Legacy Signature III User manual

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Registration
3. Owners Record
4. The Cabinetry / Our Commitment
Setup
5. Unpacking Your Speakers
6. Speaker Placement
9. Hook up Cables
12. Amplification
16. Speaker Connections
17. Fine-tuning
Technology
18. Designer’s Note
23. Specifications

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The model and serial numbers are located on the rear of the unit. Record
these numbers in the spaces provided below. Refer to them when calling
upon your dealer regarding this product.
Model No. _______________________________
Serial No. _______________________________
Date of purchase: _________________________
Thank you for selecting a Legacy Loudspeaker System. These hand-
crafted instruments will provide you with many years of listening
enjoyment. Please take a few moments to read this brief manual to insure
maximum benefit from your speaker system.

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Handcrafted
Beneath the surface of Signature III’s elegant exterior lies rigid MDF
construction. Interlocking joinery maximizes the strength of the cabinet
parts. Polyester fiberfill is selected for internal damping. A sharp rap on
the enclosure will leave you with little more than bruised knuckles.
Each cabinet is impeccably finished on all exposed surfaces with select
veneers. The exquisite finish is hand-rubbed several times to assure a
patina at home with the most elegant decor.
Our Commitment
A great deal of forethought, love and satisfaction is instilled in each piece
of Legacy workmanship. We take pride in getting to know many of our
customers on a first name basis.
Your purchase of this product is backed by the renowned “Legacy
Satisfaction Guarantee”.

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Your new speaker system has been very carefully packaged to insure that
it travels to you safely. Each speaker is protected by a double-wall outer
carton with heavy V-board corner protectors. Molded foam end caps are
used to protect the elegant cabinetry, and a plastic liner is provided as
waterproofing. Please save this packing for future transportation. If cartons
become damaged or misplaced, new ones can be purchased from Legacy
Audio.

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To allow more flexibility in seating arrangements, your Legacy
loudspeaker is designed for broad lateral coverage. Optimal listener
position is actually about 5 to 15 degrees off the axis normal to the
loudspeaker baffle. Assuming a listener distance of about ten feet, begin
by placing the speakers approximately 7 feet apart and about 1 – 3 feet
from the wall behind them. In most rooms this will afford a speaker
position at least 2 feet or more from the side walls. The amount of
recommended "toe-in" is a function of the listening angle. As the overall
listening angle increases from 40 degrees, the amount of toe-in should
increase. Your Legacy speaker is optimized for a flat response in the far
field. Best results are obtained vertically with the listener's ear at tweeter
level with the loudspeakers gently toed in toward the listener. Increasing
the degree of toe-in is recommended when placement next to sidewalls is
required. Placing the loudspeaker or the listener near a room boundary
will generally increase low frequency impact. If you are forced to position
one or both of your loudspeakers in a corner, be prepared to reduce bass
output via the control switches on the rear terminal plate of each
loudspeaker. You may also wish to reduce low frequency output with your
preamp's bass tone control.

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The ideal conductor would have negligible resistance, inductance and
capacitance. The table below shows how a few actual speaker cables
measure up.
Cable Ωs/ft pF/ft µH/ft
12 ga. 0.0033 24 0.21
14 ga. 0.0048 17 0.13
16 ga. 0.0079 16 0.18
18 ga. 0.0128 28 0.21
Capacitance is considered insignificant in each cable because its effect is
well out of the audio bandwidth; inductance can be decreased (at the
expense of increased capacitance) by keeping the conductor pair closely
spaced.
How long would a cable have to be before inductance effects would
impinge on the audio spectrum? Approximately 300 feet of 12 gauge
would be required to establish a corner frequency of 20 kHz with an 8
Ohm loudspeaker. As you see, inductance is not a problem for most of us.

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What about phase shift due to frequency dependent travel times down the
speaker cable? Measurements show that 100 Hz waves will be delayed
about 20 billionths of a second behind 10 kHz waves when traveling to the
end of a 10 foot speaker cable. Since the cilia of the ear requires 25,000
times longer than this just to transmit phase information, phase shifting is
obviously not the primary concern when considering speaker cables.
What about resistance? Finally we are getting somewhere.
Resistance is the controlling factor of the amplifier/loudspeaker interface.
Excessive resistance can cause major shifts of speaker crossover
frequencies. The lower the impedance of the loudspeaker, the greater the
effects of series resistance. A 20 foot run of 18 gauge cable can cause up
to 10% deviations of crossover center frequencies. That same 20 feet can
un-damp your damping factor and reduce your systems’ output by one-
half decibel.
In summary, there are no perfect cables. The best way to approximate the
ideal would be to keep loudspeaker leads as short as is practical.

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Ideally the loudspeaker would be among the first components selected
when assembling a playback system. This would allow the user to choose
an amplifier capable of delivering adequate amounts of current into the
frequency dependent load presented by the loudspeaker. However, when
upgrading a system, audiophiles may find themselves matching their new
loudspeakers to their existing amplification. For this reason, extensive
measures have been taken to ensure that each Legacy speaker system
represents a smooth, non-reactive load to virtually any amplifier.
Often there is much confusion regarding amplification and loudness levels.
It should be understood that the role of the amplifier goes beyond that of
driving loudspeakers to a given sound pressure level. The amplifier should
be able to CONTROL the loudspeakers across the entire music spectrum.
This means that parameters such as damping factor (values greater than
60 are acceptable) and dynamic headroom should not be overlooked
when comparing amplifiers.

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How much power will your new speakers need? That ultimately depends
on your listening environment and musical tastes. As little as five watts per
channel should drive them to a level satisfactory for background music. A
typical 45 watt per channel receiver may fill a room with the compressed
mid-band energy of “heavy metal,” but seem to lack weight or control with
classical recordings. Some audiophiles feel that 200 watts per channel is
the bare minimum to avoid audible clipping distortion when reproducing
music at “live” playback levels. Your Legacy speakers are designed to
take advantage of “high-powered” amplifiers, so don’t be afraid to put
them through their paces.
How much is too much power? Rarely is a drive unit damaged by large
doses of music power. More often than not the villain is amplifier clipping
distortion. Even through decades of refinement, loudspeakers are still
notoriously inefficient transducers, requiring huge amounts of power to
recreate the impact of the live performance. Typically less that 1% of
electrical power is converted into acoustic output. (For example, an omni-
directional transducer with an anechoic sensitivity of 90 dB @ 1w/1m has
a full space efficiency of only 0.63%)

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When an amplifier is unable to fulfill your loudspeakers demands, a
damaging harmonic spike may be leaked to the high frequency drivers.
Another important point regarding loudness is that the dB scale is a
logarithmic one. This means that a 150 Watt amplifier will potentially
sound only twice as loud as a 15 Watt amplifier. If all of this discussion of
power and loudness seems a bit abstract, consider the example below.
The average acoustical power developed by a person speaking in a
conversational tone corresponds to a mere 0.00001 Watts. The power that
would be developed by the entire population of the city of New York
speaking at once would barely illuminate a single 100 Watt light bulb.

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The Terminal Plate
At the rear of each of your loudspeakers you will find a terminal plate
housing two rows of jumpered binding posts. The upper row is the input to
the "satellite" portion of the speaker. The lower row is the input to the
"subwoofer" portion of the speaker. When left in place, the factory-
installed jumper bars allow the speaker to be driven with a single channel
of amplification. (If biamping, or biwiring, be sure to remove the jumper
bars.)
Connect each channel of your amplifier to a loudspeaker via the five-way
gold binding posts provided. Dual banana plugs or gold plated spade lugs
are recommended means of termination. Be sure that you observe polarity
when making the connections. The positive (+) terminal of the amplifier
should be connected to the positive terminal of the loudspeaker. The
negative (-) terminal of the amplifier should be connected to the negative
terminal of the loudspeaker.

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Biwiring
Biwiring allows one to minimize the cable losses between the amplifier
and the loudspeaker. This is accomplished with a single stereo amplifier
by running separate sets of cables to the satellite section and the
subwoofer section from the same channel of amplification. When biwiring,
we recommend the use of gold spade lugs or dual banana plugs. This can
make the task much easier and safer than bare wire connections. Again,
the major reasons for biwiring over conventional wiring are greater power
transfer (improved efficiency) and tighter control over the drivers (better
damping).
Passive Biamping
This option can yield even better results than biwiring due to broader
distribution of power requirements. Passive biamplification allows low
frequency current to be routed to a separate channel of amplification,
reducing strain on the satellite amplifier and preventing subwoofer back-
EMF from modulating with the upper frequencies. There are two types of
passive biamplification; Vertical biamping (which requires two identical
stereo amplifiers or four MonoBlocs) and Horizontal biamping (which does
not require identical amplifiers).

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1. Vertical Biamping
Vertical biamplification requires the dedication of a single stereo amplifier
for the left speaker, and another stereo amplifier for the right speaker. This
configuration improves channel separation and can improve imaging
slightly. If your preamp does not have two sets of left/right outputs, you will
need a pair of Y-adapters or a signal splitter, such as a dual amp balancer,
which will also allow adjustment of subwoofer/satellite input levels.
2. Horizontal Biamping
Any two stereo amplifiers may be utilized in horizontal biamplification.
Many audiophiles prefer the "sweetness" of tubes on the satellite portion
of the loudspeaker while favoring the "control and weight" of solid state
amplifiers on the subwoofer section. The biggest drawback of such a
marriage of amplification is that the two amplifiers may have different input
sensitivities or output polarities. Differences in the input sensitivities may
be overcome by using a dual amp balancer. This unit allows independent
balancing of the left subwoofer/satellite ratio and right subwoofer/satellite
ratio. It's also a good idea to check the owner's manuals to establish if the
amplifiers are inverting or non-inverting. If the two amplifiers are of
opposite polarity, then you should reverse the polarity at the inputs of

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either the subwoofer or satellite binding posts. NOTE: This only applies to
loudspeakers that incorporate the subwoofer and satellite section in a
single enclosure. It does not apply towards the separate powered
subwoofer/satellite configuration. You must always observe the polarity
when connecting the speaker wire to a powered subwoofer.
Active Biamping
This option requires the utilization of an electronic (powered) external
crossover. Active biamplification is the most appealing means of
interfacing a subwoofer/satellite system due to the control possibilities
offered, but can also be the most costly. An active crossover is inserted
between the preamplifier outputs and the inputs of two stereo amplifiers.
Vertical or horizontal biamping considerations are also applicable here. A
well designed active crossover will offer the user independent high pass /
low pass turnover frequencies for optimally blending the satellites with the
subwoofer sections of the speaker system. Other features usually found
are separate level controls for the high pass or low pass sections and a
choice of inverted or non-inverted low frequency outputs (needed when
strapping an amplifier to mono).

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Also helpful is bass equalization and subsonic filtering. When cascading
active filters with the existing passive filters within the speaker system, be
sure to allow for adequate frequency overlap. For instance, if the passive
crossover is set at 500 Hz, select a low pass corner frequency of 600 Hz
and a high pass corner frequency of 450 Hz to prevent a suck out in the
response at 500 Hz. The controlled distribution of power afforded by the
active crossover results in less amplifier strain (better clarity), greater
dynamics, and lower intermodulation distortion. However, a basic
understanding of crossover slopes and crossover frequencies within your
loudspeaker will be needed to implement the active crossover successfully.

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To facilitate proper set-up of your speakers in a variety of room situations,
we have included several heavy duty toggle switches on the terminal plate,
located on the back of the loudspeaker. All switches in the “up” position
represent the “anechoic flat” position.
Switch 1: can be used in the “down” position to provide a warmer sound
by shelving information above the 400 Hz by 2 dB. This can be helpful in
restoring system balance with closely miked program material or near field
listening positions.
Switch 2: can be used in the “down” position to reduce edginess in the
lower treble region due to room flutter or bright program material.
Switch 3: is a low frequency impedance contour when using amplifiers
with high current capability. It can be used in the “down” position to reduce
upper bass heaviness caused by standing waves (typically the
frequencies around 65 Hz, excited by the floor/ceiling interaction).To
increase bass impact leave the switch in the “up” position.
Switch 4: can be used in the “down” position to defeat the rear-firing
ambience tweeter.

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The Signature Series Loudspeaker is the result of more than a decade of
research and development. The design offers several important
advantages over conventional designs.
A very uniform dispersion pattern provides a much broader sweet spot for
the listener(s).This wide power distribution is owing to the diminishing line
source technology, which demands low crossover frequencies and high
temperature voice coils. Due to the inherent ruggedness of the drivers
used, no degrading overload protection devices are needed.
Distortion levels are kept below the threshold of audibility across the
spectrum via the use of eight custom designed drive elements. Peak
levels of 120 dB can be achieved over most of the audio spectrum with the
appropriate amplification.

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The Diminishing Line Source technology
In the past, the point source was considered the ideal in loudspeaker
design. The smaller the driver, the broader the dispersion pattern at rising
frequencies. However, this simple model overlooked one important factor.
In the real world, distortion from a transducer is roughly proportional to
displacement. The longer the throw (or smaller the piston area) required to
generate a given volume displacement, the greater the distortion
generated for that given displacement (or loudness level).
Let’s look at a simple equation for the volume displacement of a circular
piston.
Volume Displacement = Travel x Surface Area
As you can see, if we want to keep travel at a minimum, then surface area
must increase accordingly. In fact, for a given size piston, displacement
requirements increase by a factor of FOUR every time we drop one octave
infrequency. It’s now quite clear that the ideal model should be revised to
one which maintains constant directivity while increasing in piston area
with falling frequency.

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The Signature loudspeakers dedicate dual 10” carbon-filled bass drivers
with a total of 20 pounds of motor structure and a free air resonance
frequency of 18 Hz. The midbass is picked up by an ultra-quick 7” Kevlar®
Hexacone with graphite frame and a 7” curvilinear polypropylene driver
with a vented pole piece and cast magnesium basket. The dust cap is
covered with a soft PVC nose to prevent secondary radiation. A butyl
rubber surround assures linearity.
A sophisticated 1.25” textile dome with an oversized magnet (3 times
larger than standard) details the midrange. A compact ribbon with 3/8”
apertures and a Samarium Cobalt magnet articulates up to 30 kHz.
A simple dynamic braking system is included on the subwoofer section to
maintain driver linearity at high power levels (this facilitates the transient
process when a woofer is forced to change direction 160 times per second
at 80 Hz.) A “Q” control is included to allow bass contouring in difficult
rooms.