Thứ Sáu, 28 tháng 10, 2011

Designer Notebook: Inside The Development Of The New EAW KF740 Line Array
The goals and metholodogy behind a new line array.
Digital Procesing
Proprietary EAW Focusing technology, provided by the UX8800 digital processor, offers specially tailored alignment and driver processing algorithms that further optimizes performance.
It eliminates the traditional characteristics of “honk” and “splashiness” that can plague horn-loaded loudspeaker designs.
The honk of a horn is normally heard in the lower frequencies of its band pass, while splashiness (an attribute of compression drivers) is usually heard at the highest frequencies and obscures the fine detail in instruments, such as cymbals.
Likewise, cone drivers have inherent resonances in their upper frequency range that result in “muddiness” in the middle of the vocal range.
These HF and LF behaviors combine to produce a sonic signature commonly referred to as “coloration.”
The roots of EAW Focusing began with a proprietary, software-based spectrograph for acoustical analysis. This spectrograph, along with other analysis tools, was used to investigate the unprocessed responses of HF and LF subsystems in various directions and at various levels.
The analysis allowed various performance anomalies to be isolated from each other.
In this way, those anomalies that were linear, time invariant, spatially consistent, and therefore correctable, could be distinguished from anomalies without those characteristics, and which were therefore not correctable.
The EAW UX8800 digital processor that delivers EAW Focusing parameters to the KF740.
The next step was to apply appropriate DSP to the correctable anomalies. Another analysis was performed on the standard, universally used DSP algorithms.
This test proved that these standard algorithms simply did not produce filters with response shapes, temporal behaviors, or resolutions with anywhere near the required precisions or accuracies necessary to correct those anomalies to which they were being applied.
To solve this dilemma, we undertook development of custom DSP algorithms specifically engineered to provide the required filters for correcting loudspeaker anomalies.
The resulting filters had to possess the required precision and accuracy in both the frequency and time domain.
At the same time, any uncorrectable anomalies would have to be ignored by the filters. The anomalies and resonance problems cured by EAW Focusing are very specific to each loudspeaker design.
Completing this package, the vertical output can be tailored to match the requirements of any space by varying the splay at the rear of the enclosures as directed by EAW Resolution software.
The resultant configuration repeatedly produces a continuous, coherent wave front of extended range, high-resolution audio over the entire defined coverage area.