What percentage of stuff about audio that you read on the web is hyperbole or just plain wrong? I’m finding that more and more “experts” are trying to cast their opinions as the truth. Here’s an example. I received this from a reader who asked what I thought about it. It was taken from a forum.
“Analog tape should definitely be up sampled at the highest possible frequency and even then Hi-Res digital still does not quite capture all the sonic fidelities of Master Analog Tape. Forget about the numbers that are thrown out to support a position, most are meaningless without the reference levels.
Let’s take dynamic range for example. Hi Res advertises 6 dB per bit + 1.8dB. But what they don’t tell you is recording levels must be pushed down so as to ensure there is no clipping. Tape does not clip like that, it saturates, sometimes gracefully, sonically degrading or distorting in a way that is pleasant to the human ear. But as a Member said, get a hold of a Master Analog Tape Recording or get with someone that has one and have a listen. You will be so blown away that your eyes and your ears will be opened and you will know the true goal to which Hi-Res should strive to achieve instead of saying it is already better, which is the dullest thing my ears have ever heard.”
Let’s start with the first line. Upsampling is something that happens to digital signals not analog ones. If you have a CD spec soundfile at 44.1 kHz/16-bits, it is possible to upconvert or upsample it to 88.2/16. All you have to do is double the number of samples. However, it doesn’t enhance the fidelity of the music at all. The fidelity is locked in at the time of the original recording. I think what the person was trying to say is that high-resolution specs should be used when capturing or converting an analog tape to PCM digital. That does make some sense…but 96 kHz / 24-bits is more than sufficient to capture “all of the sonic fidelity of Master Analog Tape”. He’s dead wrong about high-res digital being incapable of capturing the sound of analog tape.
Let’s next take a look at the second paragraph. During a recording production, the engineer must make sure that the loudest sound doesn’t “clip” the available dynamic range of the equipment being used to record the selection. It was especially important when using analog tape because the dynamic range of analog tape is constrained…to about 72 dB. Tape does have a smooth transition into distortion, which can sometimes be used to creative advantage but pushed too far and the recording is worthless.
PCM digital doesn’t allow any overages…when you exceed 16-bits or 24-bits, there is no place left to go. But experienced engineers simply move their reference level down (typically to -14 dB) and set the loudest peaks to just barely reach 0 dB. High-resolution PCM digital audio has the potential to provide 130 dB of dynamic range and even more. Analog tape can’t come close. If hi-res digital is the “dullest thing” his ears have ever heard…he’s got a hearing problem.
Analog tape masters can sound amazing…but they have their limits just like every format. High-resolution PCM digital has the potential to eclipse every format currently available. That’s a fact that is hard for many analog advocates to accept. Lots of engineers like the “sound” of analog tape but that doesn’t mean that it is the most accurate format available…it’s absolutely not.
I’ll come back to another myth I pulled from James Lee McDaniel, the guy from Instrument Quality. He wrote:
“Over the past decades, vinyl recordings have proven to be the most practical economic delivery mechanism for a true analog music signal, and when the limitations of analog signal chain were observed, to this day remains a superior signal for subtle detail, even with the relatively high noise floor, and lesser dynamic range than high frequency with high bit resolution digital recordings.”
Do I really need to parse this couple of sentences? It’s wrong, too.
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