User manual AUDIO DESIGN HD900-5

[. . . ] owner's manual 5-Channel Class-D System Amplifier Thank you for purchasing a JL Audio amplifier for your automotive sound system. Your amplifier has been designed and manufactured to exacting standards in order to ensure years of musical enjoyment in your vehicle. For maximum performance, we highly recommend that you have your new amplifier installed by an authorized JL Audio dealer. Your authorized dealer has the training, expertise and installation equipment to ensure optimum performance from this product. [. . . ] Useful when using an external crossover, such as one built into a head unit or signal processor. "12dB": Configures the filter to attenuate frequencies above or below the selected filter frequency at a rate of 12 dB per octave (Butterworth alignment). "24dB": Configures the filter to attenuate frequencies above or below the selected filter frequency at a rate of 24 dB per octave (LinkwitzRiley alignment). Depending on the speaker system and the vehicle, different filter slopes may be required to produce a smooth transition between the sound of different speakers in the system. In high-pass mode, the sharper "24dB" setting will do a better job of protecting small speakers with limited power handling. In low-pass mode, the "24dB" setting can also help by more aggressively removing lower midrange output from a subwoofer system. The shallower "12dB" octave setting allows for more output overlap between the speakers being crossed over. In many cases, this will result in a smoother "blend" or transition between speaker systems. With ported enclosures, the use of the "Infrasonic Filter" is highly recommended to protect the speaker(s) from excessive excursion below box tuning. With sealed enclosures, the use of the filter is less necessary, but can still help protect the speaker system from excessive excursion. The "Infrasonic Filter" can be completely defeated by selecting the "Off" position on its switch. This bypasses all signal from flowing through the circuit. 11 bi-amPliFied sYstems Bi-amplified systems are defined as systems in which separate amplifier channels drive lowfrequency (LF) and high-frequency (HF) speakers and are separately filtered to send appropriate frequency ranges to each speaker system. The most common application of bi-amplification in mobile audio is to drive a subwoofer system from one or more amplifiers or channels and component speakers from separate amplifiers or channels. The HD900/5 can be easily configured to drive a complete bi-amplified system consisting of a subwoofer and four main speakers or a subwoofer and two main speakers. bi-amplified system with one Hd900/5 driving four main speakers plus subwoofer (5-channel mode) In this configuration, the "Front" channels of the HD900/5 will drive front component speakers (stereo 100W x 2 @ 4) with highpass filtering. The "Rear" channels will drive rear component speakers in stereo (100W x 2 @ 4) with high-pass filtering. The subwoofer channel will drive the subwoofer system (500W x 1 @ 1. 5-4) with low-pass filtering. Once the input sections have been configured appropriately, go to the "Front Channel Controls" Section. Select "12dB" or "24dB" on the "High-Pass Filter" and an appropriate "Filter Freq. " (80-90 Hz is a good starting point). Next, turn your attention to the "Rear Channel Controls" Section and select "12dB" or "24dB" "High-Pass Filter" switch and an appropriate "Filter Freq. " (again, 80-90 Hz is a good starting point). Finally, in the "Subwoofer Channel Controls" Section, select "12dB" or "24dB" on the "Low-Pass Filter" Switch and a "Filter Freq. " of 80-90 Hz. After proper adjustment of the HD900/5's "Input Range" and "Input Sens. " controls, you can fine tune filter frequencies and slopes and attenuate each channel section to achieve proper balance. bi-amplified system with one Hd900/5 driving two main speakers plus subwoofer (3-channel mode) In this configuration, the "Front" channels of the HD900/5 will be bridged to drive the left front component speaker system (150W x 1 @ 4) with high-pass filtering. The "Rear" channels will be bridged to drive the right front component speaker system (150W x 1 @ 4), also with high-pass filtering. [. . . ] Using the procedure explained in the previous check item (after plugging the input cables back into the amplifier) test for output at the speaker outputs of the amplifier. Unless you enjoy test tones at high levels, it is a good idea to remove the Speaker Connector Plugs from the amplifier while doing this. This output level can vary greatly between amplifiers but it should not be in the millivolt range with the source unit at half volume. If you are reading sufficient voltage, check your speaker connections as explained below. [. . . ]