You mentioned resolution and imaging. Other variables being constant, a small speaker will image better than a larger one for a variety of reasons based in physics. One reason, for example, is that the smaller speaker will have its drivers closer together. This will give better coherence as the sound radiates from a point that more closely resembles a single point. As a result, the monitor is a little more forgiving in placement than a larger speaker on this point alone. It's small size makes it even more easy to place. Your big speaker may image fine too; however, it may be better if it's moved a bit and you may not have the room for it. Another factor is the potential bass overloading of the room as the posters above have mentioned. If bass isn't controlled, then it will mask other frequencies and you will lose the resolution that you like.
So is your speaker too big? It may or may not be. If the bass is controlled, and if the speaker can be placed properly for imaging, then it's not too big. Otherwise it is toon big. But even despite that, you would get better imaging from a good monitor, but you give up lower octave bass as a trade-off. If so, then add a sub.
So is your speaker too big? It may or may not be. If the bass is controlled, and if the speaker can be placed properly for imaging, then it's not too big. Otherwise it is toon big. But even despite that, you would get better imaging from a good monitor, but you give up lower octave bass as a trade-off. If so, then add a sub.