I like what you did with the mic, but I DO NOT like the font at all. Also keep the company name together on the same line. Keep in mind, when choosing colors, that you will need to be able to put the logo on a white background AND a black background with loosing anything due to color matching. I hope this makes sense.
I like the color scheme of #25, but the font of "Overture" is too futuristic. Use the same font as "Voice." Lighten the blue of "Overture" a bit... enough to be visible on a black background but still contrasting the light blue. Do not use a box around the text like you did for 26 & 27 when you put in on a black background. For the slogan, make it a light gray.... light enough to be visible on black, yet dark enough to be visible on white, and change the word "VOICE" in the slogan to lower case.
For 39 and 40, I'm not sure if it's me, but the first part of "VOICE" doesn't look like it is sitting on the same line. It's kind of off a little.... like it's smaller than the rest of the company name.
50 and 51 look good, however I have additional changes I'd like you to make. I would like to see the "U" in overture made into a rca 77 microphone. If you google the images of this mic I think you will know what I am asking you to do. Keep the word "voice" just as it is, and add to the "U" as described above. Also lose the slogan for this round. Thanks.