Case Study

Cinema Acoustic Upgrade

Problem: In this study of a home theater, with high-end two channel listening being a priority, we were asked to optimize the existing room for the audio presentation. We were also able to optimize it for the video presentation. The room initially had Kinetics acoustic treatments in the corners, as well as some limited bandwidth absorption at first order reflection points on the side and rear walls.


Before

During

After

Solution: First we optimized the speaker/listener locations, which made a great improvement for the client. We then moved the projector to optimize its throw distance for the existing screen, which was also positioned at a new height. The FRP system was installed on all four walls and about 75% of the ceiling. This was covered with a very dark blue and black, acoustically transparent fabric, allowing for a picture that pops and does not have reflection, color or “light-up” interferences. Voicing of the entire electro-acoustical system was also performed. Before voicing, the system was strained and could not play some passages without noticeable distortion. After voicing, the system could play reference levels without any signs of strain.

Result: Below are the modeling reverberation times estimate, and the actual reverberation time measurements. As can be seen depicted in the graphs below, the room sounds very natural and articulate due to the FRP system.
·  FRP is effective down to 63 Hz. and is only 2.5” deep
·  Controls room modes, first order reflections, reverberation times and flutter echo in a linear, tunable fashion
·  Conceals with an acoustic stretch fabric system
·  Fitted on-site by professional installers

“We are truly enjoying the acoustic environment you have provided for our cinema/music listening room”.


Estimated Reverb Times

Actual Reverb Times

Click to enlarge graph

Reverberation is probably the most recognized characteristic of a room’s sound. Reverberation is the acoustic energy in the space that lingers on after the sound stimulus has been removed. Each room’s reverberation times at each frequency are as unique as a signature. Ideally, we want the reverberation times to decay at the same rate across the audible bandwidth, and within a time window of about 0.25 - 0.35 sec. This allows for neutral sound conditions. An exception is for frequencies below about 100 Hz., where we need slightly longer decays in order for our brain to make sense of the difference between what our ears hear vs. what our eyes see. Lack of reverberation control results in masking of low-level details, loss in dynamic range, soundstage, timbre and articulation.