I have had it for 3 days, I put it in the trunk to sit down and it hits quite well. I have changed my 4 speakers and added an amplifier, I raised the gain of the amplifier and still the bass is a little above the volume of the speakers (I have the gain around 70-75% and the crossover around 100hz). A big plus is that it is quite heavy and durable. I will also try a test under the seat and one glued to the back of the rear seats and I will get back to you.

It is much better and more powerful than I expected. If they don't tell you, you won't understand that it's not a huge box in the trunk. I have taken sound from hi level, meaning from the speakers. (Due to factory multimedia) It captures the bass at very low frequencies and the control it has is impeccable. I have placed it under the passenger seat and when no one is sitting behind, I pull it to the back floor mat. It is very heavy and doesn't move anywhere. You can even jump on it. I highly recommend it!!! A friend who has a subwoofer box in the trunk on vacation is crying because he has to remove it due to space...

Good value for money, I bought it for 186 € on sale, but all the blades that hold it broke, resulting in it not working properly because it needs to be properly supported on the chassis.