The Live Room
The live room is the first thing you see when entering Grape Jam's front entrance. Consisting of the Drum Room and the Piano Room, there is more than enough space to capture huge live tones.
The Drum Room has a flush-mounted array of 30 XLR inputs and 8 XLR returns. Above is a headphone amp with 8 mono outputs. The piano room has 8 XLR inputs and 4 TRS outputs. Headphone extension cables are used to provide full mobility.
Because the two rooms are only partially separated by a 3ft pony wall, we decided to approach it as one large room instead of two separate ones, with a few minor exceptions.
The rooms are treated using a variety of methods in order to achieve the most even and natural sounding environment possible. Our first concern in a room this large was getting the RT60 under control. To accomplish this, we built custom absorption panels out of dense mineral wool batts and acoustically transparent fabric, and placed them where they could be most effective. Multiple iterations of the treatment design and location combinations were tested and compared for optimization.
The designs and placements of the panels were decided based on two main factors, comb filtering and frequency response. Comb filtering is caused when a sound wave reflects back and forth between two parallel surfaces, resulting in a modulated standing wave and a ping-y echo that is in most cases undesirable. The thickness of the panels, as well as some other variables such as distance from wall and shape of the surface, allowed us to target undesirable frequency bands and manipulate properties such as phase, amplitude, etc.
In the back and left side of the drum room, the upper corner is finished with a 45 degree angle, breaking up the parallel reflections and preventing the aforementioned issues. However, we still needed their surface area for absorption in order to reach our target RT60 time of .4s. Many ideas were pitched, but nothing worked until Adam had an idea. The 45s are covered in polycylendrical diffuser surfaces with an open top and bottom. This design allowed us to fill the polycylenders with mineral wool and achieve a sufficient volume of absorption while still maintaining the space of the high end reflection. By alternating the orientation of the polys, the reflections were distributed much more evenly throughout the room and lobing, or buildup, is avoided.
Now that we had that problem solved, we needed to treat the cieling. Because of the hardwood floors, a sufficient percentage of our absorption target needed to be above the optimal drum position and the optimal piano position. This type of treatment is often referred to as a cloud. For the drum cloud we had a few objectives. Prevent comb filtering, maintain liveliness, and effect frequencies down to the low mids. In order to maintain livliness we decided on a modular design. Directly over the center of the kit is a 2ftx4ft absorption panel with 7 inches of r15 mineral wool, handing 12 inches from the ceiling. This thicker panel with a lower hang allows the panel to absorb a lower range of frequencies. The outer panels are designed in a sinosodul shape that gradually gets closer to the ciling. This allows for gradation of 1/4 wave vectors and allows more space for the high end waves to develope.