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 throughmylens87 09-04-2013 07:09 AM

Sensitivity question

So I'm on the hunt for a new cab or cabs. How much does the cab sensitivity affect the total volume? Say a Berg 2 112 rig vs a single 212 cab... The 112 cab has a 98db sensitivity vs the 212 that has a 104db sensitivity. If I'm understanding this correctly (and there's the very real possibility that I'm not) a 2 112 stack in this case would have 6db less volume with the same wattage? Or does the change somehow when you put two cabs together?

Thanks in advance for any insight you can provide!

 BurningSkies 09-04-2013 07:25 AM

Quote:
 Originally Posted by throughmylens87 (Post 14822183) So I'm on the hunt for a new cab or cabs. How much does the cab sensitivity affect the total volume? Say a Berg 2 112 rig vs a single 212 cab... The 112 cab has a 98db sensitivity vs the 212 that has a 104db sensitivity. If I'm understanding this correctly (and there's the very real possibility that I'm not) a 2 112 stack in this case would have 6db less volume with the same wattage? Or does the change somehow when you put two cabs together? Thanks in advance for any insight you can provide!
You are correct with one caveat. Sensitivity is measured at a specific frequency. Not all cabs are measured in the same place. ;)

...Ok another. Cab companies aren't always so honest with their measurements either.

 Downunderwonder 09-04-2013 07:26 AM

There isn't a short answer. We always run into "all else equal" assumptions. One thing thing you overlooked is doubling up your cabs gives you plus 3db sensitivity.

The 104dB of the 212 might be suspect too.

Generally, all else equal, 2 1x12 will get same loudness as 1 2x12.

Power handling, xmax, and power compression are other factors in the max volume when power is virtually unlimited these days.

 KJung 09-04-2013 07:32 AM

Quote:
 Originally Posted by throughmylens87 (Post 14822183) So I'm on the hunt for a new cab or cabs. How much does the cab sensitivity affect the total volume? Say a Berg 2 112 rig vs a single 212 cab... The 112 cab has a 98db sensitivity vs the 212 that has a 104db sensitivity. If I'm understanding this correctly (and there's the very real possibility that I'm not) a 2 112 stack in this case would have 6db less volume with the same wattage? Or does the change somehow when you put two cabs together? Thanks in advance for any insight you can provide!
Within the same brand a product line, the sensitivity of a 2 x 112 and 212 will be virtually identical. In the example you present, the sensitivity of the 212 takes into account the 4 ohm impedance, versus the 8ohm impedance of a single 112.

There will always be slight differences in tonality between most 212 and 2 x 112 form factors within the same product line, due to, in some cases, dual tweeters and also slightly different internal volume, etc. Trivial for the most part.

The big decision is if you want a single cab large cab solution or a 'two smaller cab' solution. Both have benefits and drawbacks regarding pricing, modularity, ease of schelp, etc.

 throughmylens87 09-04-2013 07:34 AM

Thanks for the info guys!

 KJung 09-04-2013 07:40 AM

Quote:
 Originally Posted by throughmylens87 (Post 14822252) Thanks for the info guys!
No problem. Basically, when you add a second 8 ohm 112 (which doubles the number of drivers and increases the wattage output of the typical solid state amp by between 40% and 50% or so), you get approximately a 5db or so increase, which is roughly reflected in the sensitivity specs of the two cabinets you used as examples.

Cabinet sensitivity specs are reasonably useless IMO. Many are measured at 1K, which means it, at best, gives you a rough idea of the upper midrange presence of a cab versus a true feel for the 'volume per watt'. Unless sensitivity is extremely low (for example, the Acme cabs that have that massive low end extension), most cabs of the same design perform relatively similarly on this spec (+/- a db or two).

If you have a low powered head, sensitivity can make quite a difference (i.e., with a 100 watt all tube head that you want to run 'clean', as an example). Otherwise, solid state watts are quite inexpensive these days.

 CL400Peavey 09-04-2013 07:46 AM

Quote:
 Originally Posted by BurningSkies (Post 14822223) You are correct with one caveat. Sensitivity is measured at a specific frequency. Not all cabs are measured in the same place. ;)
+1

Quote:
 Originally Posted by BurningSkies (Post 14822223) ...Ok another. Cab companies aren't always so honest with their measurements either.
+1

 KJung 09-04-2013 07:48 AM

Quote:
 Originally Posted by CL400Peavey (Post 14822283) +1 +1
Actually, his post is incorrect. He must have misread the OP (since he obviously knows about this stuff), which was talking about TWO 112's versus the 212, both with the same drivers from the same product line. With the same wattage applied (per the OP's assumption) the sensitivity of 2 x 112 versus 212 will be, for all practical purposes, identical.

His other points are valid when looking ACROSS different product lines, of course.

 BurningSkies 09-04-2013 08:00 AM

Quote:
 Originally Posted by KJung (Post 14822290) Actually, his post is incorrect. He must have misread the OP (since he obviously knows about this stuff), which was talking about TWO 112's versus the 212, both with the same drivers from the same product line. With the same wattage applied (per the OP's assumption) the sensitivity of 2 x 112 versus 212 will be, for all practical purposes, identical. His other points are valid when looking ACROSS different product lines, of course.
Actually Ken, he doesn't specify a Berg 212 in his question. Going under the assumption that he could be speaking about ANY 212, it's a crapshoot when it comes to sensitivity.

 KJung 09-04-2013 08:02 AM

Quote:
 Originally Posted by BurningSkies (Post 14822336) Actually Ken, he doesn't specify a Berg 212 in his question. Going under the assumption that he could be speaking about ANY 212, it's a crapshoot when it comes to sensitivity.
+1 I'm reading the OP 'A Berg 112 versus 212' as meaning the Berg 212, and the specs on the Berg 212 and 112 are reported, I think.

Anyway, +1 in that it is impossible (pretty much) to compare pretty much anything across brands based on the typical marketing spec.

To the OP, I again was assuming you were comparing the CN112 x 2 to the CN212 (or the HD for that matter). If that is the case, my posts are correct. If not, +1... who knows!:)

 CL400Peavey 09-04-2013 08:05 AM

Quote:
 Originally Posted by BurningSkies (Post 14822223) You are correct with one caveat. Sensitivity is measured at a specific frequency. Not all cabs are measured in the same place. ;)
Bolded answeres the OP. Underlined section is true regardless of the cabs in question. If there is no specific frequency given for where the sensitivity rating was taken, then there is no promises that the manufacturer measured the cabs at the same point.

Quote:
 Originally Posted by BurningSkies (Post 14822223) ...Ok another. Cab companies aren't always so honest with their measurements either.
Again. Objectivly true regardless of cabs in question.

;)

 BurningSkies 09-04-2013 08:08 AM

With a comparison between a 112 and a 212 with each speaker getting similar box and porting considerations and identical speakers you probably do come close to doubling the overall sensitivity, but you'll probably also notice to a greater extent the tonal benefits of having two speakers. It usually comes across as more low end extension.

 Arjank 09-04-2013 08:14 AM

There's allways some confusion about sensitivity, this is mostly because the information most manufacturers give is "wrong" or incomplete. Most show the sensitivity only in dB.

It's better to say, well this cab is 4ohms(nominal) and it's sensitivity is 97dB/2.83v/1mtr.

If you have an 8ohm (nominal) cab and it's sensitivity is 97dB/2.83v/mtr then this system needs only half the power compared to the other cab to reach the same spl.

Why do they use 2.83volts? because that's 1watt@8ohms, for 4ohms it's 2watts, 2ohms 4watts, 16ohms 0.5watt, etc. :)
And why use volts instead of watts? because the impedance of a loudspeaker is not linear.

In the OP case the 112 is 98dB and the 212 104dB, it's very likely that the 112 is 8ohms and needs 1 watt to reach 98dB. The 212 is probably 4ohms, this one needs 2watts to reach 104dB, if you would feed it 1watt the spl would be 101dB. So, in this case it's not a 6dB difference but a only 3dB difference when fed with the same power/wattage :smug:

 throughmylens87 09-04-2013 08:20 AM

Quote:
 Originally Posted by KJung (Post 14822347) +1 I'm reading the OP 'A Berg 112 versus 212' as meaning the Berg 212, and the specs on the Berg 212 and 112 are reported, I think. Anyway, +1 in that it is impossible (pretty much) to compare pretty much anything across brands based on the typical marketing spec. To the OP, I again was assuming you were comparing the CN112 x 2 to the CN212 (or the HD for that matter). If that is the case, my posts are correct. If not, +1... who knows!:)

Ken you are correct I was comparing 2 CN112 cabs to a single CN212. Thanks again for helping shed some light on this!

 KJung 09-04-2013 08:21 AM

Again, to answer the OP's question, 2 x 112 and a 212 from the same product line, using the same drivers (i.e., both the 2 x 112 and 212 being 4ohm nominal) will have the same sensitivity (for all practical purpose). This, I believe was the OP's question.

What the sensitivity actually is, based on the many ways one can measure and report sensitivity is a different matter, and in general, doesn't really matter much to the user (unless we get into extremes like the Acme).

So again, to the OP, assuming you are talking about either the Berg CN212 and 2 x CN112, or the HD212 and 2 x HD112, the sensitivity of the 2 x 112 versus the 212 will be virtually identical, and you can choose between those options based primarily on if you want a modular rig (and are willing to pay the premium for that) or a one cab solution:)

 KJung 09-04-2013 08:21 AM

Quote:
 Originally Posted by throughmylens87 (Post 14822406) Ken you are correct I was comparing 2 CN112 cabs to a single CN212. Thanks again for helping shed some light on this!
No problem. We all tend to get lost in the weeds sometimes on these kind of issues:smug:

However, the other posts are correct that once you move to comparing different 112's and 212's across brands, it is almost impossible to compare sensitivity specs, for the reasons cited.

 Arjank 09-04-2013 08:35 AM

Quote:
 Originally Posted by KJung (Post 14822414) Again, to answer the OP's question, 2 x 112 and a 212 from the same product line, using the same drivers (i.e., both the 2 x 112 and 212 being 4ohm nominal) will have the same sensitivity (for all practical purpose). This, I believe was the OP's question.
+1

yes, it shouldn't make any difference.

 Downunderwonder 09-04-2013 05:16 PM

I'm not going along with the notion that the claimed sensitivity of the 212 is so much higher because it's a 4 ohm cab. Sensitivity is specific to wattage.

 KJung 09-04-2013 06:14 PM

Quote:
 Originally Posted by Downunderwonder (Post 14824832) I'm not going along with the notion that the claimed sensitivity of the 212 is so much higher because it's a 4 ohm cab. Sensitivity is specific to wattage.
+1 I believe it I just the way Jim does his sensitivity specs. Again, and to others' points, no real standards in the industry. I believe Jim just tries to convey the 'real world performance' assuming a solid state amp (i.e., that you will get 5 to 6db more from a CN212 at 4ohms compared to a CN112 at 8ohms with the typical solid state amp... seems like a pretty good way to present things to me).

Again, and again, and again, and again, a 112 x 2 and a 212, using the same drivers and tuning will be, for all practical purposes, IDENTICAL regarding sensitivity, max SPL, and any other specs you want to look at.

Sometimes, we just need to answer an OP's question, rather than devolve into a 'how many angels can dance on the head of a pin' discussion:hiding::smug::D:p

 Vince Klortho 09-04-2013 07:04 PM

never mind

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