Build Shiva Box?? Help. New to this

Discussion in 'Home Theater Projects' started by Jeff Sch., Nov 18, 2003.

  1. Jeff Sch.

    Jeff Sch. Stunt Coordinator

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    Im thinking of taking up a project and building my own Subwoofer and Huge Speakers. Ive looked at some sites but none really show whatto do.
    Can anyone help me out and link me to a place that shows materials and stepby step instructions on how to make a sick subwoofer?
    Im looking for up to date instructions which were prolly tweaked since the originals. Also how much will it cost in materials?


    Ive looked at the shova project on
    http://www.adireaudio.com/tech_papers/shiva_apps.htm

    and checked outthe vented designs (95L) but dont understand construction of the things and all. All i see are diagrams. Nothing materials needed/boards/screws/driver etc. Can you guys help. I want to build something that would be expensive and knock the hell out of my house and my sawm40
     
  2. Brian Tatnall

    Brian Tatnall Stunt Coordinator

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    If you really want some thing that is loud. I suggest you go to a different driver than the shiva. Not that it is bad, but displacement is going to be your best friend. [​IMG]

    First I'd suggest a 15" instead of 12". Especially for a Shiva vs Tempest.

    Sd*Xmax = Linear Displacement

    Shiva: 15.8*481=7599.8
    Tempest: 16.4*779=12775.6

    12775.6/7599.8 = 1.68

    So what that all means is you get another 68% of a driver for $25 dollars more which means a lot more shaking of the house.

    The Adire drivers are becoming a bit dated for their price/performance ratio. I have a Tempest myself and I am a bit regretful I didn't look around more first.

    Try either stryke, SAE, or PE Dayton Titanic. Usually more for your money.


    www.stryke.com
    www.partsexpress.com
    www.acoustic-visions.com

    The stryke website had this which gives you an idea of what you get for your money.

    12" woofers displacement per dollar comparison:
    * 2.33L for the AV12 at $140.00 = $60.09 per L
    * 1.53L for the Dayton DVC12 at $119.20 = $77.90 L
    * 1.89L for the Titanic MKII at $149.80 = $79.26 per L
    * 1.52L for the Shiva 12" at $125.00 = $82.24 per L
    * 2.38L for the Brahma 12" at $369.00 = $155.04 per L

    15" woofers displacement per dollar comparison:
    * 3.8L for the AV15 at $165 = $43.42 per L
    * 2.4L for the Dayton DVC15 at $132.50 =$54.30 per L
    * 2.56L for the Tempest 15 at $150 = $58.60 per L
    * 4.09L for the Brahma 15 at $429 = $104.89 per L

    On preorder right now that AV15 is a steal. [​IMG]

    Good luck.
     
  3. Brian Tatnall

    Brian Tatnall Stunt Coordinator

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    As for your other questions.

    Most people just use glue either wood glue dark or yellow (the difference is dry times) or a polyurethane based one like gorrilla glue.

    For wood most people use MDF because it is cheap, but a better choich IMO is to use some plywood and get as many ply as you can for as cheap as you can.

    Your going to need speaker wire for connecting the sub to the amp and depending on if you have a amp in the box or not you need a terminal.

    Your going to need screws to put the sub in Tnuts are pretty good for that.

    You need a speaker grill if you want one.

    Then you can decide on the finish spray paint (i suggest automotive) carpteing. You can also do veneer and apply stain.


    [​IMG] :b
     
  4. Jeff Sch.

    Jeff Sch. Stunt Coordinator

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    ply wood and mdf wood. Any thinkness or do they only some in 1 size??? isnt ply wood the things that come in huge sheets. I could get at home depot. Now what about port, amp, etc
     
  5. Brian Tatnall

    Brian Tatnall Stunt Coordinator

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    They come in multiple sizes most people go with 3/4". There isn't a huge need for more if you use bracing well. However some people go for a larger front baffle (side the speaker is on).

    Plywood should be fine. It does come in huge sheets, but it comes in half sheets and quarter sheets also. Remember that you are going to need 6 sides for the sub and then internal bracing so that 'big' board can be crammed into a pretty small package.

    Home Depot is your friend. If there is a Lowes I usually like that place better or if you have a hardwood place around you that is probably your best bet.

    Remember that ply is more expensive than mdf which is why most people use mdf.

    MDF isn't really 'wood' it is medium density fiberboard. Basically some sort of sawdust/glue mixture compressed from what I understand.

    You can get a port from Adire directly or from parts express. I suggest a flared port, but your needs are really going to depend on what tuning you want the box to have and will be specific to each driver.
     
  6. Brian Tatnall

    Brian Tatnall Stunt Coordinator

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  7. Jeff Sch.

    Jeff Sch. Stunt Coordinator

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    well im looking at the diagrams right now and wow looks confusing but i get it. Do you have any pictures of this design as its being build so i can get a picture or the braces inside?? And do you put them in last?
     
  8. Jeff Sch.

    Jeff Sch. Stunt Coordinator

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    Well what Driver would you recommend???
    AV15?? Tempest???
     
  9. Brian Tatnall

    Brian Tatnall Stunt Coordinator

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    Jeff,

    The crazy part about this hobby is you can always spend more. So the first thing I would do is give myself a price range and then go from there instead of the other way around.
     
  10. Jeff Sch.

    Jeff Sch. Stunt Coordinator

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    ok. Well id like to keep it under $350-400 and get something that will sound like a multi thousand $$$ sub. Didnt want to spend $700-800 on svs. Plus i could build speakers in the future for a fraction
     
  11. Brian Tatnall

    Brian Tatnall Stunt Coordinator

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    Amp plenty of power 380W RMS@4ohm.
    Rythmik Audio 350
    $155 + $15 shipping = $170

    Stryke

    Most bang for buck, but need to wait since it is on preorder. Expected delivery is by January 1st.
    AV15 MkII
    $165.00 + $15-20 shipping = $185

    $355 Total

    Leaves you money for all the other parts.
    It will shake your house ported for sure.

    Let someone else comment also so your not just taking my word for it. [​IMG]
     
  12. Brian Tatnall

    Brian Tatnall Stunt Coordinator

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    A cheaper route.

    4 ohms=272W
    parts express 300-794
    $128.00 + $12-15 = 140

    Stryke SAE1204
    $109.00 + $15-20 = 130

    $270
    Still not a terrible option, but not on par with the above.
     
  13. Jeff Sch.

    Jeff Sch. Stunt Coordinator

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    hmmm and my vr-507 gives out 8ohm loads i think butsince it will be externally amplified, it doesnt matter right.


    Youve been so helpful. Thankyou so much!!! Post ny other info you think i would like to know. I already know more about this then i did 1 hour ago and im loving it
     
  14. Kyle Richardson

    Kyle Richardson Screenwriter

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    Brian's got it covered [​IMG]
     
  15. Brian Tatnall

    Brian Tatnall Stunt Coordinator

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    So you have a Kenwood VR-507. I downloaded the manual.

    The reciever or amp doesn't really 'give out' a specific load. The speakers intrinsically have a ohm rating usually 4 or 8 for home and sometimes 1 or 2 for car audio.

    The reciever 'sees' the ohm rating of the speaker. Some amps cannot handle the lower ohm ratings because of the voltage that needs to go through each of the components. Nicer/more expensive amps can usually handle lower impedances.

    As for you amp driving the sub. It won't unless you sacrifice the rear channels or something weird like that. Which you shouldn't do. Your reciever isn't speced below 8ohms a channel so don't go there.

    Your receiver just has an subwoofer out which gets the signal (music) there, but does not offer any amplification.

    For the sake of simplicity your going to need an external amp. Most every receiver needs that. [​IMG]
     
  16. Kyle Richardson

    Kyle Richardson Screenwriter

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    Its easier to put 3 of the sides together then the bracing. That way you can get glue on all of the bracing joints and you arent trying to slide it into the enclosure wiping all of the glue away in the process. After the bracing is installed you can then attach the remaining 3 sides of the enclosure.
    Remember, with butt joints some walls are going to be completely inset, some partly inset/partly outset, and some sides are completely outset. You want to install the completely outset side last.
     
  17. Jeff Sch.

    Jeff Sch. Stunt Coordinator

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    With that Approx $400 option, how well will it sound compared to a store bought one? Also what tools did you use for everything
     
  18. Brian Tatnall

    Brian Tatnall Stunt Coordinator

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    Jeff,

    If your going to try and compete with a brand name like SVS then you basically have 'starting costs'. Meaning someone has to design and purchase all the parts.

    A driver that is near what you can expect from them is going to cost at least $125 and an amp at least $125. So for $250-$300 your started on the route to a comparable sub. For that extra $50-$100 more your past the 'starting costs' and can really see a huge increase quickly.

    Personally, I'd focus more on the driver. Once you get to the 256w range you need another 256w to double the sound. If you know how power works let me explain.

    3db 1w
    6db 2w
    9db 4w
    12db 8w
    15db 16w
    18db 32w
    21db 64w
    24db 128w
    27db 256w
    30db 512w

    For every doubling in sound output (3db) you need 2x the power. So once you've hit 250w power starts to get really expensive without as much output. There is something to be said about headroom on the other hand, which is why in the more expensive setup I suggested the rythmik.

    To double the output of a driver you need to either add twice the xmax or add more cone area (Sd).

    It is much less expensive to purchase more (Sd) and Xmax once those 'starting costs' are out of the way.

    Stryke AV15 MKII
    Sd*Xmax
    830*23=19090

    Tempest = 12775.6
    Shiva = 7599.8

    19090/12775.6 = 1.49
    19090/7599.8 = 2.51

    So for $15 dollars more than the tempest you get 49% more linear displacement.

    For $40 more than the shiva you get 151% more driver!!!

    So if your going to choose to skimp on one then choose a lesser amp.

    Numbers are our friends [​IMG]
     
  19. Brian Tatnall

    Brian Tatnall Stunt Coordinator

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    I don't know exactly which drivers are in which SVS subs, but I do know that both Stryke and SVS have the same manufacturer. TC Sounds is the buildhouse for both. I'm sure that the AV15 will not disappoint you.

    On a little more of the realistic side box integrity is going to be very important. You need to build a solid air tight box otherwise you are going to lose a good amount of output and it isn't going to sound as good.

    If you want something just like SVS you could try to build a sonosub out of sonotube, but I'm afraid you'll need some other people to help you out with that because I have never tried it and don't know all the in's and out's of it.
     

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