A modest hypothesis on the 16 bit question

[Mallette]

Whoops. Just though I was through. Now comes the eminent Mdeneen:

>The 16-bit 48kHz stream of data from the original master digital stream is of course not recorded onto a Redbook CD.

I cannot imagine a recording engineer doing an original master for Redbook distribution at 48khz. Dither city. I record only in multiples of 44.1.

As to the rest of your Redbook discussion, I generally agree. In fact, remember that we compared CD playback from wav files ripped from my location recordings compared to the same disk doing Redbook from the Rega. In most cases, no one could tell the difference. Such difference as there was has been the stuff of much discussion and no one, including myself, has all the answers yet. Bear in mind there is no such thing as "jitter" in a wav file, so some may believe this is responsible for the slight difference in sound. Does "post recovery circuit"=DAC? Again, a wav file is feed straight to a DAC then output as a line level signal. There is no other circuit used or needed.

Dave

[Randy Bey]

I agree completely with mdeneen. The thought process going into digital reproduction, up to where it enters the DAC, is stuff that even my prodigious (read: pea brain) mind has trouble grasping. I think that I will defer to the creators' obvious excellent grasp of the subject matter.

But, the issues of jitter, power supply, filtering, and definitely the analog output stages are where the high-end differ most from the mass-market.

With all due respect, I do not think that a PC based solution will hold a candle to a good CD player, regardless of ripping technique. The PC is a swampy mass of RFI and the OS is not optimized for audio processing.

The Rega Planet is "good", but not a definitive sample. I had one for a while and did not care for the sound as compared to a Theta Data transport feeding an MSB Link III DAC. I finally settled after many swings on the merry-go-round on a Theta Miles player, which has very close attention to the issues above, and represents good "trickle down" technologies for the cost-conscious.

[Mallette]

>With all due respect, I do not think that a PC based solution will hold a candle to a good CD player, regardless of ripping technique. The PC is a swampy mass of RFI and the OS is not optimized for audio processing.

May I assume you have dismissed the Rega Planet as being even a "good" CD player? I had several good sets of ears here Sunday who have a differing opinion, and many of those in the forum seem to find it less than consumer as well. This being the case, then the type of player you seem to suggest as nirvana is completely out of reach of us unwashed masses so the whole discussion is moot. Rest of us might as well build our crappy PC systems and eat cake.

> The PC is a swampy mass of RFI and the OS is not optimized for audio processing.

This one I've heard enough. Prove it. I've never heard ANYTHING that would indicate that RFI has impact on playback. Actually, the FCC takes a rather dim view of devices putting out excessive RFI. As to the OS, with CPU's now processing at speeds reached only by supercomputers less than 10 years ago, I frankly don't think they need to be "optimized" for audio anymore than your automobile engine needs to be optimized to run an air conditioner as well as the car. I do video editing on my PC which is many, many times more demanding and rarely lose so much as a field.

I am not being snippy here, but some of these things I consider myths until proven wrong, and that means in the ears where it counts.

Dave

[Marvel]

A lot of recording has been done at 48k, but mostly earlier before filters got better. I also know lots of people who record on their pc (big studios in fact), so massive rfi in the box isn't always a problem. Many also still record at 44.1k, since they are going to put it on a CD in the end. They use 24bit though, so they can initially get a wider dynamic range.

I think it is foul that the DV format records audio at 16 bit/48k. You can go lower to 32k, but the only benefit is four audio tracks. For dialogue you won't really hear much of a difference.

Dave's recording at 88.2k has gained ground in the recording commmunity because the dithering is easier going from 88.2 to 44.1. Going 96k or all the way to 192k just takes up too much space. I know folks doing up to 100 tracks on their pc system. Getting drives to stream that at 192k gets a bit hard.

Marvel

[kjohnsonhp]

Sorry I missed the testing. I'm back in town and my $99 M-Audio card and left-over Vectra PII/400 PC (street value wll under $100) are ready to test.

In a more pricey category see what you think of this solution:

http://www.hometheaterhifi.com/volume_7_3/perpetual-technologies-p1a-p3a-9-2000.html

It's more data on the Perpetual Technologies device I've mentioned before. I need to learn more about it compared to our PC solution.

[Mallette]

Well, as you said up front, the price is certainly out of my range for small improvement, which from reading about it I suspect it delivers. OTOH, until I've heard it, I am dubious of letting any computer interpolate that which is not there into reality. Perhaps its my analog upbringing, but it just doesn't seem right to "guess" at what isn't there.

Ok, as I look at what I just wrote, it's a prejudice. Need to work on that.

As a more practical matter, however, IF you want to upsample and interpolate missing information, it would certain seem to be more accurate and a lot cheaper to do it on a PC with all the time in the world as opposed to attempting it in realtime.

As to speaker correction, it made sense. Lord knows my space/speaker setup could use some correction without having to move walls. However, it appears to be tied to the other unit rather than standalone meaning it would be useless with the majority of my listening which is analog.

Dave

[Marvel]

I waste most of my money on software I rarely use, and just make enough off to pay for it. One of those is Adobe Premiere, which I like a lot, but one of its weak points is audio. Sonic Foundry just released Vegas 4, with unlimited audio tracks, great color correction tools built in, easier keyframing, etc. Plus, and here is the interesting part-- you can do 5.1 sound, at 24/96. For a little more money, you can even encode AC3 from it. I've not liked their interface too much, but this is cool. Audio with Premiere is still a bit lame, even in ver. 6.5. Just thought is was interesting since Dave actually does recording, etc.

Marvel

[Mallette]

Marvel: I thought DVDA standard for surround was 24/96. A recent Audiophile Voice article suggested it was 24/88.2. That would make more sense as a multiple of Redbook with only debateably less res. Do you know? I hope to start recording to DVD soon.

Dave

[Marvel]

Dave,

I found this article that has tables listing what can be done in the DVD-A spec. It a not very detailed, which means I can understand it. You can do 2 channel at 44.1, 88.2, 96, all the way to 192. Surround is more restrictive. Have a read and let me know if it helps. I don't want to lead down rabbit trails. This article isn't the newest, but it explains a lot.

Marvel

DVD-A.pdf

[Mallette]

Thank you, sir.

Just what I needed. I've been thinking about doing some 4 channel work and didn't know how restrictive DVD-A standards might be. Don't appear to be at all.

I know this is two channel, however, I'm not talking HT surround. I've been wanting to obtain or rent 4 PZM mics, put them on 1 meter square of plex, them clamp them together to form a cube. This would produce 4 near discrete soundfields. One application I have in mind is Sacred Harp singings. If you are not familiar, it is also called shape note, fasola and is based on only 5 notes. Much American classical music (like Randall Thompson) is heavily influenced by this tradition. Texas has a couple of meets that have been going on over 100 years.

Anyway, they form a square to sing facing each other. I think that would be an obvious reason for four channel sound...accuracy.

Of course, this would also be great for environmental recordings like the forest stream, seashore, etc.

Dave

[Marvel]

Our church does all chant and I would love to do that with the guys who do the singing. The main cantor has a beautiful voice, but the rest are all just regular joes. When he isn't there, they don't sing. I would think that shape note singing would really benefit from a room that has good acoustics. Your idea would put you right there in the performance for sure. Used to belong to a church that put on big music productions. One of the members would record it with two pzm mics on a sony video deck. He had made mic preamps for it. The sound was very good considering his budget.

Glad the info can be of use. I also found a place today that explained how to record AC3 encoded on a regular CD-R that you could play back in your DVD player to test out mixes on the cheap, instead of doing a test burn on DVD. Kinda neat. Still would need the encoder though.

Marvel

[Mallette]

Yep. My church is is a "smells and bells" high church (Anglican Catholic) and I want to put a couple of choirs in the ambulatories, brass at the alter, and the organ is in back. I think we are on the verge of a whole new ball game of recording potential with all these DVD players people are buying.

Dave