Is it normal for the woofer to move in/out slowly

1. It's not abnormal

2. It's only bad if it drives the woofers to their mechanical limits.

If you really wanted you could hang a scope on your speaker terminals and see what's happening.

1-1.5 volts peak is fine even for tweeters (That's what I get in the power amp connected directly to my main actively tri-amplified system's tweeters and they have over a thousand power cycles on them).

Bokfudo, My speakers does this. I have a tube pre which I turn off after listening, have done this for years with no issues. Back to your question, yes my speakers does this and I don't see it as a problem hence have not investigated. But I will not worry about it.

It sounds like it is OK since the woofers are not driven to their limit and they move slowly. I wish I could leave the tubed pre on all the time but like a light bulb, that would reduce the life of the tubes.

Thanks for the answers!

Here's a question I have concerning this. What would damage the tubes more, surge from turning pre-amp on and off repeatedly or leaving pre-amp on most of the time?

Rja, thats a good question. Have no answer, however, there have been several discussions about if leaving the pre on is better than off. Based on my point of view most don't know the answer and some will offer some elaborate technical reason one way or other, its all pure speculation. Like I said I turn my on and off between listening sessions and have been doing this for years with no negative effect. I have used the same set of 6sn7 tubes over the years.