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May 10, 2006

Rick Levine belives that three individuals are responsible for the death of the high-end audio market:

  1. Henry Kloss, who decided not to publish specs of his speakers
  2. Amar Bose, who further eschewed the idea of publishing specs, as well as popularize the concept of Wife Acceptance Factor in home audio.
  3. Bob Carver, who introduced “magic” into home audio (an example Rick pointed out was Carver claiming that one of his amps could generate 3000 watts of power, dispite the fact that U.S. 120VAC power is limited to ~1500 watts of power by law and no amplifier is 100% efficient).

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The Boston Globe published an article about ongoing upgrades of the MBTA’s station public address system:

“Once acoustic engineers install and adjust new speakers over the next year, T officials say, there will be a major improvement in getting information to passengers, who have complained for decades about garbled announcements.”

There are several acoustical engineering firms from Massachusetts, New York, California, Texas, and Maryland working on this upgrade. Given the age of the system it’s been a challenge, but as you can see from the Globe article, progress is being made.

The goal of the new PA systems is to meet National Fire Protection Association speech intelligibility criteria. The Common Intelligibility Scale (CSI, which is directly related to the Speech Transmission Index, STI) is being used to quantify the performance of the current and new systems. These metrics can determine the intelligibility of speech broadcast over the PA system in the presence of background noise (e.g. trains), excessive reverbaration, and system distortion. Acoustical modeling tools like EASE are being used to design the upgraded PA systems and to optimize CSI/STI.

All in all, this should lead to a significantly improved PA system at MBTA systems - given the fact that the new announcements have been received favorably by the public, despite the fact that the optimizations have yet to be completed, bodes well.

[Thanks for the heads-up Lance!]

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