I RECOMMEND THIS PURCHASE. Everything is OK, the only thing that is really useful from the third channel is the USB port, the aux line and bluetooth on the third channel are very problematic and completely useless because the stand by function turns on too quickly when there is no sound signal, otherwise on the USB port that is on the third channel and there are no such problems on the first two channels, the sound of the sound system is good enough for the money and it is also sonically strong enough for what it is intended for, in the third channel they must extend this interval to a minimum of at least 15 seconds, I really have no other comments, however the product is very nicely made and worth every euro, I plan to buy this product again in the near future, I just hope that the manufacturer will fix this shortcoming regarding the stand by function as soon as possible.