Accurately reproducing sound?

[DaikenTana]

Howdy all

I'm trying to adjust my recordings to match what it was like to be on the field, but so far I haven't had any good results. I know that each pair of headphones have their own EQ, so that's the biggest problem. So far, I get the best results when listening to the recordings through Sony's pair of earbuds which came with my RH10, and using the on-board EQ on the MD I manage to get a very realistic result. When I listen to the recording on the computer though, it sounds completely different. It even sounds like some of the spatial stereo effect has been lost.

Any ideas?

[greenmachine]

Get some good headphones (which don't require much EQing to sound good) and maybe a better soundcard (although i don't think there are huge differences).

[DaikenTana]

Well I've figured something out. Spectrum Matching is as good as I can get it. Voxengo CurveEQ manages to do a good automatic job, but further manual matching is required.

What I did was this. With the mics in my ears, I put on some headphones and recorded them playing an MP3. I then uploaded that recording to the computer and compared it to the MP3 file. Not bad at all. After spectrum-matching between the real MP3 and the recording, I now have a good EQ adjustment which I apply to all of my recordings now. Listen for yourself:

http://www.sfhsjournal.com/hdrifiles/Real,...eal,%20mics.mp3

1. Real MP3

2. TFB2 recording

3. Real MP3

4. TFB2 recording

This is as close as I can get it so far. I've come to a conclusion that the stereoscopic realism which binaurals give you is far greater when using earbuds than headphones (those which go over your ears.) I don't really know why this is exactly; maybe it's because the sound is more directed into your ear with earbuds where as headphones tend to surround the entire ear with it; I dunno.

Edited August 14, 2005 by DaikenTana

[greenmachine]

Your natural curiosity and inventive talent are astonishing me every time anew. Congratulations - you've just discovered the fact that binaural (in ear) recordings are incompatible with playback through loudspeakers and ear surrounding headphones without correction. Now you need to understand why.

The shape of the pinna (outer ear) has a major influence on the amplitude of certain frequencies reaching your ear. I encourage you to experiment with the influence of close surfaces on the pickup characteristic of microphones. If a mic has a perfectly flat frequency response, this is only true if there are no near surfaces. Even surfaces usually exaggerate high frequencies.

I've recorded a short demonstration. I've placed a mono microphone about 1.5 feet in front of a loudspeaker, on axis with the tweeter. The first few seconds were recorded without any near surfaces, the second near a flat, even surface, third to last in an increasingly horn-shaped surrounding. You'll immediately notice the high frequency boosting and the increasingly directional effect of a horn.

Sample

[attachmentid=583][attachmentid=584][attachmentid=585]

The pinna behaves very similar. If you record binaurally (in ear), you're recording the horn-like influence of the pinna. If you listen through loudspeakers or ear-surrounding headphones, your pinna will color the sound a second time, which is what you perceive as unnatural. If you're listening with earbuds, which sit in your ear, the pinna won't have an influence on the playback side. This is the only way an unmodified binaural recording is meant to be listened to.

For more flexibility regarding playback, the solution would be to either apply a correction curve or to take the mics out of your ears and place them somewhere near them (mounted on glasses, etc.), which is my preferred recording technique. To determine a universal correction curve, you need to have two recordings of the same source - one without any near surfaces, one with the mics in your ear. What you did when substracting the in-ear recording with the original source was to correct the imparities of the microphones/placement -and- your headphones.

Sample 2,4,5 of this thread should be of interest for you to get an idea about the influence of the pinna and close surfaces in general.

This discussion could also be of interest for you.