Page 2 of Car HiFi by Athena Technologies

source units clarion s drz9255 source unit takes you into the recording studio conventional cd players can only reproduce frequencies up to around 20 khz 96 khz sampling d/a converter the spiral pattern on cds represents numbers digit means number these numbers represent measurements of an audio signal and other data when a digital recording is made measurements can be made 44,100 times each second per channel at that sampling rate frequencies up to around 20 khz can be recorded so the frequency range of conventional cd players barely extends over 20 khz high-frequency harmonics add richness and depth to sound why can t conventional cds encode data for frequencies over the limit of around 20 khz because the people who set the cd standard believed that no one could hear those high frequencies if such frequencies were on a conventional cd the filters in a conventional cd player would remove those frequencies furthermore analog filters can cause phase distortion of the signals that go through them causing the high frequencies that do come out of the player to come out at the wrong times ironically high-frequency harmonics can affect the details and the depth of sound 96 khz oversampling enables reproduction that is more faithful to the original source the 96 khz digital anti-imaging filter interpolates samples into the audio signal from the disc at a speed more than twice as fast as the cd standard sampling rate of 44.1 khz this is the first such digital filter designed for vehicle audio without oversampling the signal from a cd must be filtered in the analog domain to reduce high-frequency noise and such analog filters cause phase time distortion oversampling filters are free from phase distortion so they deliver more musical detail and more of the realistic resonances of real live sound copper plated chassis reduces distortion and noise the use of a copper plated chassis minimizes the creation of spurious electrical currents that could distort the audio signal additionally the copper plating can reduce noise because it creates an insulating shield zinc has a high specific gravity high rigidity and low resonance so a die-cast zinc panel can reduce distortion caused by vibration because components such as the power supply vfd devices for the display and the drive mechanism can cause noise in the signal those components are externally positioned away from the audio signal burr-brown advanced segment 24-bit digital-to-analog converter after the data from the disc goes through the 96-khz filter it is processed by a burr-brown advanced segment 24-bit dac with superior dynamics and resistance to clock jitter the digital-to-analog conversion is highly accurate because the dac s internal structure is a four dac configuration operating on an lr differential signal turning the display off to turn sound quality on when the drz9255 plays a cd or other source its display can be turned off to minimize interference from circuits that can otherwise degrade sound quality the drz9255 s dc dc converter keeps great sound in and keeps noise out the drz9255 is truly an audiophile source unit its external dc dc converter is comprised of components of the highest quality from its input wiring through its chassis to its output fuses this power supply gives the drz9255 both strength and precision and its six-sided shielded casing repels noise even during high-load bursts to prevent even the smallest vibration the power supply is wrapped in a die-cast aluminum casing and a copper plated chassis toroidal choke coils inside the power supply minimize induced vehicle noise and loss of power a large capacity low impedance condenser allows this external component to supply pure power clarion takes this one step beyond by equipping this power supply with a gold plated connection terminal to further minimize power loss the world s best 0.7 cm per step digital arrival time alignment this function lets you delay signals going through as many as eight channels so sound from all speakers can arrive at one location simultaneously arrival times can be optimized for the driver front passenger both front seats rear seats or all seats you can quickly and easily select the system s acoustic pattern or choose settings based on the type of vehicle or number of passengers signals can be delayed for differences in distance of up to 500 centimeters over 16 feet in increments of 7 millimeters approximately one forth of an inch 96 khz sampling d/a converter conceptual diagram of frequency phase characteristics

[close]