Like you, I recently received a new free VoIP BT digital phone with Alexa built-in, as part of an upgraded broadband package. I’m an electronics design engineer, I had high hopes for the new new digital phone. However, like you I was very disappointed. In theory the new VoIP should and probably does significantly increase the audio bandwidth, so from that point of view, the quality should be very much better.
I had successfully plugged our original old BT analogue phone into the back of the router and saw some improvement in the sound quality of incoming and out going speech. However, the analogue phone was designed to work with the old limited bandwidth, so I guess the phone may well have some built-in sound bandwidth filtering. This would potentially cutoff the bottom and top frequencies, so would effect the quality.
The new BT digital phone looks good, the screen and buttons are clear, so I thought it would be great. Unfortunately it was not. My wife said it was rubbish, I didn’t believe her straight away. Then I had a listen. The speech sounds are very distorted. In my technical opinion, the problem with the new BT digital phone is probably the shape and size of the sound cavity where the speaker is located. The result, resonances or reverberation occurs where the speech sounds bounce around inside this cavity. This causes the sound to be distorted and garbled. The louder the volume, the worst, the reverberation.
I almost bought a second BT digital phone, before the first free one arrived. I’m so glad I didn’t. It definitely doesn’t sound like HD quality device, in fact the sound quality is so poor with the one BT digital phone I have received, we have decided not to use it and instead rely upon the original BT analogue phone plugged into the back of the router.
Note to BT. In my opinion, it is an affront to claim HD sound quality in respect of this new BT digital phone, you should be ashamed of yourself. I’m very tempted to make a formal complaint to the advertising standards authority. You should consider withdrawing this phone from the market or fix it.
