JBL SP-150, Service Manual

3

www.jbl.com

E

ng

lis

h

suBwooFer rear-PaneL ConTroLs and ConneCTions

Auto-On switch: 

•  

On/Auto:

 When this switch is set in the “On/Auto” position the 

subwoofer will automatically turn itself on when it receives an audio 

signal, and will enter the Standby mode when it has gone without 

receiving an audio signal for 10 minutes.

•  

Off:

 Set the switch in the “Off” position to turn the subwoofer off. 

Select this position if you will not be using the subwoofer for an 

extended period of time, such as when on vacation.

Phase switch: 

This switch determines whether the subwoofer driver’s 

piston-like action moves in and out in phase with the satellite speakers. If 

the subwoofer were to play out of phase with the satellite speakers, the 

sound waves from the satellites could partially cancel out the sound waves 

from the subwoofer, reducing bass performance and sonic impact. This 

phenomenon depends in part on the placement of all the speakers relative 

to each other in the room.

Line-Level Input connector:

 If your receiver/processor has a dedicated 

subwoofer output, use a single RCA audio cable (not supplied) to connect 

it to the subwoofer’s Line-Level Input connector.

Crossover Frequency control: 

This control determines the highest 

frequency at which the subwoofer reproduces sounds. The higher you set 

the Crossover control, the higher in frequency the subwoofer will oper-

ate and the more its bass will “overlap” that of the satellite speakers. This 

adjustment helps achieve a smooth transition of bass frequencies between 

the subwoofer and the satellites for a variety of different rooms and sub-

woofer locations.

Volume control: 

Use this control to adjust the subwoofer’s volume. Turn 

the knob clockwise to increase the volume; turn the knob counterclock-

wise to decrease the volume.

Speaker-Level Input connectors:

 If your receiver does not have a 

dedicated subwoofer output, use speaker wire (not supplied) to connect 

its Front Left and Front Right speaker outputs to the subwoofer’s Speaker-

Level Input connectors. Connect your system’s Front Left and Front Right 

speakers to the subwoofer’s Speaker-Level Output connectors (see below).

Speakers and amplifiers have corresponding positive and negative (“+” and 

“–”) connectors. The SP150 Speaker-Level Input connectors are marked 

“+” and “–” beneath the connector levels. Additionally, the “+” connectors 

have red markings, while the “–” connectors have black markings.

To ensure proper polarity, connect each “+” connector on the back of your 

receiver or amplifier to the respective “+” (red) connector on each speaker. 

Connect the “–” connectors in a similar way. Do not reverse polarities (i.e., 

“+” to “–” or “–” to “+”) when making connections. Doing so will cause 

poor stereo imaging and diminished bass performance.

IMPORTANT: Make sure the “+” and “–” wires or connectors do not 

touch each other or the other terminal. Touching wires can cause 

a short circuit that can damage the subwoofer or your receiver/

amplifier.

Speaker-Level Output connectors:

 If you used the subwoofer’s Speak-

er-Level Input connectors to connect it to your receiver, you must connect 

your system’s Front Left and Front Right speakers to the subwoofer’s 

Speaker-Level output connectors. To ensure proper polarity, connect each 

“+” connector on the subwoofer to the respective “+” (red) connector on 

each speaker. Connect the “–” connectors in a similar way. Do not reverse 

polarities (i.e., “+” to “–” or “–” to “+”) when making connections. Doing so 

will cause poor stereo imaging and diminished bass performance.

IMPORTANT: Make sure the “+” and “–” wires or connectors do not 

touch each other or the other terminal. Touching wires can cause 

a short circuit that can damage the subwoofer or your receiver/

amplifier.

AC Fuse holder:

 The SP150 is factory-equipped with a 2A/250V AC fuse. 

If the fuse ever blows: 

1.  Unplug the subwoofer’s power cord from the wall.
2.  Use a screwdriver to remove the blown fuse.
3.  Replace the fuse with an identical 2A/250V fuse.

CAUTION: FOR CONTINUED PROTECTION AGAINST FIRE,  

REPLACE THE FUSE ONLY WITH THE SAME TYPE AND RATING.

Power cord: 

After you have made and verified all subwoofer and speaker 

connections described in this manual, plug the power cord into an ac-

tive, unswitched electrical outlet for proper operation of the subwoofer. 

DO NOT plug this cord into the accessory outlets found on some audio 

components.

Crossover Frequency 

Control

Auto-On Switch

Phase Switch

AC Fuse 

Holder

Speaker-Level 

Input Connectors

Line-Level 

Input Connector 

Speaker-Level 

Output Connectors 

Volume Control

Power Cord

JBL

150P / 230V Service Manual

Page 3 of 50