Closed Thread
Results 1 to 12 of 12

Reload Thread: fiberglass bookshelfs

  1. #1
    hoboham's Avatar
    hoboham is offline hanh



    Join Date
    Jul 2009
    Location
    Chicago, IL
    Posts
    41
    Post Thanks / Like
    Images
    8
    Mentioned
    0 Post(s)

    fiberglass bookshelfs

    So I have been working on a nice pair of bookshelf speakers for my girlfriends dorm room. i wanted to impress so im going all out.

    i picked up a pair of klipsch 6.5-inch IMG woofers, the grey ones
    a pair of the Dayton DC28FS-8 1-1/8" Shielded Silk Dome Tweeters
    and a pair of Port Tube 1-1/2" ID x 4" L Flared

    edit:
    13 by 11.5 by 8.5 so < .735 cu
    crossed at 2.2k


    so far i only have the wood done but id like to see if im headed in the right direction










    i braced the hell out of these, even got my girlfriend to stand on them .

    so next step is glass, maybe some sanding first. but any advice on making this turn out right?

    i have 2 small size aluminum fin rollers, brushes, premium 440, ton of chopped mat, and 5 yards of fishman mold fabric.

    but let me know what you think, its my first real project and i really want this to turn out
    Last edited by hoboham; 12-13-2009 at 05:01 PM.



    ____________________________

    12" Axis 2.5 cu. @ 32
    Hifonics 2610D

    bought from: woofercooker, OldOneEye, ssackett, PioneerSPL1990, k_schutte





  2. #2
    Captin Jack's Avatar
    Captin Jack is online now CarAudio.com Elite



    Join Date
    Jan 2008
    Location
    USA
    Posts
    541
    Post Thanks / Like
    Mentioned
    1 Post(s)

    Re: fiberglass bookshelfs

    those look like they will turn out nice

    what kind of airspace do you have going on there



    refs: HungNeckTight

  3. #3
    hempy's Avatar
    hempy is offline bass wiener



    Join Date
    Nov 2006
    Location
    nola
    Age
    28
    Posts
    700
    Post Thanks / Like
    Images
    1
    Mentioned
    0 Post(s)

    Re: fiberglass bookshelfs

    I like your organization methods. Looks like my workspace.

    I would have rounded over a lot more of the edges, but that's just how I do my stuff usually. I find fine edges are hard to keep fine, and I always wind up spending hours with teh bondo, but those are looking pretty clean as they are.




  4. #4
    SubNit's Avatar
    SubNit is offline can't use his mirrors



    Join Date
    Nov 2008
    Location
    3rd Coast
    Posts
    794
    Post Thanks / Like
    Mentioned
    0 Post(s)

    Re: fiberglass bookshelfs

    Looks like your off to a good start, pretty stoked to see how it's going to look when it's all finished. As for advice, stretch the fabric tight so that theres no sagging and just go for it. Judging by your woodworking skills and attention to detail I don't think you'll have a hard time

    How do you plan on finishing it? Is this your first glass project?




  5. #5
    hoboham's Avatar
    hoboham is offline hanh

    Threadstarter


    Join Date
    Jul 2009
    Location
    Chicago, IL
    Posts
    41
    Post Thanks / Like
    Images
    8
    Mentioned
    0 Post(s)

    Re: fiberglass bookshelfs

    hey thanks
    yea its a hell of a mess lol
    o and the crossover is at 2.2k

    yea they are 13 by 11.5 by 8.5 so .735 cu if it was a rectangle so im assuming less
    i think the port comes around 44, kinda low for bookselfs but i won hurt

    yea i was planning on it but then i got lazzy lol, and the edges look really nice from tests ive done, especially the triangle shape on the top



    ____________________________

    12" Axis 2.5 cu. @ 32
    Hifonics 2610D

    bought from: woofercooker, OldOneEye, ssackett, PioneerSPL1990, k_schutte


  6. #6
    hoboham's Avatar
    hoboham is offline hanh

    Threadstarter


    Join Date
    Jul 2009
    Location
    Chicago, IL
    Posts
    41
    Post Thanks / Like
    Images
    8
    Mentioned
    0 Post(s)

    Re: fiberglass bookshelfs

    yea ill be sure to stretch her out real good lol as always jk

    my only concern is attaching the fabric at first. I've seen everything from speed stick to hot glue lol so im not sure

    its going to be painted a teal-ish with possibly black carpet on the back and bottom.

    yea this is a first but definitely not the last, i bought enough supply's for 3 more at least lol



    ____________________________

    12" Axis 2.5 cu. @ 32
    Hifonics 2610D

    bought from: woofercooker, OldOneEye, ssackett, PioneerSPL1990, k_schutte


  7. #7
    hempy's Avatar
    hempy is offline bass wiener



    Join Date
    Nov 2006
    Location
    nola
    Age
    28
    Posts
    700
    Post Thanks / Like
    Images
    1
    Mentioned
    0 Post(s)

    Re: fiberglass bookshelfs

    No flush mount on the woofer as planned?




  8. #8
    hzsogood's Avatar
    hzsogood is offline **The Clean South**



    Join Date
    Nov 2005
    Location
    TX/MN
    Posts
    8,329
    Post Thanks / Like
    Mentioned
    0 Post(s)

    Re: fiberglass bookshelfs

    no flush mount? what kind of crossover you using



    Ref: Zeuslicious -



    2 DC lvl3 12's
    Memphis Mc-1000d
    46 hz 146.8 new TL

  9. #9
    hzsogood's Avatar
    hzsogood is offline **The Clean South**



    Join Date
    Nov 2005
    Location
    TX/MN
    Posts
    8,329
    Post Thanks / Like
    Mentioned
    0 Post(s)

    Re: fiberglass bookshelfs

    Quote Originally Posted by hoboham View Post
    hey thanks
    yea its a hell of a mess lol
    o and the crossover is at 2.2k

    yea they are 13 by 11.5 by 8.5 so .735 cu if it was a rectangle so im assuming less
    i think the port comes around 44, kinda low for bookselfs but i won hurt

    yea i was planning on it but then i got lazzy lol, and the edges look really nice from tests ive done, especially the triangle shape on the top
    nevermind... f'n computer is lagging



    Ref: Zeuslicious -



    2 DC lvl3 12's
    Memphis Mc-1000d
    46 hz 146.8 new TL

  10. #10
    PV Audio's Avatar
    PV Audio is offline The Vision of Sound



    Join Date
    Apr 2004
    Location
    Indy
    Age
    25
    Posts
    19,655
    Post Thanks / Like
    Mentioned
    0 Post(s)

    Re: fiberglass bookshelfs

    While I can give you points on originality, as far as the actual enclosure performance goes, it's going to be seriously lacking:

    1. Do not ever make a hifi speaker out of fiberglass if you can avoid it. It does not damp well enough at all and will almost certainly resonant at higher frequencies. You don't notice this in car audio because your main frequencies are low, but you're reproducing all audio octaves with these speakers and that will resonate. There is a reason why people build enclosure 1.5" thick walled all around. The enclosure is supposed to be an airspace, nothing more. It isn't even supposed to hold the driver in a conventional sense. In fact, people sometimes put floating washers on the mounting holes to isolate the cones from the enclosure itself. Vibration is bad.

    2. You're firing your tweeters and midrange at one another. Unless you're doing a Mirage type speaker which uses a omnidirectional dispersion pattern, this is going to be atrocious for imaging. Your tweeter outputs sound spherically, and it is going to diffract all over your woofer's baffle. More importantly. depending on your x-over point, you might end up with some serious beaming issues from your midrange and if your mid and tweet are firing at one another, you're going to get a lot of response holes.

    Perhaps you thought that it'd be a good idea to angle the baffle back because you've seen speakers like these:



    Notice that they are angled but the tweeter and midrange are at the same angle. Why do people do this? Well, loudspeakers have two things: a zero delay plane or ZDP and an acoustic center. On a normal loudspeaker, with just a simple first order butterworth x-over, you will have a response peak at a few degrees above the on-axis plane (ear level), or a few degrees below if you wired your tweeter/mids out of phase. That causes two things: time delay, and an on axis response that is angled away from the listener. The time delay is because your lower frequency drivers' ZDP is going to be behind the high frequency driver merely due to its size. That causes the response to peak at an angle towards the high frequency driver since the information from it gets to the listener later, and because of the off-axis response tilt, your "zero" plane will be a few degrees below whatever peak there is in output, and thus the on axis response will actually be angled towards the LF driver.

    By angling the baffle, you counter-act both of those. You can accomplish the same thing by using a crossover network like a Linkwitz-Riley alignment that accounts for that but otherwise, your speakers need to be resonating from the same ZDP (the exact same plane) and need to have the same acoustic center (where the "center" of the sound appears to be from the loudspeaker). The further apart they are on the baffle vertically, the more angles between the tweeter and midrange and the distance between the two drivers as far as depth (tweeter on baffle, woofer mounted behind baffle for an example), the more issues you'll have.

    I'm sorry if that doesn't make sense, but unless you want me to get into crossover theory, then I think that's the best that I can do




  11. #11
    hoboham's Avatar
    hoboham is offline hanh

    Threadstarter


    Join Date
    Jul 2009
    Location
    Chicago, IL
    Posts
    41
    Post Thanks / Like
    Images
    8
    Mentioned
    0 Post(s)

    Re: fiberglass bookshelfs

    naw sadly no flush mount i made the rings in such an order that getting the flush mount centered would be impossible
    unless there is a bit that can cut the shape i need, might be

    yea that makes sense, ah i wish i would have talked to you earlier, i was focused on static structural support, looks and at least an expectable level of performance.

    im not to worried about imaging issues manly because its going to be used in a dorm room, placed were ever it is most convenient. and definitely slightly more "show" than "go"

    it ***** that the tweeter is going to sound even worse because as it is it really doesn't fit my tastes, but it has me interested to hear more on good imagining techniques. i know from ele that as you go higher in frequency factors once negligible become very important and i have only heard bits and pieces.

    so one effect of slanting the hf is to add distance, therefore the phase would lag but in such a way to be in time with the LF, makes sense, but are there any other implications that i am missin?

    o i did the Linkwitz-Riley alignment but i couldn't do a Zobel network because i have no parameters on the woofers

    and i wouldn't mind getting into crossover theory i am studying to be a mechanical engineer but my favorite class has been circuit design go figure

    o and i really appreciate the input honestly i would have never considered all of these factors, really glad i posted



    ____________________________

    12" Axis 2.5 cu. @ 32
    Hifonics 2610D

    bought from: woofercooker, OldOneEye, ssackett, PioneerSPL1990, k_schutte


  12. #12
    Blue Fury's Avatar
    Blue Fury is offline Quagmire's Chin



    Join Date
    Aug 2008
    Location
    Fresno Area, Ca
    Posts
    2,344
    Post Thanks / Like
    Mentioned
    0 Post(s)

    Re: fiberglass bookshelfs

    Quote Originally Posted by hoboham View Post
    naw sadly no flush mount i made the rings in such an order that getting the flush mount centered would be impossible
    unless there is a bit that can cut the shape i need, might be

    yea that makes sense, ah i wish i would have talked to you earlier, i was focused on static structural support, looks and at least an expectable level of performance.

    im not to worried about imaging issues manly because its going to be used in a dorm room, placed were ever it is most convenient. and definitely slightly more "show" than "go"

    it ***** that the tweeter is going to sound even worse because as it is it really doesn't fit my tastes, but it has me interested to hear more on good imagining techniques. i know from ele that as you go higher in frequency factors once negligible become very important and i have only heard bits and pieces.

    so one effect of slanting the hf is to add distance, therefore the phase would lag but in such a way to be in time with the LF, makes sense, but are there any other implications that i am missin?

    o i did the Linkwitz-Riley alignment but i couldn't do a Zobel network because i have no parameters on the woofers

    and i wouldn't mind getting into crossover theory i am studying to be a mechanical engineer but my favorite class has been circuit design go figure

    o and i really appreciate the input honestly i would have never considered all of these factors, really glad i posted
    You're thinking that these need so much consideration in that area. They look nice tho



    ***My build: 2 SSA Xcons, Sundown, Vifa, TB, Hertz, 880prs, etc.***
    http://www.caraudio.com/forum/showthread.php?t=359675

    CA Refs: bought from: Jacka, bones22, civicman07, Zeuslicious, 90accordman, DesertDawg(<---EXCELLENT seller)
    Sold to: 97accordalpine, Jgyolai, brenTgrillzem, nicksredline, lantz, bagged97tacoma, Plottin4success, microhaxo
    ROE Refs: Bought from delvryboy, jnralp00, dcmcki, Mxman38, Excessive Amperage, GoinDef154, blackdragonx118, Assman.

    Currently For sale: Everything

Closed Thread

Posting Permissions

  • You may not post new threads
  • You may post replies
  • You may post attachments
  • You may edit your posts

1e2 Forum