Focal SUB 30A4 Subwoofer
139,00 €
Focal SUB 30A4 is a 12-inch subwoofer driver for a car audio system. It installs in a separate enclosure and connects to an external amplifier. Its single voice coil provides one electrical circuit, so there is no dual-coil wiring configuration to choose. The 300 mm cone uses a DFS® Dual Fiberglass Structure. The nominal 250 W RMS rating is the primary reference when matching amplifier power.
Focal SUB 30A4 subwoofer is a 12-inch (300 mm) driver for car audio systems. It is designed for installation in a separate enclosure and connection to an external amplifier. Its 250 W RMS nominal power rating is the primary reference when matching amplifier power. The 500 W figure represents maximum power and should not be treated as equivalent to the RMS rating.
Who is this subwoofer for?
This is a separate car audio driver, not an active subwoofer with a built-in amplifier. Installation requires a suitable enclosure, an external amplifier, and correct system wiring. This format is intended for a custom bass system in which the enclosure can be adapted to the available installation space.
The specified frequency response is 32-500 Hz. The upper limit is not an automatic amplifier crossover setting; it only indicates the reproduction range assigned to the driver.
Cone construction and component dimensions
The 300 mm DFS® (Dual Fiberglass Structure) cone uses a dual fiberglass construction. The nominal 12-inch diameter describes the driver’s size class. It is not the mounting cutout diameter or the overall external dimension.
The voice-coil diameter is 50 mm and its height is 25 mm. The magnet diameter is 120 mm. These are construction details and do not define the driver’s overall dimensions. Separate physical measurements are required to determine the correct mounting cutout and installation depth.
Connecting the amplifier
A single voice coil provides one electrical circuit. There is no need to choose between series and parallel wiring for two coils, but there is also no option to create different impedance configurations by rewiring multiple coils.
The amplifier load must match the driver’s nominal impedance. Impedance cannot be determined from the power rating or cone diameter. Maintain consistent polarity throughout the system. Reversed polarity may weaken the combined bass output when the subwoofer operates with the vehicle’s other speakers.
Set up the amplifier primarily according to the nominal RMS power, connected load, and input level. The maximum power figure is not a substitute for a continuous operating-power rating.
Crossover and level adjustment
Begin setting the low-pass filter around the point where the main speakers start to lose bass output. Then adjust the crossover while listening from the normal seating position until the transition sounds continuous. Avoid excessive overlap in which both parts of the system reproduce the same frequencies prominently.
Start with the amplifier input level set low. Increase it until the system sounds balanced, but stop if audible distortion appears. The input-level control is not a conventional volume control.
The stated 87 dB sensitivity was measured at 2.83 V from a distance of one metre.
Choosing an enclosure and installation position
Enclosure type and volume cannot be selected solely from the nominal diameter, power rating, or frequency range. A sealed enclosure generally rolls off more gradually. A bass-reflex enclosure requires accurate internal volume and port tuning. Designing either type properly requires the electromechanical parameters of the specific driver.
Leave sufficient clearance for cone movement and protect the driver from pressure or impact caused by luggage. Secure the enclosure firmly inside the vehicle. After installation, test several enclosure orientations and assess the result from the driver’s seat.
Technical specifications
| Model | Focal SUB 30A4 |
|---|---|
| Type | Car subwoofer driver |
| Diameter | 12 inches (300 mm) |
| Cone | DFS® Dual Fiberglass Structure |
| Voice coil | Single |
| Voice-coil diameter | 2 inches (50 mm) |
| Voice-coil height | 1 inch (25 mm) |
| Magnet diameter | 4.75 inches (120 mm) |
| Nominal power | 250 W RMS |
| Maximum power | 500 W |
| Sensitivity | 87 dB at 2.83 V / 1 m |
| Frequency response | 32-500 Hz |
FAQ
Is this an active subwoofer?
No. It is a separate passive driver that requires a suitable enclosure and an external amplifier. This design does not include a built-in amplifier.
What should I check before connecting it to an amplifier?
The nominal impedance is not stated in this description. Before making the connection, check it on the product label or in its documentation and ensure that it matches a load supported by the amplifier.
Which physical dimensions must be checked before building an enclosure?
Confirm the mounting cutout and total installation depth using the product’s physical dimensions. The 12-inch designation is only a nominal size class and is not sufficient for cutting the mounting opening.
Can its sensitivity be compared directly with another driver?
The 87 dB sensitivity figure can only be compared meaningfully with drivers whose sensitivity was also measured at 2.83 V from a distance of one metre.
