Below are screen shots of the wave diagrams of the part of the prelude that has an A pedal. In the wave diagrams, the vertical axis is volume and the horizontal axis is time. The upper diagram is with the guitar tuned down a major third and the lower one is with it tuned down a minor third. You can easily see the pedal notes on the 5th course; they stand out about twice the volume of the other notes. The notes on the 5th course are the parts of the blue that stick out above and below - you can count about 12 in the top one and 11 in the bottom (apparently I played one of the bass notes softly in the second piece shown here).
If we zoom in on 3 of the notes you can see the sharper peaks and quicker roll-off in the top diagram; it is from the guitar tuned down a major third. The bottom one, with the rounded attack and slow release is the guitar tuned down a minor third.
I've posted both of these fragments on soundclick, and I think you can hear the difference.
The major third is here.
The minor third is here.
I'm still baffled by this problem. The LKSM is designed to be tuned down a minor third, but that is exactly when the problem is most noticeable. It may be that I need more room treatment. From what I have read, room reflections can occur at many more frequencies than just those produced by room dimension nodes. Before I spend hundreds more dollars on room treatment, I plan to test out this theory by
- recording in another room
- recording outdoors
Note: wave and spectrum diagrams are from Audacity.