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Janak Parekh
02-19-2003, 08:28 PM
<div class='os_post_top_link'><a href='http://www.impulsesoft.com/' target='_blank'>http://www.impulsesoft.com/</a><br /><br /></div>One of the big problems of Bluetooth 1.1 for audio listening is that it only supports up to about 720kbps, or about 90kBps. This is not enough to transmit uncompressed stereo 44KHz 16-bit PCM audio, which requires 162kBps of bandwidth. However, this company is developing a reference platform that will natively support compressed audio in the headphone design itself, and will do the decoding there. It seems that this is built on a special profile, called "Advanced Audio Distribution Profile (A2DP)". Let's hope this technology hits the PDA markets... or that Bluetooth 2 hits soon -- wireless stereo listening is the way of the future.

van_mierlo
02-19-2003, 08:51 PM
Interesting....I just looked at this company yesterday :wink:

Joff
02-19-2003, 09:33 PM
I like the idea but it also means that you have an additional battery-powered accessory.

And guys, I don't feel confortable with having a microwave device right next to my brain. The ears and now the brain ... :? It hearts

Janak Parekh
02-19-2003, 09:59 PM
Joff, do you not have a cell phone? ;)

--janak

R K
02-19-2003, 10:56 PM
One of the big problems of Bluetooth 1.1 for audio listening is that it only supports up to about 720kbps, or about 90kBps. This is not enough to transmit uncompressed stereo 44KHz 16-bit PCM audio, which requires 162kBps of bandwidth.

Actually, Bluetooth gives about 270Kbps for dedicated voice and audio usage in the current Bluetooth audio profiles. This is why we're only getting about 720Kbps for data and not the full 1Mbps.

Janak Parekh
02-19-2003, 11:29 PM
Actually, Bluetooth gives about 270Kbps for dedicated voice and audio usage in the current Bluetooth audio profiles. This is why we're only getting about 720Kbps for data and not the full 1Mbps.
Hmm, do you have a link to this? I'd love to read more on it. In any case, you'd need more than 1mbps -- you need 162*8 or 1.3mbps to handle a full uncompressed raw audio stream.

--janak

Warwick
02-20-2003, 01:11 PM
I thought the 270kbps was for error correction.

I would be happy with the reduced quality to get rid of the wires, 90kBps sound I would be happy with.

Joff
02-20-2003, 09:01 PM
Joff, do you not have a cell phone? ;)

--janak

As a matter of fact, I don't :roll: (I must be the only one).
I am still waiting for data access prices to go down and data transfer speeds to go up. Will I leave long enough to see this happen :wink:

My point was I listen to music over long period of times. You normally don't spend this much time with your mobile phone. So the exposure to microwave radiation is significantly increased. But it has to be proved yet that this has some 'perverse' effects on the body.

Actually, Bluetooth gives about 270Kbps for dedicated voice and audio usage in the current Bluetooth audio profiles. This is why we're only getting about 720Kbps for data and not the full 1Mbps

Nop, maximum throughtput of BT is 720kbps once you have stripped down all the error potections used during transmission as pointed by Warwick 8O

tddisc
03-05-2003, 09:58 PM
Has anyone seen or read more about the OpenBrain or Kenwood bluetooth headphones? Both are listed at http://www.ipaqabilities.com/info/ipaqdirectory/wireless/bluetooth/headphones.shtml

OpenBrain does provide for a faxed order with funds transfered to a South Korean bank for about $250. It almost appears like a demo order form for someone interested in distributing it, but I'm guessing.

td