Pioneer TS-A25S4 10" Single 4-Ohm Car Subwoofer

The Pioneer TS-A25S4 is a 10-inch passive car subwoofer designed to add low-frequency output to an amplified vehicle audio system. It is intended for listeners who want more bass impact than full-range door or rear-deck speakers can provide. Its single 4-ohm voice coil supports straightforward amplifier matching and wiring in compatible installations.

With a 350-watt RMS power rating and 1,200-watt maximum power rating, the TS-A25S4 is built for a properly matched external amplifier rather than direct connection to a head unit. The subwoofer uses an IMPP composite cone reinforced with carbon and mica to support rigidity during bass reproduction. Its published frequency range extends from 22 Hz to 1.4 kHz.

The A-Series design uses an elastic polymer surround and polycotton spider to support controlled cone movement. Pioneer also specifies a specially designed voice coil for increased power handling. These elements help the subwoofer serve as the bass foundation of an A-Series speaker upgrade.

This is a component subwoofer, so an enclosure and external amplification are required for operation. It can be installed in either a sealed or vented enclosure, letting installers choose a more compact sealed alignment or the larger recommended vented alignment. Its 4-ohm single-voice-coil configuration is suited to amplifiers rated to operate at a 4-ohm speaker load.

The TS-A25S4 is a practical choice for a custom trunk, hatch, or enclosure-based bass upgrade where mounting depth and box volume can be planned in advance. Pioneer specifies a 0.8-cubic-foot sealed enclosure or a 1.1-cubic-foot vented enclosure. Verify cutout, mounting depth, enclosure displacement, and amplifier compatibility before installation.

Key Features

• 10-Inch Subwoofer: Adds dedicated low-frequency output to a car audio system.
• 350W RMS Handling: Supports matching with an appropriately rated external amplifier.
• 4-Ohm Single Voice Coil: Provides a simple fixed-impedance wiring configuration.
• IMPP Composite Cone: Uses carbon- and mica-reinforced polypropylene for cone rigidity.
• Sealed Or Vented Compatible: Supports Pioneer-recommended enclosure alignment options.
• 85 dB Sensitivity: Published efficiency rating at 1 watt and 1 meter.

Design & Installation

The TS-A25S4 combines a carbon- and mica-reinforced injected molded polypropylene cone with an elastic polymer surround and polycotton spider. Its single voice coil design uses a 4-ohm nominal impedance, while the subwoofer motor uses a magnet specified at 1,300 g. The driver is part of Pioneer’s A-Series component subwoofer range and is compatible with Pioneer CarSoundFit resources.

Install the subwoofer in a properly built enclosure with the recommended internal volume: 0.8 cubic feet sealed or 1.1 cubic feet vented. Pioneer lists a 9-inch cutout and publishes mounting-depth information; confirm physical clearance at the intended mounting location before cutting. Connect it to a compatible external amplifier, observe polarity, and configure amplifier gain and low-pass filtering appropriately for the rest of the audio system.