Yamaha DTXpress/DTXplorer/DTXtreme

I tried an Express III kit in the store and the headphone output was 
pretty low.   I had it at full volumn and it was just comfortable 
for easy listening.   Occasionally, I might want to crank it up, and 
there was no headroom to do that.   Is this typical for an EXPress 
III module? 

TomBrooklyn