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In Reply to: RE: Highest frequency presnt on LPs? posted by thekong on September 22, 2009 at 22:20:49
Actually LP is a pretty treble-unfriendly medium. Here are a number of issues to ponder:
1) Cutter HF response is not very extended. The best seems to be the (rare) Ortofon DSS731, -5dB at 30kHz. The ubiquitous Neumann SX66 and SX74 were significantly worse. (Note that quad albums were cut at
half speed, hence the apparent response beyond 30kHz.)
2) The cutting process uses treble limiters, as too hot treble can burn the cutter's coils, something not tolerated in a commercial venture.
3) Many LPs since the early 80s, and even late 70s, were cut through a digital delay line (to allow the groove spacing computer to do its job). These delays typically sampled at 44.1kHz, 48kHz, 50kHz, thus hard-limiting the result to 22kHz, 24kHz, 25kHz.
4) The manufacturing process is lossy, with stamper wear manifestating earliest as pure treble loss.
5) Upon replay tracing and tracking errors cause a level of distortion that reaches 10% (!) at 20kHz with most cartridges.
In the past years I have done spectral analyses on many commercial LPs.
Very often this reveals a hard ridge in the range 20-24kHz, indicating a digital master or digital delay line. Sad but true.
In nearly all cases was it clear that the spectral response above 20kHz was dominated by the distorion components of the baseband signal.
I have seen one (1) commercial LP that has something at 30kHz that I cannot reduce to mere distortion. It is probably a studio artefact.
However, when testing Japanese direct-cut LPs made in the 70s the spectral analysis looks much cleaner and with a nice and continuous response out to 40kHz or so. So it can be done, but it is inlikely
to happen on a mass-produced commercial product.
bring back dynamic range
Follow Ups:
Vinyl can go to 40k hz, especially in D2D and quad carrier frequencies. But it doesn't happen that often. Worse, the harmonics generated by the quad carrier created an artificial brightness to most of those recordings.
Another difficulty was that even Master tape decks had treble trouble, even at 30 ips. It was well into the LP era before they had that capability. In fact, liquid helium cooled lathes beat tape decks there though they did not like doing it for long periods at a stretch.
Redbook CDs cut off even lower than that.
In a true instrument (rather than a synthesizer), nothing goes anywhere near that high except the Nazard stop on a pipe organ which is only there to add "shimmer". In that instance I believe actually recording the frequency in addition to the harmonics generated is beneficial . . . but not a lot. Then again, I could hear silent dog whistles, ultra-sonic stop lights and actually hear a nazard well into my late 30s. Trust me; it is not a blessing!
At least I didn't howl at the moon.
Thanks for the very informative response, Werner. I take it that half-speed mastering, as done routinely by MFSL (and subject of much debate on this forum) is a win in this regard. Presumably it avoids the cutting head frequency limitation. (I realize it can have negative consequences at the low end, with increased interference from mechanical vibrations.)
Clearly there are great sound quality differences between pressings, between vinyls from the same pressing, etc. and this fills in more of the potential reasons for these differences. The presence of (clean) high-frequency information seems to be key to the perceived sound quality, however we manage to hear or be affected by it.
More to the point: what is the highest frequency an adult male can hear? You would be surprised how low it actually is.
Usually about 16khz in the early 20s. There are radical exceptions. I know because I was one. I could still hear beyond 24khz well into my 30s (see my response to Werner). I mention 24khz because that was the limit of the test equipment in those days.
By the time the majority of men are in their 40s 10khz to 12khz is fairly normal.
As for people who listen to incredibly loud music (even headphones) hearing decreases across the entire range but treble is even worse.
Being in my 60s now, my hearing is much more normal but still in the normal 20 year old range.
At just shy of 56, I can still hear to around 14 kHz in my right ear; I used to get up to higher than 15 kHz (I don't know how much higher, though). The sound of the high-frequency oscillators in TVs used to drive me batty! No more, alas.... My left ear, unfortunately, got hit by a disease process that destroyed the bones of the middle ear and invaded the mastoid. In that ear I don't hear below about 100 Hz, and not above about 7 kHz. I take good care of my ears these days!
If you are (were) an organist as your moniker implies, 32' (even 16') stops wide open can cause a lot of damage, as can trompettas but for a very different reason.
I am genuinely very sorry about your hearing problems. It is nasty for anyone but particularly for musicians and music lovers.
I consider myself fortunate. I don't need hearing a hearing aid yet, even for my compromised ear. I have a small pipe organ at home as a practice instrument, but it doesn't overwhelm my living room--I'm safe there! My Sunday job is on a modestly-sized pipe organ, so little danger there, either. But another instrument I have access to has just the kinds of stops you describe--I use musicians' earplugs then. I never did subject my ears to rock concerts years ago, and I'm thankful now!
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