When choosing a speaker dock, the following features can be worth looking for. (Note, the results table includes some of these features.)
Auxiliary input line
This is an analogue input that connects a DVD, portable CD, computer or tape player. All the docks tested, except Bose, have an auxiliary input line. Some of the docks also come with a 3.5mm lead, such as the Teac, EDS, JBL and Philips.
To play music outside, or wherever there’s no mains power, the speaker dock needs to be able to run on battery power. The Altec Lansing and Logitech have an internal, rechargeable battery. Two of the other docks tested can run on batteries you supply — the JBL and Philips take AA and D cells respectively. The Philips needs six batteries, which increases its weight considerably.
Recharge while docked
This feature means you can recharge your MP3 player while you play music, so you don’t need to attach it to a PC via a USB cable or buy a separate iPod charging dock.
Special effects abilities
Some of the tested docks have special features, such as a stereo field enhancer on the Altec Lansing, stereo widening effect on the Logitech or bass booster on the Philips.
This is important if you want to take the speaker dock with you on holidays, to picnics or the like. The smaller and lighter the dock, the higher the portability. Carry handles are useful too.
We consider four of the tested docks to be highly portable: the Altec Lansing, Logitech, Cyruslink and JBL.
Well-spaced keys and clear and intuitive labelling make a speaker dock easier to use. All the tested models have one.