"I have heard reference to graphic EQ's being used for tuning a monitoring system (i.e. compensating for control room and monitor inaccuracies). I also read in the Acoustics Summit of a person who said he had a 60Hz spike in his studio. Hearing these two things got the gears in my head turning. How is this done? Does one send a pure "white noise" signal directly out monitors, use a near-perfect microphone, record the signal into a digital system, and then analyze the spectrum? Sounds a little tough, but I can't think of another method."
A logical mind is a beautiful thing. You are on the right track. Tuning speaker systems to have a flat response in a room has long been a challenging task. One of the common tools for doing this over the years has been the equalizer because it makes the chore pretty easy and fast (in that it doesn't require custom speaker enclosures and crossovers), which is especially beneficial when the system must move locations frequently as is the case with touring sound and monitor systems.
Being able to hear specific peaks and nulls in a system is not that easy to do with regular program material because it is so dynamic, so a common practice is to run pink noise (not white noise) through a system to tune it. A device known as a real time analyzer (RTA) is often employed to aid in the process. Basically one connects a very flat microphone to the analyzer, which is calibrated to our hearing in the same way as pink noise. If the resulting sound coming out of the speakers and reverberating around the room is flat (which it never is) the analyzer will show that as a straight line on its display. Where the line inevitably dips or peaks represent frequencies that need to be cut or boosted on an EQ. All one needs to do is set the EQ so the analyzer shows a flat response.
Well... actually it's not that simple. The art (and it really is an art) of tuning sound systems goes well beyond a rudimentary line on an analyzer that is referenced to one mic placed in some location in a room (as if the location doesn't matter). There are many, many variables that must be factored in, but the pink noise/analyzer/equalizer combination is a decent way to get in the ballpark in the hands of someone who really knows how to use it and interpret the results. It is pretty easy, however, to do as much harm as good with these tools.
With specific regard to studio monitors, most near field designs are built to be used... well... in the near field. The intention is that the speakers are much closer to your ears than the surfaces of the room so the interaction is reduced to an extent where you are hearing primarily just the output of the speaker. Combine this with modern speaker designs that really are pretty flat and you usually don't even need an equalizer at all. In fact, the phase, distortion, and other anomalies introduced by most (inexpensive) equalizers usually make these systems sound worse. Speaker placement often has a very profound affect on their apparent frequency response. An equalizer is to be considered a last resort in these situations.
Bottom line, this stuff isn't always as cut and dried as it seems. Your best bet is to call your Sweetwater Sales Engineer and discuss your specific situation. You may be well served by adding a nice equalizer to your system, but you may just need to reposition your speakers.
