I’ve spent a few hours off and on over the last few nights running tests on that Bluetooth wireless audio setup and I’ve discovered two problem. Both of which are in the Bluetooth transmitter. The first is that the noise is actually coming from the transmitter. Here are some audio samples. One from my phone’s transmitter and the other from the Bluetooth Transmitter.
The first audio sample is the Bluetooth Transmitter to the Bluetooth Receiver, the second is my phones Bluetooth Transmitter to the Bluetooth Receiver. As you can tell by the sound bites, the cheap Bluetooth Transmitter introduces that bad sounding noise. It turns out that as the batteries discharge on the Bluetooth Transmitter the noise level gets higher and higher. Fully charged the noise is barely audible, but as the battery drains down the noise level continues to climb. There is a small amount of noise introduced by the receiver but not nearly as much as the transmitter.
The noise floor battery issue caught me by surprise. I was having trouble getting good sound the other night and before I went to bed I put the transmitter on its charger. In the morning the problem was gone, but an hour later it started to come back.
The first tests prove the concept, now I’ll just have to spend a little more on a better Bluetooth transmitter and Bluetooth Receiver pair. Hopefully I can find a combination that works better then the first try. When the new set shows up, I’ll let you know how it turns out.
Note: that the audio sample played on my phone was converted to 128 kbps mp3 format and that the number count at the end of the sample was looped 2 extra times to make it a little longer.