Noob needs some help!

Discussion in 'Home Theater Projects' started by Derek*M, Jan 21, 2006.

  1. Derek*M

    Derek*M Auditioning

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    Hey guys im new to the whole home audio scene if you could call it that, but have been doing car audio for a while so I know a thing or 2. For my first project I wanted to start out by making a set of bookshelf speakers. I was wondering what you guys thought of these drivers...

    Since it wont let me post links yet the tweets are on madisound and the part number is PL27TG05 1" Textile dome tweeter. and the mids are on parts express the part number there is 295-360 DAYTON RS125S-8 5" REFERENCE SERIES SHIELDED WOOFER. Sorry about that but if you go on both of those websites and search for that im sure that what I am looking at will pop up.

    If you dont feel that those are a good match or for any reason feel that I should not get them feel free to let me know. I am open to opinions on any aspect of this project!

    I dont really want to spend a whole lot of money on this project because it is my first and I am on a college budget. I do have a 2ch reciever that I am going to be powering them with it puts out 105 watts per channel.

    I also know that I am going to have to bulid a crossover for these which I have never done before, if you guys could give me a site that would have some info on building one that would be great.

    Thanks in advance for any help!!!
    Derek
     
  2. ThomasW

    ThomasW Cinematographer

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    Go with someone's proven design. This is a totally different world than car audio.

    What's the budget?
     
  3. Wayne A. Pflughaupt

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  4. Derek*M

    Derek*M Auditioning

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    I really dont want something pre built. The only reason that I want to do this project is so that I can learn a thing or 2 about home audio. This summer I plan to build an entire 5.1 system, but I wanna start small with something like this.
     
  5. ThomasW

    ThomasW Cinematographer

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    Budget?

    To get an idea as to what's involved in the proper design and engineering of a small 2-way, read the first post in this thread. You'll note this is a little more involved than car audio...:wink:

    http://www.htguide.com/forum/showthread.php4?t=13154
     
  6. Derek*M

    Derek*M Auditioning

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    Well I already bought a few things but I would say my budget would be around 200 for drivers and such...
     
  7. ThomasW

    ThomasW Cinematographer

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    $200 for what, per speaker, per pair?

    Generic crossovers work in a car, they don't work for home audio.

    Here's what's involved in designing a crossover. First you need to take driver measurements in the boxes you're planning on using. Then import that data into a design program. Next factor in baffle step compensation and any zobel networks needed. Now build the first version of the XO and redo all your testing. Now make the needed adjustments to the design and remeasure the performance again.

    To make the speaker measurements you'll need a DMM, a testing jig, a mic, mic preamp, a computer with a duplex soundcard and appropriate software. To design the crossover you'll need a program like Crossover Pro, LspCAD, SoundEasy, etc. These start at $70 and go up to several hundred dollars. There's a free Excel based spreadsheet for designing XO's it's available HERE
     
  8. Derek*M

    Derek*M Auditioning

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    That would be 200 for everything. Is there really that much involved in building a crossover? I wouldnt even know where to start with any of that. Is it dificult to do?
     
  9. ThomasW

    ThomasW Cinematographer

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    In your subwoofer thread you said you have M&K S100B's. If that's the case forget about building speakers until you have saved up more money. For $100/speaker all your going to be able to build is the cheapest and lowest quality speaker around. And there's no point since you have much better speakers than that already
     
  10. Derek*M

    Derek*M Auditioning

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    I didnt post a subwoofer thread... but I have already purchased the mids I just need some tweets to go with them I cant post links yet, but if you would like to see them I could email you a link to them. Thanks for your help!
     
  11. ThomasW

    ThomasW Cinematographer

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    Sorry there are DerekM and Derek*M posting in this forum.

    It's getting old when you don't post specifics. I could careless about a link, how about the make and model number of the driver?

    If you bought the Parts Express RS-125 you mentioned in your first post, then return it. It doesn't have enough Xmax or radiating area.

    And unless someone has already designed for any driver you buy, you're screwed unless you can run measurements or want to pay someone like Madisound to run a LEAP design for you.
     
  12. Derek*M

    Derek*M Auditioning

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    I really dont understand what you are saying. Im not trying to go all out here and build a world class set of speakers I just want something that is going to sound good and that I built myself just so that I can learn a few things about home theater.

    Maybe you could recomend some relatively cheep drivers that I could use, and by that I mean 200 for tweets and mids...

    Thanks for your help.
     
  13. ThomasW

    ThomasW Cinematographer

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    And the brand and model number of the driver you bought is.....?
     
  14. Derek*M

    Derek*M Auditioning

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    DAYTON RS125S-8 5" REFERENCE SERIES SHIELDED WOOFER

    I bought them off of parts express...
     
  15. ThomasW

    ThomasW Cinematographer

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    . Okay here's my opinion....

    Regarding the RS-125S, as I said in my earlier post these are not suitable to be used in a 2-way HT system (they're probably okay as computer speakers when you're sitting 3' away). They have to high a Fs (resonant frequency) and not enough cone movement (Xmax). In a HT setting you'll blow them up in a week, since they're so small and can't move enough air.

    PE has a very liberal return policy, if the drivers haven't been mounted or soldered. So for not that much more than you paid for the RD125, you can get the RS-180 which is a significantly better driver for HT use.

    BTW, this has nothing to do with building a high-end system. This is common sense, you don't use a 2 cylinder engine, when you need a 6 cylinder motor.
     

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