What is a PUSH-PULL subwoofer?

hamzahsh
hamzahsh Posts: 439
I know there is a subwoofer from SVS which has 2 12" drivers facing to each other forgot which SVS model was it. BTW can someone explain me how does it work and why would someone really care about it.

I know about Front-Firing and Down-Firing subs but I want to know about PUSH-PULL subs. I know there are subs which are known as "BASSHORNS"
what so special about them?

Hope Doc and others will answer to my questions?
:)

Need a SUB knowledge! :D
Panasonic TH-50PX80U Plasma HDTV
Polk Audio RT800i (fronts)
Polk Audio CS400i (center)
Polk Audio F/X1000 (side surrounds)
Polk Audio RTi6 (back surrrounds)
Velodyne CHT-15 (subwoofer)
Yamaha RX-V1400 (Pre/Pro)
NAD C272 (2-ch Amp)
Adcom GFA-7605 (5-ch Amp)
Toshiba SD-3109 (DVD/CD player)
Malata DVP-580 (Multi-region DVD player)
Post edited by hamzahsh on

Comments

  • Dr. Spec
    Dr. Spec Posts: 3,780
    edited April 2004
    Basically, as the externally mounted woofer is firing outward into the room, the internally mounted woofer is firing into the cabinet.

    Conversely, as the externally mounted woofer is firing into the cabinet, the internally mounted woofer is firing into the room.

    This firing arrangement cancels reactive forces in the woofers and also drastically reduces even order (particularly the 2nd order) harmonic distortion.

    This allows a considerably higher clean output than a conventional firing arrangement (all other things being equal), but eventually odd-order harmonic distortion components will spike, indicating that max output is being reached, even as even-order distortion components remain fairly low.

    The B4-Plus is unique in that it also employs tuned vents along with the push-pull config, something no other manufacturer has developed.

    M&K is a notable push-pull sub maker.

    Doc
    "What we do in life echoes in eternity"

    Ed Mullen (emullen@svsound.com)
    Director - Technology and Customer Service
    SVS
  • PolkThug
    PolkThug Posts: 7,532
    edited April 2004
    On some subwoofers you can reverse the polarity and the sub will move in the opposite direction. Back in the 80's we used to do this in car audio (isobaric). Basically clamp two subs facing each other and put them in a box meant for a single sub. Reverse the polarity on the outer sub, and then they will both move in the same direction working together.

    Regards,
    PolkThug
  • hamzahsh
    hamzahsh Posts: 439
    edited April 2004
    Thanks guys for the reply!

    :)
    Panasonic TH-50PX80U Plasma HDTV
    Polk Audio RT800i (fronts)
    Polk Audio CS400i (center)
    Polk Audio F/X1000 (side surrounds)
    Polk Audio RTi6 (back surrrounds)
    Velodyne CHT-15 (subwoofer)
    Yamaha RX-V1400 (Pre/Pro)
    NAD C272 (2-ch Amp)
    Adcom GFA-7605 (5-ch Amp)
    Toshiba SD-3109 (DVD/CD player)
    Malata DVP-580 (Multi-region DVD player)
  • VR3
    VR3 Posts: 28,647
    edited April 2004
    My M&K is push-pull.

    All I gotta say is, M&K needs to re-think their designs just a tad more. For how much they cost and what they can actually do. BLEH
    - Not Tom ::::::: Any system can play Diana Krall. Only the best can play Limp Bizkit.