Wireless Personal Monitor with Smartphone

[Bubby4j]

I work in my church's sound booth, for the youth band.

I was thinking, "It's too bad we don't have wireless personal monitors! They're so expensive!". But then I realized, what is a smartphone but a computer which has a audio output for headphones and can connect to multiple MP3 TCP/IP streams over WiFi?

They seem to me like they'd be the perfect wireless monitor! Already paid for! The only thing you'd need is some kind of device (computer?) which has a bunch of audio inputs that can broadcast them over wifi in multiple MP3 streams. Each person could customize their mix with an app on their phone. You could even have the computer do the heavy lifting combining all the streams, just have the phone tell the computer what it wants in their mix.

Seems like this could be fairly cheaply done, is there already something like this? I've tried googling but haven't been able to find much about it.

256kbps MP3 steam * 6 band members = 1.5mbps total bandwidth. Easily achievable by any good wireless router.

Sure, there'd be latency, but it wouldn't really be that much. 20ms?

 

[FMEng]

Any web stream has far too much latency for use in monitoring. MP3, or any similar codec, has a lot more latency that 20 mS. Even if you could get it down that far, it would be too much. Monitor systems have to be well down into the single digits of mS latency due to comb filtering with the sound from bone conduction in the listener's head.

 

[Bubby4j]

Well that's too bad :/

 

[Stookeybrd]

As brought up before, anything above 5-6mS is noticeable to a singer and even an experienced drummer.

The real problem is that TCP/IP is that it's not real time, not even close. The sender sends a packet and then waits for the recipient to say "I've got packet 1 of 1000", before it sends the second packet. This allows for 100% successful data transmission because if there is ever an issue it just resends the packet until the recipient acknowledges it. The only way to transmit real time over IP infrastructure is with UDP which just streams the data without waiting for a response and with no compensation of collisions or processing lag. Also, UDP is socially known as Unreliable Data Packets. It simply would not work with commercial devices.

 

[Focus]

If price is an issue, you can do wired IEM's in place of or in addition to, monitors. Decent ears can make a huge difference.

 

[TimmyP1955]

For those who don't need to be wireless, there's this: http://www.rockonaudio.com/?page=PKG-001, this: http://pro-audio.musiciansfriend.co...wired-Bodypack-for-PSM-400-Systems?sku=243606, and this http://www.peavey.com/products/acce...093/number/03001320/HB2HeadPhoneAmplifier.cfm (although the limiter is a bit too accessible for my taste).