8
REAR PANEL DESCRIPTION
INPUT SENSITIVITY
NORMAL
OFF
INPUT
SENSITIVITY
–
10dB
THX = NORMAL
The HR624 expects a line-level signal at its
input connectors.
• The reference sensitivity is –7.5 dBu=100 dB
SPL at one meter (39 inches) with the
INPUT
SENSITIVITY
control set to its
NORMAL
position (in other words, wide open).
• The HR624 is designed to operate with a
+4 dBu signal when the
INPUT SENSITIVITY
control is in the
NORMAL
position.
• Refer to the
QUICK START
section on page 4
for the level-setting procedure.
ACOUSTIC SPACE
ACOUSTIC
SPACE
HALF
WHOLE (NORMAL)
QUARTER
B
C
A
THX = WHOLE (NORMAL)
This is a three-way switch that adjusts the
low-frequency response of the speakers to com-
pensate for their placement in the room. See
page 5 for an overview of the rear panel.
• If you place the HR624 monitors against a
wall (half space
), set the
ACOUSTIC
SPACE
switch to the “
B
” position. This
activates a shelving filter to reduce the low-
frequency output by 2 dB to compensate for
the half-space placement.
• If you place the monitors into the corners
of your room (quarter space
), the low-
frequency output approximately doubles
from what it is in half space. Set the
ACOUSTIC SPACE
switch to the “
A
”
position to reduce the low-frequency
output by 4 dB to compensate for the
quarter-space placement.
• If you use the HR624s free-standing, away
from walls and corners (whole space
),
set the
ACOUSTIC SPACE
switch to the “
C
”
position (
NORMAL
).
This is where you connect your signal to the
monitor, and make adjustments to the frequency
response of the speakers to match the monitor’s
location and your room’s environment.
For THX applications, the
rear panel switches and
controls should be set to the
THX positions as indicated
in this section.
SIGNAL INPUTS
The location of the signal input jacks makes
the connectors exit down and not straight out
the back of the enclosure. This flush-mount
design allows you to place the monitor right up
against the wall if desired.
• The XLR female, TRS female (balanced),
and RCA female (unbalanced) connectors
are included for user convenience.
• Don’t connect more than one source to the
jacks.
• Unbalanced TS (tip-sleeve) lines can be
accommodated via the TRS jack. Make sure
the cable terminates with a TS plug (like a
guitar plug), or if it’s a TRS plug (such as a
headphone plug), make sure the ring is tied
to the sleeve and that the plug is fully
inserted into the jack.
• The XLR and TRS input connectors accept
balanced or unbalanced signals. The
connectors are wired as follows (per the
AES/IEC standard):
XLR
TRS
RCA
Hot (+)
Pin 2
Tip
Tip
Cold (–)
Pin 3
Ring
—
Shield (Ground)
Pin 1
Shield
Shield
• The HR624s can be used with a home
receiver even if the receiver lacks a preamp
output by using a speaker-level to line-level
signal attenuator. (See page 13 for more
information.)
