Audio System US 08 Active – Ultra-Compact Active Subwoofer

Introduction

The Audio System US 08 Active is positioned as a premium solution for under-seat subwoofers, aiming to overcome the reputation of these units as mere stopgaps. Audio System, traditionally known for larger subwoofers, enters this segment with the US 08 Active.

The subwoofer boasts a very robust construction, featuring a housing made entirely of thick aluminum die-cast. Visually striking are the grilles on the side panels, which conceal passive membranes. These membranes are designed to enhance the acoustic output, making the compact subwoofer sound larger than its physical dimensions suggest, similar to a bass-reflex design.

The unit is equipped with a premium 8-inch (20 cm) woofer, characterized by its substantial build and a large 50 mm voice coil. The integrated amplifier delivers a measured 137 Watts, positioning it as a strong performer in its category.

Sound Performance

The bass boost control is best left untouched, while the low-pass filter offers ample adjustment. The US 08 Active delivers a mature bass response with a deep cutoff frequency, providing a surprisingly low bass extension for its size. The ample amplifier power ensures strong output and a noticeable presence. The sound reproduction quality is deemed to be perfectly acceptable.

Key Features and Technical Data

Technical Specifications

• Housing Width: 25.2 cm
• Housing Height: 8.0 cm
• Housing Depth: 34.2 cm
• Construction/Volume: PM 5.5 l
• Reflex Channel (d x l): Not specified
• Weight: 5.7 kg
• Driver Diameter: 20 cm
• Nominal Impedance: 2 Ohm
• Voice Coil Diameter: 50 mm
• Power at Nominal Impedance: 137 W
• Sensitivity (Cinch max.): 110 mV
• Sensitivity (Cinch min.): 4.4 V
• THD+N (<22 kHz) 5 W: 0.10%
• THD+N (<22 kHz) Half Load: 0.32%
• Noise Ratio (A bew.): 73 dB

Features

• Low-Pass Filter: 50-150 Hz
• Bass Boost: 0-18 dB/80 Hz
• Subsonic Filter: 20 Hz/12 dB, fixed
• Phase Shift: Polarity switch
• Low-Level Inputs: Yes
• High-Level Inputs: Yes
• Automatic Turn-On: Yes
• Remote Control: Yes
• Other: Passive membranes

Evaluation

The US 08 Active is considered a mature under-seat subwoofer, effectively dispelling the notion of it being a compromise solution.

Summary Scores:

• Sound: 7.5/10
• Labor (Lab): 7.5/10
• Practice (Real-world): 7.5/10
• Overall Rating: 1.2 (Excellent)

Price: Approx. 270 Euros

Verdict: The bass boost at 80 Hz is set too high for effective deep bass extension. However, for its compact size, the US 08 Active achieves a remarkable cutoff frequency.

Award: LEISTUNGSTIPP (Performance Tip) - Kompaktklasse (Compact Class)

Conclusion

The US 08 Active is among the more sophisticated under-seat subwoofers, making it easy to forget that it's intended as a space-saving solution. It offers a compelling combination of build quality, sound performance, and features for its class.