Gradient SW-63 Owners manual

Gradient SW-63 Subwoofer

for

QUAD ESL-63

INSTRUCTION

MANUAL

DESCRIPTION

The SW-63 differs from other subwoofers in that it relies on dipole operation. Most subwoofers are bass reflex
loaded, which gives them an isotropic radiation pattern (omnidirectional) at low frequencies. This type of
radiation pattern is impossible to integrate with the dipole pattern of the ESL.
Adding the subwoofers is easy. In addition to the SW-63:s one only needs one extra stereo power amplifier, two
pairs of RCA (or XLR with the balanced one) cables and one pair of speaker cables.

BENEFITS OF THE SYSTEM

* The subwoofer is acoustically perfectly integrated with the QUAD because it relies on dipole operation like the
QUAD

* Dynamic, well controlled bass reproduction down to 28Hz (-3dB)

* Adjustable bass level enables perfect room/taste matching

* The system is able to go 10 dB louder than the ESL-63:s by themselves

* The reduced low frequency strain on the ESL-63 results in a more accurate and cleaner midrange reproduction

* The QUADs are placed on top of the SW-63:s so there is no need for stands. The SW-63 raises physically the
acoustical centre of the ESL to optimum listening height.

* Free choice of amplifiers. The SW-63 is an easy load and it is possible to choose either 16 ohm or 4 ohm
nominal impedance depending on the gain and the current/voltage capability of the amplifier.

* The active crossover includes a subwoofer mono switch. Mono operation reduces excessive cone excursions
when playing warped LP records.

* Certain recordings may sound slightly harsh on the ESL:s. The crossover unit also includes an upper midrange
attenuation switch. Attenuation is at maximum 0,5 dB or 1,0 dB.

* A small drawback: There are two acoustic centres in the system instead of one, but the subjective acoustic centre
remains at the center point of the ESL-63, because of the low crossover frequency.

GUARANTEE

This subwoofer system is guaranteed against any defect in material and workmanship for a period of twelve
months from the date of purchase.
Within this period we undertake to supply replacement parts free of charge provided that failure was not a result
of misuse, accident or negligence. Labour and carriage costs are not covered unless by local agreement.
This guarantee is void and inapplicable if the subwoofers have been subject to inputs in exess of the maximum
rating or inputs from an unstable or clipped amplifier or have been subject misuse or abuse (result of which would
be burned voice coils or other mechanical damage).

SERVICE

If servicing is required the unit should be returned to the supplier, to the distributor or to the manufacturer.

UNPACKING

The subwoofers are packed in two cartons. One of them also includes the active crossover unit, eight spikes, an
allen key and the Instruction manual. Loudspeaker and interconnect cables are not included. The AC-adapter
needed for powering the crossover unit is supplied by the local SW-63 distributor (in those countries not using
220-240 V and European 2-pin socket). Packing should be retained in case the subwoofer needs to be returned
for service.

INSTALLATION

SW-63 subwoofer is dimensioned to suit the present ESL-63 fitted with plastic feet. In this case the height of the
ESL bottom trim is more than 83 mm from the base. When installed on the subwoofer the ESL63 should stand on
its own feet and there should be a small space between the ESL bottom trim and the subwoofer front grille and
side walls.
Where QUAD ESL-63s are fitted with cork feet (the height is less than 83 mm) they should be replaced by
furniture feet of greater height (or any other suitable feet). If you are going to use spikes with your subwooters it
is recommended that you first check the placement of speakers and then fix the spikes before installing the ESLs.
Tilting is possible with spikes. When installing, first remove the subwoofer top trim (back of the unit) to fit the
ESL-63 on the SW-63 top level. Raise the ESL and place it on the subwoofer. Fix the top trim. 'tighten the nuts
(not too tight) with the allen key provided. The system is now ready for speaker wiring.

AMPLIFIER REQUIREMENTS

The SW-63 is a very easy load for any power amplifier. The sensitivity of the'SW-63 is comparable to that of the
ESL-63. Consequently the power demand is similar to that of the ESL-63. The recommended amplifier power is
50-250 W / ch / 8 ohm.

BASIC SETUP OF THE ESL-63 & SW-63 SYSTEM

The system consists of program sources, preamplifier, crossover unit, two power amplifiers, one pair of ESL-63s
and one pair of SW-63 (see fig. 1). basically it is possible to use any power amplifiers in the system.

BASIC SETUP

QUAD QUAD

ESL-63 ESL-63

SW-63 SW-63
+ - - +

POWER AMPLIFIER

FOR ESL-63

+ - + -

L/R POWER AMPLIFIER
FOR SW-63

L/R

ACTIVE CROSSOVER AC
ADAPTOR

L/R

PREAMPLIFIER

PROGRAM SOURCES

FIG. 1