B flat tight or loose strings?

My question is about The B flat note. When tuning B flat, I can do it with string tight and loose, but I realized it sounds different. So my problem, Should I leave the string tight or loose in B flat?

Tuning B flat is a matter of tuning down your B string by half a step, assuming you have a 5 string bass.
If not, tuning down an E to B-flat is an option, but the string gets too loose in that case.

Never, and I mean never, tune your strings up (i.e. never tighten them) because this adds a lot of tension to the neck and could damage it.

The reason it sounds different is because you are probably going up or down an octave. The point of a B-flat tuning is to get deeper notes, so you should tune down (i.e. loosen it). If it's a 5 string bass and you tightened it, then get it loose right away, because you just went up almost a whole octave! I'm surprised the string didn't snap!

Do you have a 4-string bass or a 5-string bass? If 5-string, and you're tuning the thickest string to B-flat, then definitely have it loose as opposed to tight. Damage to neck and stuff, as Stryfer said.

If you have a 4-string, and you're tuning the second-thickest string, you have two (main) options - either tune the string to A, or if you want it to be Bb, use a lighter gauge string. Look for .75 or perhaps .80.

If you have a 4-string, and you're tuning the thickest string, I wouldn't recommend tuning it to B-flat. If it's tight, it's too tight, and if it's loose, it's too loose. You can get the bass set up so that the lowest string is B-flat, then E-flat then A-flat then D-flat, but I wouldn't recommend that unless you're in a metal band or something.

Thank you, you both! I appreciate your help! I have a 4 string bass and the string I'm tuning is thickest one. But the problem is that the string hits the neck when playing it.

Yeah, don't tune that one to B-flat. That one, provided it's a .100 or .105 gauge and is in standard tuning, is tuned to E. It should be fairly tight, but not too tight.

If you would like it tuned to B-flat, take it to a professional and ask him to set up your bass for B-flat standard tuning. I would recommend (from thickest to thinnest) the gauges .130, .105, .85 and .65.

What I wouldn't recommend is actually doing it at all - if this is your only bass, it's far better to have it set up for E standard tuning. If you need the B-flat tuning, then I'd recommend getting a 5-string bass.

Exactly as Pip said, if it's not a 5 string bass, don't tune it to B-flat.
The lowest reasonable tuning you can go to is drop C.

Since B-flat is rarely used, and modifying a 4 string for it probably isn't cheap, I'd suggest you get a cheap 5 string bass for that. 200 euros will net you a solid 5-string and they're painless when downtuning to B-flat or even A-standard (ala Fieldy from Korn)

Once again thank you so much!