Automatic for the People Juneau AK

In recent years, there has been an explosion in the number of A/V receiver and controller products that include automatic speaker setup and equalization systems. We’ve seen manufacturers like Lexicon, Meridian, Pioneer, and Yamaha develop systems specifically for their products, while other manufacturers like Denon and Onkyo have opted for third-party offerings such as Audyssey MultEQ.

On the whole, I think this trend has been good for the industry. For one thing, it has raised consumers awareness that an audio system must be set up and tuned. It has also provided them with a way to get pretty decent sonic results without an advanced degree and lots of expensive test gear.

Automatic systems can even be useful to an experienced calibrator, because they significantly shorten the amount of time he/she has to spend measuring things like speaker distances and channel levels. Unlike the consumer, though, the experienced calibrator knows to independently verify the results of the automatic system through listening tests and additional measurements. Automatic systems aren’t foolproof. Without human oversight, they can be tricked into making some pretty goofy settings.

Acoustics Still Matter

A number of factors can throw off an automatic system, but the one that seems to crop up most often is room acoustics. Some people have the idea that automatic systems, particularly ones that include equalization, fix acoustic problems, so the room doesn’t need any absorptive or diffusive treatment. Nothing could be further from the truth. Sound reflections from untreated room boundaries interfere with the measurements, causing the brain of the automatic system to make incorrect decisions. The more controlled the reflections are, the more accurate the measurements will be. The more accurate the measurements, the better an automated system will perform.

This point was recently demonstrated when the broadcast audio producer of the Grammy Awards asked me to help with the acoustics of the pre-mix room (which was actually a converted temporary building). They were trying to use an automatic equalization system built into Genelec monitors, but it was producing inconsistent results in the pre-mix rooms untreated environment. On the other hand, the Genelec system was doing fine in the acoustically treated broadcast truck. The reflected sound energy in the pre-mix room was simply too strong for even a system as good as Genelecs to take accurate measurements. After we treated the room, the automatic system worked there, too.

Measurement Systems Don’t Hear

Sound reflections interfere with systems like the Genelec because they are not able to measure sound in the same way that humans hear it. It’s an issue common to all measurement systems (even manual) that use steady-state processes like RTA with pink noise or some type of time-based measurements with long or no time windows. Essentially, they analyze all the reflected sound in the room as well as the direct sound from the speakers. Nothing filters out the r...

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