audioXpress Magazine - July 2019

In this issue

8 Acoustic Design of Music Reahearsal Rooms By Richard Honeycutt 14 Power for All Audio Needs By J. Martins For this market update on audio amplifiers, we illustrate the state of the industry in terms of audio amplification, focusing mainly on solid state and several cutting-edge approaches, including OEM modules, amp plate solutions, and the evolution of Class-D topologies 24 Why Smart Power Audio Amplifiers Are Becoming Important to Smartphones By Eric Eklund 28 Powersoft OEM Power Amplifier Modules Flexible Power for Active Systems By Ward Maas 36 Dayton Audio HTA20BT Hybrid Stereo Tube Amplifier Hybrid Power for All By David Logvin Learn more about this hybrid stereo tube amplifier that combines a media player, vacuum tubes, and Class-D amplification in one device, complete with built-in Bluetooth wireless streaming. 42 Sonarworks True-Fi Software The Simple EQ to Fix Your Headphones By Luke McCready True-Fi by Sonarworks aims to improve headphone listening on the desktop and smartphone at a price consumers can afford. 50 AoIP Delivers on Flexibility, Is Controllability Next? By Matt Hardy This article considers approaches to matching the flexibility of AoIP network structure with new technologies and standards for control and monitoring user interfaces. 56 Buzz Abatement in Audio Amplifiers By Chris Lewis and Dimitri Danyuk This article provides several details about inductive coupling effects in audio amplifiers and the simple way to minimize them. 60 Sigma 100 (Part 2) Driving the Satellite/Subwoofer Loudspeaker System By George Ntanavaras In this second part, George Ntanavaras describes two cases for the active crossover that he used to drive the satellites and the subwoofer—one using a mini-DSP 4x10 HD versatile Digital Signal Processor (DSP) and a second one using a pure analog active crossover based on op-amps.