You'll also notice the back panel has speaker jacks for surround speakers and a center channel. Although the HTX-22HDX ships as a 2.1 system, it's possible to purchase the Onkyo SKS-22X speaker add-on package to make it a full 5.1 system.
Since our HTX-22HDX review sample was the plain 2.1 channel version, we initially thought it wouldn't require any setup or speaker calibration adjustments.
As we listened we felt the subwoofer volume was too low, so we turned up the sub with a few taps on the remote's Ch Sel button. As we continued listening we also noted movie dialogue was a bit hard to follow. Since there's no center channel volume adjustment possible in a 2.1 channel system, Onkyo offers a Center Image adjustment in the HTX-22HDX's onscreen setup menu. The Center Image control attenuates the right and left channels' volume to effectively raise the center channel volume. It improved dialogue intelligibility to the point where it was about average for a stereo or sound-bar system.
The setup menu also has a couple of potentially useful features like a user-adjustable Max Volume setting, and Power On Volume, with which you can predetermine the HTX-22HDX's initial sound volume.
We started our HTX-22HDX auditions with Ben Affleck's heist movie, "The Town." Set in Boston's Charlestown neighborhood, the film's on-location scenes supplied a very realistic soundtrack for our listening tests. The gunfire exchanges between the robbers and the police in a garage at Fenway Park had good impact, and the screams of the wounded robbers echoing in the garage were chilling. But the HTX-22HDX's subwoofer didn't have enough power to produce the heavyweight sound of an armored truck crash and the massive thud when it flipped over. Turning up the sub's volume and the EX Bass enhancement function didn't help matters; the HTX-22HDX's low-end power was consistently lightweight during all of our music and movie listening tests. The Zvox 430 HSD sound bar doesn't come with a separate subwoofer, but that speaker produced more and better bass, and played louder than the HTX-22HDX.
With the HTX-22HDX's two speakers set up approximately 6 feet apart, Diana Krall's "Live in Rio" concert DVD projected a large, open soundstage that we judged as superior to what we've heard from most sound-bar speaker systems, including the 430 HSD. Krall's piano, the acoustic bass, and the orchestral strings sounded fine, but her voice and the drums' cymbals had a harsh, tinny edge, and the applause had an oddly hollow sound. Lowering the volume to a more moderate level tamed some of the harshness.
Tom Petty and the Heartbreakers' "Mojo" Blu-ray high-resolution DTS Master Audio soundtrack felt lackluster. The HTX-22HDX can play fairly loud, but rock music sounds strained when pushed. Dynamics were limited, though bass definition was reasonably good.
The HTX-22HDX is probably best suited to very small rooms (less than 200 square feet), and for buyers who just want a small step up from built-in TV speakers.
We almost always love the sound quality of Onkyo's home theater systems, so we were surprised that the HTX-22HDX was underwhelming sonically. Although the design, feature set, and price are nice, it's really only suited for buyers who don't demand a big home theater sound.