All about Propellerhead Reason 4. Reason 4.0 is now out in beta, and we are testing it now. So whats new with Reason 4 that you couldn't get in 2.5 - 3.0 ? Well quite a lot. If god used a synthesizer Thor would be it. This beast of a synth is to large to fit in one screen 1024x786 screen. At first glance it's mind blowing. The Thor polysonic synthesizer features six different oscillator types and four unique filters. Sounds cool right? Properllerhead claims its an unstoppable monster of a sound generator that utilizes synthesizer technology from the last 40 years. Six open filter and oscillator slots let you load up three different synth filters and three separate oscillators simultaneously. Sound cool? Download Propellerhead Reason 4.