There are digital micropones you can plug into a USB port. I am
looking for such a micropohe with the highest sensitivity available.

Any suggestons will be appreciated.

In article . com,
Curioso wrote:
There are digital micropones you can plug into a USB port. I am
looking for such a micropohe with the highest sensitivity available.

Why? Sensitivity isn't particularly useful. What are you trying to do?
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

Sense noise at low levels

Curioso wrote:
Sense noise at low levels

High or low frequency noise? Do you need measurement grade repeatability?
I assume that you need an omni.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

High or low frequency noise?
Open.

Do you need measurement grade repeatability?
No

I assume that you need an omni.
Yes

Curioso wrote:
High or low frequency noise?
Open.

Okay, the issue with doing this kind of thing isn't sensitivity, because you
can always crank the gain up. The issue is how noisy the microphone is.
Because when you crank the gain up on a noisy microphone, you get noise.

The first major approach to keeping the noise floor down is to reduce your
bandwidth. Since most higher grade condenser mikes mostly have 1/f noise,
if you cut the bottom end off, they get a lot quieter.

If you really want low noise, I wouldn't recommend any of the cheap multimedia
mikes, but probably recommend a good outboard interface with a quiet preamp,
and a standalone microphone. This could be a couple hundred bucks. It could
be a couple tens of thousand bucks too. But that depends on how low a noise
floor you really really need.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

In article writes:

Okay, the issue with doing this kind of thing isn't sensitivity, because you
can always crank the gain up.

True in theory, but not always in practice. Most knobs only go to 10,
only a few go to 11. These days most mixer mic inputs and stand-alone
mic preamps have a maximum of 55 to 60 dB of gain, with only a handful
of exceptions. And if he's taking about the mic input on a computer
sound card, all bets (for both gain and noise floor) are off. I
suppose it's not out of the question to cascade two channels for more
gain, but if you need that much gain, you probably really should have
a mic with greater sensitivity or get closer to the tigers or
butterflies or whatever you're trying to record.



--
I'm really Mike Rivers - )
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 he double-m-eleven-double-zero at yahoo

On Thu, 21 Apr 2005 20:53:08 -0400, Curioso wrote
(in article . com):

There are digital micropones you can plug into a USB port. I am
looking for such a micropohe with the highest sensitivity available.

Any suggestons will be appreciated.


Yes. I just saw an ad for one last week. Studio condenser with a USB plug.
DOn't remember the brand, but it wasn't one of the biggies.

Ty Ford



-- Ty Ford's equipment reviews, audio samples, rates and other audiocentric
stuff are at www.tyford.com

Ty Ford wrote in
:

On Thu, 21 Apr 2005 20:53:08 -0400, Curioso wrote
(in article . com):

There are digital micropones you can plug into a USB port. I am
looking for such a micropohe with the highest sensitivity available.

Any suggestons will be appreciated.

Yes. I just saw an ad for one last week. Studio condenser with a USB
plug. DOn't remember the brand, but it wasn't one of the biggies.

Swee****er catalog has a full page ad for the Samson C01usb.
Large diaphragm hypercardioid condenser US$80.

I would think that manufacturers are aware of the effect of
microphone's own noise and that it defines the sensitivity they
specify.

Either way, I was hoping that someone in this group could recommend a
microphone or a source (e.g., a catalog) listing different USB
microphones that could be used for sensing low sound levels, with the
sensitivity, or noise, or some other relevant parameter .specified.

According to http://floridamusicco.com/co1.htm "Samson C01 USB" has
Sensitivity -33 dB/Pa

Others specify sensitivity in dB (e,g,:
http://www.speechtechnology.com/voic...D=Jamaica%20NX)

or dBV (http://www.dragontalk.com/USBmic.html)

or dBV/uBar; dBV/Pa
(http://www.google.com/search?hl=en&r...tivity&spell=1)

How do you compare apples to apples?

Curioso wrote:
I would think that manufacturers are aware of the effect of
microphone's own noise and that it defines the sensitivity they
specify.

Right, but those are two different specifications. You'll see a sensitivity
(in dB SPL to volts or Pascals to volts) on the data sheet. You'll also see
a noise spec on the data sheet too (which can be measured in all sorts of
different ways that can't be compared).

Either way, I was hoping that someone in this group could recommend a
microphone or a source (e.g., a catalog) listing different USB
microphones that could be used for sensing low sound levels, with the
sensitivity, or noise, or some other relevant parameter .specified.

What's wrong with using an outboard interface and a standard microphone?

Also you haven't said how low "low" is. 40 dB SPL? 10 db SPL?
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

"Scott Dorsey"


Also you haven't said how low "low" is. 40 dB SPL? 10 db SPL?



** Subliminal SPLs ???

Don't laugh too quick.




............... Phil

Guys, I think the gain problem is a tad bigger than you think. He's
talking about USB mics here! Now I can't speak from experience, but
from what I've seen USB mics are mics with a built in ADC converter
that then feeds the data out a USB cable to your computer.

So the key gain question is WHAT is between the analog part of of the
"mic" and it's internal digital converter? Is there even a gain knob
on it? From the pictures I've seen I don't think so. The cool thing is
that such a mic is very convenient to use. No preamps, no sound cards.
Just a USB port and some software. But I very much doubt that with
everything done for you that a noise floor is going to be optimum with
this "convenient" setup.

See what I'm saying?

Benj

"Curioso" wrote in message
oups.com...
According to http://floridamusicco.com/co1.htm "Samson C01 USB" has
Sensitivity -33 dB/Pa

Others specify sensitivity in dB (e,g,:
http://www.speechtechnology.com/voic...D=Jamaica%20NX)

or dBV (http://www.dragontalk.com/USBmic.html)

or dBV/uBar; dBV/Pa
(http://www.google.com/search?hl=en&r...tivity&spell=1)

How do you compare apples to apples?

Why won't you yell us exactly what you are doing with this so we have some
way to judge whether you need the $3,000 solution or the $100 solution? Or
if the USB solution is even practical for the gain you need?

Depending on what you're doing the noise canceling mics you link to may be
totally unacceptable.

In the specs, dB could mean dBV or dBm, which are only slightly different,
so don't worry too much about that part.

1 Pa = 10 uBars. See:
http://www.sengpielaudio.com/calcula...sferfactor.htm if you really
want to sort this out, but don't ask me to explain it all here!

Julian

In article . com writes:

Guys, I think the gain problem is a tad bigger than you think. He's
talking about USB mics here!

With a USB mic, there's no GAIN problem, but there might be a
SENSITIVITY problem. The mic is designed to give a full scale digital
output at some (probalby unspecified or ambiguously spcified) SPL. But
that doesn't usually meanm anything to someone who wants to know if it
will record raindrops or a quiet voice or a screaming guitar
amplifier.

So the key gain question is WHAT is between the analog part of of the
"mic" and it's internal digital converter? Is there even a gain knob
on it? From the pictures I've seen I don't think so.

Probably not, on any presently available USB mic. It's not out of the
question, of course, but that technology is generally built for people
who wouldn't know what to do with another control. You want a mic with
digital output (AES/EBU) and digital gain control from a computer? Get
a Neumann digital mic system.

The problem is that microphones are required to respond to a very wide
dynamic range, wider than anything else in the system. So in order to
provide one with high gain (= high sensitivity) you need a very quiet
preamp and A/D converter with a very wide dynamic range. You need to
be able to actually use most of those 24 bits. It's tough to build
something like that. Easier (and cheaper) to make a mic with fixed
front end gain and lower sensitivity.



--
I'm really Mike Rivers - )
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 he double-m-eleven-double-zero at yahoo

Mike Rivers wrote:

The problem is that microphones are required to respond to a very wide
dynamic range, wider than anything else in the system. So in order to
provide one with high gain (= high sensitivity) you need a very quiet
preamp and A/D converter with a very wide dynamic range. You need to
be able to actually use most of those 24 bits.

If the current trend remains on course, the day will come,
and is probably not that far off, when we will be able
dispense with preamps other than as effects. In no more
than ten years it's my bet that most new mics will be
digital with an A/D having sufficient dynamic range that its
noise will be below the mic's self noise.


Bob
--

"Things should be described as simply as possible, but no
simpler."

A. Einstein

Curioso wrote:
According to http://floridamusicco.com/co1.htm "Samson C01 USB" has
Sensitivity -33 dB/Pa

Others specify sensitivity in dB (e,g,:
http://www.speechtechnology.com/voic...D=Jamaica%20NX)

or dBV (http://www.dragontalk.com/USBmic.html)

or dBV/uBar; dBV/Pa
(http://www.google.com/search?hl=en&r...tivity&spell=1)

How do you compare apples to apples?

To convert the usual sensitivity spec S given in dB (which
is relative to 1 Volt at 1 Pa) simply take 10^(S/20). That
gives you volts/Pa. 1 Pa is 94 dB SPL. An S of -33 is 22.4
mV/Pa (which is really hot). IOW, it will put out 22.4 mV
at 94 dB SPL. At 100 dB SPL it will put out double that (6
more dB.)


Bob
--

"Things should be described as simply as possible, but no
simpler."

A. Einstein

Curioso wrote:
According to http://floridamusicco.com/co1.htm "Samson C01 USB" has
Sensitivity -33 dB/Pa

Others specify sensitivity in dB (e,g,:
http://www.speechtechnology.com/voic...D=Jamaica%20NX)

or dBV (http://www.dragontalk.com/USBmic.html)

or dBV/uBar; dBV/Pa
(http://www.google.com/search?hl=en&r...tivity&spell=1)

How do you compare apples to apples?

Oops. Went to look something up to be sure and hit "send"
instead of "save." Anyway...

1 Pascal equals 10 microbars, just different units of
measure, they both put a metric on pressure in force per
unit area.

Most of the time sensitivity specs are re 1V/Pa but if the
spec specifically mentions microbars, you can convert to the
more common Pascal sensitivity by subtracting 20 dB.

Occasionally you will see them specified in mV/Pa or
mV/microbar directly instead of in dB.


Bob
--

"Things should be described as simply as possible, but no
simpler."

A. Einstein

Thanks, Bob.

"Bob Cain" wrote in message
...


Curioso wrote:
According to http://floridamusicco.com/co1.htm "Samson C01 USB" has
Sensitivity -33 dB/Pa

Others specify sensitivity in dB (e,g,:
http://www.speechtechnology.com/voic...D=Jamaica%20NX)

or dBV (http://www.dragontalk.com/USBmic.html)

or dBV/uBar; dBV/Pa
(http://www.google.com/search?hl=en&r...tivity&spell=1)

How do you compare apples to apples?

To convert the usual sensitivity spec S given in dB (which is relative to
1 Volt at 1 Pa) simply take 10^(S/20). That gives you volts/Pa. 1 Pa is
94 dB SPL. An S of -33 is 22.4 mV/Pa (which is really hot). IOW, it will
put out 22.4 mV at 94 dB SPL. At 100 dB SPL it will put out double that
(6 more dB.)


Bob
--

"Things should be described as simply as possible, but no simpler."

A. Einstein

"Bob Cain"

Mike Rivers wrote:

The problem is that microphones are required to respond to a very wide
dynamic range, wider than anything else in the system. So in order to
provide one with high gain (= high sensitivity) you need a very quiet
preamp and A/D converter with a very wide dynamic range. You need to
be able to actually use most of those 24 bits.

If the current trend remains on course, the day will come, and is probably
not that far off, when we will be able dispense with preamps other than as
effects. In no more than ten years it's my bet that most new mics will be
digital with an A/D having sufficient dynamic range that its noise will be
below the mic's self noise.



** Err - that would take about a 140 dB of dynamic range.

I suspect that gain trims are here for a bit longer.



................ Phil

Phil Allison wrote:
"Bob Cain"

Mike Rivers wrote:


The problem is that microphones are required to respond to a very wide
dynamic range, wider than anything else in the system. So in order to
provide one with high gain (= high sensitivity) you need a very quiet
preamp and A/D converter with a very wide dynamic range. You need to
be able to actually use most of those 24 bits.

If the current trend remains on course, the day will come, and is probably
not that far off, when we will be able dispense with preamps other than as
effects. In no more than ten years it's my bet that most new mics will be
digital with an A/D having sufficient dynamic range that its noise will be
below the mic's self noise.




** Err - that would take about a 140 dB of dynamic range.

Let's see. 10 dBA self noise (RMS) on a mic is 6.32E-5 Pa.
With a -40 dB sensitivity (re 1V/Pa) mic, that's about
6.32E-7 Volts (same ballpark as EIN on a modest preamp.) If
the converter was 2Vrms FS (allowing 140 dBA max SPL), that
self noise would be about -130 dB down from FS, 22 bits, not
too far from what you say but within the limit of the trend
I think.

For now, if there were 0/20 dB gain between the capsule and
the converter we only need a converter with about 110 dB
dynamic range, 18.3 bits, and that looks pretty feasable.
Yes, there is still one switch worth of trim required but it
could be done today. With an X/10X gain selection, X
selected based on the mic sensitivity, a standard could be
established right now for digital sensitivity that about any
mic could be made to match.

Did I foul up any of the arithmetic?


Bob
--

"Things should be described as simply as possible, but no
simpler."

A. Einstein

"Bob Cain"
Phil Allison wrote:
Mike Rivers wrote:


The problem is that microphones are required to respond to a very wide
dynamic range, wider than anything else in the system. So in order to
provide one with high gain (= high sensitivity) you need a very quiet
preamp and A/D converter with a very wide dynamic range. You need to
be able to actually use most of those 24 bits.

If the current trend remains on course, the day will come, and is
probably not that far off, when we will be able dispense with preamps
other than as effects. In no more than ten years it's my bet that most
new mics will be digital with an A/D having sufficient dynamic range that
its noise will be below the mic's self noise.


** Err - that would take about a 140 dB of dynamic range.

Let's see. 10 dBA self noise (RMS) on a mic is 6.32E-5 Pa. With a -40 dB
sensitivity (re 1V/Pa) mic, that's about 6.32E-7 Volts (same ballpark as
EIN on a modest preamp.) If the converter was 2Vrms FS (allowing 140 dBA
max SPL), that self noise would be about -130 dB down from FS, 22 bits,
not too far from what you say but within the limit of the trend I think.

For now, if there were 0/20 dB gain between the capsule and the converter
we only need a converter with about 110 dB dynamic range, 18.3 bits, and
that looks pretty feasable. Yes, there is still one switch worth of trim
required but it could be done today. With an X/10X gain selection, X
selected based on the mic sensitivity, a standard could be established
right now for digital sensitivity that about any mic could be made to
match.

Did I foul up any of the arithmetic?



** You snipped my comment to avoid technical reality to make it work
though.

" I suspect that gain trims are here for a bit longer."

A 20 dB switch IS a gain trim.



............... Phil

Bob Cain wrote:
Mike Rivers wrote:

The problem is that microphones are required to respond to a very
wide dynamic range, wider than anything else in the system. So in
order to provide one with high gain (= high sensitivity) you need a
very quiet preamp and A/D converter with a very wide dynamic range.
You need to be able to actually use most of those 24 bits.

If the current trend remains on course, the day will come,
and is probably not that far off, when we will be able
dispense with preamps other than as effects. In no more
than ten years it's my bet that most new mics will be
digital with an A/D having sufficient dynamic range that its
noise will be below the mic's self noise.


Hmm, the self-noise of common pro audio mics starts at something like
12-18 dBA, working up to about 32 dBA for the real noise buckets,
right?

Mics that clip in the 124-132 dB range are considered to be "robust
enough", right?

So that means that we need convertors with dynamic range in the 96 to
120 dB range - 16 to 20 bits, right?

"Arny Krueger"


Hmm, the self-noise of common pro audio mics starts at something like
12-18 dBA, working up to about 32 dBA for the real noise buckets,
right?

Mics that clip in the 124-132 dB range are considered to be "robust
enough", right?



** WRONG !!!!

Garden variety dynamic mics are speced up to 145db SPL or more - no
frequency specified.

The Shure SM58 takes 160 dB SPL at 1 kHz and 145dB SPL at 60 Hz with ease.

Most condenser mics are speced at 150 db + SPL at ANY frequency !!!!!!!!!.


So that means that we need convertors with dynamic range in the 96 to
120 dB range - 16 to 20 bits, right?



** Nope - you ****ing compewter geek ****wit.





............... Phil

I tend to agree, at least in theory. The Neumann digital mic is claimed
to have a converter using two A/D "stages" and a clever way to
integrate them to deliver something like 130dB of dynamic range. This
still falls a bit short of their analog mics (TLM 103 has 7dB-A self
noise and can handle 138dB of SPL for .5% THD, for dynamic range of
131dB) but in practice, their digital microphone "sounds" quieter
because of a very different noise spectrum than their analog cousins.

The bigger question I think has to do with adoption of the digital
microphone interface (AES42-2001 is the current standard) by others
besides just a few cutting edge microphone people. And perhaps USB,
Firewire, or some other digital standard will actually become more
readily accepted. If so, I certainly hope that the microphone
manufacturers wake up to this, confer, and work out the new standard as
they did for the current one.

Clearly, the convergence of consumer computer technology with "pro"
audio is moving more quickly than some would like to admit.

Karl Winkler
Lectrosonics, Inc.
http://www.lectrosonics.com

Karl Winkler wrote:
I tend to agree, at least in theory. The Neumann digital mic is claimed
to have a converter using two A/D "stages" and a clever way to
integrate them to deliver something like 130dB of dynamic range.

It does use that trick, and I should say that this is not a new thing
and that the Philips guys were doing this in the late seventies to get
16 bit resolution out of 12 bit (and later 14-bit) converters. The
problem is that it's a trick that is hard to do well because the
attenuator resistors going into the converters have to be very precisely
matched and have to stay there with changes in temperature. Neumann
does some temperature compensation trickery that I couldn't figure out
on the bench and that could help.

I could believe 130 dB of dynamic range in certain circumstances, but
I would be really curious what the overall linearity of the converter
system is.

I'll say also that this really is no different than having an analogue
microphone with a fixed-gain preamp and a wide-word converter in
seperate boxes. What makes the Neumann interesting is only that
they managed to put all the stuff into one box.

This
still falls a bit short of their analog mics (TLM 103 has 7dB-A self
noise and can handle 138dB of SPL for .5% THD, for dynamic range of
131dB) but in practice, their digital microphone "sounds" quieter
because of a very different noise spectrum than their analog cousins.

Yes, but now add the preamp and converter noise numbers on top of the
mike numbers, and you get something either comparable or worse than
the Neumann.

The bigger question I think has to do with adoption of the digital
microphone interface (AES42-2001 is the current standard) by others
besides just a few cutting edge microphone people. And perhaps USB,
Firewire, or some other digital standard will actually become more
readily accepted. If so, I certainly hope that the microphone
manufacturers wake up to this, confer, and work out the new standard as
they did for the current one.

USB and Firewire really are poor choices because they can't go long
distances and clocking accuracy is doubtful at best. Fine for one
guy with a mike at a desk, but impractical if you have several
mikes plugged into a machine or thousand-foot stage runs. The current
AES standard is a good one, though it does not allow for remote control
of the preamp gain or a tally light on the mike. The ability to adjust
the preamp gain reduces the need for extreme dynamic range, but clearly
if everyone had the kind of numbers the Neumann has, it would not be
eeded.

Clearly, the convergence of consumer computer technology with "pro"
audio is moving more quickly than some would like to admit.

I think everyone admits it. The problem is that it terrifies us and
frustrates us. The worst thing that could happen is that USB becomes
a standard interface and we all spend huge amounts of effort working
around the deficiencies in the design. We've already spent the last
fifteen years saddled with the awful DAT standard thanks to the consumer
marketplace and now we're all having to deliver duplicating masters on
CD-Rs with no external error correction thanks the the proliferation
of cheap CD-R hardware. I'm just tired of cheap crap that only mostly
works.
--scott

Oh yeah, and this morning I am using a pair of BK-5s as choral spots.
They don't have anything approaching 130 dB. I'd be surprised if they
even have a 70 dB range. But they sure sound good. And once the
brass section comes up nobody will care about the noise anyway.

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

On 4/25/05 7:55 AM, in article , "Phil
Allison" wrote:

** Nope - you ****ing compewter geek ****wit.

Phil, the rest of the entire world really WOULD like you to stop describing
people you meet online like direct genetic siblings.

Thanks in advance for getting back on the prozac.

In article writes:

Did I foul up any of the arithmetic?

I don't know, but I do know that Neumann, for their digital system,
had to do some tricks with a two-stage converter in order not to
compromise the dynamic range of the microphone element. I don't
remember the details, but check their web site. They give a reasonable
explanation of how they're doing it.


--
I'm really Mike Rivers - )
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 he double-m-eleven-double-zero at yahoo

Phil Allison wrote:

** You snipped my comment to avoid technical reality to make it work
though.

You're a piece of work, Phil. I trimmed down to the minimum
to establish context for my response which is my habit and a
polite thing to do IMO. No point, I see, in even attempting
to respond to you in a civil fashion. Plonk.


" I suspect that gain trims are here for a bit longer."

A 20 dB switch IS a gain trim.

Seems to me that I acknowledged precisely that. Heavy sigh.


Bye,

Bob
--

"Things should be described as simply as possible, but no
simpler."

A. Einstein

Arny Krueger wrote:

So that means that we need convertors with dynamic range in the 96 to
120 dB range - 16 to 20 bits, right?

Yes, that's about what I figured in my attempt at a response
to Allison.

Arny, let's establish a new standard for digital sensitivity
that would allow today's technology to give a reliable
framework for realizable digital mics? How's that for
hubris. :-)

OTOH, Neumann might be a standard to follow.


Bob
--

"Things should be described as simply as possible, but no
simpler."

A. Einstein

Karl Winkler wrote:

The bigger question I think has to do with adoption of the digital
microphone interface (AES42-2001 is the current standard) by others
besides just a few cutting edge microphone people.

Oops. Didn't know about that. Does it define any standard
for sensitivity or is that still at the whim of the
manufacturer?


Bob
--

"Things should be described as simply as possible, but no
simpler."

A. Einstein

Bob, I don't see a mention of microphone sensitivity. I suppose it
would have to correlate to the application, i.e. that for mics used in
a loud environment (snare drum, etc.) that sensitivity should be low,
etc. And to some extent this is the same as with an analog setup. In
order to maximize your s/n and use of available bits, the sensitivity
should be matched to the acoustic input.

-Karl

Karl Winkler wrote:
Bob, I don't see a mention of microphone sensitivity. I suppose it
would have to correlate to the application, i.e. that for mics used in
a loud environment (snare drum, etc.) that sensitivity should be low,
etc. And to some extent this is the same as with an analog setup. In
order to maximize your s/n and use of available bits, the sensitivity
should be matched to the acoustic input.

Yes, your point is a good one. I just think there is a user
advantage in knowing a standard relationship between one of
two or three gain/trim/pad settings and the SPL at the mic.

I dunno, maybe I'm the only one that would care to see that.


Bob
--

"Things should be described as simply as possible, but no
simpler."

A. Einstein

"Bob Cain"

Phil Allison wrote:

** You snipped my comment to avoid technical reality to make it work
though.

You're a piece of work, Phil.


** You are a piece of human garbage Bob.


I trimmed down to the minimum to establish context for my response which
is my habit and a polite thing to do IMO.


** You ACTUALLY snipped my comment OUT to avoid technical reality - the
habit of a schizo and a liar.


" I suspect that gain trims are here for a bit longer."

A 20 dB switch IS a gain trim.

Seems to me that I acknowledged precisely that.


** But never admitted that your original comment " it's my bet .... "
was flawed in that regard.




................ Phil

"Scott Dorsey"

It does use that trick, and I should say that this is not a new thing
and that the Philips guys were doing this in the late seventies to get
16 bit resolution out of 12 bit (and later 14-bit) converters.


** Philips in fact used 4 times oversampling ( hence s/n) to get 16 bit
resolution from 14 bit A/Ds.




............... Phil

"Phil Allison"

"Scott Dorsey"

It does use that trick, and I should say that this is not a new thing
and that the Philips guys were doing this in the late seventies to get
16 bit resolution out of 12 bit (and later 14-bit) converters.



** Correction:

** Philips in fact used 4 times oversampling to get 16 bit resolution (
and hence s/n) from 14 bit A/Ds.



......... Phil