[JohnM]

Only problem I have is that the 'line in' on my laptop sound-card has bloody terrible response :thumbsdown: so I'm on the lookout for a quality external sound-card before I get too serious.

Can you post a plot of the soundcard cal? Most built-in soundcards have OK response, if there is something very poor in the response it may be a setup problem somewhere that could be fixed without getting a new card.

 

[JohnM]

You need to untick the "C-weighted SPL meter" box on the mic/meter settings so REW stops applying inverse C weighting.