|
Audio Asylum Thread Printer Get a view of an entire thread on one page |
For Sale Ads |
71.34.243.175
membrane shielding it from sounds generated from behind.
Aren't most microphones used in "live" recordings omnidirectional? That would seem to indicate that from the get-go the recording would be inaccurate.
Follow Ups:
1. Spaced omnis: the Cozart-Fines used this for their Mercury Living Presence LPs, and it's hard to argue with the results, at least for orchestras. Wilma claimed that having 3 spaced omnis recorded to 3 tracks and played back with 3 speakers was stunning. Biggest problem is phase cancellation.
2. X-Y: normally cardioid pair with capsules very close together at 90-135° to each other centered on the performer; Blumlein is the variation with the mics at 90°.
3. Mid-Side: cardioid facing the source, and a bi-directional with the null facing the source; gives good mono compatibility and flexibility in controlling the source vs. ambience.
4. Decca Tree: 3 omnis, L & R 3 feet apart, and center 1½ ft in front facing center
5. Surround Decca Tree - add 2 rear mics to it
6. Lots of suround techniques - I haven't gotten into that.
And of course each instrument has specific techniques that work with it.
WW
There is NO substitute for the live performance.
"Aren't most microphones used in "live" recordings omnidirectional?"
No.
Tre'
Have Fun and Enjoy the Music
"Still Working the Problem"
Well, recording technology is far beyond use of a few omni's If the goal is to pick up pressure variations in an acoustic space most accurately then a good omni is the way to go. However, in most recordings, even live venue recordings, the two voltage vectors (waveforms) that make up the left and right channels bare little to no resemblance to the pressure variations that appeared at your ears during the same performance - or even the signals from any of the instruments played. The recording engineer and or producer sit with a few to more than a couple dozen signals that were recorded from microphones and directly from electronic instruments placed at various locations in a hall and near the stage. Even signals recorded earlier or later (overdubs) are added to the mix. The sound produced is created in the production room, from the artistic compilations of these signals as listened to over the recording studio's monitor speakers (or a set of head phones).It is only by the will and imagination of your mind that you get a "observation" of a live performance when reproduced over your mega buck cables and hi-fi equipment from this otherwise contrived pair of stereo voltage signals from these skilled recording engineers.
Edits: 03/26/09
To answer your question, omni mics pick up too much room sound and reflected energy for good recordings in live environments.
Cardioid and hypercardioid mics are preferred unless picking up a lot of ambience and reverb is your goal. Do a google on microphone types and find out about various polar patterns of different pickups.
I'm told the mic with a transfer function closest to that of the human ear is the Schoeps "Sphere", a very expensive omni.
The only reason for using a microphone with spatial characteristics of the ear would be if one was going to bypass the ear. Since most recordings are made for and actually are played on speakers that radiate sound to the ears, there is no reason to duplicate the HRTF (Head Related Transfer Function) of the human head and ear.
OTOH, if one was going to listen via transducers in, or on, the ear, thereby eliminating one's own HRTF, then it would make sense to include it in the recording process. In fact, for such binaural recordings, a common method is to use a "dummy head" with the mic elements in ear-like protrusions on each side.
If you need more, google HRTF.
Kal
We hear music emanating from in front of us at a concert (for the sake of my argument, the traditional set-up). A microphone faces the stage, oriented forward like our ears and relatively near them.
The music is so recorded.
Later, a tape of the recording is played back through speakers upon that stage to us.
I'd argue the performance would be the most accurate this way.
mysterious and point out in exactly what way a mirror image (except, of course, for that right-left thing) would be different?
Microphones are placed at the ear locations of a dummy head. The playback through headphones should reproduce exactly what a person in the dummy head location is hearing.
Personally, I explored binaural recordings with some excitement and was a little disappointed. It doesn't work perfectly for me. Maybe my head is the wrong size or my ears don't match or something.
Once you leave binaural recording, there is a vast range of microphones and recording techniques. There are many directional microphones.
Sorry. I do not find the discussions you initiate to be worth more than a passing comment. And I stand by the use of simplistic.
Kal
d
1. Most of the time you seem to want to provoke rather than to explore.
2. Your original post here seems to indicate that you have not fully thought through the basic issues.
3. The more complex the matter, the more time and effort it takes to discuss it.
4. Consequently, I tend to use the hit-and-run form of response unless the topic and/or the proposition really engages me.
Kal
...and our ears 'filter' it when we are exposed to the sound, then if we used an ear shaped mic distribution to 'pre-filter' it, what finally got to our ears would not be representative of the original sound. It would be like listening through serial sets of ears.
;)
The goal of the Hi FI is to recreate the original sound. Your ears will do what they are going to do when you hear that. "Pre-filtering" would then essentially 'double filter' what made it to your ear drum, removing you even further from sonic accuracy.
yours is the most viable answer. The microphones are not trying to emulate the function of the human ear. It's function is to duplicate the experience of the instrument or voice performing in real time and space. Similarly a speaker seeks to emulate that performance in space, not what the human ear can hear. Since most sound is created in a 360 degree dispersion pattern, you would want a replication to be similar in its pattern.
Stu
Nerd!
.
omni directional
(nt)
Post a Followup:
FAQ |
Post a Message! |
Forgot Password? |
|
||||||||||||||
|
This post is made possible by the generous support of people like you and our sponsors: