Some random car audio theory
Some random car audio theory
Aside from the genre of SPL competition, I think most people want to have an as accurate as possible listening experience when in their cars, which is one of the biggest reasons we all post here and the goal we strive for. So we're spending hundreds, if not thousands, on more accurate speakers, crossovers, cleaner amps, smoother power, sound baffling and deadening, acoutic engineering, etc etc etc. So here's a new idea.
With the combination of "surround sound" headphones and one or two subwoofers, I think true sonic reproduction in a car can be easily attained and for far less money. But before anyone jumps down my throat about headphones being illegal/obtrusive/etc, keep in mind this is just theory. I'm sure the idea could be played with to somehow start a new idea in car audio, but this is just what I've had in mind so far.
Surround sound headphones. I haven't done much research on this, so I'm not sure if the technology even exists yet, but I'm sure it will be soon. Headphones are basically one small speaker over each ear meant to reproduce a flat frequency response at very close range. This is already a nightmare situation to work with, but the engineering and technologies of headphones have come so far as to almost claim true sonic reproduction. This isn't ever going to be accurate though, because bass reproduction needs to be felt, rather than heard. ANYway... I figure, why can't headphones have two speakers on each side; one towards the front of your head and the other towards the back? Hey, we got ourselves surround sound capability. This is the perfect setup for car audio and dvd theater, both of which are mobile technologies.
So just fill in the blanks from here. All you need is accurate bass reproduction. Add in a sub or two and every passenger in the car is experiencing true sonic reproduction in a car.
I'd like to hear if anyone has had similar ideas, or just expand on this one. Perhaps this idea can go somewhere, like a project car.
With the combination of "surround sound" headphones and one or two subwoofers, I think true sonic reproduction in a car can be easily attained and for far less money. But before anyone jumps down my throat about headphones being illegal/obtrusive/etc, keep in mind this is just theory. I'm sure the idea could be played with to somehow start a new idea in car audio, but this is just what I've had in mind so far.
Surround sound headphones. I haven't done much research on this, so I'm not sure if the technology even exists yet, but I'm sure it will be soon. Headphones are basically one small speaker over each ear meant to reproduce a flat frequency response at very close range. This is already a nightmare situation to work with, but the engineering and technologies of headphones have come so far as to almost claim true sonic reproduction. This isn't ever going to be accurate though, because bass reproduction needs to be felt, rather than heard. ANYway... I figure, why can't headphones have two speakers on each side; one towards the front of your head and the other towards the back? Hey, we got ourselves surround sound capability. This is the perfect setup for car audio and dvd theater, both of which are mobile technologies.
So just fill in the blanks from here. All you need is accurate bass reproduction. Add in a sub or two and every passenger in the car is experiencing true sonic reproduction in a car.
I'd like to hear if anyone has had similar ideas, or just expand on this one. Perhaps this idea can go somewhere, like a project car.
interesting idea, but when youre pulling up to a spot and you got earphones on instead of ground shaking sound projecting from the cabin of your car, how do you think that would look? earphones may do the trick, but its not really fullfilling the true sound experience.
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i love the theoritcal ideas myself, so i'll give some input. first, i believe sony and a few others have dolby surround headphones and there is even possibly a pair or two of dolby digital. its not true just due to the fact that its two speakers and not 5.1 or 6.1. There is also on some home recievers a dolby surround headphone setup i've seen, meant to synthesize 5.1 in a set of headphones. a lot of it (i believe) has to do with delay and whatnot, but dont hold me to it. if you look into the SQ competitors (which is what i'm trying to do) is that most of them only use a set of speakers up front and a sub. no need for tons of drivers, just a basic setup. with some basic measurements and a lot of time, you can set up a set of kicks so that both the driver and passenger hear the sound perfectly (the point of SQ competition). when you close your eyes, you wont just hear the sound from two points, you'll hear it all in front of you, much like a concert.
now, about the bass and feeling idea. Aura makes what are called bass shakers. they attach to the bottom of your seat and allow you to feel the bass. they take between 35-50 watts a piece and are pretty good at fooling your mind into thinking you have a lot of bass. not a replacement for a sub, but a decent accompaniment.
oh, and another thing for ya to look into. flat panel speakers should be getting into cars soon. omni-directional. can be put anywhere without being an eyesore. supposed do what you are speaking of.
now, about the bass and feeling idea. Aura makes what are called bass shakers. they attach to the bottom of your seat and allow you to feel the bass. they take between 35-50 watts a piece and are pretty good at fooling your mind into thinking you have a lot of bass. not a replacement for a sub, but a decent accompaniment.
oh, and another thing for ya to look into. flat panel speakers should be getting into cars soon. omni-directional. can be put anywhere without being an eyesore. supposed do what you are speaking of.
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not true just due to the fact that its two speakers and not 5.1 or 6.1.
In order for it to be 100% effective, the shape of the human head and its effects on a point-source sound at 2 locations of the head (each ear) is of paramount importance. The brain's ability to recognize the incredibly minute differences in sound at each ear is what allows localization in the first place. Combine these minute differences with the infinately complex sounds generated from any given acoustical interraction with your local surroundings, and you begin to get a feel for just how complex of an issue this is.
Our technology is nowhere near the level necessary to pull off such a task in a way to make it convincing. Surround sound in its current form is pretty damned entertaining, but I really wouldn't call it realistic even in the least.
Jim, I think you might be missing my point. It's true that in any audio-only setup, all you need is two sources. But no matter how hard you try to fool the mind with digital effects, you still can't accurately tell if the sound is in front of or behind you (in headphones). In essence, you're hearing the sound as if it were originating from the front of your head, anywhere on a horizontal line between each ear. My idea is mostly for mobile theater, I suppose, which necessitates four points of origin for the sound. Personally, I think home theater should have 8.1 systems, so you can tell when things are above or below you, as well, but that's a whole other can of worms.
Really, this whole idea boils down to coming up with headphones that CAN reproduce surround sound, with two speakers for each ear. On the left ear, you have the LF and LR channels; on the right: RF and RR.
As for looking cool; well I guess this kind of setup isn't for us f-body fans. We associate ourselves with the words fast and loud. But having something like this for minivan drivers, families, etc would, in my opinion, be the next logical step in mobile theater. Those bass shakers would fit in perfectly to the equation. The whole thing keeps the driver from being distracted (hey, the safer, the better), and gives an awesome theater experience for everyone else.
Really, this whole idea boils down to coming up with headphones that CAN reproduce surround sound, with two speakers for each ear. On the left ear, you have the LF and LR channels; on the right: RF and RR.
As for looking cool; well I guess this kind of setup isn't for us f-body fans. We associate ourselves with the words fast and loud. But having something like this for minivan drivers, families, etc would, in my opinion, be the next logical step in mobile theater. Those bass shakers would fit in perfectly to the equation. The whole thing keeps the driver from being distracted (hey, the safer, the better), and gives an awesome theater experience for everyone else.
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Not true, you've just never heard a GOOD recording on a set of GOOD headphones.
Case in Point, go to www.autosound2000.com and buy the CD labeled 'My Disk'. Then listen to track 85 and 86 on a set of Sennheiser HD 570's, 590's or 600. NOW, tell me you can't hear something infront, behind, or 20ft to the left or right of you. The recording is of a time trial at Indy with the mic 'walking' down pit road.
The key is, a microphone CAN NOT AND WILL NOT accuratly 'grasp' how we hear. The ONLY way to do it is to use what they call ITE (In The Ear) recording. Its basically a complete model of a human head (along with materials that absorb/reflect sound, etc) that has a mic in each ear.
I guarentee you that if you listen to those tracks on a set of good headphones you will be constantly looking around cause you SWEAR there is a PA system to the right of you and an Indy car blazing past you at 200+mph.
Case in Point, go to www.autosound2000.com and buy the CD labeled 'My Disk'. Then listen to track 85 and 86 on a set of Sennheiser HD 570's, 590's or 600. NOW, tell me you can't hear something infront, behind, or 20ft to the left or right of you. The recording is of a time trial at Indy with the mic 'walking' down pit road.
The key is, a microphone CAN NOT AND WILL NOT accuratly 'grasp' how we hear. The ONLY way to do it is to use what they call ITE (In The Ear) recording. Its basically a complete model of a human head (along with materials that absorb/reflect sound, etc) that has a mic in each ear.
I guarentee you that if you listen to those tracks on a set of good headphones you will be constantly looking around cause you SWEAR there is a PA system to the right of you and an Indy car blazing past you at 200+mph.
I'm gonna have to disagree with you, mcss. I've listened to plenty of good recordings on many sets of good headphones. Like 24 track tape on AKG, Fostex, and Sennheiser headphones in professional recording studios.
ITE recording isn't a technology that can be applied here. That's only used in research of human hearing. It's not meant to be reproduced sonically, because it would negate the whole point of reproducing audio ACCURATELY. ITE is meant to be interpretted digitally and recorded as data for research. For reproduction, you want to record everything exactly as it hits the microphone, and then reproduced exactly out of a speaker. So that the original sound wave that hit the mic to begin with is leaving the speaker and heading towards your ears just the way it started.
I believe if you say to yourself, "ok, i'm hearing variances in volume and panning, and there are digital reverb acoustics being applied to this CD" when you are listening to something recorded, you will realize it's there. You're not actually hearing anything in front of or behind you, or 50 feet away. The Indy car zooming past you is the result of a left and right microphone, which is basically a parabolic pan from one side to the other, and a parabolic rise and fall of volume.
ITE recording isn't a technology that can be applied here. That's only used in research of human hearing. It's not meant to be reproduced sonically, because it would negate the whole point of reproducing audio ACCURATELY. ITE is meant to be interpretted digitally and recorded as data for research. For reproduction, you want to record everything exactly as it hits the microphone, and then reproduced exactly out of a speaker. So that the original sound wave that hit the mic to begin with is leaving the speaker and heading towards your ears just the way it started.
I believe if you say to yourself, "ok, i'm hearing variances in volume and panning, and there are digital reverb acoustics being applied to this CD" when you are listening to something recorded, you will realize it's there. You're not actually hearing anything in front of or behind you, or 50 feet away. The Indy car zooming past you is the result of a left and right microphone, which is basically a parabolic pan from one side to the other, and a parabolic rise and fall of volume.
It is IMPOSSIBLE to achieve that without using ITE recording though. No matter what, ditially mastering, sound fields, digital phase changes, etc WILL NOT ever sound right. It always sounds fake.
Yes you can use the ITE for making recordings, its the only logical way to do so. The only way you can get an accurate recording of say a big band in a concert hall is to recreate HOW HUMANS HEAR. Using a couple of regular mic's and mixing will NEVER work.
How can you say it won't be accurate recordings?? Its the most accurate form of recording....
You need to listen to that CD....I guarentee, no Panning of stereo recordings WILL EVER recreate what it does. You hear making the turn behind you, you then hear it scream past you (with a perfect image of it coming up on you to you and then passing you, perfect images infront and behind) and then make the next turn. When the car comes in the pit and parks behind you, you want to move because it 'feels' like the car is going to run into you. How can you call that not being accurate????
Yes you can use the ITE for making recordings, its the only logical way to do so. The only way you can get an accurate recording of say a big band in a concert hall is to recreate HOW HUMANS HEAR. Using a couple of regular mic's and mixing will NEVER work.
How can you say it won't be accurate recordings?? Its the most accurate form of recording....
You need to listen to that CD....I guarentee, no Panning of stereo recordings WILL EVER recreate what it does. You hear making the turn behind you, you then hear it scream past you (with a perfect image of it coming up on you to you and then passing you, perfect images infront and behind) and then make the next turn. When the car comes in the pit and parks behind you, you want to move because it 'feels' like the car is going to run into you. How can you call that not being accurate????
The except from My Disk;
"NOTE: The effects intended to be demonstrated by the following tracks lose most of their effectiveness unless listened to with headphones or specially designed loudspeakers properly positioned.
The following tracks were included to demonstrate some of the principles that enable us to localise sounds and percieve our surroundings. Since its very beginning, stereo has done a great job of defining a lateral sound stage. The ability to completely surround us has not been a major goal until recently
These tracks demonstrate an interesting recording technique using a process known as " In The Ear" (ITE) recording. This process utilizes a small pair of laboratory probes less than 1/16" in daimeter, spaced about .050" from each eardrum of a hunman listener. Using this procedure, the transfer function of the head, ear canal, and pinnae are encoded into the recording. When listened to on a system with greater than 20dB left-to-right separation (acoustic as well as electrical), the sense of space, direction and ambience is captured with stunning realism. Even sounds that occur behind you are accurately placed. Be advised that the acoustic separation requirement virtually rules out almost all conventional stereo loudspeaker placement schemes. Conventional systems can reproduce the lateral sound stage but they usually lack the ability to convey depth and height. Most of this problem is due to an effect known as inter-aural cross correlation. This is caused when the left ear hears the right speaker as well as the left speaker, and the right ear hears the left speaker as well as the right. The recordings were made on Pit Row during the 1994 time trials at the Indianapolis Motor Speedway (how's that for a big sound stage) and are excepts from an entire afternoon of recording."
I have converted the tracks to mp3 (bitrate of 320).
Track 85
Track 86
"NOTE: The effects intended to be demonstrated by the following tracks lose most of their effectiveness unless listened to with headphones or specially designed loudspeakers properly positioned.
The following tracks were included to demonstrate some of the principles that enable us to localise sounds and percieve our surroundings. Since its very beginning, stereo has done a great job of defining a lateral sound stage. The ability to completely surround us has not been a major goal until recently
These tracks demonstrate an interesting recording technique using a process known as " In The Ear" (ITE) recording. This process utilizes a small pair of laboratory probes less than 1/16" in daimeter, spaced about .050" from each eardrum of a hunman listener. Using this procedure, the transfer function of the head, ear canal, and pinnae are encoded into the recording. When listened to on a system with greater than 20dB left-to-right separation (acoustic as well as electrical), the sense of space, direction and ambience is captured with stunning realism. Even sounds that occur behind you are accurately placed. Be advised that the acoustic separation requirement virtually rules out almost all conventional stereo loudspeaker placement schemes. Conventional systems can reproduce the lateral sound stage but they usually lack the ability to convey depth and height. Most of this problem is due to an effect known as inter-aural cross correlation. This is caused when the left ear hears the right speaker as well as the left speaker, and the right ear hears the left speaker as well as the right. The recordings were made on Pit Row during the 1994 time trials at the Indianapolis Motor Speedway (how's that for a big sound stage) and are excepts from an entire afternoon of recording."
I have converted the tracks to mp3 (bitrate of 320).
Track 85
Track 86
Relax, I'm not trying to attack anybody.
Here's my thought process; just think it over, it will make sense:
The point of audio reproduction isn't to try to reproduce how the ear would capture it. Not at the recording stage. The microphone's job is to capture audio with a perfectly flat frequency response, also known as 20-20,000hz +/- 0db. This means that there will be absolutely no coloration, or change, in the sound as it gets recorded to some particular medium (let's say digital with an infinite bitrate, just for theory's sake). So now you have your audio sample recorded exactly as it should be. The only step left is to playback the sample with a perfectly flat frequency response, so that, again, there is absolutely no coloration in the sound. This is true audio reproduction in theory, which I think we both agree on already.
Now, when I envision the ITE technology, I don't see it being able to record with a truly flat frequency response. The human ear and pathway to the eardrum allow for lots of coloration of whatever sound is travelling through them. For example, try pressing the back of your ear closer to your head. Even the slightest change and you start hearing more high-end frequencies. This is coloration. It's something you don't want when recording accurately.
As for recording live music, two mics built to the form of a human head is not the way to do it. This is something I have the most knowledge of, as I've done this very thing for many years. If you go to a concert, you can move as little as two feet in any direction while near the stage and you will hear a completely different mix every time. True sonic reproduction isn't to record it as a human would hear it. It's to record it from the very source of the sound itself, and play each source back from the exact spot it was located, relative to the listener and all of the other recorded sources in that timeframe. This is why four microphones going to four speakers as a surround sound setup, with a flat frequency response, is superior to two mics going to two speakers; no matter if the mics are mounted ITE or on 15 dollar mic stands.
I'll have to get the CD you're talking about and listen to it to really make an educated opinion about it. If anyone else can explain what I'm saying any better, please do so.
Here's my thought process; just think it over, it will make sense:The point of audio reproduction isn't to try to reproduce how the ear would capture it. Not at the recording stage. The microphone's job is to capture audio with a perfectly flat frequency response, also known as 20-20,000hz +/- 0db. This means that there will be absolutely no coloration, or change, in the sound as it gets recorded to some particular medium (let's say digital with an infinite bitrate, just for theory's sake). So now you have your audio sample recorded exactly as it should be. The only step left is to playback the sample with a perfectly flat frequency response, so that, again, there is absolutely no coloration in the sound. This is true audio reproduction in theory, which I think we both agree on already.
Now, when I envision the ITE technology, I don't see it being able to record with a truly flat frequency response. The human ear and pathway to the eardrum allow for lots of coloration of whatever sound is travelling through them. For example, try pressing the back of your ear closer to your head. Even the slightest change and you start hearing more high-end frequencies. This is coloration. It's something you don't want when recording accurately.
As for recording live music, two mics built to the form of a human head is not the way to do it. This is something I have the most knowledge of, as I've done this very thing for many years. If you go to a concert, you can move as little as two feet in any direction while near the stage and you will hear a completely different mix every time. True sonic reproduction isn't to record it as a human would hear it. It's to record it from the very source of the sound itself, and play each source back from the exact spot it was located, relative to the listener and all of the other recorded sources in that timeframe. This is why four microphones going to four speakers as a surround sound setup, with a flat frequency response, is superior to two mics going to two speakers; no matter if the mics are mounted ITE or on 15 dollar mic stands.
I'll have to get the CD you're talking about and listen to it to really make an educated opinion about it. If anyone else can explain what I'm saying any better, please do so.
Not trying to attack anyone either, sorry if it came off that way. 
Now, the way I look at it, the point of recording is to recreate how we hear. We spend countless hours setting up speakers and such to get that '4th row concert hall' soundstage.
My way of thinking is this. The only way to recreate a live experiance is to capture it in a way that recreates how we would hear it. That can't be done with a regular mic. Now, if we as humans had mic's sticking out of the side of our head it would, but thats not the case.
Our ear lobes and ear canal affect how we hear and and localize sound. Our ears don't 'color' the sound, by the way sound waves reflect/refract off of our lobes and then go into the canal and vibrate the drum is how we determine where a noise is coming from. Its an extremely difficult thing to realize using math (if you've never seen wave eqn's consider yourself lucky
) and thus impossible to recreate using a regular mic and digital processing.
Your example of how the ear colors sound by pressing on it is faulty for the purpose your are trying to convey. Our ears a made perfectly to achieve what they do, when you press on the canal you deform its shape and change the volume. Its the same thing as putting a speaker in an incorrect box, it won't sound right. The box (ear) and speaker (ear drum and the bone that vibrates) have to be perfectly matched. Thankfully, *** did that for us. So when you press on the ear you are changing the trasnfer function of how you hear and thus add color to the sound.
Now for a concert recording, to recreate a live experiance recording the source of the sound is 1 of MANY things you have to record to get an accurate recording. You have to record how the sound waves of the source interact with your ear lobes, you have also record all reflected sound from the roof, walls in front, side and behind you, reflections off the guy sitting next to etc etc. Just as with recording the signal source, all these sounds are affected by how and where they hit your ear lobe. THAT is how we percieve location of sound (how and where the wave hits your ear lobe and then reflects into your canal). Therefore the only way to get a recording to accurately record how we percieve sound location is to have a mic that records what we hear, not what a mic hears.

Now, the way I look at it, the point of recording is to recreate how we hear. We spend countless hours setting up speakers and such to get that '4th row concert hall' soundstage.
My way of thinking is this. The only way to recreate a live experiance is to capture it in a way that recreates how we would hear it. That can't be done with a regular mic. Now, if we as humans had mic's sticking out of the side of our head it would, but thats not the case.
Our ear lobes and ear canal affect how we hear and and localize sound. Our ears don't 'color' the sound, by the way sound waves reflect/refract off of our lobes and then go into the canal and vibrate the drum is how we determine where a noise is coming from. Its an extremely difficult thing to realize using math (if you've never seen wave eqn's consider yourself lucky
) and thus impossible to recreate using a regular mic and digital processing.Your example of how the ear colors sound by pressing on it is faulty for the purpose your are trying to convey. Our ears a made perfectly to achieve what they do, when you press on the canal you deform its shape and change the volume. Its the same thing as putting a speaker in an incorrect box, it won't sound right. The box (ear) and speaker (ear drum and the bone that vibrates) have to be perfectly matched. Thankfully, *** did that for us. So when you press on the ear you are changing the trasnfer function of how you hear and thus add color to the sound.
Now for a concert recording, to recreate a live experiance recording the source of the sound is 1 of MANY things you have to record to get an accurate recording. You have to record how the sound waves of the source interact with your ear lobes, you have also record all reflected sound from the roof, walls in front, side and behind you, reflections off the guy sitting next to etc etc. Just as with recording the signal source, all these sounds are affected by how and where they hit your ear lobe. THAT is how we percieve location of sound (how and where the wave hits your ear lobe and then reflects into your canal). Therefore the only way to get a recording to accurately record how we percieve sound location is to have a mic that records what we hear, not what a mic hears.
Last edited by mcss383; Oct 7, 2002 at 11:53 PM.
I think I see where the discrepency is here. The point of recording isn't to recreate how we hear; it's to recreate what is there. We do spend countless hours setting up speakers to get the perfect soundstage, but the speakers' roles are the same as the mic: to recreate what was there. Not how we hear it. When the sound finally reaches our ears from those speakers, then our ears will do all the interpretting for us. There's no need to have the mics in another set of ears, so to speak. As I listened to the samples you have posted, I still felt that the ITE system was only able to record a lateral soundstage (listened through AKG K270S headphones). The lateral soundstage was perfect in my opinion, better than any other setup I've heard, but it still wasn't able to produce a soundstage that moved front to back. Though it's true that we only have two ears, eardrums don't work like microphones. The work more like hundreds of tiny headphones in a small area. This is how we can determine from said reflections/refractions off the lobes where a sound is coming from. The microphones in the ITE system would have to do the same thing, which would require hundreds of little speakers as well.
Pressing on any part of the ear actually proves my point. Ears are all shaped differently to begin with, which means an ITE recording is going to be relative to the person that had the microphones in their ears. Moving any part of the jaw or face distorts the ears as well, which will colorize any sound heading for the mics.
I believe ITE is the best way to record a lateral soundstage (2 channel audio). But it still will not compensate for depth and height of any audio source. The in-ear mics would actually have to have two or more smaller mics inside them to be able to do this, in which case you would need the same number of speakers in your headphones. This is the same as setting up four mics for surround sound recording and then having two speakers on each side of a headphone set.
Pressing on any part of the ear actually proves my point. Ears are all shaped differently to begin with, which means an ITE recording is going to be relative to the person that had the microphones in their ears. Moving any part of the jaw or face distorts the ears as well, which will colorize any sound heading for the mics.
I believe ITE is the best way to record a lateral soundstage (2 channel audio). But it still will not compensate for depth and height of any audio source. The in-ear mics would actually have to have two or more smaller mics inside them to be able to do this, in which case you would need the same number of speakers in your headphones. This is the same as setting up four mics for surround sound recording and then having two speakers on each side of a headphone set.
ITE recording won't do much for using anything other than headphones for reasons stated in the My Disk part that I quoted. Using headphones to listen (because they are the most ideal way of getting stereo seperation) is the best way to get the effect of it. Did you listen to the end of track 86 when the car pulls up behind him? Don't listen for the false soundstage that you would get with say dolby 5.1 where it will alter the stage, imagine being in a parking lot and a car stop right behind you, it is identical (well maybe not identical, but DAMN close lol) to what you hear with headphones listening to that track. Its true to form, something you couldn't get with a mic (in either stereo or 5/6/7.1)
You sure? lol. I can turn my head and follow the PA spkr from infront of me and then behind me (smooth fluid transition, like your approaching something). You can also clearly tell the PA is below the horizontal level of the ITE. Also listening to this in .mp3 format (even though its the best I could get it) and on a computer sound card (unless you have an Aardvark card, in which case you better watch out I might steal it from you. lol) it wont be very good. 
But one could argue that wouldn't be accurate because the room you have the speakers in can't duplicate the reflections you have in a large hall and a standard mic does a very poor job of accuratly obtaining those reflections (no matter the number of mic's or the location).
that is true, but I bet when person A hears a trumpet in a hall and person B with a different shaped ear canal hears that same trumpet (in the same hall and same spot where A stood, also facing exactly the same way, same height etc etc) they are hearing the same thing. If different peoples ears added coloration to the sound then if you had 2 musician's tuning a guitar they would never agree what is 'correct' because one person would have an odd coloration with respect to the other. And getting to this, is REALLY splitting hairs, and the model we have 'established' for explaining how an ear hears is rediculously simplified anyways. lol
Maybe it comes down to preference. I've NEVER heard a surround sound recording sound real. That ITE recording at Indy with headphones is by far the most realistic thing I have ever heard (w.r.t. image width, height and depth). The closest thing I have heard to that is in a Tweeter Demo room using all Martin Logan's. But it still had that 'fake reality' (surround sound) and didn't sound realistic, it just sounded really cool and really nice. I do like those the best of any Home Theater spkr btw. hehe
but it still wasn't able to produce a soundstage that moved front to back

When the sound finally reaches our ears from those speakers, then our ears will do all the interpretting for us.
Ears are all shaped differently to begin with, which means an ITE recording is going to be relative to the person that had the microphones in their ears.
Maybe it comes down to preference. I've NEVER heard a surround sound recording sound real. That ITE recording at Indy with headphones is by far the most realistic thing I have ever heard (w.r.t. image width, height and depth). The closest thing I have heard to that is in a Tweeter Demo room using all Martin Logan's. But it still had that 'fake reality' (surround sound) and didn't sound realistic, it just sounded really cool and really nice. I do like those the best of any Home Theater spkr btw. hehe
Ugh... I feel like I'm beating a dead horse here. Somebody else chime in please.
The headphones required to get the full effect of this would need to be placed in the same spot the mics were: .05" away from the eardrum. But for all intents and purposes, this will only create the best possible LATERAL soundstage. The sheer fact that a mic can only record one channel at a time means that the headphones are going to push out only one channel. This is the same on both sides, which means it's not accurate reproduction. It is stereo. You can't hear anything in front of or behind you. Again, I would need headphones to fit .05" away from my eardrum to really be able to tell, but in theory it does not work.
Reproducing a 4.1 environment is exactly my point in the first place. The headphones will have two channels on each side and a sub somewhere in the car (or bass shaker). This is superior to two channels, which as far as you've shown is what the ITE system has. Four channels is superior to two channels, period. Now, if you can show me that the ITE mics record more than one channel at once, THEN I would say it's the perfect setup. Still, this would require an ITE medium to play the samples (CDs record in stereo, no more than 2 channels) and ITE headphones to play it back, placed .05" away from the eardrums. Again, this is only if the ITE mics record more than one channel at a time.
Again, it's only true to form if the mics can record more than one channel at a time. Also, keep in mind that DVDs are essentially playing back audio for four channels of seperation, not 5, 6 or 7. Front left and right, and rear left and right. These numbers are for the speakers used in the system, NOT the number of recorded channels on the given medium (probably DVD).
As I said before, I was listening through AKG-K270S headphones. My sound "card" is a rackmounted Echo Layla 24, so I think I'm safe. Your 320kbps 44khz mp3s are more than adequate for reproducing CD quality. CDs are all recorded at 128kbps 44khz, so that's not an issue either. Mp3 is a 2-channel medium, just like CDs, so it doesn't make any difference in this case.
The number of mics and the locations DOES matter. Very much so. The simple fact that a stereo image is far more realistic than a mono image proves this. Two is better than one. If you had ten thousand mics all facing outward in some direction from a center point, so as to record any incoming soundwaves from ten thousand directions, it would be ridiculously more accurate than ANY two channel setup.
This statement I was surprised at, because it's a basic concept and you've got it all wrong. Two musicians trying to tune a guitar wouldn't disagree, because sound is relative to the person hearing it. Both would hear the sound they're used to when tuning a string, and when they each hear the right note, they both say "yup, now it's in tune." A 400hz soundwave will always be a 400hz soundwave, but if you were to put the same mic in two different ears (different people), and graph the frequency response each time, you'd end up with two different charts, simply because of the different shapes of the ears.
Me neither, to be honest, but it sounds superior to any 2 channel recording. My assumption for this is that surround sound setups aren't meant to actually immerse you in the environment, but simply add ambience to something that is in front of you (the TV). For true immersion, the center channel is useless in 5.1 setups, so all you need is 4 channels. Then the recording setup would have to be exact to the setup you're playing it back on. Get yourself a four track tape recorder, and stand outside in a park somewhere. Set up four mics as close to you as possible, each facing outward, at ear level, towards one of the four cardinal points (north, east, south, west). Make sure all the levels are the same and use the same model mics. Record all four tracks, then go home and setup four speakers in the same exact spot the mics were, relative to yourself. Plug them in to each of the four output channels on the four-track, making sure each speaker is placed where each mic was (ie: you don't want to end up with NSEW instead of NESW). Hit play and see my point. That is true surround sound recording. It's not "true" recording, for which I would need an infinite number of mics and speakers, but neither is the ITE. Four channels will always be better than two.
I'd like to see some information about ITE. If you have any websites or whatnot, please post them, so I can look into this further.
Originally posted by mcss383
Using headphones to listen (because they are the most ideal way of getting stereo seperation) is the best way to get the effect of it.
Using headphones to listen (because they are the most ideal way of getting stereo seperation) is the best way to get the effect of it.
Did you listen to the end of track 86 when the car pulls up behind him? Don't listen for the false soundstage that you would get with say dolby 5.1 where it will alter the stage
Its true to form, something you couldn't get with a mic (in either stereo or 5/6/7.1)
Also listening to this in .mp3 format (even though its the best I could get it) and on a computer sound card (unless you have an Aardvark card, in which case you better watch out I might steal it from you. lol) it wont be very good.
But one could argue that wouldn't be accurate because the room you have the speakers in can't duplicate the reflections you have in a large hall and a standard mic does a very poor job of accuratly obtaining those reflections (no matter the number of mic's or the location).
that is true, but I bet when person A hears a trumpet in a hall and person B with a different shaped ear canal hears that same trumpet (in the same hall and same spot where A stood, also facing exactly the same way, same height etc etc) they are hearing the same thing. If different peoples ears added coloration to the sound then if you had 2 musician's tuning a guitar they would never agree what is 'correct' because one person would have an odd coloration with respect to the other.
Maybe it comes down to preference. I've NEVER heard a surround sound recording sound real.
I'd like to see some information about ITE. If you have any websites or whatnot, please post them, so I can look into this further.
Last edited by CaysE; Oct 8, 2002 at 11:16 AM.
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my wifes mini van has 2mb quart speakers in the front and 2 in the back with tweets in the top of the pillars in front. and 2 twelves in a banpass. who the fu k needs headphones!!! load clear and possitioned well for imagry and surronu sound when the laptop is plugred in for the kid. shrek sounds pretty fing good. better than my home setup i think. u waste too much time on BS ideas and not enough on proven solutions. I used to compete just got bored. if youve never been to a true comp go and u will find the answrers you seek. jusrt my .02 cents
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oh and yes it sounds better than my camaro. the bass is lower and hits harder in the maro but the clarity and imagry is much better in the van.
Hey it's great that you have a proven solution in your van, but how do you think people come up with these solutions? Why, BS ideas of course! There's a difference between people using ideas and people making them. One spends the other's money.
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um well I sure didnt win any compitions by using other peoples ideas. but headphones????? wtf that defeats the whole purpose doent it?? it wouldnt be called car audio then would it??
It's audio. It's in a car. Of course it's car audio. It's a theoretical situation for SQ with surround sound. It defeats a lot of things, like dealing with the confining space and awkward angles of the interior of a car, but certainly does not defeat the point. Say you're getting sick of hearing Shrek for the 80 thousandth time (I pray you're not actually WATCHING it while driving). So instead of turning it off and having your kid asking you "are we there yet" every 15 seconds, you can switch the system to my idea. You're not bothered with it, your kid gets to watch the movie the way it was meant to be watched (4.1 surround), and hey you could probably listen to your own music in the car in the meantime.
Of course you did. You bought products that were derived from someone else's idea. They're spending your money. I probably won't be spending your money if I turn this into a product, I'm sure, but it seems like a marketable idea to me.
um well I sure didnt win any compitions by using other peoples ideas
Last edited by CaysE; Oct 8, 2002 at 01:10 PM.
Ok, your last post makes more sense to me.
You are meaning having the mics facing away from the listener forming a 'X' (a mic in front, mic behind, and then one on the left and one on the right)?
Here's what you need to do. Go out and make a 4 channel recording like you are saying (it seems you have the components to do so, I don't) then put it to .mp3 and post it. Then I can set it up with spkrs and give it a listen. The way you are describing recording is different than anything I've heard, so I would like to give it a whirl.
After that, I will make a decision, but I still feel that ITE will give just as good a result because it takes into account the sound waves hitting the ear lobe and reflecting into the mic. Thus only needing two channels. using the 4 mic's in the 4 directions is a way of reproducing what it does IMO. Since mic's can't pick up ambiance that well doing what you are describing would do it much better than 2-channel, but I still feel ITE would do it better.
I see where I was flawed in my example, thx for pointing that out.
-------------------
thats a very narrow view. If people did that we would still be listening to mono music. Question everything.
Really? I think you need to rethink that statement. Not only is it very arrogant, its very wrong. Unless of course you invented and pioneered in everything that has brought audio to where it is today.
You are meaning having the mics facing away from the listener forming a 'X' (a mic in front, mic behind, and then one on the left and one on the right)?
Here's what you need to do. Go out and make a 4 channel recording like you are saying (it seems you have the components to do so, I don't) then put it to .mp3 and post it. Then I can set it up with spkrs and give it a listen. The way you are describing recording is different than anything I've heard, so I would like to give it a whirl.
After that, I will make a decision, but I still feel that ITE will give just as good a result because it takes into account the sound waves hitting the ear lobe and reflecting into the mic. Thus only needing two channels. using the 4 mic's in the 4 directions is a way of reproducing what it does IMO. Since mic's can't pick up ambiance that well doing what you are describing would do it much better than 2-channel, but I still feel ITE would do it better.
I see where I was flawed in my example, thx for pointing that out.
-------------------
u waste too much time on BS ideas and not enough on proven solutions
um well I sure didnt win any compitions by using other peoples ideas
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I have an mp3 player if I want to listen to somptin other thatn shrek. good luck with the idea. after all even the moron that desighned the singing fish made millions. people will buy any dumb idea with the right advertising.
Oh, unfortunatly I don't have any links regarding ITE. I would love to search for them but seeing as how I have hw due tomm in my Linear circuit analysis class, test in ethics also tommorow, hw due in EM fields thurs, and a test in my Lin sys analysis on fri its not a priority right now.
Originally posted by SHAGME
after all even the moron that desighned the singing fish made millions. people will buy any dumb idea with the right advertising.
after all even the moron that desighned the singing fish made millions. people will buy any dumb idea with the right advertising.
mcss: Now we're getting somewhere.
I could record such a thing for you, but it still won't be reproducable in any modern medium aside from dvd, which I don't have the capacity to record to. Mp3 is a two channel audio format and won't be able to play back all four channels that I would record. The same applies to .wav (which is what is recorded on CDs).
ITE is a great idea for recording an environmental experience in first-person. If the mics being used were able to record 4 channels each or more, and it was reproducable with the same number of channels in ITE-ready headphones, it would be astonishingly realistic. Here's a thought I had:
Think of your eardrum as the cone of a speaker. When a soundwave is bouncing through your ear canal, it will hit a specific spot on the cone, depending on what direction the sound came from. In an eardrum, only that specific part of the "cone" would move, not the entire cone. This helps the brain interpret which way the sound came from. On a microphone, the diaphragm represents the eardrum. The difference is, no matter where a sound wave hits the diaphragm, the entire thing moves, not just that specific spot. This negates any possibility of being able to reproduce where the original sound came from, aside from on the lateral plane.
With the right technology and a high enough bitrate, it could be possible to record and playback information with an "indepenent motion" diaphragm and processors on only two channels. They wouldn't be audio channels, though; more like ITE channels. The data stream would have to carry information about where on the diaphragm a soundwave hit it. I'll do some searching online for it, maybe I could throw them some ideas. haha
I could record such a thing for you, but it still won't be reproducable in any modern medium aside from dvd, which I don't have the capacity to record to. Mp3 is a two channel audio format and won't be able to play back all four channels that I would record. The same applies to .wav (which is what is recorded on CDs).ITE is a great idea for recording an environmental experience in first-person. If the mics being used were able to record 4 channels each or more, and it was reproducable with the same number of channels in ITE-ready headphones, it would be astonishingly realistic. Here's a thought I had:
Think of your eardrum as the cone of a speaker. When a soundwave is bouncing through your ear canal, it will hit a specific spot on the cone, depending on what direction the sound came from. In an eardrum, only that specific part of the "cone" would move, not the entire cone. This helps the brain interpret which way the sound came from. On a microphone, the diaphragm represents the eardrum. The difference is, no matter where a sound wave hits the diaphragm, the entire thing moves, not just that specific spot. This negates any possibility of being able to reproduce where the original sound came from, aside from on the lateral plane.
With the right technology and a high enough bitrate, it could be possible to record and playback information with an "indepenent motion" diaphragm and processors on only two channels. They wouldn't be audio channels, though; more like ITE channels. The data stream would have to carry information about where on the diaphragm a soundwave hit it. I'll do some searching online for it, maybe I could throw them some ideas. haha
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now that sony has your idea it will be pattended and sold under there labe lol now where did I put my bong?
Originally posted by CaysE
mcss: Now we're getting somewhere.
I could record such a thing for you, but it still won't be reproducable in any modern medium aside from dvd, which I don't have the capacity to record to. Mp3 is a two channel audio format and won't be able to play back all four channels that I would record. The same applies to .wav (which is what is recorded on CDs).
mcss: Now we're getting somewhere.
I could record such a thing for you, but it still won't be reproducable in any modern medium aside from dvd, which I don't have the capacity to record to. Mp3 is a two channel audio format and won't be able to play back all four channels that I would record. The same applies to .wav (which is what is recorded on CDs).I didn't think about these details earlier. lol
record two channels to one disk, 2 channels to another disk, use two identical cd players and amps, then send each signal to a spkr. hehe Just make sure you start each track the same or else some funky stuff will start happening.
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I have the perfect solution!!!!!! 
Why don't we just hook little wires to the nerves that go from the areola to the brain, attach them to metal posts just behind our ears like Frankenstein, and record the sounds as elec. impulses (i.e. sign waves).
If we all had those little posts attached to our heads then we all could "listen" that way!!!!!!
That way we could still hear the train coming just before it hits us. :lala:
AJ

Why don't we just hook little wires to the nerves that go from the areola to the brain, attach them to metal posts just behind our ears like Frankenstein, and record the sounds as elec. impulses (i.e. sign waves).
If we all had those little posts attached to our heads then we all could "listen" that way!!!!!!
That way we could still hear the train coming just before it hits us. :lala: AJ
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Originally posted by CaysE
areola? nipples? wha???
I think AJ's losing it... hahaha
areola? nipples? wha???
I think AJ's losing it... hahaha
I guess talkin in an "adult" chat room while posting on a message board at the same time isn't a good idea is it?

If you pay closer attention, you'll see that I also spelled sine waves wrong.

AJ
WOW LONG TOPIC
Wow this is a long topic. The "attachment things" mentioned above are called transducers. You can get them from a few different places. Not sure which one to try. They are all basically the same. They do work real well. If anyone remembers the polk audio home stereo speakers back in the day that were large as hell with like 12 small 6" speaker, well anyway they had them.
AJ: The idea you had is probably the best possible way to reproduce "real" sound. Mics work in basically the same way.... when the diaphragm moves, it sends an electrical impulse through the wire and into the recording medium. The only difference is it can only record one impulse. If we could somehow figure out how to tap every single nerve from the eardrum to the brain and record them, then plug in "output wires" to the same nerves, we'd have the absolute perfect audio playback situation. The only downside of this is that it wouldn't be possible to record from one ear and play back on someone else's. Still, it's a great idea.
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