This is to clarify the way the PSR2000's 'sound sample' (voice edit) EQ feature works. After performing some further tests, I have determined (on the PSR2000), that the bell curve area which Andrea refered to above, is approximately an octave and a half below and above the selected frequency. To test this out, I first set the 'low frequency' to 450hz (which is fairly close to concert 'A' pitch 440 hz, the note A above middle C). I then set the gain to +12db. When I play the note 'A' and compare it to the orginal (gain set to: 0), I clearly hear the difference. This difference is noticeable for about an octave below & above the 'A' note. Below this point, there is no noticable difference in gain. I performed the same test setting the high frequency parameter to a give value and boosting it 12 dbs as well and got the same results.

Effectively, the PSR2000 'sound sample' equalizer is essentially a 2 band type which affects specific frequencies (and a relatively narrow band around that frequency). It IMPORTANT to remember that this EQ function only affects the given sample.

There is a 'separate' 5 band equalizer used for customizing the sound of the entire keyboard output, located in the PSR2000's 'Mixing Console' page. This Equalizer lets you determine the frequencies (five total) and gain levels, as well as set the band width. VERY cool!

Here's a link to an excellent chart which shows the hz (cycle per second) for all the notes (pitches) of a piano. You will notice that 'hz' doubles when you go up an octave and is halved an octave lower. This should provide an easy way to determine what range of notes you are actually boosting/lowering when you select a given frequency on the PSR2000's Equalizer. In fact, this chart should be useful for all synth/arranger keyboard owners: http://www.pianoworld.com/pitch.htm