AES Section Meeting Reports

University of Massachusetts-Lowell - March 2, 2010

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Fadi Hayek, National Sales Manager for Solid State Logic, came to the University of Massachusetts Lowell to give a talk about how digital mixing in the box and analog mixing outside the box can and should live in harmony.

After an introduction by Professor Alex Case describing Fadi's rich and varied background as a musician, recording engineer, and employee of several key companies including Steinberg and, of course, Solid State Logic, Mr. Hayek began his talk by describing the advantages, ease and convenience of digital mixing but warning engineers not to pigeonhole themselves into one overall sound coloration. Instead, he suggested that we as engineers allow ourselves the "largest palate of colors" when it comes to mixing.

Armed with several sonic toys, he showed the crowd of students and professionals in attendance one way of achieving some high quality colors: the SSL Duende line of hybrid digital signal processing. SSL developed these Duende units to run high quality plug-ins in their own hardware so as not to tax the native processor's power and to free SSL engineers from any constraints of other plug-in development environments. This allowed
SSL DSP designers to do whatever it took to run their plug-ins at the highest power and quality independent of the computer system running it. This technology also eliminates bottlenecks at the Dice chip, is able to run at very low latencies, and can run at 96k, leaving routing and other processes to the native processor. Fadi demoed a few such plugins including "X-Verb, "Vocalstrip", and "Drumstrip", all of which seemed of high quality and effectiveness.

Next Fadi described a bit about latency, a topic most of us students struggle with. After giving some background on how signal flows between interfaces, computer processors and DAWs, and the tradeoff between faster latency and more CPU power, he showed us SSL's solution to the latency issue, which is their MADI Extreme PCIe card. This card allows a 64bit bi-directional pipeline from converters into the user's computer allowing latencies as low as 32 samples - less than 1 millisecond of latency.

Finally, Fadi described the differences between digital summing in the box and analog summing. Digital summing requires dithering that will round longer numbers down to shorter ones, a process not present in analog summing. Low level elements of an in the box mix are subjected to more of this, as they live well below the maximum bit resolution of the system. Using several channels of his SSL converters and sending multiple individual stems of the mix to his "Matrix" digitally controlled analog console for final analog summing, he showed us a side-by-side comparison of a session being summed in Logic and through the Matrix. The overall effect was that the tracks mixed in the analog domain had greater clarity between individual instruments, an effect that gave the overall mix a wider and deeper image. Upper mid-frequency presence and high frequency transients were also found to be more detailed and felt more accurate, more natural.

Fadi left us with quite a few interesting topics to think on as we left the presentation, but he stressed that we use our ears and try out different gear to "make your own decisions", but his suggestion is to use a marriage of the best technologies to get the best sound possible.

Matt Iannotti
Treasurer UML AES

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AES - Audio Engineering Society