookshelves and make a sub.
     
  6. Greg Monfort

    Greg Monfort Supporting Actor

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    >Has anyone built a powered tower?
    ====
    Well, I've done some bi and tri-amped systems, including towers, but never actually stuck the amp in the cab.
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    >I was thinking that it wouldn't be too hard to make one.
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    Depends on how you go about it.
    ====
    > I'm probably way off however. What I was thinking is building a cabinet which has a completly sealed top section like the size of a good bookshelf speaker. In it i'd put 2 5.5" Mids and a 1" tweeter in the D'appolito configuration. And on the lower section using 2 7" woofers and mounting a 120 watt amp on each towers side. Do you think this would be as easy as it sounds?
    ====
    Pretty much, IF you copy a proven MTM design for this portion of the speaker as Brian suggested and maintain this width/depth down aways, then you can alter it to get the required Vb for the LF. Also, the MTM ideally needs to be ~flat down to ~80Hz to keep the XO simple. Above this point driver selection and XO point/slope becomes much more critical, increasing with increasing frequency.
    ====
    > Wouldn't you just need to figure out the nessesary airspace for both chambers,
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    Yes.
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    > get a 2 way crossover at like 3000 hz (depending on drivers of course) to seperate the top end wire them series-parallel-series. To get an 8 ohm load from 3 8 ohm drivers.
    ====
    Hmm, the completed MTM would normally be nominally 4ohms and dual series is 16, or nominally 3.2ohms in parallel. All in parallel, ~2ohms. Connecting the MTM in series with anything will affect its performance due to inductance summing, so it's not a good plan IMO. Anyway, crossing over low means active XO and bi-amping for best performance overall.
    GM
     
  7. Brian Foley

    Brian Foley Agent

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    Check out this site for a good overview of DIY speakers (drivers, kit vendors, etc.):
    LDSG Index
    The two Vienna Acoustics speakers you mentioned use Scan-Speak tweeters with Seas mid-woofers. I can't think offhand of any well known kits or speaker designs that use this combination, but you would probably be happy with any number of kits that use Scan-Speak, Vifa, or Hiquphon tweeters.
    FWIW, I just recently finished assembling 5 of the North Creek Borealis kits, and they sound fabulous, even with my mid-fi Pioneer Elite receiver. It uses the same Scan-Speak tweeter used in the VA speakers you like, along with a well regarded Scan-Speak mid-woofer.
     
  8. Jason Bosch

    Jason Bosch Agent

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    Well hey thanks for the answers guys, I appreciate it.Looks like it's harder than i thought to be able to wire them, and it looks like i'll probably run into cross over difficulty. Probably not a good project for a beginner. I figured I was wrong with the impendences.... I never was very good with ohm law. I'll just keep doing research on the subject to see if i can figure this stuff out. I think i'll try for a 2 way with the scan speak drivers and the silk tweeter you guys mentioned. Thanks again guys.
     

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