Throughout the first 15 years, its flagship models were among the best you could get. The recently launched True X Surround 90A is also its most capable Dolby Atmos soundbar yet. It’s also the first soundbar with Auro-3D, an immersive spatial audio processor typically only found on high-end AV receivers. Tricky SetupPhotograph: Simon CohenSoundbars, by definition, are meant to be a simpler option than an A/V receiver for home theater sound. But Yamaha’s approach to the True X Surround 90A is anything but straightforward.