KEF’s new LS50W active music system features several really exciting technical achievements that bring the convenience of a digital music system to the ears of the audiophile. Of all of these features, none is more stunning to the audiophile’s ear than our Phase Correction. Working in conjunction with our acclaimed (and esteemed) Uni-Q driver we are able to bring you a theoretically perfect time alignment throughout the audio range.
While that might sound like a big claim, it really was quite an easy achievement for us because of our Uni-Q and our bespoke DSP.
KEF’s Uni-Q was designed and perfected over the past thirty years to eliminate the time alignment problems caused by having the tweeter and mid-range drivers on a standard speaker located in different places on the baffle. By placing the tweeter inside of the midrange and then designing the waveguides, baffles and surrounds to take optimum advantage of that placement, the listener gets a true soundstage reproduction regardless of where they are seated. For more information and detail see “Why So-Called Co-Axial Speakers Aren’t Uni-Q” KEF Blog, August 2014.
But even with the breakthrough in time alignment the Uni-Q provides, there’s still another problem thanks to simple physics: Running a signal through a crossover causes an inherent phase shift between the frequencies that were processed by the crossover and those that weren’t. In the analog world, this is an inescapable fact of life, which is why the lower the order of the crossover the better in terms of phase shift. But in the digital world, we can compensate for that phase shift without altering the original signal or causing further shifting. Basically, a well-designed DSP (Digital Signal Processor) can give you the option to eliminate the residual phase shift that occurs in the crossover stage of the DSP.
In the graphs below, you can see the phase shift caused in the crossover stage with a normal circuit and what that same signal looks like with the LS50W’s Phase Correction circuit engaged.
To satisfy your inner audio geek, we’ve given you the option to turn the phase correction on or off via the LS50W app. Grab a song you’re really familiar with and play around a bit with the phase correction. What you’ll hear with the phase correction engaged is a sharpness to the mids and highs (we dare not say hi-def, do we?) but even more stunning is the expansion of the soundstage in all three dimensions. Once you lock onto the difference you will actually be able to hear the soundstage of your favorite music with not only height and width, but with depth as well.
It’s just another way the LS50W Active Music System brings audiophile-level musical enjoyment to the convenience and variety of a digital music system.