Thoughts on the most difficult instruments for speakers to reproduce?

If using your speakers for home theater, which sports a wide dynamic range with Blu-ray’s and UHD’s, there are some interesting sonic categories that, while not falling under acoustic instruments as such can be a challenging effort for speakers to reproduce, and also reflect on their abilities into music reproduction. Take for example a ships horn from a warship or commercial ditto, like from the Blu-ray to the film “Captain Phillips” (2013) where towards the end there’re some serious bursts from such a horn flaring off on a warship. If the speakers are up to the task here you’ll experience a startlingly forceful, dry, dense and present sound, demanding dynamic prowess, ample air displacement area and very little smear (i.e.: transient “snap”), but also calls for a high degree of coherency. These are important traits reproducing instruments like (concert) piano, solo violin, drum kits and saxophone, and so is a telling ability on your speakers performance over an even wider arc, I find. A banal example on the face of it, perhaps, but I’ve found it to be quite useful; watching films from such high quality formats over your stereo brings along a new set of tools to evaluate your speakers worth in many regards, some of which may not be readily exposed with music only.