K sooo let me get this straight because I am a little confused about some tech specs and how they are derived. As well, I am a little stoned so bare with me here...
I took a look at the Klipsch KF-28 and their sensitivity rating is 98db @ 2.83V / 1m. Correct me if I am wrong but sensitivity is measured by how loud the speaker sings when giving 1 watt of power.. is this right?
Does 1W always give 2.83V? and isn't the 1m standard? If so, then why are they listing it? I think they are just trying to confuse me! Also, those speakers say that they can take 600W peak... yikes that's a lot! When you said "When that 110W SR-7001 is putting out 16W, those KF-28 would be producing 110 dB at 1 meter"... well if the speaker plays at 110db when given 110W when it's rated 150W - 600W, what the heck is this speaker going to do when given 600W?
This might be a dumb question but I don't know!
First of all, you don't always get 1W with 2.83V, it depends on the impedance. If the load impedance is 8 ohms resistive, that is the phase angle between current and voltage is zero, then
Power=V*V/R, or V = square root of (Power*R)
If Voltage V = 2.83V, and impedance = 8 ohms (resistive),
then Power = 2.83*2.83/8 = 1W
Now if impedance = 4 ohms resistive, then
Power = 2.83*2.83/4 = 2W
You can see that for a speaker sensitivity of 98 dB, 2.83V @ 1 m, the power required to obtain 98 dB will be 1W only if the impedance is 8 ohms resitive. If it is 4 ohms then you need 2W to get the same 98 dB of SPL.
According to Klipsch, the nominal impedance of the KF-28 is 8 ohms, that's why I assume it takes 1W to yield 98 dB @ 1m. For every doubling of power you get SPL increase of 3 dB, hence 16W for 110, 32W for 113, 64W for 116, 128W for 119, 256W for 122, 512W for 124, and
600W for 124.69 dB, 1024W for 127 dB.
So in theory, if the impedance is in fact 8 ohms resistive and there is no room gain, 600W peak would yield a peak SPL of 124.69 dB. In reality, things wouldn't be that simple. The specified impedance of 8 ohms is "nominal" so we have no idea what it really is at a given signal at a given time, we also don't know the phase angle between current and voltage but it is highly unlikely that the load impedance will be purely resitive. Also, there will also be room gain due to sound reflections/reinforcement, how much gain you get depends on placement of the speaker and how it interacts with your particular room.
Now let's say we ignore any room gain effect, we are talking 124.69 dB only at 1m. For every doubling in distance you get 6 dB less, so at 4m, you get 124.69-12 = 112.69 dB. Again, in reality, you mostly likely will have room gain, 3 to 6 dB is quite possible so in the end you would most likely get more than 112.69 dB from 4m, with 600W, assuming the speaker can handle the power without any sort of compression.
Keep in mind at the end of the day we are dealing with lots of assumptions and approximations, but it probably do get you in the ball park, say within +/- a few dB.
