Assessments - 4, GPA: 4.3
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Facilidade de uso
Although many people might jump into an “add-on” amplifier to power to rear coaxial speakers, a better choice is usually a subwoofer amp/speaker system that supplements the existing 4 speaker system as shown in the adjacent drawing. Such a system provides a surprising improvement in sound quality due to the usually dramatic increase in bass response. The next dramatic step up in performance is with a “multichannel” system that offers more dynamic range in the mids and highs due to higher power plus more bass response due to multiple woofers and/or more power. But, with such a system, the stereo image and overall listening experience usually becomes much more life-like due to better tonal quality midrange/tweeter speakers and usually better placement. To build such a system though, complexity goes up due to the addition of passive or active crossovers which take time to install and may inject noise into the system due to potential noise signal pick up. The results though of such a system can be dramatically pleasing. Full-Range Full-Range Full-Range Full-Range Subwoofer Supplementary subwoofer system Receiver Passive X-over Sat Amplifier (4x60 W) Sub Amplifier (2x120 W) Subwoofers High performance multi-channel system INSTALLATION TOOLS For most installations, simple hand tools are adequate to install an aftermarket amplifier. Depending upon the mounting locations used, you will need power tools for drilling and cutting plastics and metal. A good starting list is summarized below: ¦ Tape measure and ruler ¦ Marking pen and starting punch ¦ Phillips and flat blade screwdrivers (small and medium sizes) ¦ Nylon wire bundle ties ¦ Pliers: standard vice-grip and needle nose styles ¦ Light-duty trim pry-bar for removing door trim ¦ Cutting shears or nibbling tool for cutting thin and medium gauger metal ¦ Wire cutters, wire strippers, electrical tape, crimping pliers and appropriate crimp-on terminals ¦ Power drill with appropriate sized drill bits – 4 – VEHICLE WIRING VEHICLE FUSING For safety purposes, a high current fuse (or circuit breaker) MUST be installed in line with the amplifiers(s) immediately at the battery to prevent vehicle damage should the battery line in advertently shorted to the vehicle chassis. The chart at the right shows the recommended master fuse sizes for an average audio system with noted “rms” output power levels. SYSTEM FUSE CHART (Fuse size for total amplifier system power in “rms” watts) 100 W 200 W 500 W 1000 W Fuse Size (in amps) 20 A 30 A 50 A 100 A POWER WIRING Most vehicles built since 1990 have adequate current capability for your amplifier. Except for systems above about 500 W rms, the factory charging system and battery should easily support it if properly installed. Proper wire size must be chosen to ensure adequate current delivery to the amp. Wire size (gauge) of the cables need to increase in size for higher power systems. (Wire sizes larger than those noted are usually a waste of time and money since they offer Little or no performance improvements.) Wire diameter must increase (decreased wire gauge number) for higher power systems. For long wire runs the wire diameter must also increase. The wire sizes noted allow for a maximum 0.5 volts DC drop over the give wire run which results in Sound Pressure Level drops inaudible to the average listener. SYSTEM POWER AND GROUND WIRE CHART (Wire gauge for total system in 'rms' watts) WIRE LENGTH 100 W 200 W 500 W 1000 W 5 ft. / 1.5 m 12 10 8 4 10 ft. / 3.0 m 12 10 8 4 15 ft. / 4.5 m 10 8 6 2 20 ft. / 6.0 m 10 8 6 2 25 ft. / 7.5 m 10 8 4 0 or 00 SPEAKER WIRING As with power wire, speaker wire size (gauge) changes with the power required and the length of the wire run. The speaker wire chart shows the minimum recommended wire size for a single audio output channel driving a loudspeaker at a given distance with a maximum power loss of 0.5 dB, the threshold of audibility. (Wire sizes larger than those noted are usually a waste of time and money since they offer little or no performance improvements.) LOUDSPEAKER WIRE CHART (Wire gauge per loudspeaker/speaker power in “rms” watts) WIRE LENGTH 20 W 50 W 100 W 200 W 5 ft. / 1.5 m 18 16 16 16 10 ft. / 3.0 m 18 16 16 16 15 ft. / 4.5 m 16 16 16 14 20 ft. / 6.0 m 16 16 16 14 25 ft. / 7.5 m 16 16 14 12 FINAL VEHICLE WIRING Current requirements for an upgraded audio system dictate a dedicated power line be run from the amplifier directly to the battery of the vehicle. This line should NOT be run to the fuse panel of the vehicle but directly to the battery. DO NOT run to the alternator either. There MUST be a fuse installed at the battery with adequate amperage as shown in the chart above. As for the final signal wiring, be sure to route the audio cables down the side of the car opposite the power lines to avoid noise pick up from the lines. Also, try to route all audio cables away from noise sources such as engine computers and ABS brake computers. Proper power groun...