Defining the Room Layout   

    After signing the lease for the new space I spent a fair amount of time trying to figure out how best to divide the space into the rooms I wanted.  Basically I knew I wanted a largish main room, two isolation rooms, a control room, and, of course, a bathroom.  In fact locating the bathroom became a major headache once I realized how much it was going to cost to have it moved to the spot I really wanted it.  The very first compromise was made long before the first piece of steel was put in place; the bathroom would stay where it was and I'd build around it. 

    I also realized that to maximize space utilization the rooms were going to have to be rectangular; no splayed walls.  That's not as big a compromise as it might seem.  The biggest advantage with non-parallel walls is that you avoid most of the flutter echo caused by repeated reflections back and forth across a room.  The disadvantage is that room modes become a lot more difficult to determine.  I'd also read that there were three ratios of height-width-length which were advantageous should one need to build a rectangular room.

    All rooms have "modes" or frequencies whose wavelengths are integer fractions of one or more of the room's dimensions.  That's true even for rooms with splayed walls.  The rationale of building a room based on one of the three "magic" ratios is that while you get all the primary, secondary, and tertiary modes that exist in any room the fact is that almost none of them coincide with one another in frequency.  That means there are no wide gaps in the frequency spectrum that are devoid of standing waves, and that there are no places where lots of modes bunch up to cause a serious enhancement at any given frequency.   Given an approximate reverb decay time of a few tenths of a second the bandwidth of any of the room modes should be a few Hz.  When all of these broadened peaks are added together the result is a room with a pleasantly smooth frequency response, from the lowest frequency the room can sustain up through a few hundred Hz.   Above a few hundred Hz the wavelengths are small enough that normal wall treatments and diffusion can keep things under control. 

The three ratios are, letting height = 1.0:

    The total amount of space in the warehouse section was 1400 square feet; a roughly 32 by 30 foot section and a roughly 15 by 30 foot section.  The drawing, below, is a rough outline of how the studio is laid out.  The room designations and interior dimensions are indicated.   

This drawing isn't exactly to scale, but the dimensions shown are correct.  Note that the control room is not optimally shaped.  The asterisk next to the Control Room's height value is because the ceiling in that room is sloped, beginning at 8 feet (at the right side) and sloping to 10 feet in height, giving an average height of 9 feet.  This helps direct reflections from the monitors, which are located near the right wall, into a diffuser array located on the wall at left.