Volume control at the speaker?

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

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

Yes, and I think the Squeezebox does too. There are several of these devices commercially available.

The $75 Linksys WMLS11B comes with little speakers and has audio and digital out; I don't know if it can handle .wav files.

The $100 Netgear MP101 has built-in wired and wireless ethernet and handles ..wav (with downloadable firmware update), but does not have digital out

The $150 Philips Media Playerhas built-in wireless ethernet and handles video. (This seems similar to the Prismiq Mediaplayer)

The $160 Creative Sound Blaster Wireless has digital out, but doesn't seem to handle .wav files

The $200 Audiotron does not have built-in wireless (obviously you can install a wireless internet link and connect the Audiotron to that.) but it does handle .wav and has digital output.

The $200 Omnifi DMS1W does not have digital output, but can connect to a TV for its user interface. I don't know if it supports .wav

The $300 Squeezebox is from Slim Devices, the company who (I believe) were first to market.

The Philips Streamium comes with speakers and CD player (which will play MP3 CDs, too) and has wireless ethernet.

I expect he's talking about devices which can be used as a simple audio cable substitutes, rather than devices which work with a computer server. I guess to compete with the $100 Netgear, which has remote control of the music being played, an audio cable replacement would have to cost $50 for transmitter and receiver, and say $30 for each additional receiving station.

Tim

uncompressed

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

residence

encapsulated

myself,

uncompressed

your

talking

technology.

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%)

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

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

Graham

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

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

Graham

residence

encapsulated

myself,

uncompressed

your

talking

technology.

file.

My server feeds one raw .wav files. It just works.

spec to

You know these things have an analog stage, too, right?

seen a

being

A practical wireless audio distribution solution should really cost not much more than a couple of hundred bucks total. That's an assessment I've made myself about a product being realistically priced on the market. It'll drop with time of course but early adopters will pay a bit more for leading edge technology.

And the OP *doesn't need* or *want* a computer simply to hear music ! - never mind the fact that they crash all the time and add acoustic noise ! You need a simple standalone solution that you plug in and it works. Not a definition of a PC by any means !

Remember - the alternative is a piece of screened wire !

Who said he was using a *FILE SERVER* ? What about simply putting a CD into the CD player. Most ppl still do this you know !

The OP merely speculated about wireless links.

How may ppl actually *want* their homes polluted with computers to do simple tasks ? They are big, ugly, unreliable, noisy, quite expensive even now and use lots of power.

Someone has finally got their act together it seems.

Oslo, Norway? Nordic Semiconductor introduces the nRF24Z1, a complete digital wireless audio streamer solution in a 6x6mm package. The device uses the company's 4Mbit/s MegaZtream platform with an embedded Quality of Service (QoS) subsystem, a low power, robust 4Mbit/s wireless 2.4GHz transceiver, and all appropriate digital audio interfaces.

Designed for wireless audio streaming applications, the nRF24Z1 is optimized to operate in the presence of potentially disturbing sources such as WLAN, cordless telephones, and Bluetooth. The RF transceiver portion is designed to ensure that there is bandwidth enough to stream and transmit 16-bit 48Kspls/s CD quality audio without using compression. In addition to streaming audio, the nRF24Z1 also features a digital control information channel for transfer of control information such as volume, balance, track and display information.

Some key audio features include: I2S serial connection for glue less interface to virtually all audio chipsets as well as low cost A/D and D/A for analog audio, S/PDIF interface for direct digital connection to PC and surround receivers, input supports audio up to 24 bit 96Kspl/s directly, output supports audio up to 16 bit 48kspl/s directly, and programmable low 2-18ms link latency

Suited for use in portable as well as stationary equipment, the chipset is specified with 5mA average current (streaming MP3 data @ 192Kbit/s) and 15mA average current (streaming LPCM data @ 1.5Mbit/s). The nRF24Z1 is sampling. Volume production is scheduled for April 2005. The nRF24Z1(TM) is priced at USD $4.00 in 10K quantities

Graham

more than

product

early

mind the

any

the CD

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

tasks ?

of power.

I certainly don't. That's why I use silent/fanless Sun Ray thin clients for a similar application. They can be had for under 50 bucks with careful shopping.

wireless

power,

cordless

that there

without

digital

to

S/PDIF

supports

specified

current

is

quantities

Correct ! That's what the OP wanted. A *simple* standalone method of 'piping' audio to many rooms in a house.

It would indeed want to be quite low cost or the attraction vanishes. I'd venture that a higher price would be acceptable initially before it became mass-market - although that may happen quite quickly now it seems.

Graham

Hey Pooh Bear,

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?

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

:-)

And you realise that the signal *originated* in the analogue domain ? Digital

Analogue has no trouble going way, way beyond 91dB s/n ( A weighted ). In such a trivial application the analogue noise should be around - 110dB ( unweighted ) - that's around

-120dB typically A weighted.

To suggest that any analogue circuit is responsible for the poor noise figure is plain idiotic and shows a basic failure to understand the technology.

seen

I see you can't refute the THD issue. Analogue can easily do 0.001% THD ( and better ) - i.e over ten times better than the Turtle Beach spec *unweighted* ! Possibly 100 times better unweighted but I've never previously seen a manufacturer so desperate as to quote THD with a weighting. It just isn't done ! It's a wholly inappropriate thing to use weighting for.

Graham

FM's rather noisy Mark. Distortion and channel separation aren't exactly great either. Certainly a *big* reduction in quality compared to CD.

Graham

How would _you_ know?

It doesn't hurt to get some exercise you know !

Besides who wants to so nerdy as to run a file server just to listen to music ? You won't get laid that way !

Graham

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

figure is plain

The noise figures are for the analog outputs.

Tim