[AG-TECH] Bluetooth headsets

[Richard Naylor]

Evening all,

During my recent question about acoustic echo cancellers, someone asked 
about bluetooth headsets. We we just tried it out and they work. We haven't 
got two AGs going yet (later this week early next), so the following is 
results off a simulated test.

A part of our brief is to build a small room based on one projector and one 
PC. We wanted to try the bluetooth headsets to see if they would reduce the 
echo.

We used 2 audio mixers on our floor. One with a 100W amp and BIG speakers 
in the staff room and the other in the tech area. In the staff room we had 
an open mic feeding through to the ear piece of the headsets. The mic of 
the headset was fed back to the staff room speakers. No feedback was 
started (thankfully). We could hear the headset wearer very clearly and she 
could hear us. She could also hear herself with an echo, but then we had NO 
echo canceller at our end.

We used Plantronics M1500 bluetooth headsets which use a 2.5mm plug for 
both mic and earpiece. Now we will add in more headsets (we have 3), but 
don't expect any big issues. The M1500 cost NZ$510 each and have no cables 
just the clip over the ear a mic boom. There is a receiver adaptor that 
takes and delivers audio normally to a phone - in our case to the mixers.

The aim is to make these available to users in the smaller node, with a 
single channel echo canceller to provide echo cancellation at the remote 
end. Staff here didn't seem to mind wandering around with headsets on. Some 
accused us of being in the CIA, but after we played some good music over 
the headsets, they were all converted :-)

The next step is to move it up to a production level as we commission the 
nodes. But the short answer is "they work"

rich