Most AV processors and receivers these days come with auto setup routines. These can be a godsend and significantly cut down the time and complexity involved when first setting up a system. However, some rooms will “fool” these systems causing anomalies in their results and knowing how to spot and correct errors can make the difference between a magical sound and a disappointing one!
Since auto setup routines can come with AV receivers or AV processors we will just use the term “processor” in this article to cover both types. When we use this terms we mean an AV processor or receiver, it doesn’t matter which.
Auto setup routines come in a variety of flavours and each offers a different way of achieving its goal. All will require some kind of microphone and use test signals to detect room and speaker characteristics before recommending setting to suit. Because the content of the test signals is of a known type the processor can “listen” to the results using the microphone supplied the manufacturer with it. Because the microphone is also of a known type the processors will use it’s knowledge of the microphone’s performance and take this into account with its measurements. For this reason you should always use the actual microphone supplied with the processor.
The first step when using an auto setup routine is to sit down and read the manual! Knowing exactly what will happen and following the advice given can save both time and help achieve better results. Some routines will require you to move the microphone during its progress and, quote obviously, its best to know this and plan the locations you’ll use before you start!
Once the routine has completed take a moment to go into the menu again and look through the settings the routine has come up with. With all settings the first question you should ask yourself is “does it look reasonable”? Do the distances look about right and, assuming you are using a speaker set designed to work together, are the levels within a few dB of each other?
Anomalies here can be caused by any number of physical imperfections. These include “odd shaped” rooms (non square / rectangular shapes), large areas of acoustically reflective surfaces including glass, plaster of marble or possibly a speaker malfunction. Whatever the cause it will need investigation and correction before a proper listening experience can be achieved.
Next week we’ll start to look at manual setup. We’ll look at each aspect separately and see where we might be able to “tweak” the setting given by an auto setup routine to get the very best from our home cinema systems.