Sunday, January 9, 2011

Turning a Subwoofer Into a Microphone

I read somewhere that in order to increase the low end in mixes recording engineers will take subwoofers and turn them into microphones. The large Sub Mic or SubKick captures the low frequencies the same way a standard microphone does: the vibration of the diaphragm turns acoustical energy into electrical energy and is interpreted by your mixer as an electrical signal.

Being what I consider to be a very avant garde recording engineer I decided I wanted to try this. I consulted with the audio faculty and they found a three-way speaker cabinet that no one was using and they told me I could use it for fabrication. With the help of one of the instructors cut off the female end of an XLR cable and soldered the wires to the circuit board of the subwoofer. We tested the results and they were everything we hoped and I should have a sample up for listening in the next week or so.

Soldering the XLR cable to the speaker

SubKick

The XLR cable firmly attached:

subkick

The first rendition of the microphone attached to a stand:

SubKick on Stand

Recording Ukulele (09-25-2010)

Jeremy Otuel Dougherty is a frequenter of Dakota State Live Productions: “Open Mic Nights”. Jeremy is an accomplished singer and is quite skilled at playing ukulele. During a special kind of Open Mic Night entitled “The Gong Show”, he covered Trouble by Never Shout Never, a song accompanied by ukulele. I happened to be mixing his performance that night; the song and his presentation of it were deeply moving. I was really taken aback by the energy he exhibited, which compelled me to ask him if he would be willing to record this song in the studio. With some surprise he said he would be glad to, and he asked when it would be convenient for me.
I chose to use the Audio Technica 4041’s, a pair of small diaphragm pencil condensers, to mic his ukulele. The 4041’s have a boost in the high end of their frequency response curve (1), which I felt would be useful in capturing the brightness of the Ukulele. I decided to use an ADK S-7 to mic his vocals; the S-7 has boost in its low end according to its frequency response curve (2). It also has a bit of a dip in its higher frequencies; I wanted that specifically so that ukulele bleed through wouldn’t be especially bright. Jeremy later made the comment that he really liked how the mic treated his voice.
I showed Jeremy his recording space, explained the process to him, and what I hoped to achieve. He sat down and he began strumming out the chords to Israel Kamakawiwoʻole’s version of Somewhere Over the Rainbow. After he played a few times to warm up he told me a personal story about how much that song meant to him. At that point we decided to make Somewhere Over the Rainbow a focal point of the day. I had Jeremy play through this song four times with mild breaks in between. All the while I would use the talkback mic to communicate what I was doing so Jeremy wouldn’t feel out of the loop. Once we felt like we had a couple of really solid takes of Somewhere Over the Rainbow we moved on to Trouble by Never Shout Never, which we did six takes of before we felt sure we had something solid.
Mixing Somewhere Over the Rainbow was tough to mix as I felt it lacked a strong stereo image. After trying to beef up the ukulele and finding nothing I enjoyed I decided to leave it alone. I moved on to doing a final mix of Trouble, which proved much less difficult. I felt the punch of the vocals plus intermittent clapping made the song strong enough on it’s own without trying to mess with its stereo image. I put a light compression on Jeremy’s vocals using the Bombfactory BF76 compressor and decided to put a subtle reverb on his vocals with the AIR Reverb plug-in. To brighten up the ukulele a bit I used the EQ III Digirack 4 band equalizer and cut the low mids out and gave it a boost in the highs. I got the mix to where I wanted it and put a final compression on the master output using the Maxim Compressor.
The results are these two tracks and I hope you enjoy them:
Trouble by PaulSchipperRecording
Somewhere Over The Rainbow by PaulSchipperRecording
1. http://www.audio-technica.com/cms/wired_mics/b43bffe4d4295274/index.html/
2. http://recordinghacks.com/microphones/ADK/S-7
My Twitter:
 @PaulSRecording
Jeremy’s Facebook page:
http://www.facebook.com/profile.php?id=676781539&ref=ts