Taperssection.com
Gear / Technical Help => Microphones & Setup => Topic started by: notlance on August 11, 2011, 10:37:18 AM
-
I have not seen this talked about much, but I have found it very helpful to time align spot/solo mics with my main microphones. The time differences between mics can be significant and can really screw up imaging and in extreme cases create comb filtering.
First of all, a dog clicker can be really useful:
http://www.petco.com/product/9698/PETCO-Dog-Training-Clicker.aspx (http://www.petco.com/product/9698/PETCO-Dog-Training-Clicker.aspx)
These clickers produce a sharp click that can be used to check room decay time, mic phase, timing, mic orientation and placement, and presumably train your dog. The clicker's sound is not quite an impulse function, but it does contain a wide frequency spectrum. I have one on my key chain and one in my gear bag.
To see how the clicker can be used to align mic signals, see the attached screen shot which shows one click picked up by two mics. The upper signal is the Mid mic from the main MS pair, and the lower signal is the spot mic used for vocals. Note that the mics are the same polarity. The difference between the two clicks is 179 sample, which is 179 samples / 44100 samples per second = 0.004 seconds or 4 ms. 4 ms is about 1.4 meters or about 4 feet. Using a DAW it is simple to delay the spot mic to time align with the main mic. 4 ms is not a big difference, but it is audible. When the solo mic is time aligned, the vocalist seems to 'snap' into place in the recording; without time alignment, the image is more vague. In other recording situations the time difference between main and solo mics can be much greater. Last December I recorded a choir with a spot mic on a cello soloist. In that case the time difference was about 11 ms.
Significant time differences can also occur when mixing a board feed with a main pair. When getting a board feed I try to hop up stage to record timing clicks. If that is not possible I'll try to time align based on some impulse in the performance such as a rimshot.
So my two points of this post are that a dog clicker can be really useful and time alignment of main and spot mics can improve your recordings.
-
I've done this with standard stereo pairs as well, I'll find a click that came through the PA and see how close it is to being in sync. There are some programs that will even do some of this for you (RX from Izotope will in their "azimuth correction" calculation). It works best when you use spot micing with other sources, but there is some benefit with hearing the difference between what you have and what the alignment produces (and what it sounds like in between). Subtle differences, but an interesting way to swing the stereo image around.
-
That's a good idea.
I've usually tried to align the snare, but I might give that a try.
-
Lots of drummers count off the beginning of a song by tapping their drum sticks together.
I like to use that for aligning SBD and audience feeds.
-
another trick I use is ro pan source one left and source two then use headphones.... you'd be surprised how accurate you can get just using your ears
-
I've been meaning to find one of these clickers for years. Thanks for the reminder to stop by the pet store on the way home.
-
Lots of drummers count off the beginning of a song by tapping their drum sticks together.
I like to use that for aligning SBD and audience feeds.
Yes, using the drummer for timing can work well, but most of the time I record music that has no drummer, or the drummer is in the back as part of the percussion section and is not miked (think Classical music). So I'm back to clicking on stage. So far that has never been a problem since I act like I know what I'm doing, don't ask permission, and am done before anyone can kick me off.
-
I've been meaning to find one of these clickers for years. Thanks for the reminder to stop by the pet store on the way home.
Both PetSmart and Petco sell them, and perhaps others as well. My local PetSmart has them unpackaged in a bin by the cash register which is nice because you can try them out and find one that has a nice sharp click.
I teach a high school class in musical acoustics/audio/recording and my graduation present to the students is a dog clicker and this chart:
http://jinright.edublogs.org/files/2009/02/carnegie_note.jpg (http://jinright.edublogs.org/files/2009/02/carnegie_note.jpg)
Most of the students appreciate the gifts, the rest just think I am an incredible geek.
-
My local PetSmart has them unpackaged in a bin by the cash register which is nice because you can try them out and find one that has a nice sharp click.
How appropriate to find them in an impulse buy bin! :P
Most of the students appreciate the gifts, the rest just think I am an incredible geek.
Fortunately being regarded as an incredible geek is good aclaim, where as being regarded as incredibly geeky implies something of a social deficit. Subtile but critical difference.
-
Cunning, I tend to clap but these could be better. Also could be good as a small thing for getting room impulse responses
-
(AP) Indiana - Recordist attacked by Rottweiler after using "Clicker"
-
Looked up from my lunch yesterday and there was a petco across the street. Walked over an picked up a couple. It's a lower pitched click than the old metal cricket clickers I remember, but louder.
[edit- clikcing away there in the store, none of the visiting dogs seemed to even notice]
-
And all these years I've been lugging around one of those chalkboard deals with the click arm on it like in the old movies.