Wireless audio distribution?
 

"Pooh Bear" wrote in message
...

Product Specifications
. Digital Audio File Formats:
- MP3 up to 320 Kbps or variable bit rate (VBR)
- WMA 8/9 to 192 Kbps
- Internet Radio (streaming MP3)

http://www.netgear.com/pdf_docs/MP101_ds_NA_30Nov04.pdf

..wav and lpcm support was added via a software update; they are not in the
manual

Tim

Wireless audio distribution?
 

"Pooh Bear" wrote in message
...

So, if I was to point you to a company that's actually working on
uncompressed
digital audio links and they confirmed what I said, would you apologise
for your
stupid comment above ?

Wireless computer network links can and do work at ten million bits a second
or more, with nominal speeds several times that figure.

I've been monitoring my wireless network transmission to my Netgear MP101
while playing an 860MB .wav file (44100Hz/16-bitstereo), and it is sending
data at about 200,000 bytes a second, which is about what you'd expect for
an uncompressed file. The server software CPU consumption is near-zero -
less than 5 CPU seconds in the last 5 minutes.

Tim

Wireless audio distribution?
 

Zak wrote:

Pooh Bear wrote:
DaveC wrote:


Is there a wireless solution to distributing audio throughout a residence to
8 rooms? Digital?

Currently only at mp3 like quality. True16 bit linear pcm in stereo @ 44kHz
sampling requires something like about 6 Mbps of bandwidth.

Uhh... 44.1 KHz * 16 bits * 2 channels = 1.4112 Mbit / sec....
definitely possible.

It's *possible* - just not currently commercially available. That's the raw data
rate btw. It'll take a lot more bandwidth to get it wirelessly from A to B.

Graham

Wireless audio distribution?
 

Arny Krueger wrote:

"CJT" wrote in message



44.1 ksamples/sec * 16 bits/sample * 2 channels =
1,411,200 bits/sec

In any case, it's 1.4 Mbits/sec, NOT 6 Mbits/sec.

That's the raw data rate only !

Now you have to add overhead for the frequency hopping
stuff, handshaking, whatever and redundancy for lost
packets - and I've no idea how the data's encapsulated -
there'll doubtless be extra stuff there too. I'm not
calculating this myself, I have it on good authority
from some guys who are developing the product. I was
quite surprised how much overhead is required myself
actually.

Even accepting your numbers, a 10 Mbps link is adequate.
So it's not necessary to resort to MP3.

I was just listening to some .wav files stored on a file
server across the room, using a SMC 2662W USB-attached
plain-old-vanilla old-tech, low-tech 802.11b wireless
interface. The file I was listening to with Winamp was a
44/16 stereo .wav file.

There's also the slight matter of 802.11a which delivers an
uncompressed 54 mbps, over shorter distances but still
plenty fine to reach across a room or a house.

That's from *computer to computer* over a wireless network.

I never said that couldn't be done. We were discussing a standalone link
that's suitable for replacing hard wiring, where you have 'dumb box' to
receive the wireless audio. I don't see having a PC in every room just
to receve audio as a practical solution.

If you have a computer at the far end you can indeed send your file over
wireless ethernet. It takes a fair bit of the bandwidth on a slower
connection though. Standalone systems are a different kettle of fish. I
know of *none* currently offering 16 bit linear pcm and I can assure you
I've researched it very thoroughly. It may seem surprising but it's a
fact. It is being worked on though. I can't say too much on account of
an NDA.

Graham

Wireless audio distribution?
 

Don Bowey wrote:

On 8/4/05 6:12 AM, in article , "Pooh Bear"
wrote:

Don Bowey wrote:

On 8/3/05 5:07 PM, in article , "Pooh Bear"
wrote:

wrote:

wrote:
Pooh Bear wrote:
DaveC wrote:

Is there a wireless solution to distributing audio throughout a
residence
to
8 rooms? Digital?

Something similar to wireless computer networking...

Currently only at mp3 like quality. True16 bit linear pcm in
stereo @ 44kHz sampling requires something like about 6 Mbps
of bandwidth.

44,1000 ksamples/sec * 16 bits/sample * 2 channels = 1,411,200 bits/sec

Sorry, that's:

44,1000 samples/sec * 16 bits/sample * 2 channels = 1,411,200 bits/sec

or

44.1 ksamples/sec * 16 bits/sample * 2 channels = 1,411,200 bits/sec

In any case, it's 1.4 Mbits/sec, NOT 6 Mbits/sec.

That's the raw data rate only !

Now you have to add overhead for the frequency hopping stuff, handshaking,
whatever
and redundancy for lost packets - and I've no idea how the data's
encapsulated
-
there'll doubtless be extra stuff there too. I'm not calculating this
myself,
I have
it on good authority from some guys who are developing the product. I was
quite
surprised how much overhead is required myself actually.

You've provided other BS swearing about the correctness of it and have been
wrong. Your credibility slipped before this and stating 6 Mbit/s here
confirms you don't know Jack.

So, if I was to point you to a company that's actually working on uncompressed
digital audio links and they confirmed what I said, would you apologise for
your
stupid comment above ?

It appears that *YOU* are the one who 'knows jack' since you're basically
talking
straight out of your arse. I suggest you go learn something about the
technology.

I don't care a whole lot about what *one* company is *working on*. How
about you point me to an *ANSI* Standard, or even one in progress in a
Working Group?

Oh..... I remember, you like to make reference to "standards" that aren't
really Standards.

IMHO you aren't trustworthy in discussions.

And you're a worthless plonker who can't even respond to a straight question. I'd
forgotten you're one of Gay Mason's mates. Explains a great deal.

Graham

Wireless audio distribution?
 

CJT wrote:

Pooh Bear wrote:
Don Bowey wrote:

On 8/3/05 5:07 PM, in article , "Pooh Bear"
wrote:

wrote:

wrote:
Pooh Bear wrote:
DaveC wrote:

Is there a wireless solution to distributing audio throughout a residence
to
8 rooms? Digital?

Something similar to wireless computer networking...
Currently only at mp3 like quality. True16 bit linear pcm in
stereo @ 44kHz sampling requires something like about 6 Mbps
of bandwidth.
44,1000 ksamples/sec * 16 bits/sample * 2 channels = 1,411,200 bits/sec
Sorry, that's:

44,1000 samples/sec * 16 bits/sample * 2 channels = 1,411,200 bits/sec

or

44.1 ksamples/sec * 16 bits/sample * 2 channels = 1,411,200 bits/sec

In any case, it's 1.4 Mbits/sec, NOT 6 Mbits/sec.
That's the raw data rate only !

Now you have to add overhead for the frequency hopping stuff, handshaking,
whatever
and redundancy for lost packets - and I've no idea how the data's encapsulated
-
there'll doubtless be extra stuff there too. I'm not calculating this myself,
I have
it on good authority from some guys who are developing the product. I was
quite
surprised how much overhead is required myself actually.
You've provided other BS swearing about the correctness of it and have been
wrong. Your credibility slipped before this and stating 6 Mbit/s here
confirms you don't know Jack.

So, if I was to point you to a company that's actually working on uncompressed
digital audio links and they confirmed what I said, would you apologise for your
stupid comment above ?

It appears that *YOU* are the one who 'knows jack' since you're basically talking
straight out of your arse. I suggest you go learn something about the technology.

Graham


The Turtle Beach Audiotron does .wav, and if you wanted to, you could
link to it via wireless.

It rather appears that it does the typical 'sub-band codec' thing with a wav file.

Part of the audio tech spec for the Audiotron is as follows - and it's not the spec to
be expected of linear 16 bit pcm.


Signal to Noise 91dB (A-weighted)

THD+N -78dB (A-weighted) (-78dB = .0125%)

http://www.turtlebeach.com/site/prod...tron/specs.asp

I hope you understand why this clearly isn't linear 16 bit. I've never even seen a
manufacturer have the brass neck to A-weight a THD spec before ! Talk about being
desperate.

Graham

Wireless audio distribution?
 

tony sayer wrote:

In article , Pooh Bear rabbitsfriendsand
writes
Tim Martin wrote:

"Pooh Bear" wrote in message
...

Existing 2.4G audiolinks are mostly 'mp3' like. Look for the term 'sub
band codec' in the
description - although many are simply sold using the confusing and
meaningless term
'stereo quality' !

Well, I use a wireless link for my Netgear MP101, and it handles .wav files.

I see it says on the box that the MP101 uses 802.11g, which uses the 2.4GHz
technology, and speeds are "up to 54Mbps" (yea, right ...).


Product Specifications
• Digital Audio File Formats:
- MP3 up to 320 Kbps or variable bit rate (VBR)
- WMA 8/9 to 192 Kbps
- Internet Radio (streaming MP3)

http://www.netgear.com/pdf_docs/MP101_ds_NA_30Nov04.pdf

Trust me - uncompressed digital audio wireless links are not yet available. I
expect the MP101 compresses wav files on the fly.

Graham


They are, but not as you might know, or want to pay for them;))

I was indeed simply considering the consumer market ! ;-)

Graham

Wireless audio distribution?
 

On Thu, 04 Aug 2005 03:00:51 +0100, Pooh Bear wrote:


Rich Grise wrote:

On Thu, 04 Aug 2005 01:07:23 +0100, Pooh Bear wrote:

That's the raw data rate only !

Now you have to add overhead for the frequency hopping stuff, handshaking, whatever
and redundancy for lost packets - and I've no idea how the data's encapsulated -
there'll doubtless be extra stuff there too. I'm not calculating this myself, I have
it on good authority from some guys who are developing the product. I was quite
surprised how much overhead is required myself actually.

You don't have to use TCP/IP, and you don't need, or even want, lost
packet redundancy, at least not for streaming audio. If you need a
protocol at all, use something like UUCP.

If you don't account for lost packets what's going to happen to any lost audio data ? I'll
ask some more next time I talk to the guys about the protocol they're using.


You leave it gone, because if you try to resend it, you'll lose ensuing
packets, or at least they'll get out of order. You drop it, and keep
on truckin'...

And if it's just streaming bits, you won't lose whole packets, and a
bit or two here and there is insignificant for, say, MP3. ;-)

Cheers!
Rich

Wireless audio distribution?
 

Tim Martin wrote:

"Pooh Bear" wrote in message
...

So, if I was to point you to a company that's actually working on
uncompressed
digital audio links and they confirmed what I said, would you apologise
for your
stupid comment above ?

Wireless computer network links can and do work at ten million bits a second
or more, with nominal speeds several times that figure.

I've been monitoring my wireless network transmission to my Netgear MP101
while playing an 860MB .wav file (44100Hz/16-bitstereo), and it is sending
data at about 200,000 bytes a second, which is about what you'd expect for
an uncompressed file. The server software CPU consumption is near-zero -
less than 5 CPU seconds in the last 5 minutes.

Ok - that's a standard wireless computer network right ?

I'll bet that whatever utility measures the data rate is simply looking at the
raw data transferred - the actual traffic that the 'network' sees - not the RF
data rate in bps.

I wouldn't expect to see much CPU utilisation - I expect the ethernet
controllers do most of the hard work.

I was talking about a *standalone* point to point method of distributing audio
wirelessly. There's no ethernet controller to take the strain nor any OS, CPU or
whatever.

Incidentally, I decided it was time to do some more Googling since the company I
was expecting to deliver still hasn't come up with the goods.

You may find this interesting - it appears to be the first chipset designed for
this function. It's barely in production it seems. I was kinda guessing at the
6Mbps data rate. They've apparently managed to get it into 4Mbps. Still a lot
more than the raw 1.4Mbps of the raw audio data though.

http://www.nvlsi.no/index.cfm?obj=do...isplay&doc=242

" Nordic launches nRF24Z1 - an Industry First Single Chip 2.4GHz 4Mbit/s
Solution for CD-Quality Wireless Audio Streaming, with Extremely Low Latency "

Graham

Wireless audio distribution?
 

"Pooh Bear" wrote
in message
Arny Krueger wrote:

"CJT" wrote in message



44.1 ksamples/sec * 16 bits/sample * 2 channels =
1,411,200 bits/sec

In any case, it's 1.4 Mbits/sec, NOT 6 Mbits/sec.

That's the raw data rate only !

Now you have to add overhead for the frequency hopping
stuff, handshaking, whatever and redundancy for lost
packets - and I've no idea how the data's encapsulated
- there'll doubtless be extra stuff there too. I'm not
calculating this myself, I have it on good authority
from some guys who are developing the product. I was
quite surprised how much overhead is required myself
actually.

Even accepting your numbers, a 10 Mbps link is adequate.
So it's not necessary to resort to MP3.

I was just listening to some .wav files stored on a file
server across the room, using a SMC 2662W USB-attached
plain-old-vanilla old-tech, low-tech 802.11b wireless
interface. The file I was listening to with Winamp was a
44/16 stereo .wav file.

There's also the slight matter of 802.11a which delivers
an uncompressed 54 mbps, over shorter distances but still
plenty fine to reach across a room or a house.

That's from *computer to computer* over a wireless
network.

In this day and age, just about *everything* is a computer.

What's the difference between a $299 stand-alone dedicated
client and a $399 computer besides 33% higher cost?

http://configure.us.dell.com/dellsto...c=D30CL1&s=dhs

I never said that couldn't be done. We were discussing a
standalone link that's suitable for replacing hard
wiring, where you have 'dumb box' to receive the wireless
audio. I don't see having a PC in every room just to
receve audio as a practical solution.

I believe the OP said:

"Is there a wireless solution to distributing audio
throughout a residence to
8 rooms? Digital?"

One approach is to have a file server loaded with audio
files that are to be distributed. Clients at each location
download the audio that is desired at that location.

Another approach is to have intelligent clients that stream
audio from off-site services through an on-site router.

If you have a computer at the far end you can indeed send
your file over wireless ethernet. It takes a fair bit of
the bandwidth on a slower connection though.

I believe the OP said nothing about the wireless connection
being necessarily slow, given that the wireless connection
was generally available for a reasonable cost.

Standalone
systems are a different kettle of fish. I know of *none*
currently offering 16 bit linear pcm and I can assure you.

But a distributed solution running 16 bit linear PCM can be
assembled from inexpensive computers.

I've researched it very thoroughly. It may seem
surprising but it's a fact. It is being worked on though.
I can't say too much on account of an NDA.

OK, someone puts together a Linux box and some software.