Format is one of the most important yet most overlooked aspects of Podcast recording.
I am amazed to receive Podcasts recorded in wav 8 bit, 8000khz, or worse on 32
KBps mp3! To give you an idea, this is like packing a chocolate pastry in a matchbox!
Nothing much of the original will survive! I always advice recording in wav format at
44,100, 16 bit. This format renders the best quality for size. But the file size can be
huge (1 min recording =10 mb approx). But once it is recorded, a sound engineer can
mix, master, eq and polish it up and reduce it a small 15 mb file, ready to upload. This
way the saturation and quality of the source is maintained the most and all other
process like noise reduction and Eq yield beautiful results. If you are recording in
mp3, I would suggest a bit rate of 320 kbps, 44,100 at the least.
Placing the microphone
Placing the microphone or Miking is an elaborate science in itself. If the mic is too
close to the mouth, it will cause pops, and bass boost, making the sound muddy or
harsh. If it's too far, the voice presence will suffer. It is always a good idea to record a
couple of samples with different placements and see what gives the best results. Some
basic do's and don't-
1. Keep the microphone as far away as possible from unwanted sound sources like
CPU fans, A/c ducts etc.
2. Don't place the microphone directly behind a wall. This will result is reflections and
will make the voice echo.
3. Place the microphone directly in front of your mouth, around 4-8 inches away. You
can also place the microphone a little higher then your mouth and point it downwards.
4. Always use a pop screen/filter to reduce the explosive breath sounds.
As a rule, the recording levels should never cross 0 db. A level higher then 0db causes
nasty distortion in your recordings. The best way to avoid it is to do a sample
recording and hear it back. Always monitor the levels on your recording software.
Low levels can always be fixed, but distortion is nearly impossible to fix. My advice;
don't record at the maximum levels. Reduce them a little and always check that your
recording has no distortion. Or better, if you can apply a compressor in the signal
chain, it will take care of the peak levels.
An acoustically treated room is the best place for recording. Though ideal, it might
not be available to all podcasters. Never record in rooms which have lot of metallic
furniture/items or a completely empty room. These will reflect the sound waves and
will result in bad recordings. A room with carpet and wooden furniture is a better
choice. Make sure the location you choose has minimum ambient noises. Fans,
exhausts, noisy CPU all contribute to broadband noise. Make sure that there are no
phone ringing, the neighbor's dog or the doorbell!