I keep hearing podcasts that just need some really simple fixes to make a big difference to their audio quality.
Having been on a crash-course in radio production, and running the Studio 31 facility at Porter Novelli, I know that there are certain standards you must adhere to in radio. This is why you can generally listen to programme after programme without constantly adjusting the volume.
Not so podcasting. I find I keep having to adjust the volume between podcasts, and some of them are frankly unlistenable. They’re either too harsh, dull, hissy or quiet, especially when listening on the Tube. It’s similar to listening to music compilations from different sources, where you’ll find that different production approaches have yielded different volumes. And, again, I can vouch for this after over six years of home audio production.
The good news is that some simple measures can help achieve a good, consistent sound quality:
Record at the highest bitrate your device can muster. CD quality is 44.1kHz. While you don’t need to go higher than that, never record below 32kHz. This is for two reasons: it gives simply better audio quality; and it helps avoid the distortion you can hear sometimes when the signal gets too hot (also known as ‘clipping’). Distortion is only too easy to introduce to a recording but virtually impossible to remove once it’s there. The downside is that your audio files will be larger but, possibly counterintuitively, it won’t make any difference to the size of the MP3 file that pops out the other end.
Record in mono. You don’t need stereo for podcasts. And it saves filespace.
Check your levels. The distortion comes when the needles or LEDs hit the red. Ease off a little and give yourself plenty of space between your peak levels and the red line, but don’t make it too quiet because then it becomes hissy. You want a nice hot signal that isn’t sizzling.
Be careful with environment. I’ve been caught out so many times by recording something then realising there was a noise in the background – the central heating, the fridge in the kitchen, even a car in the distance that you didn’t realise was there. This is because hearing is different from recording: we actually filter a lot of noise out ourselves, while recording picks everything up indiscriminately. I know the environment is difficult to control but be mindful of it. Ideally you’re looking for a quiet, carpeted room with as many soft furnishings as possible.
Get a decent microphone. I use an AKG C1000 for my vocal recordings but I’m sure there will be loads of recommendations out there, particularly as podcasting grows in popularity. There are also interesting variations nowadays such as nice, portable USB mics that you just plug into your laptop/PC/recording device with no other cables or controls to worry about.
Download Audacity and play around with it to see what you can do. Whatever audio software you use, try and read up on compression and equalisation. Compression is where you reduce the dynamic range of a recording so that quieter bits become louder, and loud bits go quieter. This can smooth out volume imbalances. Equalisation filters out or augments different frequencies in the audio spectrum. So, you could filter out low-end rumble if you’re above a tube line, or high-end hiss if you’re near a waterfall. There’s a lot more audio trickery you can do but these two are key.
Hope this helps!