Marc,

<apologies for being off topic>

Some time ago I agreed to give a trade show presentation about Polycom's 
HDVoice codecs (Siren 7, Siren 14) being released under a license making it 
possible to use them with the asterisk open source telephone software.

In the way of dog-fooding the presentation, I tried to deliver it via an 
HDVoice capable BT headset (Plantronics Savvy Go) to a soft phone, relayed over 
a SIP link to the house PA. All on local LAN.

The latency inherent to that path made it completely impractical if I was in 
the same room as the audience. I learned the hard way that local wireless 
should not be an IP-based link. Packetization delay is a killer.

<lurker mode = on>
 
Michael Graves
mgra...@mstvp.com
http://www.mgraves.org
o(713) 861-4005
c(713) 201-1262
sip:mgra...@mjg.onsip.com
skype mjgraves

-----Original Message-----
From: Sursound <sursound-boun...@music.vt.edu> On Behalf Of Marc Lavallée
Sent: Tuesday, May 28, 2019 12:40 PM
To: sursound@music.vt.edu
Subject: Re: [Sursound] wifi audio (was Re: Deconstructing soundbar marketing 
B.S.)

Le 28/05/2019 à 13:20, mgraves mstvp.com a écrit :

> Marc,
>
> I'm well and truly intimate with WebRTC. The trouble with IP-based 
> connectivity is then latency involved with packetization.

Then my hack would not be useful if you need reatime connectivity. For a good 
quality 256Kps Opus stream (24bit, 48Khz), latency was ~130ms with a 2.4Mhz 
wifi connection. Maybe it could be improved.

> DECT and BT links don't suffer this, but they tend to be bandwidth 
> constrained (especially microphone freq response.)
>
> It's surprising that there are very few headsets with full bandwidth 
> microphone. Those that are, like the DPA D:Fine service, are offered for 
> stage/theatrical performance. They assume separate belt-packs for microphone 
> vs monitoring.

The market share is probably too small; most wireless headsets are now being 
used with phones.

Marc

>
> Michael Graves
> mgra...@mstvp.com
> http://www.mgraves.org
> o(713) 861-4005
> c(713) 201-1262
> sip:mgra...@mjg.onsip.com
> skype mjgraves
>
> -----Original Message-----
> From: Sursound <sursound-boun...@music.vt.edu> On Behalf Of Marc 
> Lavallée
> Sent: Tuesday, May 28, 2019 10:37 AM
> To: sursound@music.vt.edu
> Subject: [Sursound] wifi audio (was Re: Deconstructing soundbar 
> marketing B.S.)
>
> Le 28/05/2019 à 10:48, mgraves mstvp.com a écrit :
>
>> Marc,
>>
>> This is very interesting to me. Did you do this using Wi-Fi or some other 
>> wireless scheme?
>>
>> What I've been seeking is a low-cost, low-latency wireless solution for a 
>> headset.
>>
>> We have good, full-bandwidth solutions for wireless microphones. Also for 
>> wireless performance monitors. Nothing that combines these functions.
> Hi Michael.
>
> My hack was not bidirectional (it could be), but I suspect that the WebRTC 
> standard could be used on a phone, a small standalone computer or some of the 
> newest iOT micro-controller with Wifi and full-duplex audio.
> I have no idea how "better" it would be compared to available Bluetooth 
> headsets. And it would not be cheaper... A good start would be to design an 
> Android WebRTC app for your specific use case, and maybe this app already 
> exist.
>
> Marc
>
>> Michael Graves
>> mgra...@mstvp.com
>> http://www.mgraves.org
>> o(713) 861-4005
>> c(713) 201-1262
>> sip:mgra...@mjg.onsip.com
>> skype mjgraves
>>
>> -----Original Message-----
>> From: Sursound <sursound-boun...@music.vt.edu> On Behalf Of Marc 
>> Lavallée
>> Sent: Tuesday, May 28, 2019 7:20 AM
>> To: sursound@music.vt.edu
>> Subject: Re: [Sursound] Deconstructing soundbar marketing B.S.
>>
>> Last year I hacked a "low latency" (~100ms) stereo RTP streaming 
>> software between OSX and a Raspberry Pi. A possible solution would 
>> be, as Bo Erik suggested, to stream 4-channel on a musticast wifi 
>> network, then decode it on 4 RPIs (or similar boards), making sure 
>> they are in sync (using PTP). This is on my long list of things to 
>> try, but I would need  a specific project to kick-start this 
>> exploration. I'm in the process of setting up a 4-channel system in 
>> my home office (using two
>> 2.1 DIY "multimedia" system), so it's a good start. We could wait for the 
>> industry to provide something usable, but it would be proprietary, 
>> "professional", and expensive (because of the super-specific gold-plated 
>> hardware, patents, shareholders, marketing, logos, slick web sites, 
>> religious beliefs, etc). Also (who knows) maybe it's already possible to do 
>> it using the jack2 software suite.
>>
>> Marc
>>
>> Le 28/05/2019 à 07:40, Augustine Leudar a écrit :
>>> Weve tried local wifi networks at shows before but it was a bit 
>>> unreliable for droppouts etc then again so is Bluetooth. FOr home us it 
>>> would be fine.
>>> Four plug sockets  might be a bit more doable than audio cables as well.
>>> Wasn't there someone on here who was doing something DIY with the 
>>> rasberry pie ? Anyway it would nice to bring something commercially viable 
>>> to market.
>>>
>>> On Tue, 28 May 2019 at 09:39, Bo-Erik Sandholm <bosses...@gmail.com> wrote:
>>>
>>>> The Speakers won't be wireless as you probably want them to be powered.
>>>>
>>>> But it should be easy with bluetooth 4.0 or Wi-Fi direct to create 
>>>> a solution.
>>>>
>>>> Normal Wi-Fi could be used.
>>>> The low cost esp8266 makes this possible in a diy setup...
>>>>
>>>> Stream a 4 channel audiostream to the 4 speakers.
>>>> Have a switch on each speaker to select which channel it will playback.
>>>>
>>>> Could possibly be solved by streaming 2 stereo channels on 2 
>>>> different ip ports over WiFi instead. 😎
>>>>
>>>> Bo-Erik
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