OEM Systems PS-12 300W Powered Subwoofer — Owner's Manual

Owner's manual for the OEM Systems PS-12 — a 300-watt powered subwoofer with a 12" extra-long-throw heavy duty woofer, designed for free-standing placement in a music or home theater system.

Important Safety Instructions

• Read, keep, and follow all instructions; heed all warnings.
• Do not use near water; clean only with a dry cloth.
• Do not block ventilation openings; do not install near heat sources (radiators, stoves, amplifiers, etc.).
• Do not defeat the safety purpose of a polarized or grounding-type plug — consult an electrician if the plug doesn't fit your outlet.
• Protect the power cord from being walked on or pinched, especially at plugs and outlets.
• Use only manufacturer-specified attachments/accessories.
• Unplug during lightning storms or when unused for extended periods.
• Refer all servicing to qualified personnel if the cord/plug is damaged, liquid or objects enter the unit, it's been exposed to rain/moisture, doesn't operate normally, or has been dropped.
• Warning: to reduce risk of fire or shock, do not expose to rain/moisture and do not place liquid-filled objects (vases, etc.) on the unit.

Box Contents

• Subwoofer
• 4 spiked feet
• 4 knurled lock nuts
• 4 rubber feet
• Power cord
• Manual

Attaching the Feet

Install the four rubber feet before setup to protect the subwoofer and floor. Spikes are recommended for carpet (they penetrate the pile for a stable footing); rubber feet are recommended for hard surfaces. Three feet (instead of four) may work better on uneven surfaces like stone or tile. Do not slide the subwoofer with feet installed — this can damage the foot supports.

To install: thread the knurled jam nuts onto the desired feet, screw the feet into the enclosure's threaded inserts (starting fully screwed in), stand the unit upright, then lower feet as needed to level it and prevent rocking. Finger-tighten the jam nuts against the enclosure — do not over-tighten.

Features

• 12" extra-long excursion woofer with high-Bl motor in a bass reflex enclosure for extended bass response and high acoustic efficiency.
• Integral 300W class A/B amplifier using patented BASH technology for high electrical efficiency.
• Integral low-pass crossover, continuously variable from 40Hz–120Hz, with bypass option for use with an external crossover.
• Defeatable auto signal-sensing circuit automatically powers the amplifier on when a signal is detected.
• Double-insulated, isolated-ground power supply reduces ground loop noise.
• 8 adjustable feet (4 spiked, 4 rubber) with tool-less knurled jam nuts, installable in either a 3-point triangular or 4-point square pattern (5 threaded inserts on the bottom).

Rear Panel Controls

Connection Options

Use only one connection option at a time (do not combine):

• Option 1 (Speaker Level): if no line-level output is available, wire the receiver/amp's left and right front speaker outputs in parallel to the subwoofer's Speaker Level inputs, observing correct polarity (R+ to R+, R- to R-, etc.). Some receivers with unused (B) speaker outputs internally parallel A/B pairs and can be used instead — test by playing music through (A) speakers, then engaging (B): if (A) keeps playing, the outputs are parallel and safe to use for the subwoofer.
• Option 2 (Line Level, Front Channel): preferred when no LFE/Subwoofer output exists — connect the receiver/preamp's left/right RCA front-channel outputs to the subwoofer's Line Level inputs via a stereo RCA cable.
• Option 3 (Line Level, LFE/Sub Out): best option when available — connect a single RCA cable from the receiver/processor's LFE or Subwoofer output to the subwoofer's Left/LFE Line Level input.

Connect AC power last, using the supplied IEC cable, only after all signal connections are made.

Placement

Room acoustics and resonant modes significantly affect bass reproduction; equalization cannot fully compensate for room modes, which vary by listening position. General guidelines:

• Placing the subwoofer near a wall — and especially in a corner ("corner loading") — increases effective radiated bass output.
• Placing it close to the listening position increases perceived transient intensity and reduces the acoustic power the sub has to produce.
• Bass is largely non-directional, so placement isn't limited to the front of the room, though front placement (near the mains) can help avoid a "detached" sound; reducing the crossover frequency can also help.
• Rear-of-room or behind-the-listener placement, including corner loading in the back, can also work well.
• Multiple subwoofers in opposite corners can balance out localization.
• Leave at least 3–6 inches of clearance behind the rear-mounted bass vent; rotate the cabinet if needed so the vent isn't blocked by a wall.

Fine-Tuning the Controls

Level and Frequency: Start with Level all the way down and Frequency at 120Hz. Play bass-heavy music and raise Level until the bass sounds robust/exaggerated, then reduce Frequency to blend with the main speakers (50–80Hz typically blends well with 6"–8" woofer satellites). Fine-tune both controls with multiple tracks until bass sounds full, extended, and natural — if every track seems to produce "the same bass note," the level is likely too high.

Phase: Using music with sustained bass notes, rotate the Phase control and listen for the bass to become more distinct/localized and slightly louder. Temporarily set Frequency to 120Hz during this adjustment to create overlap between sub and satellites, then return Frequency to its desired setting afterward.

Crossover bypass: If using an external crossover (in a receiver/processor), set the Crossover switch to Bypass; the PS-12 will then pass signal up to ~300Hz, while its own Level and Phase controls remain active.

Auto Power Mode: Automatically powers the amp on when a signal is detected and returns to standby after ~10 minutes of silence. Switch to Off if you prefer to control power via a separate switched source.

Specifications

Manufacturer

OEM Systems Company, Sparks, Nevada · (775) 355-0405 · (800) 291-0561 (fax) · www.oemsystems.com