This is a story that happens time and time again in hundreds of rooms all around the world. It is a tale of terrific audio gear, talented people, good intentions and… terrible sound. In this particular case, Anthony Grimani of MSR Acoustics played the role of the “room doctor,” while a famous music studio played the “patient.” In the wings, a well-known composer waited to hear the outcome. Would he be able to use his new studio composition room? Or would he have to continue using headphones?
But the problem was the sound. The room had a sound character that made it impossible for him to hear his music clearly and cleanly. Furthermore, the acoustics of the room affected the soundstage presentation at his seat at the keyboard. What should have been a continuous 90-degree arc of musical images smoothly spread out in front of him, became a muddled combination of sounds lumped into a pile by each speaker.
The reasons for the problem were varied, but primarily involved the arrangement of sound materials previously installed in the room. The walls had all been treated with an eight foot-high layer of absorptive cotton material covered with stretched fabric. This was just too much absorption; the room sounded dry and lifeless, and the bass response was muddy and lacking detail.
Roussel was so disappointed in the sound of his room that he literally worked over headphone and left the studio sound system unused. When he heard about Anthony Grimani and his well-earned reputation, he gave him a call. When Grimani got the call from Guillaume Roussel, he was happy to help. He showed up at Roussel’s studio with a truckload full of MSR acoustic materials, special stands for simple and temporary installation, and a wealth of testing gear to verify and calibrate the room.
The biggest logistical challenge was how to install the MSR materials without removing the existing absorptive wall coverings. Grimani used 4’ x 8’ sheets of a thin Masonite material to cover up the bulk of the absorptive wall surface. This lessened their absorption and made the room livelier. The special stands were arranged around the room with modules from MSR’s Zsound™ Ensemble line, strategically mounted along the room’s perimeter:
- Side Walls: AMI absorptive panels first, then C-fuser 2D diffusers, AMI modules and Trifuser 3D diffusers.
- Rear Wall: Two Trifusers were added toward the corners with absorptive area in the middle.
- Ceiling: Two absorptive Cloud panels were mounted above and adjacent to the listening area, with two Trifusers behind them.
- Low Frequency Control: Two patented SpringTraps™ were placed in the front corners of the room with Corner Bass Filter panels above them.
The initial listening tests were very encouraging. Bass was much cleaner and tighter, the imaging was more spacious and detailed, and the music sounded livelier. But before moving into the test and calibration phase, the system verification process revealed a faulty cable, as well as a need to reconfigure the signal path of the signal processors, 5.1 channel monitor-controller, and subwoofer amplifier-processor. Speaker positioning was adjusted for optimal imaging, and the overall system balance and set-up was checked. Once everything was verified to be correct, testing and equalization could proceed.
Grimani first tested the signal path quality from source to speakers, the response of the signal processing functions for subwoofer crossover and equalization, the rubs, scrapes and distortions of the speakers, and the rattles in the room. Then he used a set of nearfield impulse responses to verify and tune the direct field of the speakers. Finally, spatial and temporal averaged frequency responses at various listening locations in the room were measured in order to set the room correction EQ to a target curve. Finally, after exhaustive listening tests by Grimani, Roussel, and Richard Frank, MSR’s Sales Manager, the speaker voicing was fine-tuned with digital filters in the processor. For a final touch, Grimani memorized precision settings for listening at the workstation, as well as the couch locations. Roussel can simply recall those from the processor at the touch of a button.
Grimani has measured, tested, calibrated, equalized and troubleshot almost 500 sound rooms, studios, theaters, and listening rooms. “There are no two ways about it,” explained Grimani, “this is complicated stuff to get right. There are many places where adjustments can be dialed in, connections can be innocently done wrong, and troublesome room interactions can degrade performance. The only way to get optimum performance is to professionally treat the room’s sound characteristics with appropriate acoustical treatments. Then you can successfully conduct a test- measure-and-listen approach that will yield reference-grade sound.
What I recommend is, first treat the room acoustically, then check and debug, then test and measure, and finally equalize, tune, and voice the speakers. As long as all the technical gremlins have been discovered and exorcised, and the steps above have been followed, you will be set up for best performance.”