In day-to-day use, the primary ergonomic feature I missed when compared to the Parasound P 7 was the output level display. Although the Halo Integrated has a fully adjustable, remotely activated volume control, and you can see where the volume has been set via the light on its knob, there is no way to quickly, reliably, and repeatedly match volume levels since the dial is not numerically quantified like the P 7’s. On the plus side, I wish every preamp had the red light on the Mute button just below the Halo Integrated’s volume control; it’s a lot nicer than having to hit the mute button twice to make sure that the mute is not on.
The first system I installed the Halo Integrated into was my upstairs home theater. At first I was surprised to find that the overall soundstage had shrunk somewhat, but after several weeks of operation, once I removed the Halo Integrated from the system and reinstalled P 7/E110 combo, I came to realize that the Halo Integrated now produced a soundstage that was slightly bigger than that of the P 7/E110 combo. Since nothing else had changed in the system, the most likely explanation is that the Halo Integrated needed some break-in time to sound its best.
Right out of the box, the Halo Integrated’s lateral imaging was tight with good specificity, but its depth rendition required some burn-in and playing time before it reached its full potential. Once the unit burned in (for several weeks), I was impressed by its imaging precision and its ability to layer the instruments on my live Boulder Philharmonic concert recordings. I was also aware, from the first time I heard the Halo Integrated, that its power amplifier was, well, powerful. Even on my most dynamic material the Halo had sufficient juice to deliver dynamics with an effortlessness that is the hallmark of a robust yet sophisticated design.
The overall harmonic balance of the Halo Integrated was spot-on. If you need warmish or coolish electronics to bring your speakers or room into a more neutral balance, this component won’t be the answer. Its “straight, no-chaser” approach is ideally suited to speakers and rooms that don’t want or need a push away from neutrality to correct for intrinsic imbalances. And because the Halo does have tone controls, on worst-case recordings I could, and very occasionally did, utilize them to produce more sonically palatable results. There was a slight loss of transparency as a sonic penalty for engaging the tone controls. (You could hear this by merely switching in the controls, even when they were set to flat.) But on the recordings that benefited the most from tonal adjustments the slight loss of transparency from engaging the tone controls was trumped by the gains in harmonic acceptability.
Bass through the Halo Integrated was tight, fast, and well controlled. Although most of my listening was done with a subwoofer, and with the Halo’s subwoofer crossover engaged, the bass remained smooth through the crossover region regardless of which system the unit was placed in. It was easy to achieve seamless integration between the subwoofer and main speakers without any lumpiness or holes in the frequency response. When I ran sinewave sweeps using AudioTest on a MacPro desktop, my B&K SPL meter placed at my nearfield listening position stayed within a 5dB window from 35 to 300Hz.
The last system I had in my computer audio setup was built around the NuPrime DAC-10 DAC/Pre and ST-10 power amplifier. The Halo Integrated’s midrange presentation had more in common with the NuPrime combo than I expected. Both did a superb job of retaining detail and giving music a presence and weight that with the right recordings could produce a stunning sense of immediacy. On “Walk Away” from the new Steel Wheels album No More Rain, the Halo made it easy to separate the vocals from the similarly pitched fiddle played behind them, without making the violin sound etched or overly highlighted.
Upper frequencies through the Halo retained their airiness while avoiding sounding tipped-up or overly emphasized. On my own DSD 128 recordings, the Halo wasn’t fazed even during the most punishing fff passages where amplifiers are most likely to falter. Again, I ran sinewave sweep tests with AudioTest, which confirmed how well the Halo controlled upper frequencies through both the Audience 1+1 and ATC SCM 7 II speakers. In both cases, the upper midrange and treble stayed within a 4dB window at listening position from 1kHz to 13kHz.
Speaking of listening positions, when you consider that the Halo Integrated’s headphone amp has no provisions for headphone gain adjustments, it mated well with a surprisingly wide range of cans. The first headphone I tried was the AKG K-7xx. These mated nicely with the Halo—no hiss or hum even when the volume was turned up to max. The AKG’s sensitivity was also a good match with the Parasound’s headphone amplifier—for most commercial releases the volume settings were between 9 and 12 o’clock. With a more difficult to drive headphone, such as the Beyer Dynamic DT-990 600-ohm version, I had to turn the volume up, but the Halo Integrated’s headphone amp still had plenty of additional unused travel left on its volume knob.