Horn speakers, most audiophiles agree, provide greater headroom, more accurate acoustic imaging, and better detail than do any other loudspeaker designs. The horns of Germany’s Avantgarde Acoustic (www.avantgarde-acoustic.com) are especially revered for their fidelity. The company’s $36,000-per-pair Duo Grosso speakers (single horn shown), for example, deliver 107 dB of sensitivity with a staggering 18-ohm impedance. These characteristics lend clarity and precision to the music, but they also make flaws in the audio-signal path more perceptible. Amplifiers usually are the source of these flaws, so Avantgarde developed its own line of amps. The new XA Series, which includes a $13,600 preamplifier and a $12,800 power amplifier, produces a signal path that is clean and clear and worthy of the company’s speakers. Like Avantgarde’s horns, the XA amps can be customized to suit a wide range of aesthetic preferences, for a sight as divine as the sound.