Do speakers have to "warm-up" too?

Sure, speaker probably do have a warm up time. Many contain capacitors, resistors and inductors that change as signal passes through them.

My Sound-Labs were very slow to warm up in spite the amount of time the electronics had been on. Sound-Labs back plates contain two large transformers, (one EI and one Toroidal). Also, 8 or more resistors (depending on which version you have), a brilliance control, switches for mid and bass EQ and several caps. All these are in the signal path.

No doubt there are other examples of speakers with similar parts, even if much fewer that this example.

As for the voice coil improving or suspension freeing up too? Could be, I would not argue with anyone who says it does.

If you have a hummm in your system the speakers will worm up before you start listening...:-)

Audioholics did an interesting piece on measuring cone movements and frequency responses with and without break in.

http://www.audioholics.com/techtips/audioprinciples/loudspeakers/SpeakerBreakIn.php

Their conclusion: no difference. But, it still comes down to the "objectivists vs. the subjectivists" argument. Your ears and brain are the only important criteria.

It's all in your head.... er, I mean ears.

As you get into the music, it sounds better.

Hpims got it...

It's the ears, inner ear components and most importantly, the synapses that connect our neuronal networks, that "warm up."