Wireless Audio

[329161]

I wasn't sure where to post this so forgive me if its n the wrong place. My question is- why aren't lossless wireless audio formats such as AirPlay and DLNA supported more, especially in regard to headphones? I know one reason is that most portable media devices support the Bluetooth standard, but it is a compressed format and doesn't sound as good to me as the other formats.

 

[jaddie]

Quote:

I wasn't sure where to post this so forgive me if its n the wrong place. My question is- why aren't lossless wireless audio formats such as AirPlay and DLNA supported more, especially in regard to headphones? I know one reason is that most portable media devices support the Bluetooth standard, but it is a compressed format and doesn't sound as good to me as the other formats.

AirPlay and DLNA both operate within networked devices on a TCP/IP network.  Of the two, AirPlay has the most potential for this, as devices act as dumb destinations controlled from an iTunes source.  DLNA is more of a file-server type system, and would require something with a user interface to look back into it, not likely on headphones.  
 
AirPlay in general is slowly spreading around the market.  It's just now becoming more or less a standard on mid-priced AVRs, for example, and there are a slowly growing number of AirPlay speakers.  There are thousands of Bluetooth devices, by comparison.  We may eventually have AirPlay headphones.  I would look to someone like Parrot to do it first.  Setup would be a bit more complex than just pairing, and there may be power issues to overcome. 

 

[jaddie]

Just to add a bit: one issue with AirPlay is the device must join a wifi network. If the network requires login or password, there has to be a user interface somehow. Not impossible for headphones, just much more complex than simple pairing.

However, there are other wireless technologies like WiSA that would work fine and have enough bandwidth to handle high rare uncompressed files. Google WiSA for info.

 

[DrSheep]

One word: cost.  Bluetooth is an IEEE open standard but AirPlay and DLNA are not.  A better one out there is Kleer for uncompressed RF transmission, but it isn't popular for the same reason.

 

[jaddie]

Yes cost, but licensing is minimal. A bigger issue is that wifi and Bluetooth and built in to most laptops and smart phones, anything else takes an add-on device, which significantly bumps the cost.

 

[329161]

Yes cost, but licensing is minimal. A bigger issue is that wifi and Bluetooth and built in to most laptops and smart phones, anything else takes an add-on device, which significantly bumps the cost.

I can stream Airplay from my Galaxy S3 Android phone using Honey Player. So I think Airplay ,at least, is just a software dependant format which uses existing wifi technology.

 

[329161]

Just to add a bit: one issue with AirPlay is the device must join a wifi network. If the network requires login or password, there has to be a user interface somehow. Not impossible for headphones, just much more complex than simple pairing.

However, there are other wireless technologies like WiSA that would work fine and have enough bandwidth to handle high rare uncompressed files. Google WiSA for info.

You would need some big players ,such as Sony or Apple, get on board for something like WiSA to be a viable option. Soon wireless applications will become increasingly in demand. I hope the audio transmission standard adopted will be a lossless one. Perhaps someone is working to improve the Bluetooth standard as we speak? Hopefully it will be backwards compatible with existing devices (this will probably be necessary for widespread adoption).

 

[jaddie]

I can stream Airplay from my Galaxy S3 Android phone using Honey Player. So I think Airplay ,at least, is just a software dependant format which uses existing wifi technology.

Yes, quite right, it's software, but it depends on a network connection, and that's the hump to get over for it to work in wireless headphones.

 

[jaddie]

You would need some big players ,such as Sony or Apple, get on board for something like WiSA to be a viable option. Soon wireless applications will become increasingly in demand. I hope the audio transmission standard adopted will be a lossless one. Perhaps someone is working to improve the Bluetooth standard as we speak? Hopefully it will be backwards compatible with existing devices (this will probably be necessary for widespread adoption).

Not necessarily, since WiSA exists now as an add-on system all that is needed as proof of concept is a small portable headphone amp with a WiSA chip that would pair with an existing base station, and otherwise be equipment agnostic, except for electrostatic headphones.

 

[329161]

Yes, quite right, it's software, but it depends on a network connection, and that's the hump to get over for it to work in wireless headphones.

It's a bit messy, but I suppose the headphone could be connected to a computer by USB and network connected in a similar way to Airport Express

 

[DrSheep]

Quote:

It's a bit messy, but I suppose the headphone could be connected to a computer by USB and network connected in a similar way to Airport Express

Don't forget that there is actually a wireless USB standard

.

 

[jaddie]

On a possibly more likely note, the Bluetooth A2DP standard used in stereo headphones is a 721Kbps data channel that is already open to several codecs, including Mpeg 2 Layer 3 (mp3) and more interestingly, AAC.  320Kbps AAC is transparent enough to be indistinguishable from uncompressed audio with plenty of overhead left in that 721Kbps.  So the possibility for high quality Bluetooth stereo audio is there already, just a matter of coding, drivers, etc.  Nothing really in the way of it happening, except perhaps market demand.

 

[329161]

I just bought the Sony mdr1RBT Bluetooth headphones and interestingly enough the manual states the supported codecs are "subband codec" and Advanced Audio Codec. It is an A2DP device as well. Also doesn't flac fall within the 721Kbps data rate?

 

[jaddie]

Quote:

I just bought the Sony mdr1RBT Bluetooth headphones and interestingly enough the manual states the supported codecs are "subband codec" and Advanced Audio Codec. It is an A2DP device as well. Also doesn't flac fall within the 721Kbps data rate?

FLAC may help fit audio into the 721Kbps rate, but since its compression ratio ranges from 30 to 50% for music, there are times when it may require nearly all of the bandwidth, which wouldn't be acceptable.  It would seem that to get everything to fit and work well the final rate for the data alone needs to be a consistent margin below the full bandwidth.  FLAC alone probably wouldn't work well all the time.