Podcasting mic issues…

On the Freestyle Podcast, we finally all have good microphones. As I have written before, I have switched to using my Audio-Technica mic, rather than my more complex dynamic mic/preamp/mixer/computer setup.

On the latest episode I ran into an interesting problem. I record in a room in the front of our house. Depending on atmospheric conditions, there can be kind of a low “road drone” noise in that room. The freeway is at least 2 miles away, and you don’t notice it that much just sitting there talking. However, the Audio-Technica is a condenser microphone, and condensers really pic up a lot more ambient sound than the simpler dynamic mics.

So my point is this: on the newest episode the audio from my mic includes this annoying background noise. Sounds like it was recorded in a plane. My voice sounds fine, but that damned noise is there, and my usual trick of using Audacity to remove the noise just didn’t work well. So…I left it in. It isn’t too horrible, but I want the trend to be toward better quality, not worse!

I have procured a few 1′ x 1′ squares of acoustic foam — the stuff they put on the walls of recording studios.  I’m going to line the inside of a box with this foam, and place my microphone inside it, and see if it improves the quality of my audio by screening out ambient noise.

I have also purchased this ART DTI Hum Eliminator, with which I hope to kill the massive buzz from my mic preamps, and use my dynamic microphones again. I may continue to use the USB Audio-Technica mic most of the time if the isolation box works well, but there are situations when I need to use my two Audix OM2 Hypercardioid Dynamic Microphones.

So I’ll be testing the Hum Eliminator this week, and post the results.

On a different but still podcasting-related note, I’ve been checking out a lot of podcasts about podcasting. The best one I’ve found is the Podcaster’s Studio. Really good podcast with very good advice. I recommend it for all podcasters.

Tascam DR-40 Recording Comparisons


I’m planning a couple of new podcasting projects in which I’ll be interviewing people. My older microphones will work well for this, when combined with my newest acquistion…

tascam2…the TASCAM DR-40 4-Track Portable Digital Recorder. I was looking for an extremely portable solution for getting good quality interview tracks without lugging my laptop around. This device has ports on bottom with which I can attach my two Audix OM2 mics. Without going into too much detail, the device has several recording settings, some of which use only the external mics (rather than the two built-in mics) to create a stereo recording. One mic for me, one for my guest. The Tascam saves all the files as high-quality WAV files. I’ll probably use Audacity to combine the voice tracks into Mono for the podcast.  There’s a built-in preamp, phantom power if you use a condenser microphone, etc, etc, etc.  And man, this thing is simple to use. Very very easy to learn.

It can be a little confusing and frustrating just learning as you go, the way I do. Below are some sample sound files, recorded with various pieces of equipment.

Audio Technica AT2020USB Cardioid Studio Condenser Microphone, samples recorded into Audacity, using a pop-filter (only one mic, even with Stereo recording).

  1. Recorded in Stereo, 16-bit WAV file.
  2. Recorded in Mono, 16-bit WAV file.

Tascam DR-40 Test Samples: I’m extremely impressed by the sound quality from the DR-40. A few notes. I am using Audix OM2 mics for the external microphones. They are not condenser mics. I tend to speak kind of softly, and thus the samples using the external mics sound a bit softer. Really nice sound, but just not as loud. The built-in mics sound fantastic. I’m really surprised that they sound so good. However, when you are using the internal mics, they tend to pick up the sound of your hands moving on the recorder, which is annoying. Not really sure how to get around this…used soft gloves? Are my hands too hard?

So I think that for recording interviews, I’ll probably stick with the idea of using the two external mics, plugged into the DR-40, and just speak a bit louder and bump the input volume up a bit.

  1. Mono,external mic, input volume 70
  2. Mono, internal mics, input volume 70
  3. Stereo, external mics, input volume 70
  4. 4 channel mode – file 1 – the external mics 
  5. 4 channel mode – file 2 – what the internal mics recorded while I was speaking into the external mics. The mics were actually pointed away from me. (in 4 channel mode, the device produces two WAV files).

More internal mic tests…

  1.  Another internal mic test – gets a nice sound, but as mentioned the noise of my hands on the device is very annoying.
  2. Additional Test – input volume 60, about 1.5 feet from my mouth, tight position.
  3. Additional Test – same as above, but mics on wide pattern.
  4. Additional Test – back to tight pattern, device close to mouth. Very good sound quality, but again the noise from handling the device is apparent.