Gradient?s parameters:

Create Professional Software Box in Photoshop CS

Using the same instrument, draw an element of the loudspeaker, like that one shown next step:

Create Professional Software Box in Photoshop CS

Blending Options-Drop Shadow

Create Professional Software Box in Photoshop CS

Blending
Options-Bevel and Emboss

Create Professional Software Box in Photoshop CS

Blending Options-Gradient Overlay

Create Professional Software Box in Photoshop CS