The Unseen Variable Sidebar: Sonic Speaker Tailoring
It's not readily appreciated that a loudspeaker's treble balance exercises a powerful control over perceived clarity, right into the midrange. The perception of a loudspeaker's quality hinges strongly on the balance the designer has achieved between the midrange and treble levels—both in the on-axis frequency response and in the acoustic power delivered to the room.
This is very critical, and if a speaker system lacks sufficient clarity, the designer may be led, intuitively or deliberately, to lift the treble power to improve things. It is amazing what can happen with as little as 0.5-1dB of treble lift, but this is a very dangerous procedure, as too much treble energy will disturb the neutrality and tonal accuracy of the sound. Violins become edgy, flutes breathy, and vocalists have too much toothy or sibilant emphasis. In addition, treble-dominant sounds no longer sit back in the soundstage, where the record producer intended them to be.—Martin Colloms