Some people have mentioned issues with the sound. What problems are people having? The sound is very clear when I hear it on my computer. Can people point out specific parts where the sound is lackluster, or be more specific about the problem with the sound?
My issue with the sound, and I don't think I'm nitpicking, is that you've encoded it with too low a bitrate. So you'd actually have to listen to the video as it's being played back from YouTube to hear the actual quality (not sure from your comment if you've done that). You basically sound a bit like a robot in the video, just the typical heavy compression artefacts one does get at low bitrates. Just listen through a headphone to the video and you'll see (hear) what I mean.
I have not actually downloaded your vids to inspect how high the bitrate is or what codec you've used for the audio, but here are some typical settings for different audio codecs that should yield decent quality:
- First and foremost, don't encode in stereo. Mono is just as good for pure voice content, and you're not recording with a stereo mic anyway I guess. Using mono greatly increases the effective bitrate (since you're not encoding a second, basically redundant, channel).
- Use variable bitrate encoding, not average bitrate or fixed. Modern codecs (AAC or Vorbis) default to this, with MP3 you might have to select it explicitly.
- MP3 needs at least 96 kpbs, preferably 128 kpbs on average
- Vorbis is fine with 64 kbps already; I'm not sure if that's even an option for YouTube compatible videos though.
- About AAC I'm not sure, 80-100 should be enough. I think that's the standard codec for MP4s so it's probably what you should be using.
TMIT's recordings seem to have a good audio bitrate (I didn't hear a lot of artefacts at all), but he does have a huge amount of noise from interference in his computer.
Also, if anyone does more professional sound recording and could give some advice that would be great. I took a look at Railscasts, which seem interesting. Any other background would be great as well.
You don't need a studio mic like the Railscast guy uses. A decent headset is good enough (I have a Sennheiser PC 151 and I can only recommend it; it's not very expensive, comfortable to wear for hours, does have great earphones and a very good microphone).
Just make a few test recordings and make sure you set the input (recording) level just right, so your voice is loud and clear without clipping.
I recommend using a USB sound adapter (just buy a cheap one for $15 or so, it doesn't matter), because they greatly reduce the amount of noise you get. The sound hardware typically found in desktop PCs and most cheap soundcards produce horrible noise from picking up all the interference inside your PC. If you listen to TMITs recordings with a headphone you can hear the fan inside his PC spinning up

. This might not be an issue for you though, you can easily find out by making a test recording.
Also, making sure you got the right recording level set up reduces noise because the signal to noise ratio will be better.
I'm not an expert on these matters, but the above is easy to follow advice and by investing an hour or so in figuring it out you will greatly improve the quality of your videos.
The sound is quite audible, its just that certain frequencies in your voice echo more than others, meaning that some peoples voices sound strange when played back, you have this problem a bit (I remember having it a lot) - TMIT doesn't.
I don't think that echo is really the problem here, to me it sounds a lot more like encoding artefacts. Of course you could be right about this as well -- using a good headset, with a noise cancelling microphone that is in a fixed position from your mouth should eliminate any echo problems though. You will also not have any feedback from your speakers since you're listening through the earphones.
You should not record the game sound through the microphone anyway. That will only sound bad and give you feedback problems. I don't know how fraps works in that regard (I've never used it), probably it does the required mixing of game sound and voice already.
If not, just record the voice over into a separate file and then mix it with the game sound at an appropriate level afterwards. How you do that depends on what software you're using.
I hope I'm not stepping on your feet with my complaints about the sound quality, guys. I really like those videos and I'm learning a lot from them.