8
Speaker Grills
Your Sapphire XLs are supplied with cloth covered grills which enhance the appearance of your
speakers and provide some protection for the drive units. To protect the drivers we recommend leaving the
grills in place most of the time. However, for the most critical listening we suggest removing the grills.
Positioning the Sapphire XLs
As mentioned, the proper placement of speakers in your room will easily improve the sound.
Because all of our rooms and tastes are different, it is impossible to specify a “correct” placement. Instead,
let us present you with some acoustical facts, then you can optimize placement in your room.
It helps to visualize sound waves as behaving very much like water waves. The sound we hear is
made up of two types of waves. Direct sound waves come right from the speaker and are not changed in
any way. Reflected waves come to us after bouncing (diffracting) off the speaker enclosure itself, or walls,
ceiling, floor or furniture. If you want to see how much these reflected waves affect the sound, move your
speakers outside and hear the difference.
Sound waves come in different lengths; the lower the note, the longer the wave. Extreme low
frequencies such as the lowest organ pedal notes are over 60 feet long! If your room is not big enough, the
wave can’t develop fully. But the biggest problem with bass notes is the phenomenon we call standing
waves. In effect the waves more or less “pile up”. This creates big peaks and dips in the bass response. If
you put a certain frequency through the speakers, you can usually walk around the room and find places
where it is very loud, and places where you perceive virtually nothing.
Just as the room affects the bass response, so it affects the mid-treble sound of the system. In the
mid-treble range, the sound waves are shorter and have peaks and dips, most of the affects (peaks and
dips) occur from enclosure edges, furniture, walls, or the floor. Sapphire XLs exhibit the deepest image
when placed away from walls and furniture. The shorter wavelengths of the mids and highs are more easily
absorbed than the longer wavelengths of low frequencies. This is why a bare room sounds so harsh
compared to a room with a lot of stuffed furniture, carpets, drapes, etc.
An ideal setup for sound would be achieved if you could:
•
Choose a room with width, height and length dimensions that are not multiples of each other. (A cube
would be the worst!) Good numbers might be something like, height = 8 feet, width = 15 feet, and
length = 26 feet.
•
Choose a room that has an irregular shape, non-parallel walls cut down on standing waves.
•
Place the speakers so that the woofer cones are at irregular distances to the floor, walls and ceiling.
This can be difficult. Use a tape to measure the distance from the center of the woofer to the room
boundaries. Move the woofers around till you have cut down on the number of related distances. (You
don’t want distances like 12 and 24”, but more like 12 and 22”). Use the distance from the woofer to the
boundaries to increase or decrease bass output. Sticking the speaker in the corner or close to walls will
give more bass output than putting the speaker out into the room. You can use this to get the best
balance between bass output and upper range output.
•
Use absorbent materials to help smooth upper-range response and improve transient response and
clarity. Why? Let’s take the sound of a bell for example. First you will hear the direct sound from the
speaker. But some of that sound bounces from wall-to-wall, ceiling-to-floor, off furniture, etc. before it
reaches your ears milliseconds later. Because the time difference is short, you don’t hear an echo, but
the sound of the bell is stretched out from something like a “ding” to a “ddiiinngg”. Some speaker
engineers have begun to realize this and are addressing the problem in their latest designs. This is why
we are now seeing very directional designs. This controlled directionality increases the amount of direct
sound in proportion to reflected sound.
