Audio, hi-fi and car audio - Volume control at the speaker?

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Wireless audio distribution?

Joel Kolstad wrote:

Hey Pooh Bear,

"Pooh Bear" wrote in message
...
Any *half competent* analogue line level
output will be capable of 110dB s/n or better

I have a suspicion that very little, if any, of the stereo equipment one might
find in, say, Wal*Mart meets this spec! Would you agree?

LOL !

Wal Mart is indeed another story.

I tend to talk mainly of what has become to be known as 'pro-sumer' gear. Stuff
that would once have clearly been seen to have 'pro' specs but is now available at
a 'consumer' price.

I have zero interest in the **** sold by Wal Mart and their ilk. Even if it does
have a supposed *big name* on it.

Graham

Wireless audio distribution?

On Fri, 05 Aug 2005 02:28:58 GMT, CJT wrote:

Jim Thompson wrote:
On Fri, 05 Aug 2005 01:23:19 GMT, CJT wrote:

[snip]
Who wants to walk down the hall to insert a CD when it can be instantly
available on a file server?
[snip]

Some of us have a 300 CD jukebox ;-)

...Jim Thompson

Who wants to walk down the hall to select a CD in the jukebox when it
can be instantly available on a file server?

:-)

Well the jukebox, actually 3 x 100CD auto-changer units tucked away in
a hall cabinet, is operated by a remote from the comfort of my couch
in the great room ;-)

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice:(480)460-2350 | |
| E-mail Address at Website Fax:(480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.

Wireless audio distribution?

"Pooh Bear" wrote in message
...
I have zero interest in the **** sold by Wal Mart and their ilk. Even if it
does
have a supposed *big name* on it.

That's what I thought you'd say. OK, I know where you're coming from now... I
just hope you realize that, by volume, there's a lot more "**** sold by
Wal*Mart" than pro-sumer stuff! (Tried to buy an SVHS VCR lately?)

I had a debate years ago with a fellow college student about the best way to
make money selling electronics... he wanted the Wal*Mart approach (low cost,
high volume, "good enough") whereas I advocated the "boutiquey" approach
(lower volumes, noticeable higher cost, honest-to-God specs that would meet
with the approval of even the most discerning Pooh Bears). I still prefer the
later, but I can see now how, from many angles, my friend's approach is a lot
easier to implement for the average Joe, even if there is a lot more
competition.

Wireless audio distribution?

"Joel Kolstad" wrote in message
...
"Pooh Bear" wrote in message
...
I have zero interest in the **** sold by Wal Mart and their ilk. Even if
it
does
have a supposed *big name* on it.

That's what I thought you'd say. OK, I know where you're coming from
now... I
just hope you realize that, by volume, there's a lot more "**** sold by
Wal*Mart" than pro-sumer stuff! (Tried to buy an SVHS VCR lately?)

I had a debate years ago with a fellow college student about the best way
to
make money selling electronics... he wanted the Wal*Mart approach (low
cost,
high volume, "good enough") whereas I advocated the "boutiquey" approach
(lower volumes, noticeable higher cost, honest-to-God specs that would
meet
with the approval of even the most discerning Pooh Bears). I still prefer
the
later, but I can see now how, from many angles, my friend's approach is a
lot
easier to implement for the average Joe, even if there is a lot more
competition.

Typical snobby view that gets 'audiophiles' a bad name - pound for pound
WalMart 'prosumer' stuff probably gives much more satisfaction/pleasure to a
vastly higher number of people than so-called 'high end' gear does and is
probably a lot more 'honest' too!

As to approach, if you want to make money it is *beyond question* that the
'pile it high, sell it cheap' is by far the most effective method - ask
Walmart (256.3 BILLION USD t/o for 2004 according to:

http://www.walmartfacts.com/docs/738...1497483218.pdf

???)..... ;-)

Wireless audio distribution?

Pooh Bear wrote:
Zak wrote:

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.

hmmm... what if you'd use say an Asus WL-HDD as a wireless file
server/access point ($90, need to add laptop drive) and say a wl-500g
(or another wl-hdd) with a USB audio dongle as playback? Will need some
programming but it runs linux. But it does not have a user interface at
all...

These all have wired ethernet as well. Fun toys.

Thomas

Wireless audio distribution?

In .net, on 08/02/05

at 09:17 AM, DaveC said:

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

Something similar to wireless computer networking...

Thanks,

sonos.com

It's a finished product, 8 rooms is a cakewalk. Even if you are slow at
unpacking boxes and conntecting speakers this system will still take
less than a morning to install.

It will play many types of compressed and uncompressed files from a
computer or a server, internet radio, and Rhapsody (US only).

It also has a very straight forward user interface. Technofobes take to
it in a minute or two.

Unless you are using a "turbo" wirless network, SONOS will coexist with
your current WiFi stuff. (Virtually nothing can coexist in the 2.5GHz
band with turbo)

-----------------------------------------------------------
spam:
wordgame:123(abc):14 9 20 5 2 9 18 4 at 22 15 9 3 5 14 5 20 dot 3 15
13 (Barry Mann)
[sorry about the puzzle, spammers are ruining my mailbox]
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Wireless audio distribution?

Zak wrote:

Pooh Bear wrote:
Zak wrote:

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.

hmmm... what if you'd use say an Asus WL-HDD as a wireless file
server/access point ($90, need to add laptop drive) and say a wl-500g
(or another wl-hdd) with a USB audio dongle as playback? Will need some
programming but it runs linux. But it does not have a user interface at
all...

These all have wired ethernet as well. Fun toys.

The original requirement was a *simple* way to get audio from A to B. This chip is
designed to do the job. Only recently released.

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

Graham

Wireless audio distribution?

TokaMundo wrote:

On Sat, 06 Aug 2005 18:33:13 +0100, Pooh Bear
Gave us:

Zak wrote:

Pooh Bear wrote:
Zak wrote:

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.

hmmm... what if you'd use say an Asus WL-HDD as a wireless file
server/access point ($90, need to add laptop drive) and say a wl-500g
(or another wl-hdd) with a USB audio dongle as playback? Will need some
programming but it runs linux. But it does not have a user interface at
all...

These all have wired ethernet as well. Fun toys.

The original requirement was a *simple* way to get audio from A to B. This chip is
designed to do the job. Only recently released.

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

Graham

Try http://www.avalonrf.com/ They have been doing it for years.
Their audio links even have sub channels with data streams.

Top of the line, true diversity multiple band choices, and the
aircraft carrier boys use it as well as cops and race car teams/tracks

On the carriers, one guy wears a hard drive DR system, and all comms
get recorded on the ship as well.

Thanks for the link but their stuff seems to be targeted at generalised data comms.

I was looking for ( and have now found ) an application specific solution to my
reqirement that doesn't involve me in doing all the protocol stuff and whatever. It's
virtually 'ready to go'.

Graham

Wireless audio distribution?

TokaMundo wrote:

On Fri, 05 Aug 2005 00:44:10 +0100, Pooh Bear
Gave us:

CJT wrote:

Pooh Bear wrote:

Which is why you have a receive buffer and there's latency between transmission and reception.

Graham

Unless you buffer the whole session (e.g. a complete song, or perhaps
even a complete CD), there's always the possibility of a buffer not
arriving in time.

I think that's the point.

You could lose *any* given sample. The simplest method of dealing with that is to continually
broadcast the data twice. If the previous error rate was 1 in 10^-6 then that method ( assuming
random errors ) should reduce it to1 in 10^-12. Not *perfect* but pretty damn good !

Sending the data twice also removes the need for negotiation over missed samples between transmitter
and receiver. It sounds like a done deal to me.

That also explains the need for a much higher data rate than 1.4Mbps.

One does not need to send the entire datagram twice. Just package
it up with FEC and let the error correction manage lost packets.

Once the bit error rate gets up over around ten percent, one would
then hear dropouts or other anomalous audio.

Yup. There are various solutions to the problem though. Some are more oriented to fixing corrupted data (
the occasional bit or so ) - other techniques can deal with lost packets.

Here's an extract from the data sheet of the part I'm now rather interested in.

4.3.3 Quality of Service engine
The primary function of the quality of service engine is to deliver a robust communication channel
between the audio transmitter and audio receiver in an audio streaming application. Several data streams
with different properties are handled. The available bandwidth is shared between audio data, service data
and remote data.

Data integrity is ensured through a number of RF protocol features:

1. Packets of data are sent in frames and integrity of each packet is ensured as every packet has a
complete build of RF address, payload and CRC.

2. Packets that are lost or received with errors are handled by the error correction level of the quality
of service engine; a two way, acknowledge protocol:
When a packet is received by ARX, it’s registered and CRC is checked.
After ARX has received a frame it sends a packet back to ATX
acknowledging the packets that where successfully transferred. Packets lost
or received with errors will be re-sent from ATX in the next frame.

3. Finally the information (audio data) is spread over the 2.4 GHz band by use of an adaptive frequency
hopping algorithm. Through this a nRF24Z1 link can handle RF propagation challenges like reflections and
multi-path fading and not least avoid heavily trafficked areas of the 2.4 GHz band. The 2.4 GHz band is a
world wide open RF band and co-existence with RF systems such as Bluetooth, ZigBee,
WLAN/WiFi as well as other nRF applications, is increasingly important.

nRF24Z1 constantly monitors the quality of the RF link and numbers indicating total link quality are
available for external control devices in registers. nRF24Z1 can also be set to interrupt external
controller devices upon poor link quality before RF link is lost. An external controller device can hence
take further actions to improve link quality or warn end user if RF link margins are poor.

The secondary function of the QoS module is to run a link initialization algorithm which manages initial
connect and re-connect if link is lost (ex: out of range) between paired nRF24Z1’s. Several schemes are
available to enable nRF24Z1 connection without end user involvement.

Graham