Double Bass Weak A string but strong rest of strings?

[Calvin Marks]

So I've tried a variety of strings and tunings and all of the notes on my bass sound good except the second string (A string) and any note I play on it - it is audible muffled and quieter than all the other strings. It's not an issue of the A string itself since I changed from E A D G tuning to ADGC and the D string then become the problem. Is it an issue with the bass bar or sound post?

 

[dperrott]

Often the sound post. Problems show up on the A string with a tight post

 

[KUNGfuSHERIFF]

Yep, soundpost.

 

[Calvin Marks]

Thx! Will take her in to get checked.