MartinLogan pmn - Manual (Page 9)

If your speaker system is not securely planted on the floor
or solid surface, it can shake as it produces sound and,
consequently, the sound can be compromised. If your
speaker is sitting on the carpet and only foot gliders are
used, the bass can be ill defined and even boomy. The use
of spikes is recommended to insure secured footing for
your speakers. (See Solid Footing, this page, for spike infor-
mation and installation instructions).
Dipolar Speakers and Your Room
MartinLogan electrostatic loudspeakers are dipolar radia-
tors. This means that they produce sound from both their
fronts and their backs. Consequently, musical information
is reflected by the wall behind them and may arrive either
in or out of step with the information produced by the
front of the speaker.
The low frequencies can either be enhanced or nulled by
the position from the front wall. Your Clarity’s have been
designed to be placed two to three feet from the front wall
(the wall in front of the listening position) to obtain the
best results; however, your room may see things differently.
So listening to the difference of the bass response as a
result of the changes in distance from the front wall can
allow you to get the best combination of depth of bass and
tonal balance.
Now that you know about reflective surfaces and resonant
objects, you can see how the midrange and high frequencies
can be affected. The timing of the initial wave as it radiates
to your ears, and then the reflected information as it arrives
at your ears later in time, can result in confusion of the pre-
cious timing information that carries the clues to imaging.
Consequently the result is blurred imaging and excessive
brightness. Soft walls, curtains, wall hangings, or sound
dampeners can be effective if these negative conditions
occur (your dealer can give you good information here).
After living and experimenting with your Clarity’s, you may
want to use Clarity ETC (energy transfer coupler) Spikes (see
figure 4), which are available from your local MartinLogan
dealer or from the Xtatic shop at www.martinlogan.com.
With the use of these spikes, the Clarity will become more
firmly planted on the floor and, consequently, bass will tight-
en and imaging will become more coherent and detailed.
It is best not to implement the spikes, however, until you
are secure in the positioning, as the spikes can damage the
floor if the speaker is moved. MartinLogan Clarity ETC
spikes will fit any common 1/4” x 20 thread insert that may
be found on your other audio equipment (racks, etc.)
Spike Installation Instructions:
1 Carefully lay your speaker on its side to gain access to
the bottom.
2 Remove existing feet or spikes. Thread new spikes into
holes and screw them in all of the way. If the speaker
does not sit level loosen one spike until level is achieved.
3 Tighten the jam nut snugly by hand. Do not over tighten
the nut.
4 Right the speaker.
Caution: Make sure your hands and any cabling are clear
of the spikes. Do not slide speaker as spikes are sharp and
can damage your floor or carpet.
5 Adjust to level by rotating spikes. Tighten the jam nut
securely when satisfied that speaker is level.
Caution: Walking the speaker may result in a broken spike.
Figure 4. The ETC Spike.
Solid Footing
Room Acoustics 9