Interesting Acoustic Locations of Charlotte (IALCs): 1601 Abbey Pl.

I am all about soundscapes.  The complexity and affective nature of how they operate and impact our daily lives (often without the slightest recognition by passer-bys) is fascinating to me.  

Recently, I've come across some acoustically dynamic locations around my fair city of Charlotte where the psychoacoustic effect from being in a specific location is particularly intriguing.  Or simply put, it's pretty cool.  So I've decided to start building a list so that others can check these places out as well.  This is not just for sound designers looking for unique impulse captures or secret recording locations, but for anyone that wants to experience the full effect of what a soundscape can do to their awareness and disposition when moving through it.  And they are totally open and free, which makes them even more awesome.

The first locale that I'd like to highlight is 1601 Abbey Pl.  This is an open ground level garage at a medical facility just off of Park Rd., quite close to the Park Rd. Shopping Center.  

As far as parking decks go, it isn't anything that special.  Acoustically however, it is potentially unique.  It is an open rectangular prism around 60m x 17.5m x 4m.  Three of the standing walls are semi-open with a single large drive-in gate and the balanced placement of barred openings (of which, the ones on the short ends of the space extend only halfway down the walls).  The structure is primarily composed of smooth concrete and iron fixtures with an elevator door parallel to the entry gate.  There is florescent lighting (which is a bit of a bummer), but it is fairly quiet and could be easily masked in most recordings.  The positioning of the entire structure offers some shelter from noise pollution that would be coming off of Park Rd. and in general, does a pretty amazing job of blocking out most other public noise sources.  

What makes this location special though is the placement of the sound dampening material.  The entire ceiling, pillars, and back wall are completely covered with a large-particle spray foam insulation (possibly the K-13 cellulose system) that creates perfectly irregular surfaces across all of these areas.  The effect is immediately noticeable when you get out of your car.  As well, the effect of sound not being dampened at both ends of the space allows for some pretty interesting reverberations.

The entire structure is like a large, half-sound-proofed, partially open-ended air column that you can physically stand in and observe, quite clearly, the movement of sound waves across its full length.

Assuming the standard velocity of sound through air (340 m/s), the roughly estimated fundamental frequency of this space is 2.83 Hz.  Therefore, you can't hear the fundamental (and realistically anything before the 5th harmonic frequency at around 44 Hz), but you can still observe an impressive phenomena.  With a highly directional transient (like a loud clap) standing at one end of the garage and facing perpendicularly to the opposite end, you can hear early reflections directly with an almost perfect .33 second delay.  

This structure might or might not have been designed to have such acoustic properties, but nevertheless, it does, and they are pretty slick for an unassuming parking garage.  Go check it out!