Multiple cabinets -> matching volume?

Discussion in 'Amps [BG]' started by DieterVDW, Jan 1, 2013.


  1. DieterVDW

    DieterVDW

    Joined:
    Sep 19, 2012
    Location:
    Gent, Belgium
    Hi,

    I just wondered about something: if you use an amp with multiple cabinets, are these cabinets always matched in volume?
    Ofcourse if you use 2 identical cabinets they will output the same volume. But how does this work with cabinets with different layouts (eg. 4x10 with an 1x15 or a 2x10 or smth.)? Or different drivers/efficiencies?

    Are drivers "configured" by design to match other drivers, or is this just a magical byproduct of the electrical wiring?
    Is the effective "force" output by the amp nicely balanced over each speaker/cabinet so they are matched volume wise because of the electrical properties of the cabinets/drivers/... ? Or is this greatly because of design qualities and is there some kind of de-facto design standard among cabinet/driver manufacturers that a certain load should lead to a certain volume?
    Or is this just a logical consequence of the laws of physics?
    However there is such a thing as driver-efficiency right?
    Or does this not matter in such a big degree that it is audible/a problem?

    In the extreme case of a 1x15 with a tweeter, the cabinet manufacturer will decide through the cabinet design how much volume is produced by the tweeter in relation to the main speaker right? I believe this is even configurable for some cabinets?

    But when combining different cabinets I could imagine one would also want to balance these cabinets with eachother.
    However this does not seem to be possible / necessary?

    I am curious to the logic/physics behind this. I'm SURE some TB veteran will be able to provide a good explanation for this. ;)
    I hope it might also interest other members.
    Somebody who can shed a light on this?
     
  2. bassgod0dmw

    bassgod0dmw Supporting Member

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    Have a look in the FAQ at the top of the page, or search out "mixing cabs" or "mixing drivers" You'll have enough reading/arguing to keep busy for quite a while.

    To answer your question, it's not possible to control the volume of two different cabinets. It's a big reason why many people do not like the ol' 410 + 115 stack. The 115 can't keep up with the 410, so you never hear it suffering...then...BOOM. You just blew the 115.
     
  3. uOpt

    uOpt Supporting Member

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    Jul 21, 2008
    Location:
    Boston, MA, USA
    Different speaker chassis have drastically different efficiency. That's very basic data in the sheet. In addition, combining speakers (such as 2x12 or 4x10) raises the efficiency even more. And to top if off the directionality is also different so all of this changes depending on where you stand relative to the cabinet.
     
  4. DieterVDW

    DieterVDW

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    Hmm I should've known I'm not the first to wonder about this ...
    Will read!
     
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  6. Mystic Michael

    Mystic Michael Hip No Ties

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    It doesn't work that way. You're making all kinds of assumptions about a scenario that doesn't even exist. :eyebrow:

    Bass cabs - especially those of varied configurations and/or different manufacturers - are not necessarily consistent or compatible with one another at all. Not in terms of frequency response, nor power-handling capability, nor in sensitivity, nor in impedance, etc. etc.

    Read the FAQ... :eyebrow:

    MM
     
  7. christw

    christw Get low!

    Joined:
    May 11, 2008
    Location:
    Dayton OH
    Disclosures:
    Endorsing: J Worrell Bass
    +1 ^ You can even run into phasing issues with mixed speakers and have things going on like strange volume nodes throughout the room or a muddled midrange.

    There's a lot to take in. That's why a lot of us recommend matching cab. Even mixing product lines from the same manufacturer can have less than savory results.
     
  8. DJ Bebop

    DJ Bebop

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    Location:
    Pacific Wonderland
    BUT I must add this, in the case of bi amping, I have had good results FOR ME in mixing cabs.

    I am running a mini rig of doom consisting of a Carvin BX1500 bi ampable amp running an Aguilar GS112 w tweeter off for low end
    and a David Eden CX 110 for the high end split at about 800 Hz :meh:

    And as goofy as that sounds and looks. I get complements from other bass players when they see and hear this goofiness.

    :)
     
  9. BassmanPaul

    BassmanPaul Gold Supporting Member

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    Location:
    Toronto Ontario Canada
    Yes but in this case you can add a little salt and pepper and you'll have a seasoned rig! :D

    Happy New Year!
     
  10. Got2SadowskyNYC

    Got2SadowskyNYC

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    Artist: Sadowsky, Bag End, Visual Sound, Pedaltrain, George L
    It has to do with Ohm rating.

    Assuming your amp is stable to 2ohms, you can run an 8ohn and 4ohm cab. The total load will be about 3ohms, BUT one cab will sound stronger. This will drive you nuts and there's nothing you can do about it.

    If you run 2 cabs with the same ohm rating, regardless of brand, they may sound different but this is due to construction and materials. You shouldn't harm the amp or cabs at all assuming that both cabs can hadle the power being sent to them.
     
  11. BassmanPaul

    BassmanPaul Gold Supporting Member

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    In your case you are not running two sets of drivers operating in the same passband. This is apples and oranges.
     
  12. NYCbassist

    NYCbassist Supporting Member

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    I have been using a matched set of 4 Ohm Avatar Neo's. One is a 1x15's & the other is 2x10's. I now just started using a Stereo Hartke LH1000 which has a Balance control. Amazingly it sounds best balanced right in the Middle. The 2 Cabs sounded great with My Carvin BX500 as well. Matching the Ohms is the Key in Most cases.
     
  13. 1958Bassman

    1958Bassman

    Joined:
    Oct 20, 2007
    If you want to control the level, you'll need to use an amplifier channel for each. The bad news- it costs more. The good news- if you buy the right amp, like a Crown/DBX/Peavey/QSC or some other brand with EQ/crossover/compressor/limiter, you'll have a buttload of control over what's happening and some of those amps aren't terribly expensive.

    Or, you can look for a GK 800RB (or more) and bi-amp that way.
     
  14. DJ Bebop

    DJ Bebop

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    Yes but it is an option for running two cabs with better results.
    And it does offer more fruit choices, now you have apples and oranges :)
     
  15. DJ Bebop

    DJ Bebop

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    OR a Carvin BX1500 BI Ampable Bass amp that has EQ/crossover/compressor/limiter or similar

    http://www.carvinguitars.com/products/BX1500
     
  16. Bass_Pounder

    Bass_Pounder

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    Location:
    Palm Coast, Florida

    No it is not.

    There are times that it is important to mix impedances to ensure proper power to the individual speakers.

    Is a 8 ohm 1X15 a good match with a 8 ohm 8X10 ?
     
  17. NYCbassist

    NYCbassist Supporting Member

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    In the real world which is where I Jam & Gig. Matching the Ohms = The amplifier putting out the same amount of power to each Cabinet.
    Yes its. A lot better than say a 4 Ohm 8X10. Again out here in the real world where I have tested just about every Scenario.:)
     
  18. DieterVDW

    DieterVDW

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    I've read the FAQ's and it was very informative.
    For me it comes down to: mixing cabs changes stuff, could be good or bad :D .

    However I find it strange you need two amp sections to balance two cabinets? If you put them in parallel and wire a (configurable) resistor with one of the cabs, you could theoretically balance them right?
    But that would mean a big ass resistor with heat sink and lots of spent energy maybe? (Limited electrical understanding ... Forgive me if I'm talking out of my ass...)
     
  19. CL400Peavey

    CL400Peavey Supporting Member

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    No. :rollno::scowl::eyebrow:

    Why would you want to give a 115 the same power as an 810?
     
  20. JimmyM

    JimmyM Supporting Member

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    You need two amp sections in order to dial in sounds that work with and not against each other, and to match volumes to your liking. A lot of times, the EQ that works great with one cab will sound like poo poo stinkies with the second, so a second amp takes care of it.

    Also, I have never even seen a real world scenario where someone takes an 8 ohm 810 and uses the same amp to power an 8 ohm 115.
     
  21. NYCbassist

    NYCbassist Supporting Member

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    To have the same volume out of each.:cool: obviously you can't put more power to the 1X15 than it can handle but what's the point of even having it hooked up if you can't hear it. Matching the impedance of Cabs is one of the first things that I was ever told about multiple Cabinets. I have never seen a reason to do otherwise.
     

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