1. Introducció
This manual provides detailed instructions for the installation, operation, and maintenance of the Audison AP BMW S8-4 Prima Series 8-inch (200mm) Subwoofer. This subwoofer is specifically designed for direct replacement of OEM speakers in BMW vehicles, optimizing performance within the factory under-seat enclosure.

Imatge 1.1: Frontal view of the Audison AP BMW S8-4 Prima Series Subwoofer.
2. Què hi ha a la caixa
Desembaleu amb cura el contingut i assegureu-vos que hi hagi tots els elements:
- Audison AP BMW S8-4 Subwoofer(s)
- Two (2) 5 mm polyurethane gaskets
- Crossover (if applicable to your system configuration)
- Cargols de muntatge
- Manual d'usuari (aquest document)
- Informació de la garantia

Image 2.1: Product packaging for the Audison AP BMW S8-4 Subwoofer.

Image 2.2: Included 5mm polyurethane gaskets for optimal fit.
3. Característiques
The Audison AP BMW S8-4 Subwoofer incorporates several design elements for enhanced performance and compatibility:
- Neodymium Magnetic Group: Maximizes performance while minimizing bulk and weight.
- BMW-Mini Optimized Electroacoustic Parameters: Engineered to deliver powerful and clear low frequencies, utilizing the acoustic load provided by the factory enclosure.
- 38 mm Voice Coil: Wound on an aluminum support for significant power dissipation and stability, even during high excursions.
- ABS Plastic Basket: Reinforced with fiberglass for durability and minimal installation depth.
- Front Magnet Design: Contributes to a minimal installation depth, ensuring compatibility with the entire range of BMW under-seat enclosures.
- Impedància de 4 ohms: The S8-4 model is designed with a 4 ohm impedance, suitable for system configurations where amplifiers can be bridged to deliver higher power.

Imatge 3.1: View of the subwoofer cone and central voice coil area.
4. Especificacions
| Especificació | Valor |
|---|---|
| Número de model | APBMW-S8-4 |
| Component | Woofer |
| Maneig de potència (continu) | 150W RMS |
| Maneig de potència (pic) | 300W |
| Impedància | 4 ohms |
| Resposta de freqüència | 35 ÷ 500 Hz |
| Pes de l'article | 3 lliures (1.36 kg) |
| Dimensions del producte (L x A x A) | 9.41 x 9.41 x 7.52 polzades (23.9 x 23.9 x 19.1 cm) |
| Diàmetre de la bobina de veu | 38 mm |
| Tipus d'imant | Neodimi |

Image 4.1: Technical drawing illustrating the dimensions of the subwoofer.
5. Configuració i instal·lació
The Audison AP BMW S8-4 subwoofer is designed for a direct replacement installation in BMW vehicles, specifically fitting into the factory under-seat enclosures. Professional installation is recommended to ensure optimal performance and avoid damage to the vehicle's electrical system.
5.1. Comprovacions prèvies a la instal·lació
- Verify the subwoofer's impedance (4 Ohms for S8-4) is compatible with your ampsortida del lifier.
- Assegureu-vos que la bateria del vehicle estigui desconnectada abans de començar la instal·lació.
- Confirm the factory under-seat enclosure is clean and free of debris.
5.2. Passos d'instal·lació
- Carefully remove the existing OEM speaker from the under-seat enclosure. Refer to your vehicle's service manual for specific removal procedures.
- Place the provided 5 mm polyurethane gaskets onto the subwoofer's mounting surface. These gaskets ensure a perfect seal and decouple the subwoofer from vibrations within the enclosure.
- Position the Audison AP BMW S8-4 subwoofer into the factory enclosure. The design allows for a minimal installation depth, ensuring a proper fit.
- Secure the subwoofer using the provided mounting screws. Do not overtighten.
- Connect the subwoofer wiring to your amplifier. Pay close attention to polarity (+/-) to ensure correct phase.
- Reconnect the vehicle's battery and proceed to system testing.

Imatge 5.1: Pro lateralfile of the subwoofer, highlighting its compact design for under-seat installation.
6. Funcionament
Once installed, proper tuning of your audio system is crucial for optimal subwoofer performance. The AP BMW S8-4 is designed to integrate seamlessly with your vehicle's acoustics.
6.1. Initial Power-Up and Testing
- After installation, turn on your car's audio system at a low volume.
- Listen for any unusual noises or distortion. If present, immediately turn off the system and re-check all connections.
- Gradually increase the volume and adjust the subwoofer level on your head unit or ampmés viu.
6.2. Ajust del sistema
For the best audio experience, consider the following:
- Configuració de crossover: Set the low-pass filter on your amplifier or head unit to prevent higher frequencies from reaching the subwoofer. A common starting point is around 80-100 Hz, but this may vary based on your full-range speakers.
- Ajust de fase: Experiment with the phase setting (0° or 180°) on your amplifier or head unit to achieve the most cohesive bass response with your front speakers.
- Configuració de guany: Ajusteu el ampguany del lificador per coincidir amb el volum de sortidatage of your head unit. Avoid setting the gain too high, as this can lead to distortion and potential damage.
- Digital Sound Processor (DSP): If using a DSP (e.g., Audison AP 8.9 bit), utilize its capabilities for precise equalization, time alignment, and crossover adjustments to maximize the subwoofer's performance.
7. Manteniment
The Audison AP BMW S8-4 subwoofer requires minimal maintenance to ensure long-term performance.
- Neteja: Periodically clean the subwoofer's grille and surrounding areas with a soft, dry cloth. Avoid using harsh chemicals or abrasive materials.
- Factors ambientals: Protect the subwoofer from excessive moisture, extreme temperatures, and direct sunlight, which can degrade materials over time.
- Inspecció: De tant en tant, inspeccioneu les connexions del cablejat per assegurar-vos que estiguin ben fixades i sense corrosió.
8. Solució De Problemes
If you encounter issues with your Audison AP BMW S8-4 subwoofer, refer to the following common troubleshooting steps:
8.1. No hi ha so del subwoofer
- Comproveu les connexions: Ensure all power, ground, remote, and signal cables are securely connected to both the ampamplificador i el subwoofer.
- AmpEstat de l'abonament: Verifiqueu que el vostre amplifier is powered on (indicated by a power light) and not in protection mode.
- Configuració de la unitat principal: Confirm that the subwoofer output is enabled and the volume is turned up on your head unit.
- Comprovació de fusibles: Inspeccioneu el amplifier's fuse and the main power fuse for the audio system. Replace if blown.
8.2. Distorted or Weak Bass
- Configuració de guany: Ajusteu el amplifier gain. If set too high, it can cause distortion. If too low, it can result in weak bass.
- Configuració de crossover: Incorrect crossover settings can lead to distortion or a lack of impact. Adjust the low-pass filter.
- Fase: Incorrect phase can cause cancellation with other speakers, leading to weak bass. Adjust the phase setting.
- Integritat del recinte: Ensure the subwoofer is properly sealed within its enclosure. Air leaks can cause poor performance.
8.3. Intermittent Sound
- Connexions soltes: Re-check all wiring for any loose or corroded connections.
- Signal Cable Interference: Ensure RCA cables are routed away from power cables to prevent noise.
If these steps do not resolve the issue, contact Audison customer support or a qualified car audio technician.
9. Garantia i Suport
The Audison AP BMW S8-4 Subwoofer comes with a 1 any de garantia del fabricant. Aquesta garantia cobreix els defectes de materials i de mà d'obra en ús normal.
9.1. Reclamacions de garantia
To make a warranty claim, please retain your proof of purchase and contact your authorized Audison dealer or Audison customer support. The warranty does not cover damage caused by improper installation, abuse, accident, neglect, or unauthorized modification.
9.2. Suport tècnic
For technical assistance, installation guidance, or further inquiries, please visit the official Audison website or contact their customer support department. Contact information can typically be found on the Audison weblloc web o a la documentació de garantia inclosa amb el producte.







