Post by: BSD2000 on November 16, 2013, 06:07:29 AM
Why the TT Meter doesn't work on vinyl (http://www.youtube.com/watch?v=n-AE9dL5FG8#)
After watching the video, a few things stood out to me and I find myself disagreeing with premise of his argument - that the dynamic range measurements of vinyl cannot be trusted when comparing the same song to a CD rip.
First, he states that he engineered and mastered the recording digitally and 'peak limited' the audio to flatten out the peaks; and that he used that digital master to cut the vinyl. That's a huge mistake. Vinyl cut from an overly processed digital master really defeats the advantages and character of the vinyl format. Sadly, this method is the most widely used today to cut mainstream vinyl records leading to dull, squashed and thin sounding records.
Also, he didn't state what resolution was used to cut the vinyl - but he does say that it was 'cut with the same file used for the CD', which leads to the conclusion that it was 44.1k/16bit - another huge mistake.
Second, he shows the wave forms of the vinyl and CD rips and the vinyl track displays more natural, uneven peaks - which he says is an unknown artifact and proof that vinyl dynamic range measurements are flawed. But one thing missing from that argument is how a vinyl record is cut. Even with a digital master, the signal must be fed through an analog chain. The analog output from the DAC is fed through amplifiers, processed for RIAA EQ (sometimes processed through analog compressors, expanders and further EQ'd by the cutting engineer) before being sent to the cutting head in a pure analog form. Some peaks in the analog waveform may naturally expand or contract during this analog stage and will end up being cut with a slightly different dynamic waveform profile than the digital source. Some natural compression and expansion of the signal will happen as it's being cut - that's just the nature of the format and signal chain.
Third, the equipment used to playback and record the vinyl isn't listed or talked about. Some cartridges are brighter and more dynamic than others; some are darker and fuller sounding. Not all phono preamps amplify the signal the same way and some are not as transparent as others; imprinting their own character to the signal. Not all preamps process the RIAA curve exactly the same way. Peaks are very frequency dependent and some signal/electrical interaction between the phono preamp and cartridge; and between the preamp and analog-to-digital converter will happen spontaneously and cannot be accurately measured in a quantifiable way. All of that will produce variables and differences in the recording, making each recording unique.
You can try some dynamic measurement experiments of your own - I attached the TT Dynamic Measurement plugin he uses in the video. Both Windows and Mac versions are included. There is no install, you just need to copy the files to the plugin folder of your audio editing software.
What do you think?
Post by: lshin80 on November 17, 2013, 07:10:24 AM