Yes Onkyo is less bassy. Thats why its more suited for movies than music. The dialogue delivery in Onkyo was the best in my opinion. Also, the amp delivers power at at 120 wrms (Onkyo) vis-a-vis 50w rms per channel (JBL or HK). So if in future you wish to upgrade your speakers, you are better off in Onkyo.
Onkyo does have a model which has an active subwoofer (i.e. the bass can be controlled). That retails for about 36k. Check that out.
Yamaha again is good for music than movies. So identify your usage first and then go ahead with the audition.