Tools of the Trade – By Pat Brown
Lakewood Church room impulse responses allow you to listen to the space, analyze the data, and take a virtual visit to one of the best-behaved arena-sized spaces in the world.
A Missed Opportunity
Last year the Houston Syn-Aud-Con classes visited Lakewood Church for an evening tour headed by Russ Berger, Reed Hall and Brian Tankersley. We had a great tour, but no opportunity to get some measurements of the sound system and room.
We returned to Houston in January for the Sound Reinforcement for Designers seminar, and made it a point this time to collect some data in this excellent space. Lakewood Church was former home to the Houston Rockets. The 16,000 seat room was converted to an auditorium under the guidance of Russ Berger Design Group. This involved significant acoustical treatment to tame the room’s decay time, which exceeded six seconds in the lower octave bands. This was halved by converting the existing air returns beneath the seating into tuned bass absorbers – clever, effective and economical.
Small Spaces Too…
Lakewood also has extensive editing suites and a world-class recording studio. Russ and I snuck up to the main studio during the tour to record a couple of sweeps using one of their Genelec monitors as the source. The acoustics of this room can be adapted per use via modular, movable absorbers.
Log-sine sweeps were recorded using a TetraMic and portable recorder. The sweep source was an iPod Touch. It was determined that our test loudspeakers could not sufficiently energize the space, so we used the left line array (JBL Vertec). The test positions are indicated in Figure 1. I used the TetraMic to record 4-channel A-Format, and then decoded to 90-deg coincident cardioid as a post-process.
Put yourself in the room.
Download Lakewood IRs
Project 31 on the IR Exchange
Some ways to use this data:
- Convolve with anechoic program using GratisVolver
- Check reverb time, clarity, etc. using a measurement program
- Evaluate direct field spectrum using a measurement program