Sub performance lacking

Discussion in 'Speakers' started by themow, Jul 8, 2009.

  1. themow

    themow Auditioning

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    Hi New the forum but a longtime browser. I recently added a sub/amp combo to my setup. Im looking for some ideas as im not too happy with the performance. I have an old sony ga7es reciever. I had a JL12w6V1 from a few years back when it was in my car. I bought this plate amp from parts express.

    http://www.parts-express.com/pe/showdetl.cfm?Partnumber=300-750

    I built a sealed box out of 3/4 mfd about 1.3cubic feet which is what JL recommends.
    I had to wire the sub to 12 ohms because it was either that or 3 ohms and i was concerned the amp couldnt handle 3. So im now giving the sub 75watts i believe. The performance is really not what i expected. the room is 15Lx15wx8h but its not sealed at all, it flows into other rooms. I got very poor results using the sub out on the reciever to the lfe input on the amp which bypasses the amps crossover. Apparently the sub out is not crossed over as i heard voices from the sub. I have the sub out to the regualr input on the amp. I have use of the amps crossover but the output is lacking even with the gain pretty high.

    I have another 12w6 so i considered building another box for the two of them so i could run them at 6ohms netting 225 watts total output to the 2 subs 112.5 each or maybe returning the amp and looking for a used crown or somehting on craigslist. Just looking for some ideas
    Thanks
     
  2. Robert_J

    Robert_J Lead Actor

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    It's not your amp, it's your enclosure. If you used the JL recommended size then that would be perfect if used it in a closet. Post the Theile/Small parameters for your sub and we can help with a new enclosure.

    -Robert
     
  3. themow

    themow Auditioning

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    From the manual

    fs 20.9hz
    qts .433
    qes .462
    qms 6.897
    vas 162.3 liters
    xmax 11.1 mm
    efficiency 86.9
    sd .0532 m2
    re 10.8
    znom dual 6 ohm
    pt 300 watts
     
  4. Gerald LaFrance

    Gerald LaFrance Supporting Actor

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    Hmm looks like you need a box roughly around,

    Width: 2.022
    Height 2.940
    Depth 1.410

    I have fooled around with building my Own Sub too and I would reccomend Dumping that Speaker for your car and get a Speaker designed more for a Home theater use then one for your car.


    here are some links to some reccomended subs from the Guys over at AVS:



    http://www.soundsplinter.com/rlp18_subwoofer_information.html


    Also here is a FAQ Page for Building Subs:


    http://www.diysubwoofers.org/faq.htm
     
  5. Robert_J

    Robert_J Lead Actor

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    You need between 2.8 and 3 cubic feet per enclosure to get a very good response from those subs. Dual enclosures wired in parallel sound like a great idea.

    I also modeled your 1.3cf box in Unibox and the response looks terrible.

    -Robert
     
  6. ShanonS

    ShanonS Stunt Coordinator

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    I would second ditching that driver and getting something more suited to HT. There are much more economical options than the one listed above, if you're interested, I'm sure Robert can point you in the right direction. You might even be able to find something to fit the box you've already built.
     
  7. Robert_J

    Robert_J Lead Actor

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    I.3cf and 300w - The Dayton 12" DVC for around $130. Awsome sealed sub.

    -Robert
     
  8. themow

    themow Auditioning

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    I recognize that this sub isnt the greatest for this application but they have been staring at me every time i open the closet and i just feel obligated to use something that i paid good money for. I plan on rebuilding the box for 2 wired in parallel. I was thinking maybe a sonotube with a sub on each end? I assume its not an issue to build a box for two with one chamber.
     
  9. Robert_J

    Robert_J Lead Actor

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    A dual sub in a single chamber is fine. Check out the Tube-zilla project at http://www.theaudioworx.com/

    Thank goodness I don't feel obligated to build a box for every sub driver I have. I've have close to 40 subs in my house.

    -Robert
     
  10. MarvinJr

    MarvinJr Stunt Coordinator

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    I looked at that Tube-zilla build, Is it just me or doesn't that seem like an excessive amount of stuffing?

    BTW thanks for the link, lots of info.
     

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