Gradient's parameters:
Using the same Ellipse Tool (U), we'll represent the primary layer of the loud - speaker's clamp.
The layer's parameters:
Fill 0% on the layers.
Blending Options>Inner Glow
Blending Options>Gradient Overlay
Gradient's parameters:
Applying the last instrument, it's possible to draw the upper part of the speaker's clamp.
The layer's parameters:
Fill 0% on the layers.
Blending Options>Outer Glow
Blending Options>Gradient Overlay
Gradient's parameters:
Blending Options>Stroke
Now we have to combine in a group all the layers composing the speaker's clamp (press on Ctrl button and mark out the necessary layers. Then make a click on the left mouse's button to take the marked layers downside on Create a new group option). The group must get the next parameters:
The Opacity is set on 80%.
Make three copies of the last made group and select Free Transform option to change the sizes for each copy and their position on the picture.
Representing the loud - speaker came to end!
More Tutorials: 
