To the best of my knowledge in a speaker, there is a coil of wire surrounding a magnet.
Is there another magnet surrounding the wire? Surely without an outer magnet, the direction of the magnetic field would not always be towards the centre, so FLHR would tell us the force would not always be up?
A circular magnet is often used on the outside of the coil with machined soft iron ends, like thick washers with an accurately machined pole piece inside the coil. Some times the magnet sits inside a soft iron pot, again at the outer edge the pot is finished of with a thick washer and a pole piece inside the coil is used. This is because it was difficult to do any machining on the very hard magnetic material and just the top and bottom of it was ground flat.The clearance between the pole piece and the inner surface of the coil is in the order of .005 inches.
Frank
The field in the air gap is in fact purely radial, in other words perpendicular to both the coil wire and speaker axis. So you can perfectly apply left hand rule.