I've just tried updating the drivers to the latest version (1.54 rather than 1.41 which is what is supplied with the PC) and this cures some problems but creates other new ones
With the 1.41 set (listed in Device Manager as 5.10.00.5273):
- the mixer intermittently loses the Stereo Mix input and the CD input on the Recording volume control: you can select them but nothing is recorded; line-in and mic still work
- the mike, as heard live through the headphones, only plays through the left channel; however it records on both channels (in mono)
With the 1.54 set (listed in Device Manager as 5.10.00.5345):
- the mixer
always fails to record from Stereo Mix or CD
- the mike plays through both channels and records in stereo (although I only have a mono mike, I've proved this by connecting an external lead and touching first the left then the right pin of the phonos at the far end of the lead!)
In both cases, the mike signal is
very noisy: having recorded noise in CoolEdit, it looks like pink noise - louder at lower frequencies than at high frequencies. With either the internal or an external mike, I'm getting noise at about -24 dB with sound peaking at about -6 dB, so signal-to-noise of only 18 dB. Turning mike boost on and off only affects the overall volume - the ratio of signal to noise stays about the same.
Sadly, Realtek's site only has the 1.54 drivers, both as offered on the web page and by looking behind the scenes on the FTP site, so I can't try other builds between 1.54 and 1.41
Anyone got any suggestions? I bought the laptop partly because it's one of the comparatively few that has a line in socket as well as the normal mike in and line/headphones out, because I'll be using it to record from records, VHS, audio cassette etc from time to time. I wonder if I should have gone for another make such as Toshiba or HP.
Apart from these infuriating sound problems, my Acer is brilliant - and it's got a proper matt screen rather than one of these toy glossy screens which reflect yourself, the room lights and the window panes: I chose that model very carefully for that reason!