Sub-building questions

Discussion in 'Home Theater Projects' started by PhilN, Sep 9, 2005.

  1. PhilN

    PhilN Auditioning

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    hello folks,
    Ive been browsing these forums for a while now and people here seem to be friendly and absolutely FULL of knowledge, so I have a question (or two) that Ide like to ask your help with. Im starting to upgrade my HT speakers and have recently purchased new mains, surrounds, and a rear surround, however Im kind of stuck at my subwoofer purchase. When I went to best buy to purchase the other speakers I spent some time demoing the subs they had there, and they all sounded weak! So I was checking things out on the web and of course found my way to SVS and some other really HIGH end stuff, now Im not afraid to buy high end if I need to but not being a newcomer to car audio subwoofer construction I felt like maybe I could just build my own? So then the questions....

    The mains Im replacing are old (but in near perfect condition) cerwin vega DX7s (12" floor-standing 3 ways) and I was wondering If using the drivers from these units for a new active subwoofer setup would work, and by work I mean be worth it in terms of performance. the speakers performance specs in there current enclosure and wiring are only rated to go down to 35Hz am I going to be able to achieve 20Hz and lower from the speakers in a better designed enclosure or am I just up against the physical limit of the speakers themselves?

    If I can use these speakers How do I find the right volume figure for the enclosure, Ive long gotten rid of any paperwork that may have had specs on the drivers, and most "calculators" for volume Ive seen on the web require some pretty exact specs on the driver to determine enclosure specs?

    To make this an active sub I would of course need to buy a plate amp to power the unit, how many watts should my amp be able to push to drive these speakers to the low frequency that I want cleanly? The 300 watt bash is affordable (economical) whereas the 500 is starting to push my limit. I mean once I buy the amp and my materials Ive invested the better part of an SVS sub, and with the Dayton's going for 140$ ea I could get two of those for the price of just the 300watt bash amp.

    Your thoughts will be greatly appreciated.

    Phil
     
  2. Robert_J

    Robert_J Lead Actor

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    Don't use those CV woofers. They are designed to work in a full range system, not as a sub. They would sound average at best. Go with a single quality sub and amp. If you have the tools and wood working skills (we can help with the design) to build a sub you can do it for a little cheaper than the low end SVS with better results. Buy the tools or contracting out the cabinet to a professional raises the price a lot. You should only do this if you have size or other constraints that can't be met with an off the shelf sub.

    -Robert
     
  3. PhilN

    PhilN Auditioning

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    short and to the point, thank you Robert!

    Phil
     

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