I bought it from same the place than others. Link is in the first or second page, if I remember right. I don't recommend to buy that 9" China radio from that seller.Antii do you have the link to this exact one a lot of people say it doesn’t work with Boston audio I can see that you have Boston audio
But the problem is the original amplifier. It is taking only two speaker wires, not four. So the balance works by them. And the fader is made by CAN-bus. That is the problem in amplified models, not basic four on six speaker models. China radios or some other aftermarket radios don't have CAN controlled fader to handle Boston amplifiers. They have four speaker wires, not two speaker wires + CAN controlled fader.
There is some modules, which should give fader control back. I tried one, but it did not work fine with my 9" China radio. That 9" Android radio has many good features like Youtube, but Mygig 730n has found again in to my car: Bluetooth is better in 730n, screen won't reflect sun, VES to rear works, fader works, etc.
If you have a car without any amplifier and basic radio, aftermaket radio might be better. Connector behind the radio shows how many speaker wires are connected. Two tells that it has CAN controlled fader. Four speaker wires are better for these aftermarket radios.
The amplifier receives fused battery current from a fuse in the rear Power Distribution Center (PDC) at all times. The internal circuitry of the amplifier switches the amplifier ON based upon a CAN bus message that is received from the radio receiver whenever the radio is turned on. The amplifier receives the sound signal inputs from the left and right rear outputs of the radio, then sends the amplified speaker outputs for each of those channels to the speakers."