First, the sound is OK. Sure, there are better speakers out there, but for the price, these speakers can be beat. I would have giving it a four start, but the installation can be a hassle.
Installation could be an issue though. The six mounting brackets on the back of the speakers are designed to rotate and lock in place when the screws on the front side of the speakers are screwed into the brackets. There's also a piece of plastic glued on top of each mounting bracket to prevent it from falling off while one try tightening the screws. This would work perfectly if the ceiling has 1/2-inch sheetrock. However, our ceiling is constructed using 5/8-inch sheetrock. As you installed the speaker through the cut-out hole, there's no way to rotate the mounting brackets over the sheetrock.
My first solution was to first remove the piece of plastic that supposed to prevent the mounting bracket from falling off during installation; removing them provided more clearance for the mounting bracket. I then used longer screws to provide more travel for the mounting bracket so they could rotate over the sheetrock and lock in place. This work to some degree, but the mounting brackets sat on an angle and didn't support the speaker solidly.
My second solution, and one that really worked great, was to create a wooden frame for the speaker and then screw the speakers directly to the wood frame. However, be warned, this required to cut the plastic mounting bracket to ensure an even-solid support...but I'm sure it will void the warranty as well. Nevertheless, I made the frame from 5/8-inch piece of wood, inserted the frame inside the attic over the sheetrock and using long wood screws, I screwed the speakers through the sheetrock and into the wood frame.
This worked perfectly...no vibration and a really solid installation. Also, at least in my case, measuring the length of the wire needed to hook the speaker to the receiver and hooking the wires to the speakers before mounting the speaker saved time, especially in a low ceiling.
Another issue one most pay attention to is the template, which is provided with the speaker. It's way too big and cannot be used as is. If you use the template without first verifying the dimensions of the speakers, you'll end up with an opening that is almost as big as the outer edges of the speakers. Instead of using the template, I measured the speakers and figured a good size cut-out hole to be 14" L X 6.5" W. These dimension worked well, but you can actually cut the opening to 13.75" L x 6.25" W and it'll work much better. (Remember, it's better to fix a hole that is too small, than one that is too big)
Now, concerning the sound; these speakers can deliver some power, but the sound is kind of flat. However, I doubt that it has anything to do with the speakers, but more with the lack of an enclosure. My next project will be to build an enclosure, which should enhance not just the bass, but the overall sound quality.