Subwoofer... in the attic???

Discussion in 'OT Technology' started by dbman96, Feb 10, 2004.

  1. dbman96

    dbman96 Active Member

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    Yeah, I know it's less than ideal... but my living room is laid out very poorly to deal with anything large. There's just no good place for a big sub. Right now I've got a 16 cubic foot sub box in a corner behind my aquarium (but I really don't think that's very good for the fish) and I'm planning on building a sonotube about 4' tall for a DD 9512 sub that I've got sitting in the garage. I'm thinking if I could just put the damn thing in the attic, it would be fine, but would I have to create some sort of vent through the ceiling or does drywall not block enough subbass to worry about it?
     
  2. dbman96

    dbman96 Active Member

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    Just a secondary question - what kind of SPL do you shoot for to get a "cinematic" home theater experience? On musical material my current sub is pushing about 119 dB at the listening position (I think I've got some cancellation issues between the big sub and the subs built-into my towers) but that big sub is only seeing about 100 watts (huge bandpass box wrapped around a JBL GTi 15" driver). This sound level seems "loud" but it lacks the impact that I think a good home theater should have. Probably mostly due to the weaksauce plate amp on it, but the room is also very large (living/dining/kitchen "great room" that's about 800-900 square feet with 9-10 ft ceilings). If I had a number to shoot for it might help.
     
  3. 04

    04 Guest

    Yeah you could put the subwoofer in the attic, assuming it doesnt get too hot or cold up there. You will want a pretty unrestricted access for the woofer to have into the listening area; if you have a long "duct" or something, that WILL affect performance.

    For a reference level home theater experience you are probably going to want a subwoofer that can do 115dB from 20hz to 80hz at ALL listening positions. When you measured your subwoofer with the spl meter, you said you got 119dB right? What meter did you use, how close was it to the subwoofer when measurement was taken, and at what frequency was it taken at? That is an extremely high spl level for a woofer with only 100 watts...
     
  4. dbman96

    dbman96 Active Member

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    I should clarify that - my main speakers are Cambridge T500s which each have a 300W powered 10" sub and passive radiator; the secondary sub picks up below about 60hz and is using a 15" sub and 100W plate amp in a large bandpass enclosure (?th order? both chambers are vented) (built from this plan: http://decware.com/hwk15.htm ). The lower powered sub contributes a HUGE amount to the subbass volume though. I need to do some more specific measurements to establish actual frequency response, honestly, and I'm using a RatShack analog SPL meter altered as listed here (with the std. RS mic in place): http://cygnus.ipal.org/mirror/www.people.Virginia.EDU/~edw3g/rsmeter.htm I doubt that the SPL numbers are true, but they should be ballpark. The number I took was about 12' from the main towers and 8' from the second sub (in the back corner of the room). I would GUESS that the bass in the music I was playing was a pretty repetitive hit in the 50-60 hz range. I'm interested to see how low I can push this setup, but with the weak amp on the 15" it really falls apart below around 35hz
     

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