[asterisk-users] MagicJack quality

[Steve Underwood]

Kevin P. Fleming wrote:
> Steve Underwood wrote:
>
>   
>> You might think a standard phone plugged into an adaptor, like a 
>> Magic-jack, would be limited to narrow band voice, as that is all the 
>> phone was designed for. It turns out most phones only aggressively 
>> filter at the low end of the band. They let a lot of energy above 4kHz 
>> through, and they do generally sound better through a wideband codec.
>>     
>
> I found it quite interesting the first time I used a Polycom IP650 (the
> first wideband capable hardphone to arrive at Digium) that the voice
> quality was much improved even using G.711! Presumably this is due to
> using higher quality speakers, mics and other audio bits required to
> provide wideband audio quality, but it would appear from this
> (exhaustive) sample set that in fact many phones (even from high end
> manufacturers) don't even provide the maximum audio quality achievable
> with G.711.
>   
That is certainly true. Many of the comments people make about codecs 
owe more to the phone than the codec. However, there are various types 
of impairment. Even a phone which doesn't sound nearly as good as it 
could in G.711 mode may still sound much better in wideband mode.

A typical $200 business desk phone costs more than a typical mini-Hi Fi 
set that has a lot more complex bits in it, and sounds fantastic by 
comparison. Basically  business desk phones are a swindle.

Steve