10
Output Connections
Full-range models have one XLR output connector marked 
FULL RANGE LINE OUT. The output connector is wired in 
parallel with the input enabling connection of multiple 
enclosures in a “daisy-chain” fashion. 
Subwoofer models have two sets of output connectors, 
one set for the left and one set for the right audio chan-
nel. Each channel has a FULL RANGE LINE OUT connector 
and a 100 Hz LOW-CUT OUT connector (active 100 Hertz 
filter applied, non-defeatable). 
We recommend balanced connections be used. Balanced 
connections will reduce AC hum and interference, espe-
cially with long cable runs. Unbalanced connections may 
be suitable for short cables.
HPR122i, HPR152i and HPR153i
Insert the XLR connector into the jack marked FULL 
RANGE LINE OUT. Connect the other end of the cable to 
the next down-stream audio device’s input connector. The 
output connector is wired in parallel with the input con-
nector and is not effected by the 100 Hertz low-cut filter 
switch setting.
HPR151i and HPR181i
FULL RANGE LINE OUT: Use the outputs marked FULL 
RANGE LINE OUT (Left and/or Right) when connecting to 
down-stream powered loudspeakers which accept full-
range audio or have their own filtering. 
100 Hz LOW-CUT: Use the outputs marked 100 Hz LOW-
CUT OUT (L and/or R) when connecting to downstream 
powered loudspeakers that have no low-frequency filter-
ing but the low-frequency roll-off is desired. Do not use 
the 100 Hz LOW-CUT OUT connectors for connecting to 
other subwoofers. Instead, use the FULL RANGE LINE 
OUT. Be sure to turn off any loudspeaker connected to the 
100 Hz LOW-CUT OUT before turning off the subwoofer’s 
AC power. This prevents any undesired turn-off transients 
(thumps, bumps) in the connected devices.
If using the subwoofer’s 100 Hz LOW-CUT OUT 
connector to provide signal to the top-boxes 
(HPR152i and HPR153i), be sure the top-box’s low-
cut filters are OFF. Do not apply a second filter as 
the sonic performance of the system will be nota-
bly degraded.
IMPORTANT! If using full range loudspeakers 
from another manufacturer, we recommend they 
be connected to the QSC subwoofer’s 100 Hz LOW-
CUT OUT. This will ensure proper phasing of the 
full range loudspeaker with respect to the sub-
woofer.
Full-range loudspeaker’s Input (IN) 
and Output (OUT) Connectors
Subwoofer loudspeaker’s Input (IN) 
and Output (OUT) Connectors