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In Reply to: Re: You probably missed it...(link) posted by Frank.. on June 18, 2004 at 01:33:07:
*** However it's still a valid indication that low level resolution might be poor. ***If that is so, it is poor on ALL formats equally: LP, CD, DVD-A and SACD, since the behaviour can be replicated on recordings from all three formats.
*** Do some research and you'll find out that it's the simple truth. ***
Actually, i have done some research and what you say doesn't appear to be the simple truth. it is true that there are many contraints and limitations in pressing vinyl and it is possible to make a bad LP - there are many examples in the 70s and 80s due to commercial constraints of putting as much music as possible onto a side that filtering and compression was necessary.
However, there are also ways to avoid or mitigate those limitations. And given that LP is a "dead" format these days, LPs pressed for audiophiles are done by who do take the extra care.
*** Now you are confusing extended bandwidth with dynamic range capabilities. ***
No I wasn't. You were the one who said it was "impossible" to reach 20kHz at full dynamic range. but clearly the technology to do so was there in the 70s.
*** The technology was available but in the end hardly practical and difficult to implement. ***
So then it's not impossible to have extended frequency response and dynamic range, then, as you originally claim?
As for practical/difficult, my father had a Quad capable system, supporting both matrixed and discrete Quad LPs. you do need a special stylus for the discrete quad lps, but they were no more expensive than a reasonable stereo only stylus. we played quad for many years. it was quite practical and no more difficult than stereo. And even when quad died, a lot of the technology (such as the stylus shape and half speed mastering) was carried over to improve stereo LPs.
*** Sample a loud scratch and look how your setup reacts. ***
I have. It looks exactly like a loud scratch.
Follow Ups:
***No I wasn't. You were the one who said it was "impossible" to reach 20kHz at full dynamic range. but clearly the technology to do so was there in the 70s.***No you didn't get my point or are twisting my words.
I said it is impossible to reach 20kHz at the full dynamic range *you* claimed. (80..90dB)Fancy audiophile pressings are limited by the cutting heads limitations just as much as normal pressings.
If hf content is pushed to hard then the cutting head gets into trouble.***So then it's not impossible to have extended frequency response and dynamic range, then, as you originally claim?
***Yep, flat response up to 50kHz? Simply not possible.
The encoded quad info in the disc beyond 20Khz had a lower level.
*** I said it is impossible to reach 20kHz at the full dynamic range *you* claimed. (80..90dB) ***And i supplied a counter example to your "impossibility"
you may not realise this, but not all cutting heads are equal. there are different types, and they have different limitations. also, 20kHz at full dynamic range is easy to obtain if you slow down to half speed mastering. widening the spacing between grooves will also help.
just because you have visited one pressing plant and attended one seminar means you know everything there is to know.
by the way, DVD-A has limitations that require filtering as well. 96/24 5.1 channels require MLP encoding to fit into maximum bitrate of 9.6 Mb/s. however, MLP assumes it is able to achieve a certain level of compression.
Some program material cannot be compressed easily and generate "illegal" files. For example, by definition white noise cannot be compressed, so 96/24 5.1 of white noise will generate an illegal MLP file. The solution is - guess what: filtering the high frequencies.
SACD avoids this issue by specifying a higher maximum transfer rate for the player: 16 Mb/s. so if the material cannot be compressed by DST, it is still legal and able to be transferred to SACD without filtering. you do reduce the maximum playing time though.
***by the way, DVD-A has limitations that require filtering as well. 96/24 5.1 channels require MLP encoding to fit into maximum bitrate of 9.6 Mb/s. however, MLP assumes it is able to achieve a certain level of compression.***'require filtering'? Apart from very rare occurring events in normal music content other filtering requirements than that to fulfill the nyguest criteria are not neccesary.
***Some program material cannot be compressed easily and generate "illegal" files. For example, by definition white noise cannot be compressed, so 96/24 5.1 of white noise will generate an illegal MLP file. The solution is - guess what: filtering the high frequencies.***
White noise at full level is very usefull in a music format.
Filtering at 30kHz instead of 40kHz probably solves the issue.
No big deal.***SACD avoids this issue by specifying a higher maximum transfer rate for the player: 16 Mb/s. so if the material cannot be compressed by DST, it is still legal and able to be transferred to SACD without filtering. you do reduce the maximum playing time though.
Obviously dst is less efficient in reducing the bitrate so a higher bitrate from the player is needed.
The maximum playing time is less than that of a dvda with mlp.
DVDA with mlp is a more flexible format. If the bitrate is too high than mild filtering can be used to remedy the problem.
Filtering hf is only needed during the difficult passage.Maximum playing time isn't compromised by a fancy ability to handle vary rare occurring musical signals or non musical signals like wideband noise at high levels.
Frank
you were very quick to criticize limitations in vinyl technology that require certain signals to be filtered or compressed in rare circumstances (and even then the problem can be solved by using half speed mastering or widening the groove spacing).but a very similar limitation is in DVD-A where certain signals require filtering before they can be mastered onto DVD-A.
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