All of our Paragon3/Paragon4 models will work with a Rolling Thunder setup right out of the box (HO and N scale). The receivers (the little box that receives the audio from the model and sends it to the sub woofer) are identical regardless of scale, and the difference is in the size of the sub woofers. An N scale model will work with an HO scale set up and vice versa, but the models' audio is mixed and created using the appropriate scaled sub woofer so the quality of the audio will be better (and scaled for your layout) if you use the N scale system with N scale and the HO scale system with HO.