If you are recording a good talent in a well treated room with professional equipment, you likely don’t need much processing but a few tweaks here and there can take your audio from acceptable to amazing.
Outboard vs Digital Processing.
You’ll want to do all of your processing inside your DAW (Digital Audio Workstation, i.e. recording software), after recording. That way you can undo and redo until you get it right. Outboard gear is very cool to look at and fun to collect but you only get one chance to get it right, once it’s recorded it’s impossible to undo the effects you dialed in. Audio purists and engineers can make good use of expensive outboard gear but it’s not for anyone trying to get great audio in the minimum amount of time. Nearly every modern DAW comes with the effects mentioned below.
In layman’s terms, compression makes the quiet parts louder and loud parts quieter, it “beefs up” your audio to make it seem louder and more present. I’d recommend a ratio of between 1:2 and 1:5. That’s the ratio of gain reduction above your set threshold. Set attack and release times to the minimum and the threshold about 5db-15db less than the peaks in your recording (peaks around -6 to -18 is good practice). Voice over mixed with a hot music track will need more compression than a dry VO to “cut through” the bed. Broadcast spots are generally compressed the most because they compete with everything else on the air while an instructional video doesn’t need as much as you have a captive audience.
If you have a good room with good equipment, very little if any EQ is needed. You will almost always want to roll off some of the bass, generally everything under 80-100Hz, to reduce the “boomy-ness”. Beyond that, a bump in the highs around 10k can make a VO cut through a music bed and be more easily understood with some voices. A good rule of EQ is to don’t over do it, you probably need less than you think. Adding highs will make the VO jump out more, too much and it can sound unnatural very quickly but that can be good for hard sell car spots and radio imaging.
Hard Limiting is basically an extreme form of compression. It’s useful to “chop off” any errant peaks in your audio so you can turn everything else up louder with out having those stray peaks over-modulate and distort. It’s kind of like giving a hair cut to your audio, use it to trim the top and level it out, then you can up the volume without issue. Also, hard limiting is useful to master your spot after you mix it to get the most volume for your signal without being held back by a few stray peaks.
Adobe Audition and several other DAW’s have a preset to “Make Room For Vocals”, which is very useful. This is basically an EQ setting that lowers the frequencies in your music bed where the human voice lives in, so there are less competition around those frequencies. It’s helps “gel” a mix together and allows you to turn up the music bed without sacrificing intelligibility of your VO. If you want to get fancy, you can route this effect through a “side chain” so that the equalization is only happening when the voice channel is above a certain threshold. In short, the side chain setup will only apply the EQ to the music track when there is VO over it. Pretty snazzy.
You can also help gel it all together by applying some light compression to the final mix, 1:1.5 to 1:3 would be appropriate for a final mix compression.
What Are You Listening With?
Make sure you consider that your speakers are going to sound different than everyone else’s. Try listening through a few different sources. I will typically produce audio on my studio monitors, then listen through studio head phones, followed by some cheap ear buds and then take a trip to the car to hear how it sound through the car stereo. Sometimes, I’ll even play it through the TV. The differences can be quite dramatic and you want your mix to sound good on all of them. Studio monitors tend to make you think you need less processing due to their clarity and detail, while ear buds will make everything sound like it needs way more. Listening through a few different sources can help you decide much better than through just one set of speakers or headphones.
Hope these tips help. Audio is very counter intuitive but once you start experimenting with different ways of shaping it to get the desired result, the learning curve can be quite enjoyable.
If you have any questions or need help with your audio feel free to drop me a line, my contact info is above.