DIGITAL SIGNAL PROCESSING, A QUICK TOUR Meadowlark Audio speakers accept digital audio directly from your source, typically a streamer. So, if you’re thinking of moving up to next generation stereo, or if you’re buying your first serious stereo, it’s a good idea to understand the basics. At the beginning of digital audio, when Sony and Phillips got together to create the standards used in Compact Disc, they established a data format called Sony/Philllips Digital Interface Format or S/PDIF. That’s what’s on a CD. Like any datastream, it’s a string of 1s and 0s that can be stored or transmitted like any other digital file. When CD was being developed by Sony and Phillips, their idea was to make a 120mm optical disc that could hold the entirety of their longest piece of music of interest, Beethoven’s 9th Symphony, which at the time consumed two LPs, about 75 minutes. With the available data densities, that allowed for a 16 bit word for both left and right channels coming once each 1/44100th of a second, or 44.1KHz. At that data density, resolution and dynamic range were pretty good, but not great. Today’s HD Audio data densities are much higher, meaning fantastic resolution and dynamic range. Conveniently, the format remains the same so a modern system that processes at 24bit / 192KHz will also process your CD quality files. In our speakers, the onboard Digital Signal Processor inputs S/PDIF (or AES/EBU), then goes to work on the datastream, rearranging it in a number of ways to accomplish all of the things that were once done by analog circuits, plus much more. This process is lossless, meaning the data are not degraded, merely rearranged. So unlike conventional methods, DSP avoids damaging the music signal. Following the manipulations that we impose in both amplitude and time domains, the conversion to analog - DAC - occurs directly before amplification. In a three-way speaker we employ three distinct channels of DSP, each feeding it’s own dedicated amplifier by way of it’s own dedicated DAC. This gives us complete control over exactly what signal goes to which driver - including control over relative timing. It also gives complete control over how your speaker sounds in your room. Here is the flowchart showing how the simply and purely the signal goes thru our speakers:
And here’s what happens as we design at the processor’s control panels. You can see the exquisite control we have over what how the speaker functions. All without any losses. Here is the frequency/amplitude transfer function we impose on the midrange driver of Ibis, showing the extremely fast roll offs that limit the driver’s band to between 160Hz and 2200Hz, with a downward slope in the midband to suppress the driver’s natural inductive rise. If you don’t know what that means, no problem, it’s great. And, in the lower left, you’ll notice a delay of 53 microseconds to time its output correctly with respect to the tweeter.
And here’s what a room equalization file might look like. Try that in analog!
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DIGITAL SIGNAL PROCESSING, A QUICK TOUR Meadowlark Audio speakers accept digital audio directly from your source, typically a streamer. So, if you’re thinking of moving up to next generation stereo, or if you’re buying your first serious stereo, it’s a good idea to understand the basics. At the beginning of digital audio, when Sony and Phillips got together to create the standards used in Compact Disc, they established a data format called Sony/Philllips Digital Interface Format or S/PDIF. That’s what’s on a CD. Like any datastream, it’s a string of 1s and 0s that can be stored or transmitted like any other digital file. When CD was being developed by Sony and Phillips, their idea was to make a 120mm optical disc that could hold the entirety of their longest piece of music of interest, Beethoven’s 9th Symphony, which at the time consumed two LPs, about 75 minutes. With the available data densities, that allowed for a 16 bit word for both left and right channels coming once each 1/44100th of a second, or 44.1KHz. At that data density, resolution and dynamic range were pretty good, but not great. Today’s HD Audio data densities are much higher, meaning fantastic resolution and dynamic range. Conveniently, the format remains the same so a modern system that processes at 24bit / 192KHz will also process your CD quality files. In our speakers, the onboard Digital Signal Processor inputs S/PDIF (or AES/EBU), then goes to work on the datastream, rearranging it in a number of ways to accomplish all of the things that were once done by analog circuits, plus much more. This process is lossless, meaning the data are not degraded, merely rearranged. So unlike conventional methods, DSP avoids damaging the music signal. Following the manipulations that we impose in both amplitude and time domains, the conversion to analog - DAC - occurs directly before amplification. In a three-way speaker we employ three distinct channels of DSP, each feeding it’s own dedicated amplifier by way of it’s own dedicated DAC. This gives us complete control over exactly what signal goes to which driver - including control over relative timing. It also gives complete control over how your speaker sounds in your room. Here is the flowchart showing how the simply and purely the signal goes thru our speakers:
And here’s what happens as we design at the processor’s control panels. You can see the exquisite control we have over what how the speaker functions. All without any losses. Here is the frequency/amplitude transfer function we impose on the midrange driver of Ibis, showing the extremely fast roll offs that limit the driver’s band to between 160Hz and 2200Hz, with a downward slope in the midband to suppress the driver’s natural inductive rise. If you don’t know what that means, no problem, it’s great. And, in the lower left, you’ll notice a delay of 53 microseconds to time its output correctly with respect to the tweeter.
And here’s what a room equalization file might look like. Try that in analog!