Not at all, merely an example to show the inappropriateness of the terminology used. If you use "speed" in connection with "sound", quite simply there is no other meaning. There may be words for what Amir wants (I don't know them), but it seems to me that those which he has chosen are not they. You will also note the absence in the original mail to any reference to "the experience of a hifi system..in physical terms". It was couched in basic physical parameters, unrelated to how a hi-fi sounds.