What is true 3d audio?

Many engines claim it, and I know blitz3d says it does 3d audio (although I haven't used it as I don't have surround speakers)

Is it just positional sounds ie the sound seems to come from its position in 3d space?

Or do any of them actually have interactions with the environment so that you can get echoes down halls, sound dampening of objects colliding with carpet instead of say a wooden floor, doppler shifts for moving sound sources, interference effects for inphase/out of phase sound wave forms.

3D Audio is simply when a sound is emmited in 3D space- if youre racing and a car is behind, then the sound will appear to be coming from behind.

True 3D sound works with surround sound only really since doing it with 2 speakers doesnt allow sound generation from behind :)

Most 3D audio implementations feature doppler shifting, including Blitz3Ds sound system. And some feature reverb, etc. but this typically requires an EAX (or similar) compatible soundcard.

There isn't yet (to my knowledge) any systems that support true audio simulation in the sense of reflecting sound waves off surfaces. There are some research prototypes, but I don't think any are commercially available.

Some soundcards can emulate surround sound on a stereo setup, by altering sounds depending on the direction they are coming from (instead of simply panning the sound between the two speakers). This gives a similar effect to surround sound when wearing headphones.

there's kinda-3d, with works only on headphones ..

I've an expensive mic that does just that... seriously if you record a fart from yourself, and listen back you'll laugh your ass off as you really would swear you did another one. :P

yes you can create such a microphone by yourself.
They just selling their patends with very expensive quallity because in this sound market price = repect.

Haramanai... Alot of precision goes into it.

an SM58 is a better mic than a standard £10 one. Alot of tech goes into the membrane and the actual mic unit.

If your mic's cheap it will pick up some frequencies more than others.

Also, how will your home made mic pick up the sound from different locations??? :P


[edit]

By the way,

In the sound world, price doesn't equal respec' unless you is a chav! :)

Yes ofcourse. Some time back we just buying cheap mic's and we wera changing the mevrane with an expensive one. We were saving to much money with this.
Also have you ever recorded a live acoustic group?
If you had then you will know the trick with the two microphones for stereo.
The same trick it's for suround but with 4 mics.
If I remember well mics with the technic for stereo was around (or they still around) but the manual setup was always the best solution.

And the Chavs made me to abandon my old job.
I was so sick of them... and they are anywhere in the music business.

Singer : I only sing with my shure microphone(eq SM58)

Me : Ok where is your microphone?

Singer : YOu DOn't HaVe One?

Me : Do you wand me to bring and an Ibanez for your quitarist?

And then the singer get it out his microphone.
And boss fired me.

As long as you give the option to turn it off, use it.

If someone doesn't have their 5.1 set up right... IE... My dad... You get really nasty dropouts in the sound depeneding where the cam is... .. I have to stare right at someone to hear them... and I couldn't turn it off in Fable: tlc.

It was upsetting.

Blitz3D really has 2D sound but can be handled internally with reference to an object positioned in 3D space. It's nothing that you couldn't do manually using BB, B+ or Max.

I think there are a couple of possibilities here. Probaly in future, beyond the hardware physics chips, there'll be hardware 3d-sound chips which, as mentioned above, calculate how the sound `would sound` based on the environment you are in and the properties of materials that surfaces are made of, etc... all properly reflected and everything. So when you're in a big hall there's a bigger echo etc. I guess you could simulate that easy enough for particular known circumstances.

The other thing is, maybe you might've experienced it, but I received a demo cd of a 3d audio thing where when you listen to it with headphones, instead of hearing sound `inside your head` between the headphone speakers, you actually hear sounds as if they are OUTSIDE of your head, as would be the case with real audio sources. And it doesn't seem to be based on having a finite number of specific sound sources, it can record any sounds from any 3d location and encode it in such a way that when you play it back it truly does sound like what you're haring actually is located in 3d space, like several feet away or whatever. It's really cool. I think that will be the future of 3d sound, as well, so that you really are hearing things as if you are inside a room and sound sources are outside of you, as they would be in real life. It's not some fakey wakey surround sound speaker-based thing, it's real three dimensional audio.

That's what I referred to... heard that -probably same- cd uh.. back in '99 already orso. That's the same result I get with my binaural mic. When I go out to record a car passing by, some 40meter away from me, and I listen back.. I hear it as I 'heard' it while recording.

I once recorded the ambience at some office I worked once.. the window was open.. cars/city outside. I kept listening on headphones for hours. I didn't even realise I was listening to a recording anymore.. until hours later I stopped the playback and reaslised the city outside went to sleep. :D

Yup, and i know the stereo trick using two mics. Thats not 3D sound though :)

I'm not sure what theyre called but the best microphones i used for accoustic recordings (Real world- in the park etc and not accoustic bands :) ) was a set of headphones that sat in ear with two mic's in each. When you recorded that, i agree, you do get some awesome playback :)



Ahh yes, as CS_TBL wrote, Binaural mic :)