At the heart of IMPRINT is MultEQ, which was developed by the founders of Audyssey Labs-Prof. Chris Kyriakakis and Prof. Tomlinson Holman (inventor of THX theater sound)-in an effort to understand and correct the fundamental causes of room acoustical distortion. It works by capturing frequency and time domain information from the sound system within the acoustical environment in order to identify the problems. It then creates a set of equalization filters to correct for frequency response and time domain problems for each speaker in the system. Based on these measurements, MultEQ calculates an equalization solution based on a selection of a target curve from those developed by our team of sound engineers. It's a unique solution that leads to spectacular sound quality experience that's customized to each specific vehicle and sound system.
How Does It Work
IMPRINT isn't just another equalizer or time correction device. It is the only system for the automotive environment (to our knowledge) that measures the entire listening area, capturing time domain information from each listening location and applies a proprietary method for combining this information to represent all seat locations. This results in a maximized listening experience in all seats, not just for the driver.
During the measurement analysis, MultEQ assigns more than 500 control points to the plotted frequency response of the vehicle. Each control point is then adjusted using MultEQ's dynamic filter methodology. These points optimize the sound reproduction to the specific vehicle's listening environment with much greater precision than can be achieved with traditional parametric equalization.
How? First, MultiEQ creates a precise inverted filter. The filter applies a peak of the same shape everywhere there is a dip. Conversely, every peak is corrected with a dip. With more than 500 points used to create the model, the filter is incredibly accurate-considerably more so than even the best parametric or graphic equalizers, which are typically limited to a certain number of bands.
Then there is the issue of time domain. This is a fairly easy concept to understand. Sound emits from a speaker eventually hitting your ears. A few milliseconds later, copies of that same sound signal hit your ears after being reflected and modified by the car seats, dash, windows, etc. Since these reflected sound copies arrive so closely to the direct sound, your brain meshes everything together. This results in the smearing of transients, ringing and comb filtering. In other words, it muddies up the sound.
MultEQ filters are specifically designed to address these time domain problems and concentrate most of the signal energy in the direct sound. Reflections thereby can be dramatically reduced, allowing more pure sound from the speaker to arrive at each seat. This dramatically improves the soundstage because matched frequency response is one of the cues our ears rely on for imaging.
Here's what's interesting. Whereas typical time correction can only be applied to one channel of an amplifier, MultEQ time corrects based on frequency. This allows for time correction between multiple drivers on the same channel, not just the channel itself.