Look in Reaper, File, Project Settings, Advanced Tab, and select the -6.0 dB Stereo pan or -6 dB Mono pan, either one without the Gain compensation, and you will have the equal power pan.
Right clicking individual pan controls in the channels will bring up a selection dialog as well for overriding the default pan.
Other curves are possible within Reaper and some curves produce a result or effect when actively panned that may be desirable in some circumstances.
Meanwhile, I changed my default to -3 dB gain compensated. This is what I was used to hear during the years I used Sony Vegas as my main daw. Signals keep a more consistent volume while they get panned across the stereo sound stage. Incontrast, they seem to loose volume when panned hard left/right using Reaper's default pan law 0 dB.
I definitely prefer a mode where pan-centered sources play at their original level, thus I need to check the gain compensation option.
Everyone can find his prefect preference in Reaper :-)
Linear Mode
