Changes in string tension?

[FLV]

I'm using a 5-string neck-thru bass with a set of 40-125 D'addario nickelwound strings tuned to E standard. The setup is fairly low, although I tend to avoid adding too much fret noise to my sound. All seemed well until yesterday's rehearsal. I actually had to travel in a -10°C cold for about 20-25 minutes to get to the place. I've tuned up and started playing. Suddenly the strings began to feel really stiff and uncomfortable, I was struggling playing some of my lines. Then I went to another rehearsal where I actually tune half a step down and it felt perfect again.

I went back home, tuned back to standard and measured the string height. To my amazement it went from around 2,1mm to 2,6 on the B string (on the other strings the change was similar as well). It couldn't be the bridge since the height over the pickups stayed the same as it was before. I've checked it again this morning and there was no change - the action was still higher.

What might be the problem here? I know the temperature and air humidity might've caused the wood to warp a bit, but the relief doesn't feel significantly different. Should I use thicker strings (the bass is rather heavy)?

P.s. The strings are about 2 months old.

 

[trowaclown]

Sounds like the neck has bent more for a more pronounced forward bow. How are you checking the relief? Remember that the truss rod affects the neck mostly below the 12th fret, and much more heavily from the below the 6th fret.

 

[FLV]

Sounds like the neck has bent more for a more pronounced forward bow. How are you checking the relief? Remember that the truss rod affects the neck mostly below the 12th fret, and much more heavily from the below the 6th fret.

By depressing the 1st and last fret on the B string, then check the amount of relief around the 9th fret. I often use a thin business card as well. Also, I do a similar thing with the G string, and check the relief around the 3rd fret. I might have to do a more thorough measurement later today.

 

[mech]

What might be the problem here?

What you have is normal. Wood (neck) and metal (strings/truss rod) expand and contract with temperature changes and the relief will change as the parts change. Any change in relief will affect string height. The only effect humidity has short term is as a conductor of the temperature.

A .125-.045" set is already pretty heavy for E-C, IMHO.

 

[shawshank72]

This is why in the winter months I leave a bass at our rehearsal spot.

 

[202dy]

String tension remains constant at pitch.

 

[lz4005]

A .125-.045" set is already pretty heavy for E-C, IMHO.

OP is probably mistaken about being in "E standard".

 

[FLV]

Yeah, in this case what I meant is B standard on a 5 string. Ok, I made some neck adjustment and it seems back to the previous state. Now regarding the string gauge - does it make any difference?

 

[mech]

Yeah, in this case what I meant is B standard on a 5 string. Ok, I made some neck adjustment and it seems back to the previous state. Now regarding the string gauge - does it make any difference?

The heaver the string, the more the change will be, IME. I prefer .130-.050 sets but have a few instruments whose necks don't handle them well and use .125-.040 on them.

 

[FLV]

Precisely. I was thinking, since this bass neck is rather heavy, if a thicker gauge string would offer more stability and hence that it'd be less susceptible to temperature and/or humidity changes.