Sub specs and connections questions - Rava

Discussion in 'Archived Threads 2001-2004' started by ScottAndrew, Jan 23, 2002.

  1. ScottAndrew

    ScottAndrew Stunt Coordinator

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    Howdy,

    2 questions, if anyone cares to help:

    I see a lot of posts where people describe how their subs produce frequencies below the advertised specs - i.e. the spec says 25hz, but it produces 20hz, 18hz, etc. Is that normal, or does it take some special room configuration? I'm looking at an Adire Rava for the long wall of my 18x14 hardwood-floored room, next to the TV, and I'm wondering if I would get any response as low as 20Hz. I usually watch films at 20 to 30db below reference. (I listen to a lot of music, too, that's why I'm considering the Rava.)

    Question 2: If I connect my speaker's L/R wires to the subwoofer instead of using the subwoofer cable, does that severely degrade my signal or use the receiver's power instead of the subwoofer's power? My receiver has a 100hz crossover and I'd like to use the sub to set that closer to 80hz, but not at the expense of significant performance reduction elsewhere.

    Thanks,

    Scott
     
  2. Ned

    Ned Supporting Actor

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    You won't be able to hear 20hz at 20-30db under reference. The "sound" of 20hz is more of a trembling sensation in the floor and walls rather than in your ears and it doesn't become apparent till about 90db (at least for me using test tones).

    The Rava may be spec'd to 25hz but it will probably still have some audible output to 20hz or below but the maximum level won't be very high. If a sub is spec'd to do 20-80hz it should be able to output 20hz at comparable levels relative to its output at 30/40/50hz. The problem here is that spec's lie often. They say it can do 20-80hz but the 20hz output is laughably low (dunno how accurate the rava specs are).
     
  3. ScottAndrew

    ScottAndrew Stunt Coordinator

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    That's very useful to know. Sounds like in this case the spec might not translate to real-world performance. If I have to blow out my eardrums playing a movie real loud to also get that "rumble," I can probably do without it.

    Thanks
     
  4. Jack Gilvey

    Jack Gilvey Producer

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    With any sub, very deep bass needs to be pretty loud to be detectable at all, given our reduced sensitivity to it. This is why some folks run their sub a little over calibration, especially if they don't calibrate to DD reference. I'd agree with Ned that at 20-30db below reference you'd probably never know if you had a sub that could do 20Hz.

    In the case of a Shiva in a medium-Q cabinet(Rava), it can actually perform *better* in-room than anechoic specs might indicate given how well room gain can complement its shallow rolloff (approx. half that of vented subs). Depends on the room, of course, size and construction.

     

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