Stereo Amplification

[KEW]

How is the headphone volume level?
I have not checked this lately, but I do remember doing so some time ago.

Same problem...lack of volume until at least 50.

It is relatively new (w/in 2 yrs) and it has always been this way.

I know part of the problem is the JBL speakers...as they are bookshelf speakers, they do not produce the necessary bass. However, if I move to full range speakers, most are beyond the capability of the amplifier, which means I will have to change the amp anyway.

If you get very little sound out of the headphone jack, that sounds like a pre-amp issue.
Does your CD player have a headphone jack? Is it radically louder?

Try using the radio, just to by-pass the external connections.

If your pioneer has preamp outs and main amp ins, you can try different combinations between them to see where the weak link is.

 

[Tomorrow]

The problem you are describing has little or nothing to do with your AVR amps. The speakers you are using are quite small, don't move a lot of air, and you have a large room to fill. If room-filling sound is what you desire, I don't believe you have any need AT ALL to upgrade from your Onkyo. The Onk is driving the JBL's to their limits already.

However, you do need to upgrade your speakers to something larger and/or more efficient. If you enjoy the JBL sound, S38's would be an absolute minimum size I'd recommend for a room the size of yours. The newer L-series (recently discontinued) can be found at good prices on Harman's Ebay website. These would be perfect for your room if you have the space to accomodate them... http://cgi.ebay.com/JBL-L880-Series-4Way-Dual-6-Floorstanding-Loud-Speaker_W0QQitemZ180440689790QQcmdZViewItemQQptZSpeakers_Subwoofers?hash=item2a031a6c7e