Rebec U5.8 is a compact sized active subwoofer that produces really pleasant bass reproduction. The surface area required by the case is only 28 x 20cm, but the subbar has more conical surface area than a traditional round element, because the U5.8 hides a 6 x 8″ double speaker element in its interior.

After a retrofitted or factory-installed player
If you install the Rebec U5.8 behind the car's factory-installed stereo, the package includes all the necessary installation cables. The subwoofer can turn on automatically when it receives a signal and comes with ready-made power, grounding and speaker cables. If you connect the subwoofer behind a retrofitted player, you only need an RCA cable. Everything else comes with the U5.8.
The subwoofer also comes with a wired controller that can be installed on the dashboard or, for example, the center console, with which you can adjust the subwoofer's input sensitivity (Gain), low-pass filtering (LPF) or bass boost (Bass Boost). In addition, the regulator has a 0°/180° phase reversal. The subwoofer itself does not have any physical adjustment screws or buttons, but you can easily make all adjustments from the listening position with a separate control. The controller has a fixed cable of about five meters.

Built-in amplifier and high sensitivity
Rebec's amplifier offers the element an RMS power of 97 Watts (max 150W). The double-layer 2 x 2.2ohm element has a high sensitivity of 91 decibels, so the U5.8 brings a kick to the bass side even at lower volumes.
Technical information
- Active subwoofer
- Element: 6″ x 8″
- Impedance: 2 x 2.2ohm
- Amplifier RMS / Max: 97W / 150W
- Playback range: 60 – 150Hz
- Phase reversal: 0° / 180°
- Wired regulator
- Input sensitivity:
- 0.6 - 4V (RCA)
- 2 – 10V (Speaker level)
- With:
- 5.0 meter power cable with fuse
- 1.5m grounding cable
- 5.0 meter speaker cables (When using speaker level input)
- 5.0m excitation cable (when using RCA input)
- Dimensions: 280 x 200 x 74mm

Installation / adjustment instructions
- Before switching on the devices, adjust the input sensitivity (Gain) to the minimum, the phase shift (Phase) to 0° and the low pass filter (LPF) to about half.
- Set the player's Bass/Treble settings to zero, any BassBoost/Loudness settings off. Adjust the volume to about half of maximum.
- Start adjusting the input sensitivity (Gain) carefully to a higher level. If/when you hear distortion coming from the subwoofer, adjust the input sensitivity (Gain) lower until the distortion is no longer heard. If you hear a distorted sound from other speakers in the car, adjust the player's volume to a lower level.
- After the input sensitivity, select the desired low-pass filtering (LPF). The low pass filtering is adjusted according to the car's other speakers and this adjustment is car/equipment specific.
- Finally, select Phase. The phase shift has two positions 0° / 180° and choose the one with which the subwoofer sounds better. The phase shift is affected by the type of car and the installation location of the subwoofer.