SP-300.4 MINI . AMPLIFIER

As shown in 1.webp, the amplifier features distinctive Italian styling with signature orange shock-absorbing rubber bumpers, designed for professional Car Audio installations.

1. ACOUSTIC ENGINEERING EXCELLENCE: WHY CHOOSE SP-300.4 MINI

In professional Car Audio competition and high-fidelity sound reproduction, the ultimate engineering challenge is uniting extreme acoustic output, pristine tonal fidelity, and an ultra-compact mechanical footprint. The SP-300.4 MINI represents the pinnacle of the Spaudio engineering design philosophy: a no-compromise 4-channel Class D amplifier.

• CLASS D THERMAL EFFICIENCY: The amplifier utilizes a stable and reliable circuit design. By leveraging Class D switching architecture, it achieves superior energy efficiency, minimizing thermal dissipation and alternator strain in a small size footprint for easy installation.

• SMD & DOUBLE-LAYER PCB TECHNOLOGY: The system is built upon an audiophile-grade 2-layer PCB. It utilizes advanced surface mount component technology. This design is backed by strict audio precision quality control verification.

2. MANDATORY SAFETY & PRE-INSTALLATION GUIDELINES

Installing a high-current audio amplifier requires professional competence. Any deviation from specified installation instructions can cause serious damage to the amplifier, speakers, and/or the vehicle's electrical system. Damage caused from improper installation is NOT covered under warranty.

• Disconnect Vehicle Battery: Whenever working on the vehicle, it is recommended to disconnect the battery prior to starting work. Failure to do so may lead to a risk of electric shock or equipment damage.

• Inline Main Fuse Protection: Install a circuit breaker or fuse within 20cm of the battery. This effectively lowers the risk of severe damage to you or your vehicle in case of a short circuit or accident. The SP-300.4 MINI does not have internal fuses; an external fuse box of 125A is suggested.

• Flawless Chassis Grounding: Locate a proper ground point on the vehicle's chassis and remove all paint, dirt, or debris to reveal a bare metal surface. Attach the ground wire directly to that contact point.

• Thermal Dissipation & Airflow: Determine the mounting place for your amplifier, keeping in mind there should be sufficient air flow for proper cooling. Note that 2.webp and 3.webp display the secure mounting bottom plate and advanced heat-dissipating aluminum fin structure designed for this purpose.

3. PANEL ANATOMY & PARAMETRIC CONTROL FUNCTIONS

The input controls and high-current power terminals of the SP-300.4 MINI are logically segregated on opposite sides of the chassis to prevent high-amperage electromagnetic fields from contaminating sensitive audio signals.

FRONT PANEL (AUDIO PROCESSING & INPUTS)

Refer to 4.webp for the exact front panel layout.

• GAIN CONTROL (INPUT LEVEL): The gain control matches the input sensitivity of the amplifier to the source unit being used. The operating range varies from a minimum input signal of 200mV to a maximum input signal of 6V.

• FILTER MODE SWITCHES: These controls allow control over the frequencies played. The front channels (CH1/CH2) feature a switchable High Pass Filter (HPF) and OFF setting. The rear channels (CH3/CH4) provide an option for Low Pass, Full Range (OFF), or High Pass.

• FREQ CONTROLS (HPF/LPF): In LPF or HPF mode, the crossover frequency can be tuned continuously from 50Hz to 250Hz.

• POWER / PROTECT LED: The POWER LED illuminates green when the amp is switched on. When the amp is in short circuit or thermal protection, the red PROTECT LED is on.

• RCA INPUTS: Direct low-level signal inputs for CH1, CH2, CH3, and CH4.

REAR PANEL (POWER & SPEAKER TERMINALS)

Refer to 5.webp for the exact rear panel layout.

• POWER BLOCKS (+12V, REM, GND): The amplifier features direct insert power terminals. The +12V must connect to the battery, GND to the bare chassis, and REM to the source unit's remote turn-on lead.

• SPEAKER OUTPUTS (+ / -): The direct insert speaker terminals are utilized for component connections. The block supports standard 4-channel independent wiring or high-power Bridged configurations across CH1-CH2 and CH3-CH4.

4. MECHANICAL DIMENSIONS & ENGINEERING FOOTPRINT

As highlighted in the schematic overlay of 6.webp, the amplifier's compact profile allows hidden installations in tight cabin spaces:

• Length: 310 mm

• Width: 112 mm

• Height: 46 mm

5. SYSTEM WIRING SCHEMATICS & LOAD CONFIGURATION

Your amp can drive a 2 ohm minimum load for max power per individual channel.

• 4-CHANNEL WIRING (2-4 OHMS): Connect four individual speakers directly to the respective CH1, CH2, CH3, and CH4 positive and negative terminals.

• BRIDGED WIRING (4 OHMS MINIMUM): For extreme output across two high-power speakers or subwoofers, the amplifier can be bridged. Connect your speakers across the designated BRIDGE (+) and (-) terminals for CH1-CH2 and CH3-CH4. Bridging delivers an immense 900W x 2 at 4 Ohms.

6. SCIENTIFIC GAIN CALIBRATION

Setting the Gain correctly prevents distorted audio and thermal harmonics that can damage voice coils.

1. Turn the gain control on the amplifier all the way down (counter clockwise).

2. Turn up the volume control on the source unit to approximately 3/4 of maximum.

3. Adjust the gain control on the amplifier until audible distortion occurs.

4. Adjust the gain control down until audible distortion disappears.

5. The amplifier is now calibrated to the output of the source unit.

(Advanced Acoustic Engineering Note: If utilizing a digital multimeter for precision calibration, target voltage can be calculated using Ohm's Law: $V_{target} = \sqrt{P_{RMS} \times Z_{load}}$).

7. CERTIFIED TECHNICAL SPECIFICATIONS

All electrical and acoustic parameters are laboratory tested. (Note: Output specifications reflect continuous RMS power; for professional US catalog and competition applications, peak threshold ratings are strictly designated as BURST power).

8. DIAGNOSTICS & TROUBLESHOOTING

If your amplifier experiences operational anomalies, consult the following diagnostic steps:

• No Power / LEDs Off: Check the external 125A fuse. Ensure the +12V, REM, and GND terminals have secure, bare-metal connections and proper voltage.

• PROTECT LED ON (Red): The safety protection circuit engages when the amp is in short circuit or thermal protection. You need to check the amplifier or wait for the amplifier temperature to cool down before restarting.

• Distorted Audio: The gain control might be set too high; repeat the 5-step gain calibration procedure. Ensure all speakers match the minimum impedance requirements (2 ohms stereo, 4 ohms bridged).