Do speaker cables need a burn in period?

Cables - no break in
Tubes - once warm, no burn/break in; they just degrade over time from day one and sound best when new. "Burn in" for a day or so is best used to determine that the tube is stable and not about to fail.
Speakers - yes; they are motors and some of the materials that flex need to break covalent bonds to perform optimally
Cartridges - same as for speakers
Turntables - yes, motor/platter bearings need to wear the metal surfaces over time to reduce micro-machined irregularities
Electronics (DACs, preamps, amps, CD players) - no, (except for the CD motors, sled and rotational) but the electronics do need warm up to function optimally.
People ear/brain system - yes, the biggest single audio component that is the most variable of the recorded/playback/listening experience. More "brain burn in" is always a good thing. No wonder many sip the etoh or smoke/vape the herb while listening.

Steve. There are wires in all the devices you stated. You might want to consider that  part of the break  you are hearing is in the wires! 

More "brain burn in" is always a good thing. No wonder many sip the etoh or smoke/vape the herb while listening.

Looks like someone still behind the time.  This has been talked over again and again.  Manufacturers have lots of components that they can compare side by side, some old some brand new, so there is no need to resort to "brain burn in" argument.

taras22,

Thanks for the invite.  I might be at the Toronto show (hope to go).

No worries, I'm not a leafs fan (not a hockey fan - I'm a bad Canadian that way).   Oh, and I don't take any of these discussions seriously in terms of personalities or holding any animosity at all.  Nothing on an audio discussion forum is worth that. 

Cheers!

blueranger,

Do any of the nasayers believe in equipment break in? Tube break in? Speaker break in?

To be clear: I'm not a "naysayer" in the sense I claim cable burn in doesn't happen.  I've just found the arguments I encounter FOR it aren't very convincing.  As well,  I've never heard any equipment I've ever bought, cables or otherwise, "burn in."  Doesn't mean it doesn't happen.

As for burn-in of tubes:  I don't know.  (I actually have a brand new pair of tubes I'm going to be putting in my CJ pre-amp.  Unfortunately, even in as a casual test of burned in vs non-burned in tubes, it wouldn't work in my situation.  The reason I'm replacing my tubes in the first place is that the old ones have become more noisy, hiss coming through my speakers, so there ought to be an obvious change when I put in the new ones. I hope there is!)

Burn in of speakers:  Much more plausible than what's been offered for cables.   But there seems very, very little hard data on the subject.  And analysis by the people who have tried measuring speaker burn in - e.g. drivers burning in - generally seem to point out if it happens the audible results would tend to be very subtle, and that any likely audible difference in break in happens fairly quickly, vs the hundreds of hours one often hears about in high end audio.