Hacker News Reader

Comment by rocky1138 | Hacker News Reader

I'm completely ignorant on the need for this technology. Can anyone explain a potential use-case? The website simply states "Home entertainment systems, automotive infotainment systems, and industrial sensor-based systems rely on precisely synchronized components to deliver optimum results."

What are "optimum results?"

View on HN

If you're playing the same audio from multiple sources but slightly out of sync the effect can be pretty unpleasant depending on the delay and how sensitive you are to timing.

My friend was using wireless speakers for his projector. Noticeable lag between the speakers and the mouths on screen. Ended up throwing wires to the speakers to fix it.

Many systems (hell, even my almost ten year old mid-range Sony TV) have options to adjust audio offset. I'm surprised something like a projector or AV Amp wouldn't.

I'm super hopeful this could simply be used in my microwave, stove, car, really anything with a cheap clock in it to sync the time between them to some accurate source, and automatically apply DST.

Most countries have radio signals that transmit the time (including DST). The issue is there has traditionally been no global standard on how it works - each country/region has their own implementation:

https://en.m.wikipedia.org/wiki/Radio_clock

Related: this post [1] from the other week on HN, describing a neat little project to build a low-power radio station which emulates the output of radio station WWVB (a fairly well-known station out of Colorado, which transmits the time signal to large parts of North America).

You could build one of those in case you aren't within range of one of the NIST-operated stations :-)

[1] https://news.ycombinator.com/item?id=13258631

For home entertainment, if you have a wifi speaker in 1 room, another in another room and they're playing the same music, you'd want them to be playing the same part of the song at the same time, otherwise it's like hearing an echo.

Cars have their own network, although afaik their speakers are nowadays still wired. Maybe for a pimped van with 3 rows of seats and 6 seatback-screens (like on a plane), you'd want to be able to sync the video, if indeed there's a use case for that.

I see. Will this make a difference with streaming radio?

Great idea, but I'd say practical applications are limited..

Industrial sensors shouldn't rely on Wifi. Hospitals shouldn't rely on WiFi. In a car just run ethernet alongside power.

Since you can't guarentee wireless maximum latency on WiFi, I still wouldn't use it for multi-channel audio (only multi-room, which NTP is good enough for anyway probably). Especially a problem if you want to sync against Video.

So its a nice idea, but it will probably affect very few people..

The playback buffer size is usually much larger than the wi-fi latency. This should allow multi-channel and video to sync without issues.

That still introduces other issues though. You will probably need larger than 200ms to be safe, which will make the setup annoying for applications such as gaming.

Or it would need great error correction. Either way, wifi equipment needs to accept interference (nothing you can do)

Well, considering Sonos has multi channel and multi room capabilities wirelessly, it can work. That said I have no idea how this spec works vs whatever proprietary magic they've got going on.

Reply on news.ycombinator.com