Recording 12+ analog channels on a PC at 192KHz/24-bit. Is..

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Just speculation but, if he's after classical recording maybe he should
investigate digital stream? 2.8 million samples per second (IIRC) @
1bit depth would probably do the trick. Might be a tad spendy, but
maybe should be considered. That is, IF classical is his game.

 

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"will" <wpmusic@sio.midco.net> wrote in message
news:1121609943.132506.43950@o13g2000cwo.googlegroups.com
> Just speculation but, if he's after classical recording
maybe
> he should investigate digital stream? 2.8 million samples
per
> second (IIRC) @ 1bit depth would probably do the trick.
Might
> be a tad spendy, but maybe should be considered. That is,
IF
> classical is his game.

192 KHz 24 bit stereo is 9,216,000 bits per second.

Sorta shames 2,800,000 bits per second, no?

 

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The MOTU HD192 has 12 in/outs and goes upto 192K.






"William Krick" <wkrick@gmail.com> wrote in message
news:1121466399.193405.113540@g44g2000cwa.googlegroups.com...
>I have a friend who has a home studio. He's enlisted my help in
> building a new PC to use for recording.
>
> He needs to record 12 or more _analog_ channels simultaneously on a PC
> at 192KHz/24-bit.
>
> I've been researching the current PC based recording hardware
> technology and I'm not sure that this is even possible.
>
> 12+ analog channels at 192/24 produces a huge volume of data. This
> data has to come into the PC over the PCI bus, and at the same time, be
> moved stored on the hard drive. It seems to me that the PCI bus and/or
> the IDE bus would present an insurmountable bottleneck.
>
> Is anyone out there doing this? If so, what exact hardware are you
> using, both PC hardware and recording hardware. I'd really like to
> know.
>
> I'm confused about external A/D converter units (like the FireFace) vs.
> internal units like the Hammerfall series.
> Which are people using, and why?
>
> Are people using Windows XP?
>
> What actual recording/editing software is up to this task?
>

 

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Ahhhh... And the crazy friend surfaces!!!!! And I do indeed hear the
holes in swiss cheese.... Woohhhaaaaaaaa!!!!!

Actually the original post comes from a conversation I had with Mr.
Krick one day as I lamented my current 20 bit Layla based set up.
Wasn't bad for it's day. In fact was kind of fun.

But I've done so much to improve sound quality in other areas in the
interim. Got some great pre's (including the Mercenary River NV). Got
some great mic's including a U87. It's time to do something in the
area of conversion. Want the best converters I can find in the $3K-5K
range.

Resolution sort of became the focus of this discussion. Probably my
fault. Should have made more clear that my top consideration is best
quality converters for the price range indicated, end of story. Am
looking into Aurora 16. Thank you for that suggestion.

All of this said, I'm not sure resolution isn't a consideration. Some
here have said that there is no difference, you'll only dither to CD
quality anyway. Maybe so. I couldn't claim to know for certain. But
after recording a track I tend to apply multiple filters (high pass,
compression, limiting, etc). It makes no sense to me from a
computational standpoint that greater resolution during filter
applications does not minimize error at the final dithering stage. But
then again it makes no sense to me that Carl from Aqua Teen Hunger
Force doesn't have his own friggin show either. That guy's friggin
funny.

Have any of you out there who've said no difference recorded large
scale projects at extremely high resolution and A/B'd them with lower
resolution versions? Do you know for certain that artifacting isn't
minimized overall?

 

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<tpatsch@gmail.com> wrote in message
news:1121729937.613803.161970@g14g2000cwa.googlegroups.com


> Actually the original post comes from a conversation I had
> with Mr. Krick one day as I lamented my current 20 bit
Layla
> based set up. Wasn't bad for it's day. In fact was kind
of
> fun.

I still have a 20 bit Layla, but it ties my DAW in knots
after about 30 minutes of recording with 20 channels.

> But I've done so much to improve sound quality in other
areas
> in the interim. Got some great pre's (including the
Mercenary
> River NV). Got some great mic's including a U87. It's
time
> to do something in the area of conversion. Want the best
> converters I can find in the $3K-5K range.

I think several posters have mentioned Lynx Studio. If
you're spending that kind of money Lynx can absorb it
getting to 12 channels, and you'll get great performance for
your money.

> Resolution sort of became the focus of this discussion.

Audible or measured?

> Probably my fault. Should have made more clear that my
top
> consideration is best quality converters for the price
range
> indicated, end of story. Am looking into Aurora 16.
Thank
> you for that suggestion.

So then you'd need a Lynx AES16 card on top of the Aurora?

> All of this said, I'm not sure resolution isn't a
> consideration.

There's a controversy over what is enough resolution.

> Some here have said that there is no
> difference, you'll only dither to CD quality anyway.

Worse than that, look at the dynamic range (IOW resolution)
of the real-world input signals. The real world is a noisy
place compared to modern converters.

> Maybe
> so. I couldn't claim to know for certain. But after
> recording a track I tend to apply multiple filters (high
pass,
> compression, limiting, etc). It makes no sense to me from
a
> computational standpoint that greater resolution during
filter
> applications does not minimize error at the final
dithering
> stage.

Of course not. However, if you have a signal with 80 dB
dynamic range (outlandishly high in the real world) and pass
it through a converter with just 90 dB dynamic range, the
resulting signal's dynamic range is degraded to only 79.6
dB.

> Have any of you out there who've said no difference
recorded
> large scale projects at extremely high resolution and
A/B'd
> them with lower resolution versions?

Not large scale projects. I did some work with really
stripped-back projects to get a project that started out
with super high dynamic range.

> Do you know for certain
> that artifacting isn't minimized overall?

Listen for yourself:

http/www.pcabx.com/technical/sample_rates/index.htm

They are billed as sample rate tests, but I also did some
dithering down.

Here's some simpler tests:

http/www.ethanwiner.com/BitsTest.html

and

http/www.pcavtech.com/test_data/

 

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In article <1121729937.613803.161970@g14g2000cwa.googlegroups.com> tpatsch@gmail.com writes:

> All of this said, I'm not sure resolution isn't a consideration.

Oh, it certainly is. What most of us think is NOT a consideration is
recording at 192 kHz sample rate. That's sample rate and not
resolution. While in theory, they're not related (you need only
infintessimally more than one sample per half-cycle of the highest
frequency in order to reconstruct the waveform with perfect accuracy)
intuitively, having a couple more samples to average out errors surely
couldn't hurt.

But there are some component performance issues that are present with
real world components today that prevent really accurate performance
at 192 kHz. While there are certainly some 192 kHz converters that
sound better than some 96 kHz converters, it would mostly be your
imagination at work if you thought that the best 192 kHz converter
sounded better than the best 96 kHz converter. Dan Lavry has a paper
on his web site that you might find stimulating:

http/www.lavryengineering.com/documents/Sampling_Theory.pdf

> Have any of you out there who've said no difference recorded large
> scale projects at extremely high resolution and A/B'd them with lower
> resolution versions?

I can't imagine how a valid experiment like this could be constructed.
You could send the same analog audio sources simultaneously to one set
of 192 kHz converters and to another set of 96 kHz (or lower)
converters, record the outputs of both, use the same mix parameters to
mix both, and compare the mixes, but:

- You would have recorded with two different A/D converters. Even if
both were the same make and model, simply switched to different
sammple rates, you still have no guarantee that they're actually
operating identically other than the number of samples they
generate per unit time.

- Mixing (assuming "mixing in the box" here) may not work the same
for two different sample rates. You're adding (nominally) twice as
many samples for each time interval, so rounding errors may make
the mathematical results different.



--
I'm really Mike Rivers (mrivers@d-and-d.com)
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

 

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On Tue, 19 Jul 2005 01:38:57 +0200, tpatsch wrote:

> Ahhhh... And the crazy friend surfaces!!!!! And I do indeed hear the
> holes in swiss cheese.... Woohhhaaaaaaaa!!!!!
....
> Resolution sort of became the focus of this discussion. Probably my
> fault.
....

The question posted was:
| He needs to record 12 or more _analog_ channels simultaneously on a PC
| at 192KHz/24-bit.
....
| It seems to me that the PCI bus and/or the IDE bus would present an
| insurmountable bottleneck.

The answer was clear: for modern PC hardware this 10MByte/sec datastream
is no problem, but the need for 192/24 is not very clear.

> But after recording a track I tend to apply multiple filters (high pass,
> compression, limiting, etc). It makes no sense to me from a
> computational standpoint that greater resolution during filter
> applications does not minimize error at the final dithering stage.
....

The endpoint for a recording are always ears. Ears have their limitations,
so to record sound there is no need to do much more than these
limitations.

24 bits makes life easier, but there are queastions about the need. Some
say the 96 dB of 16 bit sampling already is more than enough. More samples
might help to get better results from algorithms, some say that if 44.1/16
is more than enough for the end result, it is good enough for algorithms
too if the algorithms are good.

To avoid problems, with current posibillities of technology, 24/96 could
be a good choice. There seems to be no extra benefit in 192/24. So most
answers contained a question about the "need" for 192/24.

--
Chel van Gennip
Visit Serg van Gennip's site http/www.serg.vangennip.com

 

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<tpatsch@gmail.com> wrote:
>
> Have any of you out there who've said no difference recorded large
> scale projects at extremely high resolution and A/B'd them with lower
> resolution versions? Do you know for certain that artifacting isn't
> minimized overall?



A quick Google search of this group will answer that question for you.

I've never gone as far as doing a "large scale" project at hi-res, but
I've done some test sessions comparing 48k to 96k. My opinion was that
if there was any difference (and I couldn't even say for sure there
was), it was so small as to be insignificant. The weight of the guitar
pick would make more difference.

I understand the reasoning behind capturing at higher resolutions, but
I'm also familiar with the concept of overkill. At some point, the
extra storage space and processing overhead requirements totally swamp
any theoretical benefit.

--
"It CAN'T be too loud... some of the red lights aren't even on yet!"
- Lorin David Schultz
in the control room
making even bad news sound good

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