Need Small Sub for Dorm room

Discussion in 'Archived Threads 2001-2004' started by Andrew Lin, Jul 8, 2002.

  1. Andrew Lin

    Andrew Lin Extra

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    Hey guys -
    So I've been looking around at the DIY subs that people have been making and I've been inspired to make one. However since I am still a student living in the dorms, it needs to be a rather small sub. I had seen a couple versions using the Adire Audio Shiva driver with a 1 cu.ft sealed enclosure, however none that include a plate amp.

    I was wondering why that was, and would it be possible for me to extend the enclosure a bit farther keeping the volume the same just with a PE250W amp.

    Also, with the subs that I've seen w/o a plate amp, they talk of a Linkwize (sp?) equalizer and a separate amp, what is it and why not just use a plate amp?

    Sorry for the barage of questions.. Thanks for your time!!

    BTW the AV1s are close to being done =)
     
  2. Griff

    Griff Stunt Coordinator

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    The linkwitz crossover attempts to flatten the peaks associated with a small cabinet, and sometimes incorporates a "bass boost".
    I think that you should go for a slightly larger cabinet, it will be simpler and produce better results without an active cross.
    Would you go for a ported or sealed subwoofer?
    Here is some apps for a sealed http://www.adireaudio.com/Files/Seal...plications.PDF
    And here are some ported ideas http://www.adireaudio.com/Files/Vent...plications.PDF
    I am assuming that you are a poor student like the rest of us so that rules out the passive radiator route.
    That plate amp is perfect, wire the voice coils in series to represent a 4 Ohm load.
     
  3. Ryan Schnacke

    Ryan Schnacke Supporting Actor

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    Most of the near 1 cu. ft. sealed designs I've seen use the parts express Dayton DVC 12 inch driver instead of the Shiva. Similar driver but with a smaller Vas and Qts so its better suited to the smaller boxes. I think the sealed Shiva boxes should be closer to 2 cu ft for best performance.
     
  4. Brian Bunge

    Brian Bunge Producer

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    Andrew,

    If you want to use a 1ft^3 enclosure, the Dayton DVC 12" driver from Parts Express would be a better choice. A 1ft^3 enclosure is really too small for a Shiva.

    A Linkwitz Transform (LT) circuit allows you to place a driver in a less than optimum sealed enclosure and "transform" the Qtc and Fc to whatever you wish. The LT circuit can be used with any type of amp, it's just that in most of the applications that we have been discussing use high excursion drivers and will also require large amounts of power. Many times in excess of 1000 watts. Since there are very few plate amps that have that kind of output it makes more sense to use an outboard amp.

    Griff,

    Wiring the voice coils in series will give you a 16 ohm load. Wire them in parallel for a 4 ohm load.

    Brian
     
  5. Griff

    Griff Stunt Coordinator

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    Yeah, i just realised that, its late here in Melb, and im not quite seeing or thinking straight.
     
  6. Brian Bunge

    Brian Bunge Producer

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    Griff,
    I figured it was an honest mistake! It's 9am here and I'm not exactly awake either! [​IMG]
    Brian
     
  7. Andrew Lin

    Andrew Lin Extra

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    wow Thanks for all the replies guys! You get up too early.. well you are on the east coast as well.

    So then are my choices between using plate amp and using a separate amp and linkwitz with a 1 cu.ft box with a PartsExpress DVC 12"? Or does this depend on the size of the enclosure since I believe Brian said that the linkwitz circuit is used for less than ideal enclosure sizes? Can I use the PE250W amp with this driver in a 1 cu.ft enclosure?
     
  8. Brian Bunge

    Brian Bunge Producer

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    Andrew,
    Yes, you can use the DVC 12" with the 250W amp in a 1ft^3 enclosure. I think Jack Gilvey has done so with his DVC 12" before and said it was a good alignment. I personally have not tried it myself but do have two of the drivers sitting around! [​IMG]
    Brian
     
  9. Peter Jessee

    Peter Jessee Stunt Coordinator

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  10. Griff

    Griff Stunt Coordinator

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    1ft is damn small, going up to 1.9ft will get you a better response.
     
  11. Seungsoo Hwang

    Seungsoo Hwang Stunt Coordinator

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    Is 1cuft your max size? I have a 2.5cu sealed shiva in my dorm room, and believe my, my room is TINY. Priorities, I guess [​IMG].
     
  12. Andrew Lin

    Andrew Lin Extra

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    hmm 1cu.ft is not a set limit, I would just like to keep it as small as possible trying to pack everything in the car for the long trip back to San Jose last quarter almost left me with no seat =).

    Seeing pictures of Jack Givey's 1 cu.ft DVC 12" sub with the 250W plate amp as given me more inspiration. Peter Jessee, would you happen to have pictures of yours? What dimensions did you use for your box??

    Once again, thanks for all the help guys!
     
  13. DavidY

    DavidY Supporting Actor

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    Currently, I have a 12" original SVS driver in a sealed 0.75 cu.ft enclosure....but, it's in my pickup truck. Needed a larger enclosure in order to perform it's best, but I needed the room in the extra cab for my work stuff.

    Dave
     
  14. Peter Jessee

    Peter Jessee Stunt Coordinator

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  15. Jack Gilvey

    Jack Gilvey Producer

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    About 1 ft^3 stuffed to get the Qtc down a bit is great with the 12" Dayton DVC. As expected given the much higher Qtc, a Shiva in the same box sounds quite boomy (tried it), so the DVC has the edge in a small Vb. Won't go lower-than-low (my PR box with the same driver has a distinct advantage there), but makes a great little sub.
    Dimensions are not critical with a sealed sub, just shoot for at least 1ft^3 internal volume.
     

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