Speaker Cabinet Material

VR3
VR3 Posts: 28,774
edited September 2004 in Speakers
As most all of you know, I have set out to replace my Pioneers cabinets...

WELL

The school gives us plywood, free! from 1" thick to 1/8" thick...

So for DJ speakers, that will be used mostly in the den, will 3/4" plywood work fine??

Since wood is free, here is what i have decided on...

2 - 2" ports, 1" deep (box builder suggested)
1.25 Pounds of polyfill per speaker
Tuned to 34 hz, -3DB is 37hz
Internal Dimensions - W: 15", H: 36", D: 20"
- Not Tom ::::::: Any system can play Diana Krall. Only the best can play Limp Bizkit.
Post edited by VR3 on
· Share on FacebookShare on Twitter

Comments

  • Mjr7531
    Mjr7531 Posts: 856
    edited September 2004
    Plywood is fine, you just have to make sure that it is a high grade of Plywood, around 'a' (That's highest right?) Otherwise the plys will rattle.
    · Share on FacebookShare on Twitter
  • RuSsMaN
    RuSsMaN Posts: 17,986
    edited September 2004
    Flip the mids and tweets, or do them side by side, mirror imaged.

    Maybe run the tweet free-air on top of the cab, in a psuedo time-aligned array.

    Cheers,
    Russ
    Check your lips at the door woman. Shake your hips like battleships. Yeah, all the white girls trip when I sing at Sunday service.
    · Share on FacebookShare on Twitter
  • VR3
    VR3 Posts: 28,774
    edited September 2004
    May I ask to the advantages? Or...are you joking? lol
    - Not Tom ::::::: Any system can play Diana Krall. Only the best can play Limp Bizkit.
    · Share on FacebookShare on Twitter
  • RuSsMaN
    RuSsMaN Posts: 17,986
    edited September 2004
    Why even rebuild them, if they are going to be essentially the same as they are now?

    Just thought you might want to build 'outside the box'.

    Cheers,
    Russ
    Check your lips at the door woman. Shake your hips like battleships. Yeah, all the white girls trip when I sing at Sunday service.
    · Share on FacebookShare on Twitter
  • VR3
    VR3 Posts: 28,774
    edited September 2004
    Ah!

    Well, they arnt the same...

    The current cabinet is 11" deep...

    And uses Spring Clip connectors...

    I plan to use gold plated binding post (similar to the LSi line) and the stock crossover, dont wanna mess with an aftermarket crossover...want to keep the cost down...

    I wanna rebuild them because the current ones look like crap....it was the first time I had made a grill and put on Vinyl wrap...
    Hmm....dunno, the Pioneers sound actually pretty good the way they are configured now...I wouldnt want to mess with the design that sounds *ok*

    Volume Of Cab - 6.25
    PE Part Number - 290 105 (woofer)
    Internal Dimensions - 15x36x20
    Tuning Frequency - 34.93
    Vent diameter - 2" - 1" deep
    Fill - 1.25 pounds

    http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=269-919
    Port Tubes - x4
    .30 x4 = 1.20

    http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=270-034
    Tweeters - x2
    5.00 x2 = 10.00

    http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=260-317
    1 Pound Polyfill - x2
    10.00 x2 = 20.00

    http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=260-309
    Gold Plated Terminals - x2
    4.00 x2 = 8.00

    http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=260-335
    Grill Cloth - x1
    7.00 x1 = 7.00

    Total - 46.20 (Not Including S/H)

    I used the same tweeter they use now, just new and dosn't look bad. The new design will have no grill...don't wanna mess with a grill.

    The gray part of the cabinet (as pictured) will be black grill cloth, the sides will be veneered oak..

    Just want to provide my Mom with a system that is more *presentable* and isnt such a *eye sore*

    Originally, I was going to do an open baffle, but the woofer has like 11 cubic cabinet volume, and with an open baffle, it would be half of what it is now. Limiting it to about 50hz reponse instead of 37hz...
    - Not Tom ::::::: Any system can play Diana Krall. Only the best can play Limp Bizkit.
    · Share on FacebookShare on Twitter
  • brettw22
    brettw22 Posts: 7,623
    edited September 2004
    Plywood isn't dense enough for long term stability, is it? Wouldn't MDF be the better choice? All the speaker manufacturers can't be completely wrong.......
    comment comment comment comment. bitchy.
    · Share on FacebookShare on Twitter
  • VR3
    VR3 Posts: 28,774
    edited September 2004
    MDF isnt free ;)

    All about cost.............................................................

    MDF would up this project 20-40 more dollars. Right now, that is ALOT of money for me since I am currently officially unemployeed.

    I would much prefer to use MDF, but I can afford it for a project like this
    - Not Tom ::::::: Any system can play Diana Krall. Only the best can play Limp Bizkit.
    · Share on FacebookShare on Twitter
  • Mjr7531
    Mjr7531 Posts: 856
    edited September 2004
    Why not compromise? You could use LDF ;)
    · Share on FacebookShare on Twitter
  • madmax
    madmax Posts: 12,434
    edited September 2004
    I would use the free plywood to make a work table so that when you have enough cash for the MDF you will have a place to work on them.
    madmax
    Vinyl, the final frontier...

    Avantgarde horns, 300b tubes, thats the kinda crap I want... :D
    · Share on FacebookShare on Twitter
  • Jstas
    Jstas Posts: 14,842
    edited September 2004
    MDF is used because it is less than half the price of a cabinet or furniture grade plywood. Both matierials are pretty much acoustically dead.

    If you are going to use MDF for DJ speakers, MDF does not have the same structural strength as MDF. Infact, plywood is about 5-8 times as strong depending on the grade.

    I use cabinet grade plywood. I'm not sure what the official grade name is though. I do know that the stuff you are looking for has a laminate layer that is basically a veneer. This grade of plywood is expensive but finishing is easy because you already have a milled and finished side ready for staining, priming, paiting or even just clearcoating. This grade also has no voids and a much more even glue coverage between the sheets. It's expensive because it uses roughly twice as much material (wood, adhesive, filler panels) than regular cheapy sheathing or construction grade plywood. Because it has more adhesive, no voids and higher quality wood in the layers, it is more dense than regular plywood. Also, internal laminate layers are often laid with crossed grain patterns, alternating between the sheets. They tend to be strong and won't resonate.

    Personally, I use the plywood for high pressure or stuff that needs something with strong support. A plywood cabinet will not always need as much internal bracing as an MDF cabinet. All of my subwoofer boxs have been plywood because you have real wood for the screws and nails to bit into, you don't need a reinforced mounting plate, glue actually sticks to plywood and I can throw my plywood boxes against a wall and they bounce off. MDF just makes aweful cracking sounds and ends up breaking. Especially if it gets wet.

    If the box is going to see serious abuse, I'd use plywood. If it's just hanging in a corner, use MDF. Either way, MDF or cabinet grade plywood will make a nice spekaer box. It comes down to cost and ease of use. MDF is a cinch to cobble together. Plywood isn't. MDF is a pain to finish nicely, plywood isn't. MDF is cheap, Plywood isn't.
    Expert Moron Extraordinaire

    You're just jealous 'cause the voices don't talk to you!
    · Share on FacebookShare on Twitter
  • VR3
    VR3 Posts: 28,774
    edited September 2004
    Well, if I do the Pioneers (they will have to be MDF) the shop teacher informed me if the project is large, then the wood is not free and therefore is 45 bucks a sheet...

    If I do this full range speaker, I may qualify to get the plywood free...hmm

    Will talk to the shop teacher bout it
    - Not Tom ::::::: Any system can play Diana Krall. Only the best can play Limp Bizkit.
    · Share on FacebookShare on Twitter