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Anybody ever do this and if not, why not?

Discussion in 'Amps and Cabs [BG]' started by Joe Nerve, Sep 17, 2010.


  1. Joe Nerve

    Joe Nerve Supporting Member

    Oct 7, 2000
    New York City
    Endorsing artist: Musicman basses
    I just ordered a GKMB210 and plan on adding an 115MBE in the near future. Got me thinkin...

    If I get a long speaker cable I can put the 15 on one side of the stage and the 210 on the other, instead of stacking them. I'm no newbie here, but never gigged my own seperate bottoms, (NV 610 or combos has been it for me) and never really gave this any thought.

    Why don't people do this at smaller bar gigs where they're not going through the PA? Me thinks it would fill out the band and sound awesome. Me thinks too that since nobody does it there must be a good reason, except for maybe that nobody ever tries because it doesn's ever seem to be done. ??????? Hmmm... Joe Nerve wonders, and will probably experiment unless you convince me otherwise. Yeah, I realize it'll probably upset the guitar guys a bit, but who cares. :)
     
  2. Adam Bomb

    Adam Bomb

    Mar 26, 2008
    Bezerkely, CA
    Hey. IIRC, "they" say that the soundwaves will crash into each other in the middle and cancel each other out and you will become invisible. Something like that. Don't know why. And don't know why guitarists don't care about this phenom; they all seem to want to rock stereo rigs. My last pedal is in stereo, going into a pair of MB210s, but what does that matter when they are stacked? I may try this too. At least at a rehearsal.

    If it turns you invisible, please post vid clips. Thanks.

    --Bomb :bassist:
     
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  3. JimmyM

    JimmyM

    Apr 11, 2005
    Apopka, FL
    Endorsing: Ampeg Amps, EMG Pickups
    it works better for guitar because their wavelengths are shorter and don't bump into each other nearly as bad as bass freqs. in order for it to work optimally, you have to have as much space between them as your lowest wavelength, which on a bass tuned to E, is something like 28 ft. that's why pa subs are usually clustered or there is only one...to prevent that from happening. i know some bassists do it and like it, but i figure why tempt fate.
     
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  4. Munjibunga

    Munjibunga Retired Member

    May 6, 2000
    San Diego (when not at Groom Lake)
    Independent Contractor to Bass San Diego
    Bomb has a point. If you separate bass speakers more than a quarter wavelength (two feet or so), their sound waves interfere with each other and cause nodes of higher and lower SPL. It looks kinda like this. Note the positions of the speakers together (Fig. 38) and then, say, 26 feet apart (Fig. 44). The diagrams are for 50 hz and 100 hz.

    Array8.jpg Array9.jpg
     
    Das Jugghead, NKBassman and Rickter like this.
  5. I did that ALL the time, not so much now. And to my and the bands ears it sounded great! No canceling. I had a funky rig, a Dynaco ST-70 stereo tube power amp (still have) and a Dynaco stereo pre, two 1x 15 altec cabs set on each side of the drummer. I ran a Y cord into the pre, one side straight, other with a MXR phase 90! MAN once THAT ALL got going it was STAY AWAY FROM THE BROWN ACID TIME! :D:bawl::help::cool::p Maybe we didn't notice the canceling BECAUSE OF THE BROWN ACID?
     
  6. Munjibunga

    Munjibunga Retired Member

    May 6, 2000
    San Diego (when not at Groom Lake)
    Independent Contractor to Bass San Diego
    Well, with indoor venues, you have tons of boundaries, so reflections probably fill in the gaps.
     
  7. gillento

    gillento

    Oct 15, 2005
    Luxembourg, Europe
    Nordstrand pickups
    That's the issue I had years ago with my Eden Metro Combo (behind me) and the MBX210 wedge shaped cab in front of me.

    Actually it was advertised to be used like that by Eden at the time.
     
  8. cb56

    cb56

    Jul 2, 2000
    Ozarks
    Is that why the sound man never puts the bass into both sides of the PA system or the monitors on the other side of the stage? Oh wait....
     
  9. billfitzmaurice

    billfitzmaurice Commercial User

    Sep 15, 2004
    New Hampshire
    Owner, Bill Fitzmaurice Loudspeaker Design
    Not possible.
    This applet shows what happens when you have two sources, with every possible combination of distance, frequency etc.
    http://www.falstad.com/wavebox/

    The best result is seen when you click the 'setup' to single sources, be it point, pinhole, line or slit. You see the resulting red and green representations of the wave's positive/negative phase as uniform in the listening area. With any of the multiple source options things get all muddled up. Moving the frequency slider to the left, for lower, shows what happens to the lows when you have cabs separated. Moving it to the right, for higher frequencies, shows what happens to the mids and highs when drivers are mounted side by side in the same cab.
     
  10. JimmyM

    JimmyM

    Apr 11, 2005
    Apopka, FL
    Endorsing: Ampeg Amps, EMG Pickups
    listen, if they're smart, they either use only one sub, cluster the subs in one spot, or they separate them out far enough where their lowest wavelengths won't cause comb filtering. and if they're smart, they'll roll the lowest freqs off the bass in the monitors.
     
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  11. wcriley

    wcriley

    Apr 5, 2010
    Western PA
    To keep stage volume down, my bass runs through the monitor cabs in addition to my backline cab.

    I can say from experience that with this setup, my "sound" changes radically if I move even a few feet in any direction. And it's NOT just the difference in cabs.
     
  12. Mr. Foxen

    Mr. Foxen Commercial User

    Jul 24, 2009
    Bristol, UK
    Amp tinkerer at Ampstack
    Also to note: putting the same signal though left and right speakers isn't stereo, stereo stuff is seperate for each side.
     
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  13. Munjibunga

    Munjibunga Retired Member

    May 6, 2000
    San Diego (when not at Groom Lake)
    Independent Contractor to Bass San Diego
    They do it (put subs on both sides of the stage - I know you're being facetious) because not many venues can accommodate centered subs. They just live with the fact that some people in the audience are not going to hear much bass, and some are going to hear too much.
     
    RRR likes this.
  14. Munjibunga

    Munjibunga Retired Member

    May 6, 2000
    San Diego (when not at Groom Lake)
    Independent Contractor to Bass San Diego
    A question for Bill F.: If you center two direct-radiating subs (in this case, JBL PRX518S) is it beneficial to arrange them facing in toward each other, similar to the way you recommend doing it with horn-loaded subs?
     
  15. JimmyM

    JimmyM

    Apr 11, 2005
    Apopka, FL
    Endorsing: Ampeg Amps, EMG Pickups
    clustering to one side when you can't center them will work pretty well, too, and certainly better than splitting them when you don't have the room.
     
    Munjibunga likes this.
  16. Almost right...
    Exactly right.

    Guitar wavelengths are shorter/smaller, so when they interfere, they only make the guitar players brain invisible.

    Randy
     
    12BitSlab likes this.
  17. 1n3

    1n3

    Sep 13, 2007
    USA
    I've done this, but in the opposite circumstance; where bass volume on stage was so low, and the stage so wide, that the guitarist couldn't hear the bass well enough. So the loudest cab was behind me; the other cab was behind the guitarist.

    Without PA support, I wouldn't want to do this, for reasons already mentioned.
     
  18. I believe what "they" are talking about here is a phenomenom called "comb filtering". This is one of the advantages of line array pa systems vs. clusters in concert audio.
     
  19. BROWN ACID?
     
  20. +1 I'll have to try this at our next house concert, party. We were having trouble with subs. So center or one side, yes?
     
  21. Primary

    Primary TB Assistant

    Here are some related products that TB members are talking about. Clicking on a product will take you to TB’s partner, Primary, where you can find links to TB discussions about these products.

     
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