Can tube rolling change bass?

Usually the tube rolling can change the sound signature slightly. So the difference is not bigger.

Yes, it can.

I might add that a change in speaker cable can assist in adding incremental bass as well. As mentioned earlier I noticed an increase in bass. Let me add that the bass was tighter and somewhat deeper. It was NOT and increase that
created a totally new sound it just enhanced. I may have mislead some by a less descript measure of improvement.
My answer was directed at your question and the simplest answer is, yes. The amount and degree will depned on your total system and in some cases the answer could be NO.
FME, it helped.

I am using low z have not tried the hi z. I thought it was for tube amps. The builder of these speakers suggested putting more poly inside the speakers for more bass response, anybody tried this? also the speakers are 3 way speakers but are on the large monitor size being 23.5 tall and 9.5 wide and 11 deep. I only have them about 9in off ground at this time on some inexpensive stands, but plan on getting better stands and raising them 24in off ground. I don't think the speaker have but about 80 hrs on them and recommended breakin is 100. So we will see, they are sounding better all the time though. thank you gentlemen for all your info. Scott