This was in the Meyer/Moran study thread, but it's so important that I think it deserves its own space. On the subject of whether the HiRez formats are in fact audibly superior to CDs 44.1/16. Science says no, since a CD exceeds (with the exception of the silence floor between -96 and -144db that 24-bit has) the abilities of human hearing.

They're both right.

I just realized, after two weeks of thinking about it -- the answer.

The DSD versions of the Living Stereo tracks were taken from the first generation master; the same physical piece of tape that was in the studio with the actual musicians. It was directly transferred to the DSD master, track-for-track.

The CD versions are copies: The original 3-track masters have to go through the mixdown so that the final master is a 2-track 1/4" analog tape. That's a 2nd generation copy, just as every other "mixed" record (99.5% of every analog recording you've ever heard) is made from. Some CD's are even made from 3rd generation safety masters if the original mix master isn't available or is deemed too fragile.

Every "copy of a copy" is just like a Xerox copy of a Xerox copy -- every generation loses quite a bit of detail. Pretty soon it's just blurry.

So on the CD, you're hearing a copy of the master tape. On the DSD, you're hearing the actual master tape transferred straight across.

The same is true if you're listening to a modern-day remix of an album that was originally analog but being mastered digitally -- it will be a 1st generation transfer, but mixed down to two channels (but still first generation since there's no quality loss with the digital master.)

It's not the "Hi-Rez-ness", it's the fact that it's a digital multichannel format that can accept a 1st generation master.

Now if we ever come up with a 16 or 24 channel consumer format, every album can be a 1st generation transfer -- but you'll have to mix the record yourself at home.

-John

This was in the Meyer/Moran study thread, but it's so important that I think it deserves its own space. On the subject of whether the HiRez formats are in fact audibly superior to CDs 44.1/16. Science says no, since a CD exceeds (with the exception of the silence floor between -96 and -144db that 24-bit has) the abilities of human hearing.

They're both right.



Sorry John, I have to disagree here.
What it should be saying is that a CD can exceed the abilities of human hearing. Most these days do not & have the dynamic range & subtlety of being whacked across the head with a lump of 4x2. Which, oddly enough, is exactly what the ripped waveforms look like too.
You also have the additional issue of quantization distortion due to errors in badly designed and/or cheap DAC to take into account.
Finally there is the inherent fragility of the 16-bit Audio stream to take into account. 24 bit audio just sounds better. Almost certainly because of the problem with Quantization errors/distortions caused by poor converter design, but the fact does still remain.
The first part is the worst these days, as most CD are so overcompressed & excessively brickwall limited as to be distorted on playback because of Inter Sample Peaks. That did not happen on most DVD-A releases - although yet again bad to worse "mastering" still has a heck of a lot to answer for.

What is the s/n of the analog tape used in the 60s when a lot of the RCA living stereo material was orginally recorded and even more importantly how good were the mics back then?

These are hybrid SACD's. The SACD and the CD layers are derived from the same master tape generation. If you hear an improvement when playing the SACD layer than it is the format and not the tape generation that may be behind your conclusion. I hear an improvement even when the CD layer is mastered directly from the master and not derived from the DSD sample.

He may be referring to those discs using THREE channel masters. In those cases (many, though not all of the Living Stereo series are three channel), the CD is mixed down and, if I understand correctly, is one generation removed from the 3 channel SACD.

What is the s/n of the analog tape used in the 60s when a lot of the RCA living stereo material was orginally recorded and even more importantly how good were the mics back then?

The S/N of the tape machines wasn't all that hot (though surprisingly quiet on playback nonetheless), but as far as the mics go, the microphones of that era were stunningly good, with the Neumann (often badged Telefunken, who had distribution rights for Neumanns for a good while back then) M50 being a prized orchestral omni to this day. Neumann KM56's were used quite a bit too, and prices for a vintage KM56 are north of $5K for a single mic these days. Telefunken also rebadged the Schoeps M200 series microphones, a favorite of the Mercury Living Presence folks.

This is not to say that modern mics aren't as good, many are. Schoeps Colette series and the DPA 4001's (formerly Bruel & Kjaer) are highly-regarded microphones for classical work. But quite a few engineers have soft spots for the old favorites, hard to argue against a proven winner.

The S/N of the tape machines wasn't all that hot (though surprisingly quiet on playback nonetheless), but as far as the mics go, the microphones of that era were stunningly good, with the Neumann (often badged Telefunken, who had distribution rights for Neumanns for a good while back then) M50 being a prized orchestral omni to this day. Neumann KM56's were used quite a bit too, and prices for a vintage KM56 are north of $5K for a single mic these days. Telefunken also rebadged the Schoeps M200 series microphones, a favorite of the Mercury Living Presence folks.

This is not to say that modern mics aren't as good, many are. Schoeps Colette series and the DPA 4001's (formerly Bruel & Kjaer) are highly-regarded microphones for classical work. But quite a few engineers have soft spots for the old favorites, hard to argue against a proven winner.

So microphone technology/quality is about the same now as it was in the 60's and what has changed is the advent of digital recording which has a higher dynamic range than analog tape.

Is it safe to say that it was the analog tape machines that were limiting in the 60's and that microphones are now the limiting step in recording quality?

Is it safe to say that it was the analog tape machines that were limiting in the 60's and that microphones are now the limiting step in recording quality?

Actually it's the microphone preamps, and their noise floor, can, at best, do about a -100db noise floor. Since 16-bit audio has a noise floor of -96db, that's pretty much an even match. But 24-bit has a -144db noise floor, so there's no way to even approach that with current electronics without resorting to nitrogen cooling.

Actually it's the microphone preamps, and their noise floor, can, at best, do about a -100db noise floor. Since 16-bit audio has a noise floor of -96db, that's pretty much an even match. But 24-bit has a -144db noise floor, so there's no way to even approach that with current electronics without resorting to nitrogen cooling.

What is the s/n on 1960 vintage analog tape? This is what I see as the limiting step in the production RCA Living Stereo SACDs.

What is the s/n on 1960 vintage analog tape? This is what I see as the limiting step in the production RCA Living Stereo SACDs.


About 65db. The actual machine that we're talking about here is the one on the left at http://www.aes.org/aeshc/jpg/conv109/ampex!.jpg. In the ones I've worked with, we used to keep a big floodlight on inside the cabinet at night to keep the machine warm so that the azimuth wouldn't drift.

The Ampex specs for a 350 can be found at http://ftp.ampex.com/ampex/manuals/audio/350man/350-0101.gif

The half-track figure would apply, but it would be slightly better than that because the 3-track recorder was a slightly wider track.

You might also want to take a look at http://www.aes.org/aeshc/docs/mtgschedules/109conv2000/109th-vinyl-report-1.html
just for fun!

It's not the "Hi-Rez-ness", it's the fact that it's a digital multichannel format that can accept a 1st generation master.

-John

As mentioned in the other thread, that is NOT the only improvement to be heard with these DSD masterings. Plus they come with a downrezed CD version that can be directly compared to the DSD stereo track.

The DSD track is a little more transparent and has a rawer analog sound to it than the CD layer.

About 65db. The actual machine that we're talking about here is the one on the left at http://www.aes.org/aeshc/jpg/conv109/ampex!.jpg. In the ones I've worked with, we used to keep a big floodlight on inside the cabinet at night to keep the machine warm so that the azimuth wouldn't drift.

The Ampex specs for a 350 can be found at http://ftp.ampex.com/ampex/manuals/audio/350man/350-0101.gif

The half-track figure would apply, but it would be slightly better than that because the 3-track recorder was a slightly wider track.

You might also want to take a look at http://www.aes.org/aeshc/docs/mtgschedules/109conv2000/109th-vinyl-report-1.html
just for fun!

So the Living Stereo SACD/CD series has a s/n of 65db about 1/2 as good as a modern CD recording? Nothing wrong with these discs though, they sound great. I have around 8 or 10 of them. I really like the Van Cliburn/Fritz Reiner recording of Beethovens Emperor Piano Concerto No 5. Thanks for the answers to my questions.

So the Living Stereo SACD/CD series has a s/n of 65db about 1/2 as good as a modern CD recording? Nothing wrong with these discs though, they sound great. I have around 8 or 10 of them. I really like the Van Cliburn/Fritz Reiner recording of Beethovens Emperor Piano Concerto No 5. Thanks for the answers to my questions.

Yeah, but 65db is still a respectable noise figure. If you were in a concert hall, the noise floor would be about 50db (or higher) all on its own (crowd + air conditioning), so 65 db above that would mean that the orchestra (or band) was playing at a deafening 115db!

Now just to show how unnecessary 24bit audio is (on an analog transfer) , you gotta remember that the only difference between 16 bit audio and 24 bit audio is that the 16-bit has a -96db noise floor, and a 24-bit has a -144db noise floor.
Both the 16-bit and the 24-bit versions of an analog transfer are identical, except that the bottom bits are all constant, pure noise. On the 24-bit version, you're listening to about 10 bits of constant, pure noise, and on the 16 bit version, you're listening to about 2.

No comments about the machine photograph yet -- it's great. http://www.aes.org/aeshc/jpg/conv109/ampex!.jpg
The three-track on the left would have been typical of what those "Living Stereo" discs were recorded on.

Nearly all were all-tube electronics, but the first transistorized model is shown in a brochure here: http://recordist.com/ampex/docs/apxbrochures/ag300/ag300.pdf

Check out the specs on the last page.

=John


PS: Of course what you're actually listening to on one of those "Living Stereo" transfers is tape being played back on a modern machine, with quieter playback electronics than the original recorder would have had. It's still mostly dependent on the tape oxide formulation and how accurately the machine was biased for that particular batch of oxide.

John, one thing which DVD-A has over CD which is an improvement is the higher sampling frequency of 96kHz for mulit-channel and up to 192kHz for stereo vs. the 44.1 kHz for CD. This does make for a better remastering or new original recording than Cds sampling rate of 44.1 can do.
Also, Just heard the Joni Mitchell, "Help Me" sample. Amazed how much Penteo can pull out from the stereo master. One question,I thought originally that Penteo left the left front channel and right front channels the original stereo mix , not the stereo mix minus the center channel.If it is the second way, would make for a better 5 channel surround upmix.
mgpt6

One question,I thought originally that Penteo left the left front channel and right front channels the original stereo mix , not the stereo mix minus the center channel.If it is the second way, would make for a better 5 channel surround upmix.
mgpt6

Hey thanks. I'm actually getting requests for upmixes to "non-surround" Penteo, with just the 3 fronts, replacing the phantom stereo center with a hard, true center -- the way we used to monitor in recording studios.

You can download a DTS test file on the thread "Penteo Test for you to try".

=John