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Frequency Response Effects
As you listen to music, images of the instruments that created the sounds are elicited. For
instance, one can tell the approximate size of a drum from the sound it produces. On a
high-resolution playback system, finer details can be heard; i.e., is the head made of plastic or
calfskin? Is the player using light sticks or heavy ones?
A relatively broad-band emphasis (or de-emphasis) of a given frequency range can tend to
exaggerate (or diminish) the relative size of the instruments playing in that range. A useful
tool for evaluating these distortions of size is a recording of a small group of unamplified
acoustic instruments made with a simple microphone set-up.
Listening for Size Distortions
Play a recording of this type, with the volume adjusted to achieve a natural playback level. As
you listen, create a mental image of the players based on sounds being recreated. Then ask
yourself, "Does this sonic image correspond to the musical instruments that generated these
sounds?"
Is the portrait a natural one, or are certain elements distorted? Does a stand-up bass sound like
the correct size, or is it exaggerated, sounding like it is ten feet tall, or as if the strings are the
size of ropes? A speaker with excessive in-room bass response can create these effects. On the
other hand, a speaker system with rolled-off bass can shrink the size of instruments, turning
the same stand-up bass into a cello-sized instrument.
