"The CD is limited to 22,000 cycles, whereas the LP is able to re
Reply #1 – 2007-08-05 19:04:17
hi , I found this interview of bob ludwig :http://mixonline.com/mag/audio_bob_ludwig/ He says that "It is customary to believe that the CD is superior to the LP in terms of bandwidth, but this is not the case. The CD is limited to 22,000 cycles, whereas the LP is able to reproduce frequencies up to 50,000 cycles, which in the PCM world equals a sampling rate at 100 kHz. Theoretically, the LP might be able to store frequencies up to 50 kHz but: - I believe that given surface roughness of mass production vinyl material (this can be measured) is huge enough to mask all signal frequency content above - let's say - 30 kHz due to the linear-speed-induced "roughness frequency" a.k.a. noise or ground clutter - in music, frequency content of 30 kHz+ is surely present through instrument overtones/harmonics ... this could be perceived via interference with the base frequencies. Since the human ear is rather insensitive towards these extremely high frequencies and since the corresponding amplitudes in music are really low, the chances of losing these frequencies in background noise of a mechanical playback system are far too great to be ignored. - a mechanical pickup stylus (like the ones used with record players) has a given mass (which results in corresponding inertia) and a pickup-specific stylus compliance which limit the useable frequency range way below 30 kHz - music reproduction is way more than just an extended frequency range (that no one can hear anyway) ... think possible dynamics or robustness against defective media (the LP is very pooor at these when being compared to CD), impulse response (if tonearm weigt and stylus compliance do not match, impulse response will suffer, too) or frequency response linearity (which is often way off the ideal 0dB-Line with non-matched input capacities of cartridge and phono amp or improperly-applied RIAA-equalization). Additionally, the cartridge will pickup sound from your speakers at higher listening volume levels ... this kind of acoustical-electrical feedback isn't really what you want when enjoying music. - LP's do wear off by simply playing them ... I really doubt an LP will make 22000 playback cycles The bottom line is that LPs mastered with DMM still sound really good. Absolutely, DMM-recorded LP's of properly-mastered music material do indeed sound good on a proper playback system. But think of the limited dynamic range ... pianissimo-passages in e.g. classical music will always suffer from typical vinyl hiss and rumble. To me, digital music storage is far superior in every technical aspect ...