Why factory Audi bass runs out
Audi’s standard system and even the Audi Sound System use a small woofer in the doors or the rear shelf, driven from the head unit. Bose and Bang & Olufsen add a proper amplifier and a subwoofer in the boot side, but they are tuned for balance, not depth. A dedicated subwoofer with its own amplifier gives the low notes their own driver and their own power, and the rest of the system stops straining at volume.
Two ways to do it on an Audi
Active under-seat subwoofer. A slim enclosure with the amplifier built in, mounted under the front passenger seat. Power runs from the battery on a fused cable, the signal comes off the factory system, and the boot stays completely free. This is the answer for A1, A3, A4, Q3 and TT, and for most e-tron owners who do not want to give up boot space. From €450 fitted.
Subwoofer and separate amplifier in the boot. A passive sub in an enclosure, a mono or multi-channel amplifier on a hidden board, everything fused and secured. More output, and the option of driving the door speakers from the same amplifier. Suits A6, Q5, Q7 and the larger e-trons. From €750 fitted, with a spare-wheel-well build on request.
Audi models we work on
| Model | Typical setup |
|---|---|
| e-tron / Q4 e-tron | Active under-seat sub, or boot sub and amp on the 12 V system |
| A1 8X | Active under-seat sub |
| A3 8P / 8V | Active under-seat sub |
| A4 B8 / B9 | Under-seat sub, or boot sub and amp |
| A5 | Under-seat sub, or boot sub and amp |
| A6 C7 / C8 | Boot sub with amplifier, spare-well build available |
| Q3 8U / F3 | Active under-seat sub |
| Q5 8R / FY | Boot sub with amplifier |
| Q7 4L / 4M | Boot sub with amplifier |
| TT 8J / 8S | Active under-seat sub |
Wiring it in without touching the MMI
The signal is taken after the factory amplifier through a high-level input or a line-output converter, so the MMI keeps control of volume, fade and balance and nothing needs coding. The power cable runs from the battery — under the bonnet on A3 and TT, in the boot on A4, A6, Q5 and Q7 — with a fuse at the battery end and a remote turn-on tied to ignition, so the sub sleeps with the car. Cables go under the sills and carpet, never across a footwell. We finish with a tune in the car: crossover, gain and phase set by ear and by meter.
Why Radio King
Seven years of Audis through the workshop in Rosemount Business Park, Dublin 11, hidden wiring as standard and a one-year warranty on the parts and the work. You can hear an under-seat sub on the demo stand before you decide. 4.8 stars on Google.