“Previously, I had mentioned the Xcelsus XXM325 was my new favourite small-format midrange, besting the widely-heralded Scan Revelator 12M in both realism and dynamic output, among other things. Now we have been beta testing the new XXM4 for over a month now and this driver takes the performance of the 325 up to several more notches! I have tried the XXM4 with the magnesium cone as well as the new carbon fibre cone, and I can 100% say without a doubt this is the best small midrange I have ever heard. The frequency extension is stunning for a “non-wideband” driver. The dynamic output is delivered lightning-fast, which is a byproduct of the spiderless design reducing Mms. The tonality of the drivers is so natural and clearly delivered in such an effortless fashion, I find myself in disbelief that this is merely a 4″ driver. The spatial character of the drivers is good, tonality and frequency response is excellent, dynamics and resolution are outstanding. I simply cannot imagine another small-format driver could possibly deliver better performance in a car system. Xcelsus has once again achieved what I thought was impossible, and I cannot wait for the larger spiderless drivers to become available.