Any way to turn the bass up more?

I have a Onkyo HT-S5400. Bass knob on the subwoofer is all the way up. Under setup subwoofer is all the way up, and bass is all the way up. As well as double bass selected.
You can hear the bass but it's not that much. There has to be a way to overhaul the bass. Is there something I'm missing? please help.

ps. This is specifically a problem when listening to music. Then when I switch to tv the bass is wayyyy to high.
Is there something I can do about this?

Hi comma,

Apologies for the late response. I will have our engineering department research this for you and let you know as soon as we have an answer. Thank you for your patience

Hi comma,

When you are increasing the "level calibration" in the menu do you have the master volume set to a low number such as 15 if so then try to increase the maste volume to at least 50 then try increasing the level for the subwoofer.

Id like to have decent bass when listening to music without having the whole system be really loud. Turning up the volume just turns up the volume...not the bass.
When you say "master volume" you're just talking about the volume right? (the main volume knob on the receiver says "mast volume")
There are no settings for master volume in "level calibration"

It sounds to me like you have your receiver in "Direct" mode for that input which would just push the audio to the front two speakers and you would get no bass. Press the music button on your remote til your receiver says "Stereo" then you should get proper bass. At least this is what I did with my receiver to try to mimic your problem and it worked. If you want it to keep this mode every time you will have to change it in the Listening Mode Preset in the setup if that applies to your receiver. I'm just basing this all on my current and previous receiver. Also if you want the sound to fill the whole room, use ProLogic IIx Music mode.

I am never in direct mode...in direct the system barely puts out any sound.
I am having this problem in prologic IIx.
Like I said, the bass works fine for tv/etc...it's just when my ipod is plugged in...

That's odd, definitely sounds like something's broken, sorry I couldn't help.