OEM,
I can't remember from where I copied this chart, but similar ones are online, and are more associated with recording/mixing sites. I love them because they remind me why I listen: music!
If I recall correctly, the entire horizontal bars are the audio frequencies produced by the instruments, with the red portion of the bars representing the fundamentals and the yellow portions the harmonics. Both affect tone, help us identify what instrument we're actually listening to, and are a function of instrument design, tuning, or both. The kick drum signature you're hearing through your monitors are the upper harmonics. Seeing (from the chart) the kick drum's harmonics start at about 500hz and represent half of the total range of the drum (up to about 8khz), it would make sense you hear it through your monitors. Or, more importantly, you should hear it!
Roscoe and JLM bring up great points about the 80hz region being responsible for a lot of our bass perception, and the 120hz being smack in the mid bass range and related to mid-bass body. If you look at the narratives near the bottom of the chart, 80hz is near the middle of the zone often subjectively associated with a sound having "body," and 120hz is in the range subjectively associated with "boom/punch." JLM points out allowing a subwoofer to carry more of the load up to 120hz (through both the subjective "body" and "boom/punch" ranges) could compensate for the lack of "body" in some monitors. The chart supports what both said 100% (not that they needed to be validated!)
Here's a interesting way of looking at the chart. It lists the kick drum's range (fundamentals and harmonics) as 50hz-8khz. If you take the midpoint of that range and follow it down to the subjective descriptions near the bottom of the chart, you'll end up between the subjective "fullness/mud" and "whack" and "tinny" sounds. Many of the frequency ranges contain both positive and negative subjective narratives. Which description actually applies depends on how the instrument should actually sound (by design or tuning), or ones personal preference. The midpoint range of the kick drum actually falls in the subjective "honk" sound...but since the kick isn't a brass or a woodwind instrument this may not apply But that midpoint includes the "fullness/mud" subjective range, but does not include the "whack" or "tinny" ranges.
However, all the descriptions fall within the total range of the kick drum. The key is the midpoint, or the balance of the instrument...as reproduced by the audio system. Perfectly reproduced, the kick drum would sound full (balanced.) But under-reproducing the lower frequencies and/or over-reproducing the upper frequencies would shift the midpoint toward the "whack" "tinny" range. Doing the opposite would shift the midpoint towards the "mud" range.
Another thing I like about the chart is how it highlights what we hear so much about: the midrange. Notice how often the transition between fundamentals and harmonics occurs in the midrange.
