What are the smallest speakers that are clean and flat down to 20hz?

Physics can be a pesky thing, and the mutually exclusive nature of including "small" and "clean at 20 hz" in this post does seem a little paradoxical. I use 2 RELs in my hifi rig and they're sort of smallish I suppose, as are the drivers in my Silverline Preludes (3.75" woofers)…I have a 92 lb 500 watt Mackie studio specific sub (in my studio specific studio) with 2 12s (active and passive) that supposedly does 19hz…but it's on the large side. So, no free lunch. 20hz…hmmm…large Wilsons maybe?

Is there a small, inexpensive car that goes zero to sixty in under 2.5 seconds? And I also want it to handle like a Porsche and hit a top speed of 250 mph. And have a full size trunk with the ability to drive underwater and get great gas mileage…for under 1200 bucks...

Conversely, what are the largest speakers with little to no bass? Inquiring minds…