On Thu, 23 Jun 2016 08:28:04 -0500, Richard Robinson
wrote:
Bob Latham said:
In article ,
Richard Robinson wrote:
Hello. I'm baffled and looking for help.
I've been trying to play audio over my home wifi :- the backend is a
raspbery pi sending audio out via USB into a DAC, the frontend is a
laptop running Debian 8, sending to a pulseaudio "SMC9514 hub digital
stereo (IEC958) on pi@raspberypi" sink (I find pulseaudio deeply obscure
and offputting, but I haven't found much else that offers the
possibility of doing this at all).
Not used a RPi, so can't help much with that at all. BTW, Jim is no
fan of pulse audio - neither am I, so I'm not grumbling - but
pulse audio or not, I suspect the WiFi is the problem, see below.
This connects, to the extent of
getting a noise out of the speakers, but the sound is useless - broken
up, stuttering, as much silence than sound - it gives the impression
that the data's just not being sent fast enough.
What transfer rate do you get if you just copy a file via WiFi from
the laptop to the RPi?
Wifi-wise, the pi is the bottleneck, with 'iwconfig wlan0' giving "Bit
Rate=54 Mb/s" (the rest of the system could go faster).
That sounds like it's telling you the theoretical maximum rate for
802.11g rather than the actual rate being achieved:
802.11b 2.4GHz 11 Mb/s
802.11g 2.4GHz 54 Mb/s
802.11n 2.4GHz 320 Mb/s
But
handwavingly, this is ~5megabytes/sec, CD-quality sound is
~10megabytes/min, so I'd have expected that to be plenty.
5MB/s is approximately equal to 54Mb/s (bytes vs bits), so, even if
you are being told the actual rate being achieved, you could easily be
maxing it out.
So what am I missing ? Is there some deep reason why this won't work, am
I doing something stupid, what's going on ?
I don't think your WiFi can be handling the throughput. You might
wish to investigate the coverage in as scientific a manner as
possible. It is generally accepted that to achieve a stable WiFi
connection, you need a signal-to-noise ratio of around -70dBm or
better. You can get smartphone/tablet apps that measure WiFi signals.
I have used an Android mobile phone app called WiFi Analyser, which I
rate as being pretty good ...
https://play.google.com/store/apps/d....wifi.analyzer
.... while for i* there's this, although I have no experience of it ...
https://itunes.apple.com/gb/app/netw...562315041?mt=8
Use one of these or something similar to check out the WiFi coverage.
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