Phil Leigh;618564 Wrote: > I agree that digital has no such limitations - and sounds better for it > IMO - but your explanation of RIAA EQ is way off... it's basically a > severe curtailing of low frequencies at three turnover points to > preserve the integrity of the cutting heads and make it actually > possible to cut the record withput serious distortion in the first > place - the RIAA eq circuit in the playback chain reverses the process, > somewhat like Dolby or DBX NR compansion... albeit inaccurately as you > say. > > Even worse, many record labels and cutting/pressing plants didn't use > the RIAA curve, they used their own flavour...
The RIAA curve has a 40 dB swing from 20 Hz to 20,000 Hz. Heavy bass needs a very wide groove, so the bass response is reduced up to 20 dB when cutting the record. Highs, which don't take up much groove width, are boosted up to 20 dB. During playback, this curve is reversed. The bass is boosted back up 20 dB at 20 Hz and the highs are cut back 20 dB at 20,000 Hz. Without the RIAA curve, LPs would be of very short duration and have much more high frequency noise. The curve was standardized in the mid-1950s and most records after that were not too far off target. Probably a bigger wild card than the LP or the preamp's RIAA curve is the variable response of cartridges and their interaction with cable capacitance. Many moving coil cartridges in particular had very interesting response curves. -- mlsstl ------------------------------------------------------------------------ mlsstl's Profile: http://forums.slimdevices.com/member.php?userid=9598 View this thread: http://forums.slimdevices.com/showthread.php?t=85590 _______________________________________________ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
