The Rise of "Hybrid" Vinyl-MP3s

Khyber writes to let us know that First Word Records, a U.K.-based record label, is now selling vinyl records that come with codes that allow you to download a 320-kbit MP3 of that record's content. The article mentions another independent label, Saddle Creek, that also offers DRM-free downloads with some vinyl records. The co-founder of First Word is quoted on why they didn't DRM the download: "Making a legal, paid-for version of the file less useful than a copied or pirated one doesn't make sense."

Comments

Possibly better than CDs?

[powerpants]

If the MP3s are coming straight from the record label, maybe they could be encoded straight from the master mix, rather than a down-sampled 24-bit, 44.1kHz CD. My understanding is that CDs go up to 20 kHz (which is pretty close to the highest pitch humans can hear), but that the bit-depth is somewhat course at that range.

Is there an audio engineer around who can explain if there's much to be gained this way?

Re:Possibly better than CDs?

[iangoldby]

My understanding is that CDs go up to 20 kHz ... but that the bit-depth is somewhat course at that range.

You are probably thinking of 'one-bit' (or bitstream) digital to analogue converters. (Wikipedia article.) It gets around the problem of producing 16 bits of resolution with a single bit by switching at a frequency many times that of the sampling frequency and averaging over time.

In its purest form, it would switch at 2^16, or 65536 times the CD sample frequency. If one CD sample value is 0, the DAC would be off for 65536 DAC output samples. If the CD sample value is 65535 it is on for 65536 DAC output samples. For intermediate values it is on for the given proportion of the time. In other words, the CD sample value determines the duty-cycle of the output from the DAC. The one-bit on/off output is then averaged over time. This results in a conversion with almost no non-linear distortion of the signal.

Unfortunately a frequency of 65536 * 44.1 kHz would be in the THz range, so the actual frequency that a 1 bit DAC operates at is somewhat lower. For lower frequency audio signals the averaging process is still very accurate, but it loses some accuracy for the highest frequency audio tones mostly when there are rapid transients in the high frequencies. You might refer to this as a 'coarsening of the bit-depth'.

A full 16-bit DAC doesn't suffer from this problem because each sample from the CD is converted straight into a voltage proportional to that sample value in a single step. But it is very difficult to make a completely linear 16-bit DAC, so the non-lineararity of the DAC introduces its own distortions. But these distortions do not depend on frequency as they do with a 1-bit DAC.

Re:Possibly better than CDs?

[exp(pi*sqrt(163))]

Look, if you're going to make up justifications for using vinyl, make them more convincing. Much of the theory about human hearing is based on the assumption that the ear acts as a linear system. If the ear were a linear system there is no way it'd be possible for "certain confluences of sound react with each other and produce further sounds". In linear systems harmonics at different frequencies simply add, there is no possible 'interaction' that can happen between them.

But nonlinear systems are quite different. The classic example is soliton waves. When two of these meet, they don't simply combine additively. In particular, different harmonics don't necessarily pass straight through each other and its quite possible for two very high frequency signals to interact and produce a low frequency signal in the result. And of course there really is no reason to expect the ear to remain close to a linear system, even ordinary sound waves in air become nonlinear if the sound is loud enough.

So if you want to sound convincing, talking about nonlinearity is your best bet. I can guarantee that 90% of the engineers you talk to won't have a sensible response because they've never studied nonlinear signal processing, and they'll be less likely to laugh at you.

Re:Possibly better than CDs?

[leenks]

Not strictly true. If you play two frequencies, say 28000hz and 28500hz together, they will beat and you will hear that. Sure, you can't hear the frequencies but you can hear the effect. This could be why mediums that apply a hard filter appear dull at times.

Modern digital equipment sounds far better than it should because of the tricks employed in the converters. Oversampling and noise dithering has a massive effect on the sound, and you aren't really hearing the true digital signal but a smoothed one. Before such techniques were used, digital equipment got huge criticism for being clinical sounding (quite rightly). Vinyl and other analogue systems don't have this problem obviously, but bring loads of others to the table (wear and tear, damage, static, etc).

For some material, 16bit is definitely not enough. It's fine for a lot of modern chart material, where the mastering has multiband compressed it to hell and back to make it sound louder than the competition, but those tracks don't need the dynamic range of a Chopin valse, or a Beethoven symphony. The quiet bits on 16 bit recordings definitely lose a lot compared to 24bit (side by side comparison using old and new gear) - but I think it is really the recording and production stages that need 24bit or more, not necessarily replay because of the tricks that can now be applied.

Anyway, what does it matter? It's the material played that is ultimately important, not the method of reproduction.

Somewhat pointless

[11223]

Given that I can buy totally unmolested WAVs from Beatport, what's the point? I find it hard to believe that there are vinyl purists who want MP3s, or that those who would work with an MP3 wouldn't rather deal with a master-quality WAV which can be manipulated even more.

Lossy compression is just as insidious as DRM when the bandwidth for CD-quality uncompressed audio is available.

And to those who say you can't hear the difference, if you slow the track down by 50%, you can. If you don't know why you would do that, ask a DJ.

Re:NOT better than CDs

[Endo13]

No, "better" in this case is not subjective at all. I think you entirely missed his point. His point is that you can create any sound you want with digital. Any sound at all. If you wanted to make a digital version of a track that sounded like it did on vinyl, you could do that and put it on CD. The issue here is that CD audio is a lot closer to the original live audio. Therefore it's a better reproduction. Just as 3.141592653589793238462643383279502884197169399375 10 is a better representation of Pi than 3.14 is. So the question isn't so much "do you like CD or vinyl better". The question is "do you like live music or vinyl better". Because with CD, you've basically got the exact same sound as if you were actually at the concert.