The 'R' of RPlusD stands for 'Response', and this part of the utility is designed to emulate various DSP hardware EQ units, such as Behringer's DSP1124P, with the aim of helping you set them up to flatten your room response. It does this by identifying response peaks and then performing some clever calculations to generate a set of parametric filter curves, for frequency, Q and level, that should flatten the peaks. These can then be fed into your equaliser. Unfortunately, equalising the direct signal instead of installing suitable acoustic treatment is rarely a good idea in the studio, as it causes both direct and reflected sounds to end up with skewed frequency responses. However, I take author Doug's point that hi-fi and home-theatre users, who may find that extensive bass trapping isn't practical in their listening environment for aesthetic reasons, can achieve cost-effective improvements by carefully positioning their loudspeakers and using a little corrective EQ.