Max volume from 2 small cabs?

Discussion in 'Amps and Cabs [BG]' started by socknroll1, Oct 9, 2011.


  1. greencow

    greencow

    Feb 7, 2008
    Using both cabs at the same time is a bad idea. If both cabs are the same impedance then they will get the same amount of power. Each driver in the 2x10" will get twice the signal compared to a single driver in the 4x10" That means you have a good chance of blowing speakers in the 2x10" long before the 4x10" ever reaches its limits. Phasing issues is another topic that has been discussed in here a lot.
     
  2. steve_rolfeca

    steve_rolfeca Supporting Member

    Not all 10's, 12's or 15's are created equal. Other people have already pointed this out. But just to clarify, here are four names which make nonsense of your question:
    - Barefaced Big Baby
    - Baer ML112
    - AudioKinesis Thunderchild
    - fEarful 12/6

    These particular cabs all use variants of a "super-duty" 12 made by Eminence, crossed off to a mid-high driver. They will all comfortably handle around 500 watts, weigh under 50lb, and given enough power, they will play louder than any 2*10, even high-end stuff.

    Between the four, there's a pretty wide range of tones to choose from, and the math is pretty disturbing. The Thunderchild in particular, pretty much redefines what "small" means in a high-output cab, at 14" x 14" x 22". A pair of any of these, will sound happier and less compressed than a $2,400 pair of Bergantino AE210's when the going gets hot, and cost quite a bit less.

    There are also 15" variants of some of these, which will punch even bigger holes in most people's preconceptions of what is "loud", and how much power a particular speaker or cabinet size can handle.
     
    31HZ likes this.
  3. Fixed, I think...correct me if I'm wrong.
     
  4. JimmyM

    JimmyM

    Apr 11, 2005
    Apopka, FL
    Endorsing: Yamaha, Ampeg, Line 6, EMG
    It's not just speaker area...it's also displacement.
     
    steve_rolfeca likes this.
  5. Sigh...I will never get this stuff. Define displacement?
     
  6. alexclaber

    alexclaber Commercial User

    Jun 19, 2001
    Brighton, UK
    Director - Barefaced Ltd
  7. Russell L

    Russell L

    Mar 5, 2011
    Cayce, SC
    Well, here's how it's gone for me:

    Markbass 121H combo (1x12), 300w/500w at 8/4 ohms. Nice, but not enough excursion to produce lows at needed volume.

    Added a Markbass 151P cab (1x15). As an extension speaker, the rig was at 500w/4 ohms, but the 15 is limited by what the 12 can take. Not good, but sounds great at low volume or with the lows rolled off.

    Separate Little Mark III head with 151P cab---back to 300w/8 ohms. This rig can get about as loud as when I was at 500w at 4 ohms and still handle the lows without running out of excursion. So far it's handling all I can throw at it. It makes it seem as if 15s are lower and handle more than 12s, but I know that's not right. Nonethless, I'm convinced that two of these 151P cabs will get me through anything. They are also the lightest in weight for also having the highest quality I could seem to find (37.3 lbs.).

    Dunno if that helped any. I've been playing an Ampeg V4 through an SVT 8x10 at the blues shack. Really nice. Took the LMIII and 151P last week, and I gotta say, I wasn't short on volume or lows, comparatively. Amazing, but that's not to say a 115 will do as well as an 810. Nonetheless, it shows that I don't have to lug an 810 to get my sound.
     
  8. billfitzmaurice

    billfitzmaurice Commercial User

    Sep 15, 2004
    New Hampshire
    Owner, Bill Fitzmaurice Loudspeaker Design
    Car engine sizes are classified the same way, by cubic centimeters displacement, the amount of volume occupied by the cylinder, not the area of the piston face.
     
  9. Driver size is less important than efficiency and voicing and mechanical specs. In other words, what do you mean by 'ultimate'?

    If ultimate means to you purely volume, then a heavy duty neo 15 in a small box will typically give you lots of volume, reasonably good mechanical ability (i.e., loud without farting) and not much real low end. The 2 x Schroeder 115L+ stack is a good example of this... massively loud, small and lightweight, doesn't need a lot of watts, but mostly low mid punch versus true low end.

    The opposite of that would be defining 'ultimate' as the most true low end in the smallest boxes available. At this other end of the continuum, the Acme Fullrange/Flatwound 2 x 112 neo stack would be king. MASSIVE low end, all the way down to the fundamental of the B string, but not the loudest of stacks, and it will take a shocking amount of power to get them to full volume performance

    A nice middle ground would be cabs that stradle both of those extremes, and would be examples/executions of 'ultimate' defined as 'balancing size, low end, and power/efficiency to result in reasonably small, reasonably loud per watt, and reasonably full in the low end performance'. Good examples of this are the Baer ML112 x 2, the Bergantino HD112 x 2, some of the Barefaced 112 or 115 cabs, etc.

    So, you can pretty much get what you want pretty easily, once you define what 'ultimate' means to you. For most, it would be my last definition IMO.
     
  10. alexclaber

    alexclaber Commercial User

    Jun 19, 2001
    Brighton, UK
    Director - Barefaced Ltd
    I think the biggest mistake with all cabs is to expect to get 500W from a cab! It doesn't help that loads of magazine reviews and adverts and websites talk about cab X putting out 500W when actually they mean it can handle 500W. In reality a typical bass cab is less than 2% efficient, so if a cab can handle 500W it puts out a mere 10W at full tilt.

    Here's some maximum acoustic power output in watts for some non-electric instruments:

    Double bass (i.e. upright bass) = 0.16W
    Piano = 0.4W
    Snare drum = 12W
    Pipe organ = 13W
    Bass drum = 25W (that's a big orchestral one being hit with a stick, not the quieter, smaller and more heavily damped ones operated by a pedal in a drum kit)

    If any bass cabs could put out 200W let alone 500W or 1000W you couldn't bear to be in a room with them, you'd go deaf in seconds!
     
  11. Watts isn't an acoustic measurement, sound is usually measured in decibels or dBs, and in teh case of loudspeakers Sound Pressure Level is expressed as dB produced by 1 watt input measured at 1 metre, usually at a certain frequency.

    The sound output depends on the efficiency of the cabinet to convert the electrical input into mechanical movement by the speaker/driver which in turn produces the sound you hear. There are huge variables in component and cabinet design which affect what any given input will produce, both in tone and volume.

    It's hugely complex and the only way to get what you want is to ignore ALL THE NUMBERS and play your instrument through the amp/cab and decide if it does what you want it to. If it does, look at warranty support durability, weight etc. and if OK buy it, if not try something else. There's no shortage of great kit out there.
     
  12. alexclaber

    alexclaber Commercial User

    Jun 19, 2001
    Brighton, UK
    Director - Barefaced Ltd
    You can convert dB SPL at a given distance from the source, with a given degree of directionality, in a given acoustic space (free air, half-space, etc) into acoustic watts but it's complicated. But when watts are used regarding amps and cabs it's always in an electrical sense and doesn't tell you how many acoustic watts are coming out!
     
  13. billfitzmaurice

    billfitzmaurice Commercial User

    Sep 15, 2004
    New Hampshire
    Owner, Bill Fitzmaurice Loudspeaker Design
    +1. Watts really have no use where sound gear is concerned. Speaker output is determined by the voltage applied, amp output is determined by voltage swing capability, amp load capacity is measured in amperes, and the electrical service capacity required for the amp is also measured in amperes. Watts are as insignificant where the decibel output of a sound system is concerned as they are with the lumen output of a lamp.
     
  14. However, honestly reported wattage (i.e., amplifier wattage output at a given THD and within a given frequency range), in the real world, is a pretty good proxy for the consumer in evaluating all of the above. Again, I believe your comments about 'watts being meaningless' is an overstatement (I understand you are trying to make a point, though, and I get it:))
     
    steve_rolfeca likes this.
  15. billfitzmaurice

    billfitzmaurice Commercial User

    Sep 15, 2004
    New Hampshire
    Owner, Bill Fitzmaurice Loudspeaker Design
    And there lies part of the problem. Is that RMS? Peak? Music Power? PPM? Tube watts? TC watts? :rollno:
    A volt is a volt, an ampere is an ampere, and that's what engineers deal with. Watts are what marketeers deal with.
     
  16. I again agree with you in general. The vast majority of manufacturers provide RMS wattage levels, and I've found the reported levels to, for the most point, have at least a moderate correlation with max volume, all other things being equal (i.e., tested through the same cab that can actually use the additional power).

    However, to your point, in the real world, 'all things are never equal', and I totally agree with you that overweighting wattage output of a head (much less the maximum thermal rating of a cab) in a buying decision might not result in the best decision.
     
  17. BassmanPaul

    BassmanPaul Inactive

    Not a wise choice! To work properly together as a 6X10 the 2x10 has to be twice the impedance of the 4x10. That is an 8Ω 2x10 with a 4Ω 4x10. That way all the drivers are receiving about the the same power. The way you have it your 2x10 is in danger every time you use them together.

    <sigh> beaten to it by a Green Cow! :)
     
  18. cableguy

    cableguy

    Jun 4, 2009
    North Bend, WA
    +1

    I have the fEARful 12/6-12/sub and it can get pretty damn loud. I use a GK 700RB-II which has the same power as your head. (On paper as many people have said) It is small and modular. 95% of my playing I just use the 12/6. When I need to go to 11 I add the 12/sub. Some people like (2) 12/6 so the have mid-drivers in both cabs. My 12/6 weighs 39lbs. Neo prices have skyrocketed lately though so availabilty of the 3012LF is is getting tough. Good luck.
     
  19. jay loren

    jay loren Supporting Member

    Apr 9, 2011
    PA/NJ
    Thanks, bongomania, greencow, and Paul.
    I'm still new at this. In my previous life I was a guitar player playing exclusively combos...
     
  20. BassmanPaul

    BassmanPaul Inactive

    Ahhh! Yet another guitar player who has learned where the real power in the band lies! :D
     
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