In some explanations to the formulae of the doppler effect, and also in answers to certain questions, the approach taken is to look at the observed velocity. In such approaches, the observed velocity is treated as being different to the actual wave velocity. However, in a real situation, the conclusion that I have come to after hours of thought is that frequency (hence period) and wavelength are the only variables which change. However, the observed wave velocity should equal the actual wave velocity.
So, am I right in coming to that conclusion?
Any help is appreciated :)