BurnsFamily Blog

My podcasting business is picking up, so I needed a second mic for studio 1A. I wanted to designate my current mic (Audix OM-2) as the “guest mic” and pick up a new one for me. I really wanted a condenser mic since I’ve heard they’re more sensitive and can more faithfully record the human voice. I’ll use the new mic for Episode 7.4 of the Security Hype podcast.

I originally bought the Audix mic based on the recommendation of the local Guitar Center salesman. Julie recognized the brand right away, and Music Tech Magazine did a review of this mic in 2004, so I blindly bought it. Today, I did my research and had a shopping cart with BSW all filled out for the replacement mic, but I didn’t necessarily want to wait for shipping so I stopped by the local Guitar Center to see what they could do for me.

I had my heart set on an Audio Technica AT-2020 but my local Guitar Center didn’t sell them in-store (web only). They had a package deal on the AT-2020 and an AT-2021 (a pencil “instrument” mic), which I didn’t want or need. The local salesperson, Gabe, highly recommended avoiding a “small step up” and not to waste money on a $99 (or cheaper!) condenser mic. He personally used and recommended the Rhode NT1-A. I’ve heard very good things about this mic and the host of the (insert name) podcast I listen to also uses it. I didn’t want to go all the way up to the Audio Technica AT-4040 which was another $70. Gabe said that the Rhode is in the same league as the AT-4040 and other more expensive mics.

He cut me a great deal on the rest of the package I was interested: mic stand, pop-filter, cable, etc, so I quenched the “immediate gratification” bug at the same time.

The hardest part of getting the Rhode setup is fitting it into the darn “spider” shock mount. I’m new to all of this so I’m sure it’ll get easier the next time.

With the mic physically setup, I plugged it into my mixer (Alesis MultiMix8 Firewire) and fired up GarageBand 3. After recording a few passages with my voice it was very apparent that the Rhode mic is much “smoother”. The Audix OM-2 (a $100 mic) isn’t bad — Julie said the Michigan Tech Jazz Singers used that mic when performing — but it was more “shrill” and didn’t see as “full” as the Rhode.

We positioned both mics right next to each other, then Julie sang along with a song in iTunes. (She’s a very good singer.) Then we listened to the same passage over and over, and enabled/disabled the Audix and Rhode tracks to compare the sound. Doing A/B comparisons gets tedious so we did something really cool (I think):

1. Run “RMS Buddy” to inspect the RMS levels of each mic track, then
2. Adjust the gain of the Audix mix track to match the Rhode’s track (within 0.5 dB), then
3. Pan the Rhode NT1-A Mic all the way to Right channel
4. Pan the Audix OM-2 mic all the way to Left channel
5. Insert Roger Nichol’s “Inspector” Audio Unit plugin in GarageBand’s Master Track (to monitor the entire output)

When we listened to the mix, Julie’s voice was dead center but there were some minor differences between the channels at time. It’s subtle when we listened with all the other audio going on, but the mic differences were MUCH more apparent when we looked at the spectral meter in Inspector.

Inspector color codes “Right channel” information in RED, “Left Channel” in BLUE. Audio information that is common to both is PURPLE (red+purple. Makes sense, right?) So in this case RED content is unique to the Rhode mic and BLUE content is unique to the Audix mic. Now we can “see” why the two mics “sound” different. We both thought the Rhode mic sounded more “natural” and life-like. When trying to describe the sound of the Audix we both used words like “thin” and “hollow”.

Remember, this is the exact same content recorded into two mics at the same place, with levels normalized between each other. Notice the sensitivity in the low-end and high-end. In other graphs (not posted here), the “overall” shape of the Rhode’s spectrum was much “flatter” than the Audix mic. The mic sounded boomier and had more “sizzle”, but it didn’t sound better than the Rhode by any stretch of the imagination. During production use I will enable the 75Hz “high pass filter” on the mixer to steeply cut out that unnecessary information, but I wanted a complete “picture” for this comparison.

You can definitely hear more “room presence” with the Rhode mic, especially if you get more than a few inches away from it. But I didn’t hear the computer in the background like I thought I did (and which the first GuitarCenter salesman originally warned me about, steering me away from condenser mics for my first purchase.) In another post I’ll test out an inexpensive and portable “anechoic box” I’m making right now. Stay tuned!

Summary: Is the Audix OM-2 a bad mic? Not at all, I’m very pleased with that $99 purchase and it’ll be great for guests, but I do prefer the sound of my voice in the Rhode NT1-A. The next question is: what happens to our sound after going through the MP3/AAC translation process. My hope is that by starting with better audio information from the Rhode mic the final mix will sound better too. Drop me a line and let me know if you can tell a difference in my voice in episode 7.4 of the Security Hype podcast.