You don't have to. The charging cable included in GoDuo's package is a splitting cable, which only occupies one USB-A port on your power adapter or computer; and the other side splits to two micro-USB plugs which can charge the two speakers units at the same time.

Yes. We also include an auxiliary cable in the package in case you prefer the AUX mode.

Any Bluetooth enabled devices, such as mobile phones, tablets, computers (both Windows and Mac), game consoles, etc.

Yes, you definitely can connect GoDuo with Echo Dot as external speakers for better music experience. The connection can be setup via Bluetooth or 3.5mm audio (auxiliary) cable.

Although GoDuo speakers are not designed for syncing wirelessly by 4 speakers, you can make it work in either or the following ways. 1. Use audio split (Y-shape) cable. For the split side (two plugs), connect each plug to one speaker of a pair, and leave the other one sync via wireless. Then the four speakers will play music from the same source. 2. If your phone supports Bluetooth 5.0 or up, two sets of speakers can connect to your phone and play music at the same time. For example, for Samsung Galaxy S8 or S8+, enable "Dual audio", then you can connect with two pairs of speakers and play the same music on them simultaneously. In either way, you will have two speaker unit playing stereo music (two playing left channel and two playing right channel).

Yes.

Yes.

Yes, it comes with a dual charging cable that will charge both speakers at the same time.