I needed a sub to add to my Dolby Atmos system on my boat, I didn't have a lot of space for it so my options were limited, then I found this sub that fitted nicely where a drawer once was. Meeting the angular and distance requirement for Atmos speakers in a boat's salon is all but impossible, so I wasn't going to spend a lot of money on top of the line ceiling drivers. This sub matched up with my system nicely and at an affordable price. of course there are some expected imaging sacrifices, but I certainly hear a big difference over the old 5.1 system I had before. I was so satisfied that I just ordered another one for my desk computer sound system at home.

Introduction:

The Amazon subwoofer cannot be used in a group setup with multi room audio. You're only able to pair The Amazon sub with one echo, or two echoes for stereo but not a multi room group system.
Using an echodot fourth GEN, running out of the line out on the back of the echo into the sub, you are now able to incorporate a subwoofer into a multi room System. I have my bedroom set up with two echo 4th Gen as the main loudspeaker, the third echo dot as the preamp for this subwoofer. There is no noticeable lag with any of the speakers in this setup.
Physical description of subwoofer:
The sub is thin enough to be slid under Neath most beds. No jacks on the back of the unit so this would work perfectly.
With the cloth grill pointed out at you, on the left side there is your baseport. On the right side the top knob is your volume knob which has click stops. The bottom knob is your crossover. Blow The two knobs, or two sets of stereo RCA jacks. The top set left and right or outputs if you're using the subs Bluetooth. The bottom set are inputs. Below these RCA jacks is your optical jack. Below the optical is your power jack. I do not find any physical switches on the subwoofer itself for on off. Do the crossover is supposed to low pass at 60 HZ, I feel like it's more around 120 HZ, but it's still decent enough to knock out a lot of the highs and really any vocals other than some plosives.
If you listen to rock jazz or country I feel you will be satisfied with the sound of this unit. If you're more into hip-hop or EDM, you may want to look for something a bit bigger which will have more low end to it. For a bedroom I feel this is perfect!

I had to figure out the cords and configuration out with the receiver. But overall I am pleased.

Depending your expectations. I bought 2 of these and threw them under a sectional.
I had a Soundbar tied with my receiver and apparently the little 4 inch sub in a box sounded deeper than both of these subs under the sectional. Even with the low pass frequency properly adjusted, as well turned all the way down to the lowest Hz... I would consider this a budget sub and tucked away in a corner, not in plain view or dead center of the room or dead center of a wall. LFE does work because I use 2 of these subs on 1 LFE channel with an RCA splitter cable. These are what I would call "corner subs" or "anti social subs".
Anti social meaning away from everything but all wall in a corner. lol

I work for a well known car audio manufacturer, but we don't make a small powered sub that would fill my needs in my small home office (converted spare bedroom). I bought the Bestisan 6.5" powered subwoofer knowing that it wasn't going to impress me compared to the large, high wattage subs I am around all day at work, but I wasn't looking for anything to shake the pictures off my walls. I also wasn't worried about taking a risk on a value priced brand that I had never heard of because I have access to a whole department full of Electronic repair specialists. I received the powered subwoofer on Friday and had it hooked up and working in about 10 minutes. I played around with placement in the room and settled on the corner under my table. I faced the subwoofer towards one wall, and the port towards the other, leaving some room for air to move. I am very pleased with the result. The room definitely has a "hot spot" which is almost in the opposite corner, but overall the output and sound quality were impressive considering the size and price of this unit. It does vibrate the pictures hanging on the wall in the opposing rooms, even though that wasn't my intent. I will spend more time playing around with the crossover freq. and the gain, but for now I am very pleased with my purchase. I will update later as to it's durability. Just keep in mind, this is a small subwoofer, with a small amp. It will not last very long if you ask too much of it. If you crank the gain up and play bass heavy music, you will blow the woofer!! Keep your expectations in line with the real world capabilities of this value priced small powered subwoofer, and you should be very happy with your purchase.