Sig One:
Composition The render is placed in the centre of the sig. This is okay, one of the only places that looks good but goes against the rule of thirds. C4D placement is pretty good to, though leaves some of the sig feeling empty and doesn't draw focal attention to the render.
Effects The effects are pretty poor, sorry. Frosted glass looks horrible, C4D needs more blending and the splatter needs some texture and lighting.
Colour Colour in this isn't to bad, I guess. Try to infuse more colours into your sig. With just the blues, it looks okay but the shades don't work together, giving it an un-natural feeling.
Depth Depth isn't bad actually. Render seems to be rising upward in a wave of C4D. Splats look to flat.
Lighting Not even thought about. Not lightsource, no light, no shadow and no effort at all but into making the light work.
Flow Horrid. Render gives no flow and is constrained by the C4D. Try using a different render with more 'action' or to create some flow with smudging.
Blending Render doesn't blend at all. You really need to create a sig around a render, not find a render to go with the sig.
Other Everything is too pixelly.
Text is badly placed and should follow render flow and blend more.
Nice border.
Remove the frosted glass effect, take some tuts, look at others sigs and try to work out what looks good and what looks bad.
Not gonna CC sig 2 as sig 1 is better.