I managed to put my Kicker SS56.2 Splits into my doors yesterday.

The sound stage seems to be rather low and slightly to the passenger side.

The speakers are currently mounted in Co-ax mode, mainly because, at the time, I didn't have the tools and things to put the tweets where I really want them.

Is there anything, apart from moving the tweets up, that I can do that will improve my sound stage?

Let us know which car for a start, and I'm sure some of the experienced installers an give you detailed ideas.

Low and to the passenger side sounds quite familiar - left speaker is probably closer to hitting you in the ears than the right because it's closer to on-axis. Angling your tweeters should help to rectify this, but I'll leave it to the pros to advise how/where, pending the car model as well.

Sounds to me like the main reason is that the left tweeter is more on axis, and therefore, louder to your ear. The problem with high tweeters is that there positioning cant NOT be fixed with TA. Our brains use the loudness of high frequencies for location. Whereas lower frequencies (midrange) are located by time.

If you dont belive me get someone who is running active to alter the TA on the tweeter chans, and I bet you will be hard pressed to hear a difference.

Therefor, the best way to fix tweeter issues is by positioning them correctly in the car, with similar axis position to each other.

I've found that TA does work on tweeters. I have my tweeters in the dash firing at hte windscreen and I only us TA for them, no level changing to get the stage centred.

I have confirmed this also by only playing sound through the tweeters with a mono track and adjusting hte TA alone to get a centre image

*EDIT* BMWTurbo posted was logged on through GF's account

I'll second that, on mine that, TA plays a huge part on my tweets, and changing by even a few milliseconds makes a huge difference, wheras changing the mids doesn't make a huge noticable difference (on smaller adjustments).

Its all dependent on what frequencies your tweeter is playing.

Above ~3kHz, and the wavelength of sound is too small for each of your ears to differentiate the difference between. Your brain uses the differences in the phases of a wavelength between each ear, and their time difference, to localise the centre of the sound.

If the wavelength is too small, then your brain cant tell the difference in phases between two signals. It reverts to its Interaural Intensity Difference mode, which uses the intensity of the sound (loudness) to locate the centre. If two signal reach your ears at the same intensity, then the 'source' is directly in front of you.

Try and think of it as more of a frequency dependant issue, not a speaker dependant. If you're running 2-ways, you'll find the tweeter still responds to TA, because it is still playing ITD frequencies (crossovers arent brick wall filters, after all).

Also, since TA affects time of driver firing, this will also have an effect on reflections.

To change the centre of the stage, you'll need to start moving your midrange driver around more. To change the height without putting the tweeters up, you'll need to investigate a technique known as Digital Inverse Filtering, and EQ'ing around the frequencies affect by the Head Related Transfer points. Believe it or not, you can raise your stage simply by boosting and dropping specific frequencies for the tweeter.!!

Answer - '91 Daihatsu Feroza. No speakers in the doors off the factory line.

Question - What's TA?



And I am NOT moving the pods, they will not be moved unless being replaced.

And there's also a very noticeable difference between when I have the driver's window down or up. (I drive around with my windows down a lot.)

T.A. is "Time Alignment" or sometimes called "Time Correction" and is usually found in more expensive head units that can run "active"

In a car the RH speaker is closer to you than the LH speaker (visa versa for the passenger) TA delays the signal from the speaker closest to you so all the sound reaches you at the same time. It is especially important for the sub if it's in the boot

By the way I drive around with the window down too but any sound stage is mostly lost

Think about where your window is in relation to your speaker when the window is down

This is interesting - I've noticed that playing with tweet TA did little, but changing the volume (I can go -20dB to +20dB on tweets independant of mids) makes more of a difference. I'm going to try setting TA back to 0ish, and try adjusting with gain more than TA and see how I go

My H/U doesn't have TA, it's a Pioneer DEH - 5750.

And I think the the reason is definately the fact that the right tweeter is off axis, so I should try to make it louder to move my sound stage back towards the centre?

you could give it a go - sounds correct in theory or turn it slightly more on axis? just to test?

I can't turn the speaker upwards without a great deal of trouble, I had enough trouble just putting the thing in the pod and modifying the door to fit the damn thing in there. lol

This is just the beginning I tell you!

In two years time you will have three head units, five amps, various speakers lying round your room and numerous install attempts under your belt. You can turn back now or do you want to continue?

Lots of Laughs!!!


Its a lot of hard work to get things right. I just wasted all of tonight trying to re-install my amps. I cut up sheets of MDF and drilled holes and all sorts of stuff only to realise in the end there's not enough space where I wanted to install them.

If you want better sound you will eventually say to yourself "I gotta do it" even if it means a lot of previous work goes down the drain

Good luck with your project mate!

Yes, I can somehow see myself with 3 cars one day.

My house, various ICE components strewn all through it.

And the messy workshop downstairs/in the garage.

speaker anlges improve thing. the hardest thing is to try and get angles and distances to your ears as equal as you can.

the further of axis. the quieter and less detailed a speaker is...

this is like putting ur head on the drivers side window. this is 90degrees off axis to the drivers speaker.



in my car i have my mids in the doors firing with some pretty decent angles. if u draw a line straight from the speaker it goes into the opposite side persons shoulder or chest. this angle is fairly extreme and sticks out from my door a good 4" but even a bit of extra angle. can improve things dramatically as it is no longer firing into a leg/ centre console.

the further away u get ur tweeters the better generally so right in the bottom corners of the A pillars or down in the kick panels is a good place.

if u dont have any angle on ur mids. its not a good idea to have ur tweeters pointing straight at you coz then both ur tweets and mids are on completely different anlges. so if ur speakers are flat try having the tweeter on say a 15degree maybe 30 degree angle...

My speakers point roughly to where the opposite occupant's chest is.

But when I put the window up a little bit the sound moves from one side of the car to the other, depending on what side you are sitting on. It moves to roughly towards the centre console side of your face.-

Aiming a speaker becomes less important if you concentrate on dispersion. Baffles and waveguides. Use these appropriately, and you can get a larger sweet spot with less directional reliance.

You mean reflecting sound of other things?

There are four types of diffusion. Refraction (changing speed of waves - common in light), Resonance (storage and emittance of energy), Diffraction (waves bend around corners) and reflection (waves impacting surface and changing direction).

I got one wrong. Dispersion is scattering of waves, so just ignore that for now. Think to yourself, how can I modify my environment, or speaker placement, so that the waves 'bend' around corners. For example, my dash. Its in the perfect shape of a diffuser, so I can really mount a speaker in the firewall, pointing almost at the floor, and the waves would bend around the smooth contours of the dash to project themselves 'up'.

If done correctly, I can get an almost on-axis response, quite far off-axis.

This seems a little too advanced for me at the moment.

All I really want is a sound that is centered well.

Well, you posted this in the SQ forum, not general. So you should of been prepared to get some pretty serious answers.

As you have read, its not that easy and simple to get a centre image.

But considerin the fact you said you didnt have TA, the only way would be to play with the positioning of your speaklers

Hmmm.. very interesting ~thematt~, abmo touts these methods alot, although unfortunately sometimes can be hard to understand, its great to see that you've done your research and can share your insights in an easier to understand way.

The idea that I can bend sound to get either a larger sweet spot or a better off axis response is a very intriguing one, the use of diffraction could potentially improve a systems imaging dramatically, and coupled with clever speaker axis could take a system from great to outstanding.

I understand the use of reflections, resonances etc, but diffraction has me a little confused, should I be thinking along the lines of directing sound like air is directed? kinda like aerodynamics? Or does sound flow more like water? I understand that sound is radiated in a perfect sphere from its reproduction source (or a half sphere with a suitable baffle) so getting my head around exactly how to direct it is a little bit of a mystery.

My knigdom for a diagram to help explain this!! or possibly some mathmatics to help quantify it.

Wheelz, from my 3d studio max knowledge of diffraction (visual, not audio) its when light waves are changed to alter their visual effect. the simplest example is the colours you see in an oil slick, or the surface of a CD. its the different angles the reflected light takes after being reflected off a surface, or more accurately, lots of tiny surfaces

Ha! That last one about the 4 methods of sound, I actually got from Abmo (*shhh*).

The other stuff I have found from White papers on JAES, as well as a few well-written books here (one by Vance Dickason - clever man, and the other by Richard Clark and David Navone). Both well worth the read. Oh, and my Acoustics textbook from Uni (covered in dust I assure you).

Sound behaves in a similar manner to light (using wave theory, not particle theory), which behaves in a similar manner to fluid flow. Differences being, sound is slower, light can change its speed easier, and fluid flow doesn't get absorbed by its environment. Ignoring these small differences, the basic physics principles still apply.

Now I've attached some very very poor pictures (short of scanning in my acoustics textbook, these will have to do). The first picture, is an open baffle setup. Ignore if you please the backwave. All waves are emitted from the FRONT of the cone. (lets pretend a sealed back mid, with no baffle step).

The second picture is an infinite baffle response. Now both pics one and two are POINT SOURCE, so every point at the same distance away from the source, in any direction, has the same amount of energy. Therefore to the listener, they sound exactly the same. In infinite baffle, the wave that was going backwards, is reflected INPHASE with the front firing wave, and sums. Bingo, easy 3dB step up. More if your baffle is really good.

The third picture is NOT a point source, but a speaker cone. We now have a problem called BEAMING. This is where the wave begins to lose its energy at the outer limits of the wave. Therefore we have attenuation. This is primarily size related and has almost nothing to do with anything else. You know it as on-axis (within the beam) and off-axis (outside the beam) response.

The fourth pic is adding in a non-absorbing surface. Think of it as infinite baffle with the baffle now creating different angles. The fifth picture, I just discovered, is identical.

The sixth picture is a poor demonstration of diffraction. If reflections force the wave back on itself (and collapses the potential 'sweet spot') then diffraction will 'open' it up. The wave will run the surface (just like aerodynamics - before it loses surface tension, becomes turbulent and detaches) and actually move around the corner.

The seventh picture is the inside of a car, with the speaker in the firewall (for ex.). If our dash didnt absorb the energy of the wave, and was shaped almost perfectly, then the sound will run the length of the curves up and around. If your 'diffuser' is positioned properly wrt the driver, then your 'on-axis' response wave will be curving around.

This means you can get on-axis response, whilst not being directly in the on-axis beam of the driver. If you do it well enough, you can get a good sweet spot to be of decent size.

Click to view attachment
Click to view attachment

Some points to ponder. The shape of the diffuser is almost entirely frequency dependent. That means that if you want to curve higher frequencies, you need to do it 'faster' and 'sharper' because of the length of the wavelength (basically, sharper curves).

In the near-field, all the energy on the curve is approximately the same. In the far field, energy dissipates due to air molecules, friction etc. and therefore drops off quickly (around 6dB per meter in 'open space'). So start diffusing close to the cone, or it wont work. The closer, the better.

Separation from the 'guide', due to stupid things like steering wheels getting in the way, will play havoc with the wave. Bumps, grooves and pockets will do the same thing. As soon as a wave separates, you'll never reattach it (in a car, anyway).

This is the principle waveguides are built on.

thanks ~thematt~, that is probably the best explanation I could have ever recieved, not only did you explain diffusion, you cleared up the explanation of beaming and reflection restriction aswell.
Awesome mate, now Im really inspired to create some wave guides and use diffusion to its best advantage.
I really must come listen to your car sometime soon, just gotta find a reason to get up WA way!!
Now all I need is some hard core mathmatics, so I can reconcile frequency response wave size with the curves I can create.
Im off to do some research in prep for some serious door trim/dash modding.
Thanks again ~thematt~ much appreciated!

*blink*

that is a decent effort matt it is 11:40pm, and I understood your explanation!

Well done

I'm gonna have to hit you up for some more explanations on the science of sound

Very well done, I seem to have taken a larger interest in this now. There's a lot of science involved

Cheers guys, hope it helps. I have a bit more Ill add later on, with crappy pictures, but Ill add a few bits now.

There is an equation, C=f*lambda, where c=speed of sound (343m/s) f=frequency and lambda=wavelength. Speed of sound is constant in the car, so the higher the frequency, the smaller the wavelength.

Also, the higher the frequency, the less energy within the wave. Less energy means its easier to dampen, absorb and reflect. This is why high frequencies fall off a lot quicker when you enter far-field (note, far field for 3+ kHz starts at around 3cm) then the lower frequencies. They are also a bitch to control reflections off things like glass.

Just as a side note, near field/far field transition is given as = (D^2/2*Lambda) when D>Lambda and D=the largest diameter of the radiator (cone diameter).

As mentioned before, in the near field, all waves are of equal energy (no dissipation) and the majority of the waves received by the listener are direct waves. In the far field, reflections, resonance, combing etc. play a big part to the listener, and the sound drops off at ~6dB per meter.

So if you want to dampen high frequencies, use dash mats

If you want to reflect high frequencies off somewhere like the windscreen, do it in the near field or combing will occur (nasty..). This basically means have your tweeters within 3cm of the glass.....

Ill leave you with a question of interest. Lets put all this together to be something tangible to most people. We have midbass/midranges (for 2-ways) in the doors, and midranges (for 3-ways) in the kicks (for example). Now how can we use diffraction to our advantage? (Think, off-axis for one person, on-axis for another, and relate to my previous post).

please...~thematt~

do continue with your lesson.

We've all been playing politics in the yard for about a year or so, and I'd quite like to know the answer you had in mind when you posed the above question.

PS this post has NOTHNG to do with the fact that I'm about to mount a 4" midrange in the kicks, near the firewall.

really.

I totally forgot about this!

I'll see if I cant put something together later on this evening. I too, am soon going to mount some mids in the footwell area (kicks/firewall), so I can at least run through some design assumptions/science behind it!

I'd have to disagree with this ones, at least from my personal experience / findings.

Two reasons:

1) I've always made careful use of time alignment of both mids AND tweeters in my systems in order to have the two signals 'hitting at the same time'. If you think about it rationally, the only reason you time align one driver is to get the signal to reach your ear the same time as from another driver. If your ears couldn't pick up differences in timing on tweeters, then you wouldn't need time alignment on your mids either...because the only reason you T/A those is to get them playing in time with your tweeters. This is until you consider subbass.

2) Focal's Utopia Grand Be hi-fi speakers cost around $160,000 and are considered by many to be in competition for the title of 'the worlds best speaker'. If you read the info on the speakers, the cabinets are actually designed with the tweeters physically set back futher then the mids in order to 'physically' time align them. Many high end hifi speakers use the same idea. Why would they do this if timing had no impact on high frequencies? Seems a little odd to me

Delta Time Alignment doesnt affect tweeter frequencies. You cant change stage placement by TA'ing with tweeters, the wavelengths are simply too small.

The reason why many (and not just the Utopia's - which IMO are waaayyy overpriced) systems set their tweeters back is to ensure correct phase at the crossover point with the midrange.

I think it will depend on the system if your running a 2 way system with tweeters playing low, 2khz for instance then they will be playing those frequencies that you can hear time differences in, but if there in a 3 way playing the frequencies they should 5khz+ (6khz to 7khz+ would be my preference) then there shouldn't be any affect and it really only relies loudness.

I've tried this with my tweeters and there 6khz xover and although I detected a sound difference it definitely did not shift the stage around at all, whereas playing with balance made a large difference.

I use TA for the tweeters.
anyone who says it doesn't make a difference in stage positioning isn't listening properly.

camberra????
I did lots of work with the 4".
put in a 5" if u can and a big 9" midbass for the unquestionable kick drum quality.

Quote regarding the Focals"



They don't specifically mention a reference to the tweeter, but since they've used the same positioning approach on the tweeter as they did on the other dricers, I can only assume it's for the same purpose.

One thing is for sure...when I apply time alignment on my tweeters, I could definaely hear a change. Maybe it's the change on phase I'm hearing, maybe it's the change in time, but what ever it is I could hear it clear as day. There was always one point where mids and tweeters would blend perfectly, and the instantly i moved from that time alingment setting by even the smallest measure (7mm) the sound would lose some composure.

I concur.

Not sure why, but when I mess with the T/A on my tweeters, stuff happens.

As it does when I mess with the levels.

Zion - Would love to fit a 5" but 4" will already be pushing it..

and I only have about a 7L enclosure to play with, not sure how a 9" driver would play in that sort of enclosure...

I use TA on my tweeters. I've crossed my tweeters anywhere from 3150 down to the 1250 they are crossed over now.

I have a track on an Autosound disc I use with 7 drum beats from one side of the stage to the other, I TA the tweeters first, and then the mids, both with only the set of speakers I'm TA'ing running.

You can easily discern the difference when TA is run on the tweeters. You can also hear a difference with the tweeters TA to the mids.

I can't see any reason why you wouldn't TA ALL (Except for the furtherest driver - Thanks muzzy66) speakers in the system.

i TA'd both my midranges and tweets and nothing happened.

no effect watsoever

gheyness.

I'll rephrase, and echo Luke's statement. Forget about what speaker is playing. Its about the frequencies (or more specifically, wavelength). Plus, we are talking about DELTA alignment, not parallel. So the ability to shift image left or right by utilising TA. What you mentioned before Muz, about coherence between mid and tweeter firing at the same time, is parallel TA. This is an absolute MUST for seperated drivers.

When the wavelength of a soundwave is shorter then the diameter of your head, they are easily diffracted. This scattering increases rapidly with increasing frequency, and (depending on the size of your head) a shadow is cast on the 'other side' because of it.

This actually starts to become a cue for localisation at around 500 to 1000Hz, because below this point the difference in sound for a particular wavefront is less then 0.5dB from the left ear to the right. As I'm sure you are all aware, 0.5dB is the proven limit of audible change. The higher the frequency, the larger the shadow, and the better we can localise due to differences in the 'loud' and 'soft' sounds created by this shadow.

For example. A sound occurs right in front of us. We hear that sound at equal intensity from both our left and right ears. A sound occurs 60degrees to our left. The left ear recieves the full sound, the right ear only recieves a 'dull portion', due to the diffracted waves trying to go around our heads. That tells our brain the sound is 60degrees to our left.
Click to view attachment
This is well know as Interaural Intensity Difference.

The other localisation cue is called Interaural Time Difference, and is based on each ear being able to hear difference portions (phases) of a wavelength. The higher the frequency, the lesser the difference in detectable phases between the ears, and the more difficult we can localise using it. It actually peters out at around 2kHz+, and our ears transfer our main localisation feature to IID.
Click to view attachment
Keeping in mind a tweeter should be playing high frequencies, mids play midrange, and woofers playing low frequencies, and that crossovers arent brick walls, and speakers play massive amounts of distortion outisde the crossover points (at varying levels of attenuation). IF you have a tweeter playing the frequencies they should (5k and above), THEN alternating time alignment WONT have an effect.

Obviously if you have tweeters running low crossover points (and/or - eg. 2-ways), you are still playing frequencies in an area that is localisable for ITDs. Also, the shape of your ear and the size of your head has a large impact. If your tweeter wasnt playing midrange frequencies, you wouldnt be able to detect it.

As to Focal setting their tweeters backwards, its a common feature used by almost ALL manufacturers worth their salt. In fact, if they dont, ask yourself how the designer manages to maintain phase coherence without it (some use phase inversion and shallow slopes to allow rectification at the crossover point, others just dont know what I'm referring to <-- they're the speakers you dont buy). Sonus Faber, Avante Garde, there are heaps of them that do this.

It is NOT to ensure that both sounds reach your ears at the same time (the point of time alignment) because sound travels at a single speed independant of frequency (and moving them apart would increase this problem) but to ensure that the phase at the crossover frequency is the same for both drivers. This allows better blend between drivers.

I notice differences when moving only 0.1ms with TA. I even find you can pick the phase change when you are 'near' the centre of the stage.

I run 0.0ms on my left mid, 1.0ms my right mid, 1.1ms on my left tweeter and 2.3ms on my right tweeter. There is a clear sound difference with only changing in 0.1ms intervals. I've also found that in my system, it sounds best when I have an even difference between the tweeters and between the mids. IE 1.2ms difference in the tweeters and 1.0ms difference in the mids.

I'm amazed that other people aren't noticing any difference.

[edit: forget it. I'm SO behind the times]

i'd dispute this and say the main localisation feature to be our pinnae/brain mechanism.

for instance, if i put an earplug in one ear and not the other the sound is attenuated in one ear by 10-20dB or so. SO, if i were to turn the tap on in the kitchen, spin around and then try to face the direction the sound comes from i find i am facing within about 5 degrees or so of the sound.

but using the IID theory, i should be facing a far greater angle away from the direction of the running water. i often think that blumlein buggered up in this step and that, for high frequency localisation, the primary direction finding cue is actually the pinnae/brain and not IID.

i still cant get TA to work with my mids on the dash

7L is a lovely volume for a reasonably small driver, far more then you'll likely need. The 7" Revelators actually work perfectly in that volume, so it's a pity you are limited in size!



I don't find a need to TA every speaker.

The main intention of time alignment is to get all drivers to play in time. You bascially take the furthest away driver, and then delay every other driver so that it's playing in time with that one.

There isn't any need to delay the furthest away driver, because it's already the furthest away!

I try to use time alignment only as much as I absolutely need to, in order to avoid unwanted phase changes. If my tweeters are 20cm closer then my mids for example, then I will apply ~20cm of time delay onto my tweeters, and then finetune by ear (usually +/- 1cm or so).

Ahh, I thought you mean't don't need to T/A tweeters, becuase you can't identify timing on high frequencies - i getchya now!

As for moving the tweeter back for 'physical' time alignment (e.g. the Focal's), couldnt wavelength potentially be a factor?

I know that according to theory sound waves all travel at the same speed, however because low frequencies have a longer wavelength could this possible result in the low frequency reaching your ear before the high frequency does, even though they travel at the same speed?

For example, if you have a 10cm pole and a 1m pole heading towards you next to each other at the same speed, in theory the longer pole may hit you before the short pole does.

If sound signals worked in a similar fasion, could it be possible that the wave with the longer wavelength could reach your ear before the wave with the shorter wavelength, despite them travelling at the same speed - hence requiring extra distance applied in order to reach your ear at the same time?

Edit:

Just thought about it, and the results of the above 'pole test' would be dependant on the alignment of the poles. If they are aligned by centre (i.e. midpoint of one pole side by side with the midpoint of the other pole) then the longer pole would hit you first. However, if they were alligned by the front of the pole (i.e. front of one pole lined up with the start of the other pole) and launched at the same speed, they would in fact reach the target at exactly the same time (assuming everything else including speed is consistent).

Therefore, assuming speed is the same, the only thing determining which pole reaches the target first would be the initial allignment of the poles.

I assume that metaphorically, this whole 'alignment' of the poles is equivelent to the 'phase' or a sound wave.

If the longer wave and shorter wave leave the speakers at the exact same distance and the same time, they will essentially be in phase (moving side by side) and reach the listener at the same time.

If the longer wave is closer then the shorter wave (by say, 1cm) when fired, and they are fired at the same speed, then the waves will be slightly out of phase and the longer wave will reach the listener first.

Just had a uni assessment so my brain isn't all there, but am I somewhere along the right track at all?

Sorry, I should have clarified that.. I meant all bar the 'furtherest' driver can use some TA, no point in TA'ing ALL including the furtherest as you'll only be offseting.

a driver only puts out one continuous wave. this wave consists of all the different frequencies that occur @ that instant in time.

SO, if i could build a driver that played every frequency, then there is no way the long wavelength could reach the ear before the short wavelength could because that would imply that there are two wave's with two different speeds.

one driver = one wave.

2 drivers = 2 waves.

so if we have 2 drivers then we need to ensure that the ear recieves 1 wave. so what we do is if there is one driver creating one wave closer to the ear than another driver we would then move the driver so that they are both aligned. suppose the drivers location is fixed, we electronically move the wave back so it aligns with the other driver. so the closest driver plays @ the exact instant in time that the wave from the furtherest driver passes the closest driver.

this is different to 'time alignment' due to crossovers etc. that was explained above

Be careful with that one wave statement Scorp, you'll confuse a lot of people!!

One wave, yes, but its actually not REALLY one wave at all. Its a combination of many waves, that are interacting with each other (and yet not interacting....). Visually, it is seen as a single wave.

And the pinnae is used more for vertical height cues then horizontal, still very important, but not as much so, given the fact that we developed through evolution as horizontal hunters as opposed to vertical ones (like birds).

Those frequencies, like mentioned, are related to their wavelengths, and its this length that becomes important. At 2kHz, the wavelength is 17cm, which is about the distance between ones ears. At 4kHz, that same wavelength becomes 8cm. This simply demonstrates that a wavelength makes a full cycle between one ear to the other, so phase differences are too obscure (as the phase can be anywhere up to 360 degrees out).

You'll actually find that localisation cues around 1.5 to 3kHz are very poor. There isnt really any dominant localising feature here, but as you get lower ITD's dominate, and as you get higher IID's dominate. However, when you combine the fundamental (below 1-1.5k) with its HOMs (above 3-4k) you can quite effectively shift localisation due to a combination of both at once (IF the reproduction is musical in nature - because of the natural ability of an instrument to have modes).

A tweeter though, isnt designed to play fundamentals. It has no suspension. Its a HOM unit, designed from the ground up to reproduce harmonics. Its ability to play into the ITD zone is very poor, because the distortion levels are too great, and if you use it properly, the crossover will be quite high. High enough to limit (or completely null) the effect of ITD's.

probably. its how i think and that seems to confuse ppl, including myself



actually, i think ill go and re-try my pinnae test with a 10kHz tone outside to see if i can still localize it with one ear.

if i can, my theory will fit the explanation a lot better than the IID theory.