Help needed in resolving mudiness & resonant frequencies

[Craig Gundry]

After nearly three months of research, experimentation/troubleshooting, and a bunch of expenditure, I have arrived at a brick wall in my quest to get the equipment & environment situation correct for decent voice over recording. I am hoping the audio sages here can point me in the right direction before I spend any more time or money in waste.

In short, the problem I am encountering is a general mudiness in recordings and extensive presence of resonant frequencies regardless of microphone, input/recording device, or experiments with the design and location of my booth.

The booth I am troubleshooting is a 54” x 63” X 73” PVC cage lined with acoustic blankets and a carpet over hardwood floor. I also constructed five 4” rockwool panels which are temporarily laid against the corner walls in attempt to absorb nearby wall reflections. I’ve conducted a bunch of unsuccessful experiments over the past few weeks including placing the rockwool panels inside the booth, loading up the booth with pillows and extra sound-absorbent stuff, relocating the booth in my garage, taking out all furniture and equipment, microphone placement, etc…All to no avail!

Attached below are pics of the booth and recording environment.

I originally purchased a Rode NTG-3 shotgun mike in hope of using it for both voice over and video work. The recordings were terrible! By the time I realized an MKH-416 would have been worth an extra $300, B&H would no longer accept a return on the Rode. So I purchased two other mikes to try: Aventone CV-12 & Shure SM7b. The resonance in the CV-12 recordings (regardless of polar pattern) was full-spectrum, off-the-chart! I couldn’t even isolate problem frequencies with surgical EQ. Although the SM7b is much better (when set for flat or performance-boost), the recordings are still muddy with pronounced resonant frequencies scattered throughout the 100-1400 hz range.

While experimenting with Audition and iZotope RX 8, I discovered that reverb may be playing a role. Running a de-reverb filter seemed to make the recordings more workable and didn’t need as much aggression with notched EQ to reduce the resonant freqs. Nevertheless, no amount of surgical EQ, de-reverb, or de-noise seems to be successful in salvaging them. Or at least that I’ve been able to accomplish.

Following are links to unedited samples of the Rode NTG-3 and Shure SM7b recordings in the booth.

• Rode NTG-3: https://cloud.cisadmin.com/index.php/s/XyPxn6nZdLiHMCE/download
• Shure SM7B: https://cloud.cisadmin.com/index.php/s/5gCXEjLJN9NnMol

If it’s useful to hear my voice in other recording situations, here’s a few links to some video interviews on YouTube:

I realize a PVC ‘blanket booth’ in a living room isn’t exactly an ideal studio set-up. But unfortunately, that’s what I’m working with under current conditions. I can deal with poor sound isolation by recording late at night. I just need to get the audio quality under control. The recordings are for a personal video series and don’t need to be at pro-level of perfection, but at least a level where poor audio quality doesn’t distract from the viewer’s experience.

Any advice in remedying the recording situation or suggestions for successful post-production cleanup is VERY, VERY GREATLY appreciated!!!!

 

[Max Warasila]

Go ahead and take a short recording with the microphone 3" in front of your face and let's take a listen.

 

[Art Welter]

After nearly three months of research, experimentation/troubleshooting, and a bunch of expenditure, I have arrived at a brick wall in my quest to get the equipment & environment situation correct for decent voice over recording. I am hoping the audio sages here can point me in the right direction before I spend any more time or money in waste.

Although the SM7b is much better (when set for flat or performance-boost), the recordings are still muddy with pronounced resonant frequencies scattered throughout the 100-1400 hz range.

If it’s useful to hear my voice in other recording situations, here’s a few links to some video interviews on YouTube:

In short, the problem I am encountering is a general mudiness in recordings and extensive presence of resonant frequencies regardless of microphone, input/recording device, or experiments with the design and location of my booth.

The resonance in the CV-12 recordings (regardless of polar pattern) was full-spectrum, off-the-chart! I couldn’t even isolate problem frequencies with surgical EQ. Although the SM7b is much better (when set for flat or performance-boost), the recordings are still muddy with pronounced resonant frequencies scattered throughout the 100-1400 hz range.

Following are links to unedited samples of the Rode NTG-3 and Shure SM7b recordings in the booth.

If it’s useful to hear my voice in other recording situations, here’s a few links to some video interviews on YouTube:

Any advice in remedying the recording situation or suggestions for successful post-production cleanup is VERY, VERY GREATLY appreciated!!!!

Craig,

Listening to your voice it sounds to me that the "pronounced resonant frequencies" are simply a result of the proximity effect (bass boost) from using a typical cardioid microphone at a close range. A simple inverse curve can reduce that bass boost, though the interaction of the proximic effect and each person's mouth cavity resonance for each different vowel, volume, and distance cannot be equalized with a single "one size fits all" filter.
I couldn't quickly find an example of the SM-7B proximity curves, but although they would be a bit less than the attached Beta 58, you may get as much as 10 dB (twice as loud) bass boost moving from 3 inches to "kissing" the screen.
Using a good omnidirectional microphone pretty much eliminates the proximic effect, but allows more level from the reverse side in to the recording, a problem in noisy environments.
If you need the cardioid pattern, but want to avoid the proximic effect, using an EV RE-10, RE-20, RE-27 or Shure KSM8, SM-53 or SM-54 are all good choices. They will allow you to "work the mic" distance without affecting the tonal balance near as much as the mics you have been using.

Art

 

[Tim McCulloch]

Listening over computer speakers I prefer the Shure and agree with Art that the uniform nature of the LF build up in either mic sounds like proximity effect. There seems to be a bit of added 'sizzle' as well in the Shure recording.

Perhaps getting another 2 or 3 inches of space between your mouth and mic will help, and any deficit might be more easily fixed with EQ than trying to undo the prox effect.

I've a friend in Scotland who has been using the Aventone mics for recording and streaming classical music. He's very happy with them "for the price" but his use is very different from yours. I suspect what you're hearing is some kind of tube saturation; you might give Aventone an email or phone call and inquire.

All that said, I do not currently think the problem is with your booth, but until you're happy with the way your voice sounds over the mic we can't say for sure.