Infinity PS28 User Manual
PS Series
PS28 Subwoofer
SERVICE MANUAL
Infinity Systems, Inc.
250 Crossways Park Dr.
Woodbury, New York 11797 Rev1 3/2007
1
PS series PS28 subwoofer
- CONTENTS -
BASIC SPECIFICATIONS …………………..……………..1
DETAILED SPECIFICATIONS…………………..……….…..2
PACKAGING……………….……………………….…....….…4
CONTROLS AND CONNECTIONS…………..…….………..5
OPERATION….……………………………………………..….7
EXPLODED VIEW/PARTS LIST …………….….…....……8
TEST SET UP AND PROCEDURE………………..…....……9
BLOCK DIAGRAM…………………………..………….…..…10
TROUBLESHOOTING FLOW CHART………………..........12
ELECTRICAL PARTS LIST (120v) ………………………….13
PCB DRAWINGS……………….……………………………..17
SEMICONDUCTOR PINOUTS……….……………….……..21
SCHEMATICS (120v)………………………………………...22
Basic Specifications
PS28 Powered Subwoofer
Frequency Response: 35Hz – 150Hz (±3dB)
Maximum Amplifier Output: 150 Watts RMS (20Hz – 150Hz, with ≤ 0.1% THD)
300 Watts Peak
Crossover Frequency: 50Hz – 150Hz, 24dB/octave, continuously variable
Driver: 8" (200mm)
Dimensions (H x W x D): 17-7/8" x 10-5/8" x 16-1/2" (454mm x 270mm x 419mm)
Weight: 31.7 lb (14.4kg)
Infinity continually strives to update and improve existing products, as well as create new ones. The specifications
and construction details in this and related Infinity publications are therefore subject to change without notice.
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PS series PS28 subwoofer
INFINITY PRIMUS PS28 150W Powered Sub/ Plate Amp
LINE VOLTAGE Yes/No Hi/Lo Line Unit Notes
Europe 220-240VAC, 50-60Hz Yes 220-230 Vrms
Parameter Specification Unit QA Test Limits Conditions Notes
Amp Section
Type (Class AB, D, other) AB AB
Type (Class AB, D, other) G G
Rated Load Impedance 4 Ohms
System average impedance 8.79 Ohms
Voice coil DCR 4.35 Ohms
Rated Output Power 100 Watts
THD@ Rated Power 0.5 %
THD @ 1 Watt 0.1 %
DC Offset 10 mV-DC
Damping factor >100
Dynamic power RMS 125 Watts
Highest RMS value 152 Watts
Input Sensitivity
US 120VAC/60Hz Yes 108-132 Vrms
Input Frequency 50 Hz
Line Input (L&R) 16.5 mVrms
LFE Input 11.7 mVrms
System Gain (Line input) 41 dB
System gain (LFE input) 44 dB
n/a 120V model External Sink required for Class AB
n/a 230V Model
n/a Nominal
n/a Average impedance from 10 to 500Hz
n/a Reference
95 Single input driven
0.3 22K filter
50 @ Speaker Output
40
Reference
Reference
50 Nominal Freq.
±2dB To 1W Single input driven, AP Zo=600 Ohms
±2dB To 1W LFE input driven only, AP Zo=600 Ohms
±1dB G=118 Single input driven, AP Zo=600 Ohms
±1dB G=165 LFE input driven only, AP Zo=600 Ohms
Normal Operation
Normal Operation
Impedance used for electrical
measurements
1 22K filter
Measured at speaker terminals, Output
power 90 Watts
AVG Power over the first 4 consecutive
peaks, when tested with a burst siganl 3/20
at 50 Hz
Signal to Noise
SNR-A-Weighted 100 dBA
SNR-unweighted 85 dBr
SNR @ 1W-unweighted 65 dBr
Residual Noise Floor 1
Input Impedance
Line input L&R , LFE >10 K ohms
Filters
Low Pass (fixed or variable) Variable -Subsonic filter (HPF) Hz
Limiter (yes/no) YES -THD at Max. Output Power <1 %
Features
Line Level inputs (L&R) YES
LFE Input YES
Phase Switch (yes/no) YES
Volume pot Taper (lin/log) LOG
Variable crossover YES
ATO YES
LED indicator YES
Input Configuration
Line In (L,R) L ,R -Line level in LFE LFE
Signal Sensing (ATO)
Auto-Turn-On (yes/no) YES -ATO Level @ 50 Hz 1 mV
ATO Level @ 1 KHz 1 mV
ATO Turn-on time 5 ms
mVrms(max)
85 rel. to rated power A-Weighting filter
80 rel. to rated power 22K filter
60 rel. to 1W Output 22K filter
1.5
n/a Nominal
±2dB Crossover range 50-150 Hz
±2dB Fixed
Functional
Functional
Functional Dual RCA conenctor (RED-WHT)
Functional Single input (Yellow color)
Functional
Functional
Functional
Functional
Functional Located at the amplifier panel
Functional RCA inputs: L , R Summed to Mono
Functional
Functional
Functional One input driven
Functional One input driven
Functional
Volume @max, w/ A/P Swept Bandpass
Measurement (Line freq.+ harmonics)
Amp connected and AC on, then input
signal applied
Auto Mute/ Turn-OFF Time 10 minutes
Power on Delay time 3 sec.
Transients/Pops
ATO Transient 5 mV-peak
Turn-on Transient 50 mV-peak
Functional T before muting, after signal is removed Auto turn of time (T) must be 5 > T <15
Functional AC Power Applied
10 @ Speaker Outputs
100 @ Speaker Outputs AC Line cycled from OFF to ON
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PS series PS28 subwoofer
Parameter Specification Unit QA Test Limits Conditions Notes
Turn-off Transient 50 mV-peak
Efficiency
Stand-by Input Power 12 Watts
Power Cons.@rated power 195 Watts
Protection
Short Circuit Protection YES --
Thermal Protection 65 deg. C -DC Offset Protection YES --
Line Fuse Rating
120 VAC 2.5 Amps
230 VAC 1.25 Amps
100 @ Speaker Outputs AC Line cycled from ON to OFF
Maximum allowable input power under
15 @ nom. line voltage
210 @ nom. line voltage
Functional Direct short at output
Functional @1/8 max unclipped Power
Functional DC present at Speaker Out leads Relay or crowbar (for driver/fire protection)
Type-T or Slo Blo
Type-T, Low breaking capacity
nominal Input voltage and frequency, HOT
or COLD operation.
100 Watts @ 4 Ohms nominal line voltage
Temperature rise should not exceed 35K
rise
External fuse with UL/SEMKO rated holder
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PS series PS28 subwoofer
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PS series PS28 subwoofer
CONTROLS AND CONNECTIONS
Rear Panel
¡
Subwoofer-Level Control
™
Crossover Adjustment
®
¡
™
£
¢
∞
£
Phase Switch
¢
LFE Input
∞
Line-Level Inputs
§
Power Switch
§
~
FUSE
T 2.5A L 250V
TYPE
AC
120V
60HZ
200 Watts
PS28 (120V)
RECEIVER/PROCESSOR
L R
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PS series PS28 subwoofer
SUBWOOFER CONNECTIONS
CHOOSE THE SUBWOOFER CONNECTION THAT IS MOST SUITABLE FOR YOUR RECEIVER/PROCESSOR
If you have a Dolby®Digital or DTS
receiver/processor with a low-frequency
effects (LFE) or subwoofer output:
®
SUBWOOFER OR
LFE OUTPUT
If your receiver/processor does
not contain a Dolby Digital or DTS
processor but has a subwoofer output:
NOTE: Some receivers have one
subwoofer output. In that case, it is
recommended that you use a Y connector
(not included) to maximize performance.
PS28 (120V)
7
PS series PS28 subwoofer
OPERATION
Power On
Plug your subwoofer’s AC cord into a wall outlet. Do not use the
outlets on the back of the receiver.
Initially set the Subwoofer-Level Control ¡to the “min”
position.
Turn on your sub by pressing the Power Switch §on the rear
panel.Turn on your entire audio system and start a CD or movie
soundtrack at a moderate level.
Auto On/Standby
With the Power Switch §in the ON position, the LED on the
rear panel will remain lit in red or green to indicate the
On/Standby mode of the subwoofer.
RED = STANDBY (No signal detected,Amp Off)
GREEN = ON (Signal detected, Amp On)
The subwoofer will automatically enter the Standby mode after
approximately 10 minutes when no signal is detected from your
system.The subwoofer will then power ON instantly when a
signal is detected. During periods of normal use, the Power
Switch §can be left on.You may turn off the Power Switch
for extended periods of nonoperation, e.g., when you are
away on vacation.
§
Adjust Level
Turn your Subwoofer-Level Control ¡up to the “5” position
(halfway). If no sound emanates from the subwoofer, check the
AC-line cord and input cables.Are the connectors on the cables
making proper contact? Is the AC plug connected to a “live”
receptacle? Has the Power Switch §been pressed to the “On”
position? Once you have confirmed that the subwoofer is active,
proceed by playing a CD, record or cassette. Use a selection that
has ample bass information.
Set the overall volume control of the preamplifier or stereo to a
comfortable level. Adjust the Subwoofer-Level Control ¡until
you obtain a pleasing blend of bass. Bass response should not
overpower the room but rather be adjusted so there is a
harmonious blend across the entire musical range. Many
users have a tendency to set the subwoofer volume too loud,
adhering to the belief that a subwoofer is there to produce lots
of bass.This is not entirely true. A subwoofer is there to enhance
bass, extending the response of the entire system so the bass
can be felt as well as heard. However, overall balance must
be maintained or the music will not sound natural.An
experienced listener will set the volume of the subwoofer so its
impact on bass response is always there but never obtrusive.
Crossover Adjustments
The Crossover Adjustment Control ™ determines the highest
frequency at which the subwoofer reproduces sounds. If your main
speakers can comfortably reproduce some low-frequency sounds,
set this control to a lower frequency setting, between 50Hz
and 100Hz.This will concentrate the subwoofer’s efforts on the
ultradeep bass sounds required by today’s films and music. If you
are using smaller bookshelf speakers that do not extend to the
lower bass frequencies, set the Crossover Adjustment Control to
a higher setting, between 120Hz and 150Hz.
NNOOTTEE
: This control will have no effect if the LFE Input ¢ is used.
If you have a Dolby Digital or DTS processor/receiver, the Low-Pass
Frequency is set by the processor/receiver.Consult your owner’s
manual to learn how to view or change this setting.
MAINTENANCE AND SERVICE
The enclosure may be cleaned using a soft cloth to remove
fingerprints or to wipe off dust.
The grille may be gently vacuumed. Stains may be removed with
an aerosol cleaner, following its instructions. Do not use any
solvents on the grille.
All wiring connections should be inspected and cleaned or
remade periodically. The frequency of maintenance depends on
the metals involved in the connections, atmospheric conditions,
and other factors, but once per year is the minimum.
In the event that your subwoofer ever needs service,
contact your local Infinity dealer or distributor or visit
www.infinitysystems.com for a service center near you.
Phase Control
The Phase Switch £ determines whether the subwoofer
speaker’s piston-like action moves in and out with the main
speakers, 0,˚ or opposite the main speakers, 180.˚Proper phase
adjustment depends on several variables such as room size,
subwoofer placement and listener position.Adjust the phase
switch to maximize bass output at the listening position.
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