Take the next tool to continue creating the loudspeaker of the audio system to be:

Create Professional Software Box in Photoshop CS

Blending Options-Gradient Overlay

Create Professional Software Box in Photoshop CS

Gradient's parameters:

Create Professional Software Box in Photoshop CS

Blending
Options-Pattern Overlay

Create Professional Software Box in Photoshop CS

Using the next instrument , create the central part of the loudspeaker:

Create Professional Software Box in Photoshop CS