I was delighted to find a well specified P.A. System at a very good price compared to other suppliers. The order was delivered very quickly within a couple of days. It was very well packed. It arrived with a fully charged battery so I t worked straight out o f the box. Running on the battery, it is very low noise with no hum! Having two wireless Mikes makes it extremely flexible. I haven't tried the sub or Bluetooth facilities yet. I don't think it is intended for use connected to the mains as there is a noticeable hum so remember to charge the battery. I would thoroughly recommend both the P.A. and Astounded!