Hey there, I'm really excited about my new Ibanez Sr505. It's my second bass, and I couldn't ask for anything more. The tone is orgasmic and the neck feels perfect to me.

As much as I want to tune down to Db and play some heavier stuff, I feel like it might damage the bass. I don't know why, but I'm scared to drop the tuning. Am I being stupid or does tuning down damage your bass in the long run? I plan on having this for years and years and don't want to do anything that will affect the bass. Thoughts? Thanks.
tuning down shouldn't damage it because you actually put less stress on the bass.
It won't damage it at all, but do you own a capo? Cause you could put that on the second fret and play the lowest 4 strings and have it sort of tuned to Db.
Go ahead and de-tune to your heart's desire. It will not harm your bass at all.
"Maybe this world is another planet's hell?" - Aldous Huxley
well yea its ok to detune...but being an owner of an SR300 SR505 and SR755

i can tell you ibanez factory sets them to standard ( EADG on the 4s and BEADG on the 5 )

and as soon as i get em home and detune em the neck doesnt feel as tight as it does in standard...its ok to do of course but if you want to retain that sweet flattness or tightness you're gonna need a setup at the bridge and even possibly at the truss rod.....

i noticed the difference and didnt care much until i got a pro-paid-for setup it was much better, having the bass setup for specific tunings

good luck!
If you're detuning ALL the strings then over time the effect of less tension on the neck will affect the setup (as in the neck will warp), but its not damaging or permanent, it simply requires truss rod adjustment. If you're only detuning one string you shouldn't have anything to worry about.
what floggger said but in doing so if you tune even from E to D over time it will wear out your saddles. IVe been tuning one bass from E to D for 3 years then suddenly I started breaking my low string a month after new strings. After taking it to a tech he quickly asked if I constantly change tunings he then showed me that I now have a rasp on my saddle. He sanded it down but I will have to replace it soon.