The KickStand performs two functions at the same time: it stops vibrations from entering the mic and it stabilizes the microphone to more accurately capture of the sound. The science behind the KickStand is really not that complicated. In fact this is all well known stuff… the KickStand so happens to bring it all together in a single device.
Isolating The Microphone
It has to do with motion and countermotion, very much like the recoil of a rifle. Shoot… the bullet goes forward while the rifle moves backwards. In this case, sound or vibration is coming from the kick drum, the drum riser, the floor, the bass guitar and the PA system. The vibrations are transmitted through various mediums including the floor and air.
When sound from the kick drum is mixed with resonant sounds from other sources, the two combine and invariably some frequencies will combine ‘in-phase’ and get louder, while other will combine ‘out-of-phase’ to cancel each other out. This causes a comb-filtering effect. Whether sounds are combining or canceling, this will ultimately change the sound of the source.
The 2″ thick foam isolation pad is made from high density open cell acoustic foam. Too dense and vibrations will be transmitted as if a solid object. Too thin, and the low frequencies will ‘jump’ across the narrow space. Too soft or too thick, the stand will loose its stability. Finding the right balance is critical. The foam isolation pad provides the isolation, very much like the springs on your car. It makes riding over bumps acceptable.
Stabilizing The Microphone
This is where things get interesting: Each vibration or audio frequency has a different wavelength. If you allow the microphone to vibrate back and forth, it follows that the distance from the batter head will change which will cause a slight Doppler effect as the mic moves away from the source. At low frequencies, this will cause a minute phase shift.
If you can hold the microphone in a steady state while the rest of the world is vibrating and moving, you will get a clearer picture. For some, this level of precision is not required. For others, they use terms like ‘floating in the mix’ to describe how the kick drum seems to gain clarity. The heavy steel plate acts like the shock absorber. If the foam was left alone, like springs on a car, the mic would float all over the place. The ‘massive’ stabilizing plate holds the mic boom and microphone in place to ‘steady the ride.’ These two combine to deliver a more accurate rendering. This makes the KickStand a must have for the more demanding engineer.
Review by Craig Anderton
Excerpt from Harmony Central… Read the full review online.
“The object [of the KickStand] is to isolate the mic from floor vibrations to give the cleanest possible recording. But how do you actually prove or disprove that it works as advertised?
…verifying the KickStand performance presented a unique challenge. After some thought, I came up with a solution. For the “control,” I’d mount the mic on a tripod sitting on the floor, then compare the mic output to the same mic sitting at the same place on the floor, but using the KickStand.
As luck would have it, though, part of the studio has a section with a floating floor. The floor board had a sufficient amount of flex that I could get it to move up and down by pushing on it hard. I thought that if this could be done predictably, and without generating noise, it would actually be a better test because if the KickStand could reduce low-frequency thumps, that would minimize problems due to hi-hat and kick drum pedals, lead guitarists prancing across the stage, and the like.
I stood on the floating part and, keeping my feet on the floor, bent from the knees and moved up and down (sort of like a mild squat thrust). This shook the floor a reasonable amount, and was easily reproducible – my height and weight were not going to change during the course of the review! Best of all, the process made virtually no noise.
Now look at Fig. 2, which shows a recording of the mic with tripod (left) and with the KickStand (right). Yes, I was as surprised as you probably are: That’s a major difference. I measured the average RMS power of each sample, and found that the version with the KickStand reduced noise by about 8dB.
So, mission accomplished. I was able to test the KickStand’s isolation perhaps not with total scientific precision, but with enough predictability to find out what I needed to know: This really works. If you’re mic’ing kick drums, for about $75 KickStand is a great addition to your toolkit.”