You could absolutely say that the summation of all the frequencies a driver produces is also a soundwave. It would just be irregular and ever changing.

And a driver is far more capable than a single instrument seeing as it could reproduce an entire orchestra, choir and band's worth of sounds all at once. The sound it is producing is a summation of all the sounds it is producing and our experience of listening to it is definitely better described as multiple sounds as your brain can easily pick apart a violin and a drum playing and the same time.

It doesn't matter how many upvotes this gets it is wrong. A single driver absolutely does produce multiple frequencies or sound waves at once. It is just that at any single point in time the sound pressure it is producing is a summation of those frequencies.

EDIT. My first sentence was too harsh.

Generally when discussing sound signature of equipment, resolution is talking about 'ability to resolve' which is very much related to both the level and speed of decay in the treble region. A level high enough to hear clearly and a quick decay so that note don't bleed into each other and are separate and distinct will be described as high resolution.

Or resolution can be used to describe actual audio signal resolution in terms of bitrate and frequency. 24bit, 48khz etc.