The following are GENERAL tonal characteristics of maple, rosewood, and ebony fingerboards:
Maple--this is a bright, tight-sounding wood with a defined bottom end, a tighter midrange, and a crisp, detailed top end. maple requires a finish, so a lot of guys tend to think the fingerboard feels a bit "sticky." however, the use of satin finishes as of late has been a big step towards improving the feel of a maple board. maple is often favored by cats who want a bit more top end or definition in their tone or for brightening up a warmer-sounding guitar.
Rosewood--this is the most popular fingerboard wood and has a warm, rich tone with less top end than maple. rosewood doesn't require a finish, and lots of players like the feel of it because of its slightly oily nature. rosewood fingerboards are often favored by players who want to warm up a guitar further or for attenuating the highs on a particularly bright guitar.
Ebony--this is the hardest and densest of the three woods and has a tight, crisp tone which is even brighter than maple. ebony doesn't require a finish and has a very tight grain-because of this, people often refer to ebony as "fast playing" or "slick." it's easily distinguishable from dyed rosewood by its closed grain pattern as opposed to rosewood's open grain pattern. ebony fingerboards are often favored by players who want a very glassy and crystalline top end or a lot more definition and tightness in their low end. for this reason, it's often preferred by bass makers.
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