Because the waveforms have the same frequency and differ only in shape. If you used an oscilloscope to test it should be enough. but, for example, checking with headphones may be worse for an untrained ear (read strongly depends on subjective perception). On the other hand, the waveforms with the frequencies as given above sound in the hearing organ at a frequency of 0.5Hz, which ensures the existence of two separate channels (less depends on the subjective reception).
Please. A computer as a generator. 105Hz, sine in one channel, triangle in the other. I don't know how you can not hear the difference between these waveforms, I hear clearly. The signal was transmitted using a stereo BT transmitter with a built-in battery. You already know the receiver.
I have not yet encountered headphones that would introduce a delay (at least noticeable by a human, because there must be some). This receiver also does not show any deviations from the norm. The problem of delays, with all headphones and transmitters, appears when, while watching a movie or, for example, playing on a computer, we cover the receiver's antenna with our hands, or turn our head in such a way that we lose range for a moment. If at this point we lose any data packet, the effect of "diverging" the sound with the picture will appear. If this happens, simply stop broadcasting for a few seconds and then resume it. Very often you can hear a soft click / crack or something similar in the headphones, indicating that the transmission is over. When we hear this sound, we can click "play" again and the sound will be synchronized with the video again.
While listening to music, this phenomenon does not bother us at all, if we add an image to the sound, and we have a poor range and lose it every time we turn our head, it can actually be tiring. The problem may also arise when the receiver is too close to the transmitter, because colloquially speaking, the signal may have "too small angle" to hit the receiver. Google how 2.4GHz waves spread and you will understand what I mean.
And you could provide a link to a specific offer on Ali or under what keywords exactly you were looking for this module, because for now the headphones themselves pop up or those large modules to which you still need to solder buttons and LEDs.
And you could provide a link to a specific offer on Ali or exactly what keywords you were looking for this module
I just entered Ali's search engine ... "TZT 1 pcs Bluetooth headset" and found it for $ 4, but if you try, you will probably find under $ 3.
Was there any BT4.0 in the modules you tested?
I'm pretty sure it is, but I don't remember whether it's the receiver or the transmitter. However, if my memory serves me correctly, it was a module designed to be "soldered" to the proper PCB (containing uC) "for a sandwich", but I will not give my head. I'd have to search my resources.
I understand what's going on, nevertheless most of the BT speakers I had, despite being 1m from the laptop, the delay was still large enough that it was impossible to watch the movie, with a light hand of 300ms
I admit that I was more interested in these 2 receivers after a cursory reading of their specifications, so I will wait for their reviews. On the other hand, in what I found, it is probably impossible to change the onerous voice greeting.
I would like to ask about the noise. I have a mono Bluetooth headset, one for driving. It is silent. Do not listen to noise or squeaking. I tested a lot of stereo headphones and there this problem appeared. After pairing with the device, an unmerciful hum or squeal was heard. Same when playing softly. As you know, it is bothersome, did you also hear the hum here?