Speaker Area and Volume

Discussion in 'Amps/Cabs Tech Corner: Amplifier, Cab & Speakers' started by Cap'n Crunch, Aug 24, 2004.

  1. Cap'n Crunch

    Cap'n Crunch Guest

    This has been explained to me but I still don't get it. If I have a 100 watts going into a 1x12 at "x" ohms, and assuming the efficiency and ohm rating of other speakers I try is the same as my 1x12, how much louder (expressed in db and relative %) are:

    1x15?
    2x10's?
    2x12's?
    3x10's?
    4x10's?
    4x12's?

    Any explanation or elaboration on this would be much appreciated!

    Mike
     
  2. John Phillips

    John Phillips Member

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    It's almost impossible to give any accurate answer. Firstly, it's unlikely that you'll find speakers of different sizes with the same efficiency (which itself has the area factored in, since it's measured by putting sound through the speaker), and secondly the different frequency responses make the apparent loudness vary, especially in a mix. Not only that, cabinet design matters too.

    As a very general rule, I tend to think of a 2x10" as being around the same volume as a 1x12", with a 1x15" being slightly louder. But all other things being equal, the 2x10" will most likely cut through the mix better.

    A 2x12" is louder than a 1x12", but how much depends on the cab design. I hear it as being around 2dB normally. But it also disperses better, so out to the side it may sound more, and directly in front may actually sound less (although still louder).

    4x12"s are obviously louder again... with the same conditions. Hard to put an exact figure on it unless you measure it.

    OK, that doesn't help much... :)
     
  3. Cap'n Crunch

    Cap'n Crunch Guest

    Thanks! specifically, I'm looking at building a 4x10 to replace a 1x12. Looking for clean headroom with lots of lows (the amp is kicking out the lows, I don't need the cab to accentuate them further). 80 watts thru the 1x12 is just not loud enough.

    I just ran the 80 out through a MASS line out and back thru a 220 watt SS amp into the same 1x12, and it got a lot louder (maybe 75%), with the same feel. But I'm using all 220 watts!

    I'm thinking of running wet/dry into the same cab - 80 watts to a pair of 10's, and 110 per side into each of the remaining 10's. I'd like it to be as loud as I've got it now, but using the 300 watts in a distributed way as I've described, (no more than 110 watts and no less than 40 watts into any one speaker) and I am hoping that the extra overall speaker area will more than compensate for the reduction in wattage to any one speaker.

    ????

    Thanks,
    Mike
     
  4. John Phillips

    John Phillips Member

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    If you have 10" speakers that will handle that sort of power...!

    ... yes, that should give you a much bigger sound than the 1x12". I'm assuming the 4x10" is going to be closed-back though, or you still won't get a huge lot of bottom-end.

    300W will be a lot louder than 80 - it's nearly four times the power, so you could expect an extra 5dB of headroom over the same 4x10" run from the 80W amp, and that itself will be louder than the 1x12" by a couple of dB probably.

    You might want to use different speakers - you're obviously going to need two that will handle over 110W each, but the other two might sound better if they're closer to the power of the amp at 80W... eg two 50W speakers.

    If you're going to build a cab like this, I would make it with an internal divider so that the 220W section is isolated from the 80W section as well - which will prevent any unwanted cancellations or distortion caused by the effects of the larger movement of the high-powered pair. You could then maybe even make the 80W section semi-open-back for better dispersion...
     
  5. Cap'n Crunch

    Cap'n Crunch Guest

    Thanks again, John.

    I'm encouraged by your feedback. Now I'm questioning whether the 80 watts into the 2x10 dry section will be loud enough to balance with the wet 220 watts into the 2x10 stereo section? Or should I be hitting this 2x10 section with a like amount of wattage? If so, then I couldn't use my 80 watts of tube power at all, and would have to get a second power amp....

    Another way of putting it, is 80 watts into a (the "right") 2x10 config. about as loud as 220 watts into the 1x12? This 220 into 1x12 is my only reference point right now, and it's got just enough headroom.

    Or will I really even need all 220 watts into the wet section, given that I'm now pushing 4-10's overall? Maybe 80 into 2x10 will be enough, given the overall xtra speaker area?

    Mike
     
  6. scottl

    scottl Member

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    I guess we are done with the archtop for now :(
     
  7. Cap'n Crunch

    Cap'n Crunch Guest

    Hey man, doesn't a 335 count?

    Seriously, I developed (Since December) a mean case of cubital tunnel syndrome and a pinched medial nerve. Couldn't bend at the elbow, numb in the last 2 fingers of the right hand, and losing sense of control over the pick. It reached its peak in March. I stopped playing entirely for a month, and went back to the L-5, and zap! I could feel where a lot of it was coming from.

    I can no longer drape my arm over a big bodied guitar like that, and especially not sitting, where the elbow is obtuse beyond 90 degrees. It kills me after an hour, with a 3 day recovery.

    335 standing up? No problemo! So I'm getting some killer Rogers/Metheny tone now. I'll still break out the L5 for jump style gigs and such - standing, and no more than 1 set.

    You should be happy dude. I'm totally focusing on changes and stuff now. Avoid blues jams like the plague....

    Mike
     
  8. Cap'n Crunch

    Cap'n Crunch Guest

    BTW, relative to this thread, Metheny used and uses 4x10's as part of his rig, and Rogers was using a 4x12! I'm starting to see why....

    Mike
     
  9. John Phillips

    John Phillips Member

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    I would say that 80W into a 2x10" would be about the same volume as into the 1x12" - ie not as loud as 220W into the 1x12".

    But in fact, if the 80W is tube-driven and the 220W is solid-state, you may be surprised how little perceived volume difference there is. Even if you don't think the tube amp is distorting - it might be, slightly; that's one of the reasons tube amps tend to sound louder, since the onset of distortion is soft. With a solid-state power section you know about it immediately, and it's not nice.

    What speaker are you using just now? I'm assuming from the fact that you're putting 220W into it that it must be something like an EV, Peavey Black Widow or the like... which are also very efficient speakers. It's unlikely that you'll get two 10s which are any more efficient, even together.

    I would definitely go for the 'complete' solution you already thought of. I might go even further than the previous idea of enclosing the two sets separately and enclose each of the high-powered pair in individual boxes too, if you're likely to want to run stereo effects. That will maximise efficiency and separation. You could also make the top section angled, if hearing yourself is an issue.

    The advantage of running both amps into their own speakers is that you not only get more power, but you can 'tune' the tone you want using just the tube one, then make up any volume shortfall with the solid-state without affecting the sound.
     
  10. Cap'n Crunch

    Cap'n Crunch Guest

    Yup, it's a 4 ohm EV. I like the 2 - 2x10 idea, if nothing else, for the weight, because the 10's I'm likely to use will be heavy! Maybe look to the Eminence Delta's for the 110/ea stereo wet. Then do 50-watter's for the 80 tube watts into the 2x10 mono.

    Maybe do it like this:

    bottom cab - closed back (or ported) 100 watt mono 2x10 (dry)
    top cab - open back 200 watt stereo 2x10 (wet)

    Better chance of matching volumes that way, plus get the punch and airiness combination, etc... ?

    In this way I'd have no more than 110 watts driving any 1 speaker though, so again I'm concerned about overall clean headroom -- but we're putting 300 watts into 4x10's - so will this retain (or enhance) the clean headroom as compared to what I'm getting from my 220 watts into the EV?

    Thanks,
    Mike
     
  11. John Phillips

    John Phillips Member

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    I'd do it other way round - or you probably won't hear the 100W dry section.

    I would make the top section an open-back (or semi-open) 100W, and the bottom as the closed/ported 220W.

    This is going to be louder and with more headroom than 220W into the single EV 12", for sure.

    220W into the two 10s will be about the same volume, probably - but you'll be adding another 80W tube-driven 2x10" on top of that.
     
  12. Cap'n Crunch

    Cap'n Crunch Guest

    I'll be able to hear the 80 tube-watt cab? I'd be concerned that the 220 watt wet into the closed 2x10 cab would be "way" louder than the 80 watt dry open cab. I'd love to hear the dry cab not just for tonal reference as you suggest (which is great), but even after I bring up the wet section to volume. You now what I'm saying? It would be like a waste of 2 speakers if I couldn't hear them too well in the "mix".

    Thanks yet again,

    Mike
     
  13. John Phillips

    John Phillips Member

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    That's exactly why I think you should put the 80W section in an open-back at the top. If it's in a closed-back near your feet, you won't hear much from it if there are two other speakers running at nearly four times the power above them.

    But if the tube-driven speakers are in an open or semi-open cab at the top (closer to your ears, and especially if you make it an angled cab so they're pointing slightly upwards too) I think you'll hear them OK, especially as tube power amps have more presence than solid-state, so the volume difference may be less than you expect.

    Solid-state is ideal for the extra bottom-end you want from the closed-back section though.
     
  14. Cap'n Crunch

    Cap'n Crunch Guest

    Sounds good, thanks. I'd still be concerned about 10' out front, but worse case I'd just have to get a 2nd SS power amp. At slightly lower (matched) volumes though it would probably sound HUGE!

    Thanks a bunch John, I'll be mulling it over....

    Mike
     

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