Many home-theater enthusiasts never give a second thought to how the AC power from the wall outlet affects their audio/ video system. But AC power plays a crucial role in picture and sound quality, and can make the difference between good and great performance.
The new Adept Response High Resolution Master Power Conditioner from Audience is a heavyduty solution to cleaning up a theater room’s AC. The device filters incoming noise, isolates components from each other, and provides twelve outlets to power an entire home-theater system. At $3800, the Adept Response is most likely to be used in upper-end systems.
I have a fair amount of experience with high-performance AC power conditioners, but the Adept Response took me by surprise. Comparing my system’s sound with the components plugged into the Adept Response and straight into the wall, I heard a wide range of obvious, musically significant improvements. The most important of these was a removal of a synthetic or artificial character overlaying the music. With the Adept Response, instrumental textures sounded more lifelike and natural. Consequently, the Adept Response gave the system a sense of ease that fostered greater involvement with the music.
The new Adept Response also rendered a wholesale improvement in bass definition and detail. Without it, bass guitar notes tended to be a bit ill defined, lacking precise pitch definition. Switching to the Adept Response tightened up the entire bottom end, making it easier to distinguish pitch in the lower registers.
I also heard a remarkable increase in resolution, inner detail, and space. For example, low-level percussion in The Planets [XRCD] that had been obscured suddenly became vibrant and alive. There was also a greater sense of air between instruments, along with far greater front-to-back depth. If I removed the Adept Response, the sound became flat, hard, less involving musically. Keep in mind that the improvement rendered by all AC conditioners will vary somewhat with the quality of your AC supply (rural AC power tends to be cleaner than city power) and with the particular components in your system. My system is least likely to realize an improvement by AC conditioning: I live in a semi-rural area and have multiple dedicated AC lines in the theater room; moreover, my theater room’s AC has a separate ground from the rest of the house. (See Hands-On Home Theater this issue.)
But why should AC power quality affect the sound under any circumstances? First, the incoming AC line often contains high-frequency noise that gets through a component’s power supply and ends up in the audio signal. Noise on the AC line is generated largely by industrial users connected to the power grid. This noise isn’t heard as a hiss, but rather as harshness in the midrange and treble, a less “black” background, a reduction of dynamic contrasts, and a grainy texture overlaying music and film soundtracks. Clean up the incoming AC power, and one often hears an improvement in all these areas.
But cleaning up the incoming AC power is only half the battle. Noise doesn’t just get into your system from the AC power grid; it is also generated by audio and video components within your system. Any component containing digital electronics (which would be most products these days) generates high-frequency noise that appears on the component’s ground, where it is coupled to the AC power line through the component’s power cord. This noise then gets into other components plugged into that AC line.
The Adept Response counters these phenomena by filtering incoming noise and electrically isolating each of its AC outlets. The company claims you can plug in a phono preamplifier (the component most sensitive to noise) in the outlet next to a digital controller with no degradation of the phono preamp’s performance.
In addition to cleaning up the incoming AC power and preventing the noise of one component from polluting another, the Adept Response provides 12 AC outlets— more than enough to power an entire system. A front-panel display indicates the incoming voltage, and a pair of coaxial connectors provides isolation for a cable or satellite input. Everything about the Adept Response is beefy, from the front-panel power switch (a magnetic circuit breaker), to the 20-amp Neutrik Powercon connector, to the Audience PowerChord AC cable.
The Adept Response is expensive, but after hearing what it can do for your system, you may not want to do without it.