Vocal – Guitar Separation with Figure 8 Mics

Thursday, April 9th, 2009

I record solo acoustic guitar almost exclusively, but a couple of months ago one of my buddies wanted to lay down a few tracks with vocal and `ukulele. And he wanted to sing and play at the same time. I remembered reading about an arrangement of figure 8 or bidirectional mics that gave maximum separation in a situation like this, so I pulled out the Rode NT2a and NT2000 and set them up. We were amazed by the separation between vocal and uke, even though the mics were only a foot apart.

Figure 8 mics have a pickup pattern that looks like this:

Figure 8 polar pattern

but it’s important to remember that this diagram is a 2D representation of the 3D pattern in space. Basically the pattern looks like two balloons on the front and back grills of the mic, with a null, or area of minimum sensitivity in between.

So for the vocal mic we aim the “balloon” of sensitivity at the singer’s mouth and the plane of minimum sensitivity at the singer’s guitar or uke or mandolin. And we arrange the instrument mic with its diaphragm pointed at the instrument but the plane of the null at the singer’s mouth. It’s more complicated to describe than it is to do.

Here’s a video that demonstrates this technique:

Certainly other mic patterns could be used, but no other pattern has a deep a null, and no other is as easy to aim. If you need to record a self-accompanied vocalist, a pair of figure 8 mics, either large diaphragm switchable condensers, or bidirectional ribbons, would be a good investment.



This entry was posted on Thursday, April 9th, 2009 at 7:48 pm and is filed under Audio, Tutorials. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.


7 Responses to ' Vocal – Guitar Separation with Figure 8 Mics '

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  1. Andy Rogers Song said in post # 1,

    on April 12th, 2009 at 12:45 am

    Thank you so much for sharing this topic/post to us! God Bless!

  2. jason brian merrill said in post # 2,

    on April 15th, 2009 at 7:07 pm

    thanks for explaining this!!!

  3. Fran Guidry said in post # 3,

    on April 15th, 2009 at 9:39 pm

    Hey, glad to help if I can. Jason, this is a great way to take advantage of those ribbon mics.

    Fran

  4. Victor Tsaran said in post # 4,

    on May 16th, 2010 at 9:56 pm

    Wow, totally awesome. Thanks a lot for sharing.
    Off to get a pair of 8-figure mics. 🙂

  5. Fran Guidry said in post # 5,

    on May 19th, 2010 at 5:15 pm

    Hey, Victor,

    I’ve really gotten a lot of use out of my medium priced LD switchable mics, and the figure 8 pattern probably gets the most time.

    Fran

  6. Jeff Young said in post # 6,

    on March 11th, 2011 at 12:23 pm

    Fran:

    I really appreciate the time and effort you put into demonstrating and explaining various concepts. Also I appreciate your level of objectivity. I have been recording for about 10 years (at home for a hobby) and have come to many of the same conclusions you have. I’ve spent all kinds of money early on chasing the best mic’s (LD’s SD’s )/preamp/compression etc and in the end it really comes down to the guitar player, the guitar and the room. (In my opionion , in that order). After 100’s of different configurations of mic experiments I’ve concluded that its all personal preference where you place the mic. If it sounds good then thats where you should put the mic. For me I like to record and sing at the same time and by trial and error I came to almost the same set up you recommend with the two figure 8’s . I adjust off that configuration for taste.
    By the way I use the rode’s most of the time now – both LD’s . I borrowed a couple of high end mics a last year from a studio guru I befriended and concluded they were really exceptional at picking up all the “bad stuff” in my room ,better than my cheaper mics. However apparently they are great in a well designed studio.
    Thanks Fran

    Jeff from mississippi

  7. Fran Guidry said in post # 7,

    on March 11th, 2011 at 2:10 pm

    Jeff, thanks a bunch for stopping by and commenting, especially when your comments all say I’m right (grin).

    Fran

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About the Blog

    Howdy, my name is Fran Guidry and this is my Homebrewed Music blog.

    I play Hawaiian slack key guitar and recorded my solo acoustic CD at home. Most of the recording information I find on the internet seems focused on bands, drums, multitracking, and so on but my main focus is recording solo acoustic guitar. Lately I’ve been enjoying video recording along with audio, so that shows up in the blog as well.

    I’m also a guitar nut. I love big ones and little ones, handmades and factory guitars, cheap ones and expensive ones. So I’ll be sharing the fun of exploring guitars as well, along with the challenges of amplifying acoustic guitars for live performance.

    Welcome!

Philosophy

    My recording philosophy is pragmatic, skeptical, not super critical. After all, the performance is by far the most important component of a track, and every aspect of any recording is a matter of taste.

    But I do like to know “about stuff.” Back in hifi days I learned about double blind testing. I learned that we humans can easily hear differences that don’t really exist. The more I’ve learned about our human auditory system, the more I’m skeptical of what people say they hear, especially if they claim that a particular microphone or preamp or cable has some magical property.

    I’ve only been recording since 2001, and when I started I found the usual places on the internet. I sought advice and accepted it, thought I would improve my recordings by using more expensive equipment. It didn’t work.

    Two things that did seem to lead to better recordings were experience and room treatment. Getting an appealing sound is the combination of many small details, and learning those details only comes from experience. Amd the sound of the recording space is obviously a big factor.

    I’ve only recorded seriously using digital technology, but I remember trying to record rehearsals and gigs back in analog days. I don’t have any nostalgia for analog recording and playback systems at all. I think even low end digital systems can capture marvelous recordings. So when I look at gear, I look for good specs: low noise, broad flat frequency response, wide dynamic range, low distortion. I’m not interested in colorful components, mics and preamps with a sound, I want the sound to be the sound of my guitar.

    But the last word is that I’m just learning and I hope you find something useful in my posts.