Accessories
Reviewer Dick Olsher wrote concerning the SALLIE (Stereophile-Vol. 1, No.
11):
"Reflection off the wedges is quite minimal; placements right up against the back of the
speaker are okay, and will not color the front wave.’ 'With Sallie ... the back wave really
died.’
'The wedges are very effective in attenuating sound from 250 hz up.’
‘I verified to my satisfaction that Sallie performed as effectively as a pair of ASC Studio Traps
behind each speaker in controlling the A-1’s back wave. I imagine that any dipole speaker would
benefit from a date with Sallie. At a cost of around $1,000/pair Sallie is worth getting to know
well"
Sallie is an acronym that stands for "Sonic Attenuator
for Lower Levels of Interference Effects". The need for
SALLIE is due to the inherent nature of dipole loudspeakers,
wherein the energy from the front and rear of the panel are
both radiated into the listening room. Under certain conditions, such as
highly reflective room surfaces, acoustic anomalies, such as the comb-filter
effect, can occur. Furthermore, back wave energy reflected off of nearby objects,
including the wall behind
the speaker, can cause undesirable interference effects,
reducing the purity of the sound.
SALLIE eliminates back wave interference problems by
absorbing the exact degree of backwave energy necessary to
eliminate audible room effects and restore pristine reproduction.
It has been found that a critical amount of backwave energy
enhances the presence of the sound without causing negative
effects. The amount of backwave energy released into the room
is determined by the distance between the back of the speaker
and SALLIE. For a given room this distance is easily determined
empirically. Furthermore, SALLIE can save the high expense
of acoustically treating the back wall that might
compromise room decor. Sallie is hidden by the speaker
and does not interfere with room aesthetics. Every dipole
speaker and sound room can use SALLIE.
Tip Toes are a conical shaped floor support device that provides excellent mechanical coupling of loudspeakers to the
floor. Tip Toes are used in place of carpet
glides. They have a height of 1.5" and an upper diameter of
1.5". They attach to the bottom of the speaker with a 1/4"-20
threaded stud.
Toroidal
Audio Transformers
Toroidal audio transformers provide the
ultimate clarity and smoothness in sound. This technology was developed
for, and is standard with, the all full-range PX speakers. It is available as an
option for all other speakers, including the Dynastat and Marquee and MiniStat hybrids.
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