Excursion Maximum 101
Kicker SoloX Subwoofers
Recommended Applications
Page 25
As you read the specifications for your SoloX you may notice a new parameter called EXmax. EXmax stands for
Excursion Maximum and expresses the maximum one-way linear excursion capability of the driver based on:
1.
Linearity (how much distortion the speaker system exhibits)
2.
Excursion limits of the moving parts (how far it can move before it breaks)
3.
BL (the strength of the motor assembly)
In other words, EXmax tells you just how far the woofer is capable of moving before reaching the physical limits of
the moving parts, diminishing motor strength and NOT taking into consideration how much distortion is created.
Strange statement huh?!
Let’s break it down.
When a woofer is used for EXTREME SPL (notice that
...
EXTREME SPL
) applications, it is driven well out of the linear
range that would be used if sound quality (low distortion/high linearity) were your goals. Any woofer can be driven
to the point where it starts exhibiting non-linear response. At this point the distortion of the system starts to rise
and BL starts to fall off. There may be more linear excursion available but your ears tell you it is starting to sound
bad, un-natural, so you stop turning up the volume as you have reached the limits of that system for a linear
response (low distortion). But what if low distortion was not a measuring criteria? What then?
This is where EXmax comes into play. SPL is all about compressing air, and besides, who cares if it is 40% distortion,
Mr. SPL Microphone sure doesn’t! Your not listening to it for pleasure, only trying to compress the air inside a vehi-
cle to impress a microphone. We personally would never want to listen to a system at 40% distortion for more than
about .05 seconds...tops.(most people under the age of say...umm...80 would agree) But if you are standing out-
side a vehicle sealed up tighter than a frog’s bum burping test tones to get a really big number on a meter, sub-
woofer linearity (distortion) is not a factor. Compressing the air is your goal in this scenario, not necessarily linearity.
This does not mean a high SPL sub is designed to be non-linear or exhibit high distortion, it just means ANY sub
driven into non-linearity will exhibit high distortion. But if the sub can continue to compress air even though it is
operating at a high distortion level you will get more SPL. Make sense? Great!
The SoloX was designed to excel in vented enclosures and achieve extreme SPL numbers when asked to do so. That
is why the EXmax specification is shown, to let you know just how far this baby can go when asked to bring the
house down! The EXmax figure is derived from driving the SoloX until 55% linearity is achieved and measuring the
EXmax at that point. The SoloX has a
TREMENDOUS
amount of motor strength and an over-built cone/suspension
system which allows it to drive well into the non-linear operating range and still compress air to make SPL.
So what you are saying is that the SoloX is a high distortion/high SPL subwoofer?
No! No! No!
We are saying the
SoloX is capable of
EXTREME SPL
output and at those levels you will have high distortion. (ALL subs have high dis-
tortion when played into a very non-linear range) If the SoloX is played under NORMAL (in other words... NOT
EXTREME SPL
) conditions it can play very loud and very low with very high linearity/low distortion, just like you
would expect from a KICKER subwoofer.
Now that you know what EXmax is and what it means, hit the wood shop, eat some dust and get your enclosure
built. Your SoloX wants to go outside and play!
