Streaming Hi Res over WiFi experiment
Posted by: PBenny1066 on 27 October 2011
The result was not very good, dropouts every 20 seconds or so, unlistenable.
What I find strange though, is that I copied the HiRes album over Wifi, from the USB stick on the Unitiserve to my NAS, and it took about 30 minutes to copy the album, 1.8 GB.
So the wifi is capable of copying this volume of data in 30 minutes.
The album is 48 minutes long. So why doesn't it play seamlessly over wifi ? There was no other traffic on the network or the wifi when I did the test, so it can't be explained by other network traffic.
Any feedback appreciated, not in any way urgent, my system is working fine, but I seek to better understand how networks really work. Or don't..
Cheers, Paul
You may be able to squirt 1.8Gb of data over your WiFi in 30 minutes but that gives no indication of how consistent the connection is - it could be that your WiFi is experiencing quite wide variations in throughput over time that cause a stream of audio to drop out.
Unfortunately WiFi is not (and cannot) be guaranteed to perform to any kind of level.
Cheers
Phil
Paul
Wi-Fi has a very peaky/bursty data rate (unlike cable ethernet which is more predictable), and so even though your album may have copied at an average of approximately 8Mbit/Sec ((1.8*1024*1024*1024*8/30*60)/1024*1024) = 8.192), it may well have been fluctuating between 1Mb & 20Mb during the 30 minute period.
A 24 bit 96 Khz file must transfer at roughly 4.4 Mbits/sec ((96000*24*2)/1024/1024) in steady state to play with no dropouts, and as you've seen, this is rarely achieved with 802.11g wireless speeds.
If it's any consolation I have exactly the same problem, and am just about to wire an ethernet cable through the house from my server to my Uniti.
Peter
This shouldn't make any difference at all ...
Cheers
Phil
Peter,
Am I right in saying the same is true for Wireless N networks too? The throughput is not much different from Wireless G but the range is better. This is my understanding. Please correct me if I'm wrong?
Regards,
Frank.
All opinions are my own and do not reflect the opinion of any organisations I work for, except where this is stated explicitly.
Reason for the experiment is that we live in rented accommodation, my job requiring us to move continents every 3-4 years. So wiring Ethernet cable is not really an option.
Interestingly, I played around with streaming CD music (WAV) over the wifi and that worked fine.
My next experiment will be to try Powerlines (ethernet over then mains). Will report back.
Cherers, Paul
Peter,
Am I right in saying the same is true for Wireless N networks too? The throughput is not much different from Wireless G but the range is better. This is my understanding. Please correct me if I'm wrong?
Regards,
Frank.
All opinions are my own and do not reflect the opinion of any organisations I work for, except where this is stated explicitly.
It's true for all wireless networks...
Phil
Reason for the experiment is that we live in rented accommodation, my job requiring us to move continents every 3-4 years. So wiring Ethernet cable is not really an option.
Interestingly, I played around with streaming CD music (WAV) over the wifi and that worked fine.
My next experiment will be to try Powerlines (ethernet over then mains). Will report back.
Cherers, Paul
The Ethernet over Mains units can be similarly affected by noise or breakers in your mains wiring. The only way to get a decent consistent data "pipe" is to use wired Ethernet...
Phil
Thanks, but I'll continue experimenting and report back - for many folks (perhaps a sizable minority), running ethernet is not an option. I'll continue with the regular CD quality streaming - so far I haven't encountered any problems, but perhaps time will tell.
The Hi Res stuff very nearly plays, i will next try to improve this by mini sing network traffic - turning off superfluous iPads , ipods etc.
Paul
Also an even more serious issue is that they flood everything with high to very high levels of radio frequency interference. Certainly not good news for sensitive high quality audio equipment.
Having said people with more modest systems have reported some success with it.
Simon
Eh hum... I'm a little uncomfortable to confess that I'm achieving 24/96 playback through WiFi with a Squeezebox Touch and an pretty ordinary 802.11g six years old D-Link router...
And I'm doing nothing special. The router is located into another room where the music files server is too, and I've even set the server to send PCM data to the Touch (this consumes even more bandwidth).
I'm usualy doing Internet browsing with my laptop on my knees while I'm listening music, and this is not causing any trouble to the playback. I tested up to where I could push my luck about it, and only a large data transfer between my laptop and my files server through WiFi achieved to cause small interruptions in the playback here and there (the Touch paused to refill its input buffer).
I agree with Simon about the RFI generated by WiFi near such sensitive audio circuitry is something to avoid if possible... and this is why I'm using an outboard DAC with the Touch (and the best one, the nDAC! 
).
Bye.
Thanks for the replies, seems like Powerline will be no advantage but i think I'll fiddle around with it anyway.
Back to streaming over WiFi, does the US have any sort of buffering ? I've noticed that when playing internet radio there is obviously a buffer, which in my case does an extremely good job. Internet is very flaky where I live in Malaysia but I get v good results even with some 320 k streams.
So, for those who can't or don't want to run cables everywhere, could buffering be a future solution to streaming HiRes over wifi ?
No doubt I've oversimplified things once again and there will be some very good technical reason why this wouldn't work, but I had to ask ! Simon, are you there !........
Cheers, Paul
Wifi has many optimisations and security considerations baked into the standards to support this. PLA is a set on non ratified adhoc agreements and so is less mature. PLA uses wideband radio spectrum on an unofficial level, so is ultra prone to interference and nuisance Ofcom call outs. ( PLA forum say they don't use radio, it's just a byproduct of modulating RF current into a conductor- which is of course how you create radio wave fields!!!) where as wifi uses protected (assigned) radio spectrum and so is a lot more reliable. Given the choice between wifi or PLA, wifi has it ever time in my books.
Simon
Whilst I don't have any hires music to stream I do stream "high quality" tv from BBC iPlayer across my wireless n network with nary a glitch. I would think the forthcoming upgrade to n from g for the Naim streamers should change the game. Even using g I can reliably stream normal cd rips through 2 thick stone walls. I can see why ethernet is optimal but modern wifi can work perfectly well in the right environment. Maybe I'm lucky in having no other house within 400 metres or more. I use a dual band Netgear router.
If you are the only user on your wifi then you are good, if you are sharing it with other users at home then issues with throughput might happen.
Streamed CD is 'only' 1.4Mbps and so should be no real strain for your wifi unless conditions marginal.
Simon
FYI, we have played yesterday evening with a ND5XS, cheap D-link router, no problem to stream 24\96 wav together with other trafic on the wifi: an i book, a PC, an Iphone. 2 hours of music without a single drop.
The new streaming board (802.11 N) is definitively stronger, so N is not only a matter of range...
Speaking of range, we have done another experiment at a dealer's, on its rack the Qute was always loosing the network, we changed for the boosted antenna (on the Qute), all fixed, no more problems. Then we tried a Superuniti with a regular antenna, no problems either...
BTW these 2 units are fantastic.
Here is the simple workaround for getting "wireless" to work in a system where you want to stream hi resolution files.
You use a simple Airport Express and make it apart of the network then take the ethernet out from the AE into your device and voila, you have a wireless connection but it is using a wired connection to the unit. Works a charm as the network is basically extended and you are not streaming wirelessly per se from the router but extending the signal to another spot. If you are using an Apple Airport Extreme at the business end then these two have zero issues talking to one another.
I do exactly as realhifi describes with my Qute. Streams HiRes just fine over the AirPort Express 802.11n now. Too many drop outs on 802.11g to be usable.
Thanks for your post. What you describe is exactly what I have - an Airport Express in wireless bridge mode, which is connected by Ethernet to the US, with Airport Extreme as the base station. And it struggles with the HiRes.
Don't understand your commen that it "is not streaming per se". Signal is going through the airwaves between the base station and the A E unit.
Perhaps I'll try the N frequency for the wifi. But from what I've read, although it is much quicker than "g", it's range may be less, particularly if thick walls are in the way.
Cheers, Paul
Paul,
There is some confusion over 802.11n and range because it can operate on 2.4 and/or 5GHz. 5GHz gives more bandwidth but walls are a problem. 2.4GHz has greater range.
802.11n operating in the 2.4Ghz frequency (which is the most likely case) will provide greater range and bandwidth than 802.11g.
I am using 802.11n through two floors and easily have enough bandwidth to stream HiRes through an Airport Express.
I guess I'll just have to fiddle around to find what works. I'm sure the NAS is up to the job, it's brand new Synology, Hitachi 7200 rpm drives. Perhaps minimizing other network traffic would help.
It's not a huge problem at present but I am trying to plan ahead for the day when my HiRes library is much bigger than it is now.
Cheers, Paul
The wifi access point position is often over looked. You need to make sure it's away from metal surfaces, is at least a few feet of the ground, and has space around. Like all radio equipment make sure there is no bad RFI near by such as un suppressed computer or SMPS. These things will affect the ability of the wifi to work.
Simon
Actually there is a company called Black Fire who has a patent application (WO/2007/087644)
for doing reliable high-res (up to 192 kHz/24 bit) streaming though wifi systems, using their own protocol and software driver for PC and Mac. There is a rumour that few high-end audio manufacturer is their oem partner now.