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Phase cancellation, what's the skinny?

Discussion in 'Amps and Cabs [BG]' started by Downunderwonder, Jan 20, 2012.


  1. I know it exists because I've heard it and read about it a lot but I don't understand it. The only time I heard it was way back in highschool physics class! Maybe I'm hearing it all the time and it just sounds "normal".

    Bear with me in my musings of what is going on with phasing....

    My understanding of porting is the "free lunch" is a boost of the low end with a phasing cut of sub freq so low they don't matter and a similar cut in mids which together we hear as "good". The amount and position of that bump/cut is a big chunk of the "voice" of a cabinet.

    My own 2x10 SWR JrIII and Trace Elliot 15 rig sounds fine to me. My ears aren't the greatest but it sounded fine to a recording engineer fella at a gig when I asked him so I can only assume there is no phasing in that combo.

    I'm thinking if mismatched cabs generally sound ok it must be that most cabs are tuned for same enough frequency bump and it's the amount of bump and the different drivers EQ response that make them sound so different individually?
     
  2. billfitzmaurice

    billfitzmaurice Commercial User

    Sep 15, 2004
    New Hampshire
    Owner, Bill Fitzmaurice Loudspeaker Design
    The predicted doom does eventuate most of the time. You just aren't aware of it if you don't have a phase coherent system to compare it to. One might also think that Fosters is a fine beer, if that's all one has ever tasted.
     
  3. So having extra noise from adding any old cab is just so sexy the brain ignores the less than stellar sound quality, unless you run into a really bad combination?

    I suppose with the 15 down on the floor the highs that were always lost might have less phase effect on the new high altitude highs from the 10's. Certainly the bass came alive when I added the 2x10, stacked vertically of course.
     
  4. It won't sound bad until you hear something better ;)
     
  5. billfitzmaurice

    billfitzmaurice Commercial User

    Sep 15, 2004
    New Hampshire
    Owner, Bill Fitzmaurice Loudspeaker Design
    That, and the fact that if you've never heard a really good rig you have no basis for comparison.
     
  6. Fosters isn't fine beer?!
     
  7. billfitzmaurice

    billfitzmaurice Commercial User

    Sep 15, 2004
    New Hampshire
    Owner, Bill Fitzmaurice Loudspeaker Design
    My New Zealander mates say that Fosters tastes just like Steinlager...
    after you pass the Steinlager though your bladder. :meh:
     
  8. Slowgypsy

    Slowgypsy 4 Fretless Strings

    Dec 12, 2006
    NY & MA
    Yeah... that's called Phase Cancellation... :bag:
     
  9. Prolly New Zealand's version of Bud Light.
     
  10. Seems all that's to be said about phase cancellation has been said!

    Fosters is Australia's revenge on the world. They like to call themselves "The Lucky Country" but deep down they resent being transported at swordpoint from their homelands.

    I have heard proper phase coherent rigs, but not a/b. More like weeks apart.
     
  11. Bassmec

    Bassmec

    May 9, 2008
    Ipswich UK
    Proprietor Springvale Studios
    There is far more phase cancellation going on in multiple pickups and active EQ systems before your sound even leaves the bass guitar than you will ever find between 10 and 15 bass guitar drivers in similar design cabs.
    Unless of course you have them wired so the cones move in opposite polarity, 180 out of phase or you are mixing ported and infinite baffle designs.
    This is always a case of suck it and see, the rules are there are no rules.
    [​IMG]
    I like this combination best, I think more than one amp to balance things like volume and EQ is a must though, as I need
    to perfect the tone and level for the fifteens which are a lot more forward in the mid than the 10's. For overall EQ I use an SVT11P or mesa studio pre into a Lehle dual splitter.
    There is however well enough dogma about this subject on this forum, to accidentally step right in a big pile of it.:D
     
  12. BurningSkies

    BurningSkies CRAZY BALDHEAD Supporting Member

    Feb 20, 2005
    Seweracuse, NY
    If you're listening to the rig close up, you're not going to hear it like you would in the room...and you have to listen to your sound in a variety of locations in the room, so you'll need to make a walking sweep of the room to hear what's going on. If an engineers walks up to your amp and says he doesn't hear it while standing in front, then he's not really sure what he's looking for.
     
  13. fdeck

    fdeck Supporting Member Commercial User

    Mar 20, 2004
    Madison WI
    HPF Technology LLC
    My grandfather had a way to describe bad beer: "Your horse has diabetes."
     

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