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Korg MR-2000S Review (Bonus Material)

9/30/2009

More on 1-Bit

The following is quoted from Korg''s article entitled “The 1-Bit Advantage—Future Proof Recording”:

It''s easy to follow the benefits of higher and super-high sampling rates. But what might at first confuse the reader is the benefit of moving from high bit rates down to 1-bit. Surely the increased resolution of higher bit rates must be more accurate, right?

The basic concept here is that once the sampling rate is increased to such high levels, each step doesn''t need to be defined with such detail. With such frequent readings of the current state of the audio waveform, each step need only be defined is the simplest of terms—has the signal increased since the last step, decreased or remained the same. 1-bit offers only two values, a 1 or a 0. Either up from the previous sample or down. And at these super-sampling speeds, a steady state can be represented by alternating 1s and 0s. The chance for error in such a system is much less than in multi-bit approaches. Consider this:

In a 1-bit system, the possible values for each measurement are simple, either it''s a 1 or a 0; there''s little chance to get a wrong value. In a 24-bit system, there are 16,777,216 possible values. So which system is more likely to be accurate for each reading?

That description explains the benefits of 1-bit conversion better than I could hope to myself. But I will add a few things informed by what I''ve recently learned about 1-bit recording. The first is that most PCM converters today employ this “over-sampling” technology in their front-end design but use filtering and dithering early in the conversion process to bring the sample rate closer to the consumer delivery (CD) sample rate of 44.1 kHz, and in so doing need to employ multi-bit formats. There are many debates about the benefits of doing so, but to a growing number of engineers this is clearly the wrong approach. They maintain that if the material is kept in the original high-resolution format throughout the digital “life” of the data, until it is delivered to our ears after a final D/A conversion process, all the better will it sound. A lot of inertia is involved in getting a whole industry to shift gears, but we saw it happen with the CD and then with the DVD. Will there be enough consumer demand to put the gears in motion to standardize and refine a 1-bit delivery format (SACD or otherwise) in the near future? Only time will tell.

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