Gradient's parameters:
On the created layer you have to introduce with the next instrument 
a kind of depression in relief.
Blending Options-Gradient Overlay
Gradient's parameters:
Blending Options-Stroke
Gradient's parameters:
On the created layer you have to represent an embossed membrane's part of the bigger loud speaker.
Blending Options-Outer Glow
Blending Options-Inner Glow
Blending Options-Gradient Overlay
Gradient's parameters:
On that embossed membrane's part must be drawn the flare. It's possible to represent it with this instrument 
.
Fill 0% on the layers.
Blending Options-Gradient Overlay
Gradient's parameters:
Applying this instrument , create the lowest layer of the big speaker's center. It must be colored in 898989.
Blending Options-Outer Glow
Blending Options-Stroke
Using the same instrument, draw the last layer of the big speaker's center.
Blending Options-Outer Glow
Blending Options-Gradient Overlay
Gradient's parameters:
Blending Options-Stroke
Gradient's parameters:
And the final result!
