Dismiss Notice

Psst... Ready to join TalkBass and start posting, make new friends, sell your gear, and more?  Register your free account in 30 seconds.

Bridging and phase reversal

Discussion in 'Amps and Cabs [BG]' started by HeavyDuty, Aug 31, 2002.


  1. HeavyDuty

    HeavyDuty Supporting Curmudgeon Staff Member Gold Supporting Member

    Jun 26, 2000
    Suburban Chicago, IL
    There's an interesting discussion over on TBL about the inherent phase reversal you get when you bridge a particular Crown amp into a pair of cabs. Is this common to most or all power amps?

    From reading the discussion, this phase reversal can seriously affect the tone of your rig - the comment was "all the booty was gone" - making it sound much thinner than it would unbridged (duh).

    I haven't noticed this phenomenon with my Carvin DCM-1000. My Carvin forces you to use a single Speakon output when you bridge - is that how they get away with it? Do Crowns (or others) use a pair of speaker outputs when bridged, which would then be out of phase to each other?

    Or is this phase reversal an input or amplification stage issue having nothing to do with output configuration?
     
  2. The phase inverting is usually done in the input section. But it could have been anywhere.

    The sound change due to the phase difference is IMHO utter nonsense, and hearing it is pure phychological. What difference would it make through which terminal of the amp output supplies the more positive voltage? It goes through the voice coil the same way anyway. This is like comparing clockwise (CW) wound voice coils against counterclockwise (CCW).

    What do I care if my car engine spins CW or CCW?
    What do I care what wall outlet pin supplies the null or the phase?
    What do I care ?

    As usual, I may be wrong.....
     
  3. What's this??????????

    If I type the word car I get a hyperlink to a commercial car sales site????????? (or whatever, I didn't look)

    Have we gone crazy?????????
     
  4. HeavyDuty

    HeavyDuty Supporting Curmudgeon Staff Member Gold Supporting Member

    Jun 26, 2000
    Suburban Chicago, IL
    Bah. False alarm - it turns out that he had a miswired speaker cable. Nevermind.