Archive for the ‘Audio’ Category
An Equalizer Can’t Fix your Room’s Problems
Most stereo systems come with some level of user adjustable equalization. The equalizer electronically adjusts the frequency balance of the music being played before it ever reaches the loudspeakers. It is most common to see users set their EQ in what is known as a smile curve. A bit higher at both ends than it is in the middle forming a curve reminiscent of a smile. Given the way human hearing works, this is actually a sensible approach.
While many people may use the equalizer to try to modify the tonal balance of their audio system to compensate for room effects, this is really a very sub-optimal choice. Rooms do indeed affect the balance of frequencies that reach the listener. Unfortunately, however, specific room effects are very localized within the room. The room distortions that reach one listener may be completely different for another listener located just a foot or two removed from the first listener. In these cases adjusting the audio with the equalizer may correct for one specific section of the listening area, but may make it worse for everyone else in the room.
Most people have experienced the dueling remote control effect in home theater rooms, or even with their ordinary television audio in their living room. This occurs when one person can’t make out the dialogue clearly, so they turn up the volume thinking this is simply a matter of the TV not being loud enough. A spouse seated in another part of the room, or even right beside them on the sofa finds the raised volume objectionably loud and had no problem hearing what the characters were saying. While this is often attributed to the husband suffering from the early stages of hearing loss, it is quite often attributable to audio distortions caused by room effects. If the vocal range of the audio spectrum is being distorted or partially cancelled in the area where one partner is sitting, it can strongly affect vocal clarity.
Rather than adjusting the volume or the equalizer to boost the vocal range thereby making it worse for others in the room, the correct solution is to take steps to eliminate room acoustic effects. Installing acoustic panels on the side walls to reduce distorting reflections can make a huge difference in the clarity of not only the vocal range, but of the entire musical spectrum. Once this is done, arbitrary equalizer adjustments become unnecessary.
The smile curve, however, can adjust for the innate sensitivity of the human ear. In normal circumstances, the human ear hears best in the range where the human voice falls. It hears bass tones much less efficiently, so adding a little boost at the low end can compensate for this. As we grow older, often beginning in our twenties, most of us begin to lose hearing sensitivity in the uppermost frequencies as well. The other end of the smile can help correct for our aging ears. Use the equalizer for this, but not to correct for room effects.