I recently read few posts about aiming tweeter into the windscreen and i was inspire to do so a while back when Fhrx (i think) set up a car with DLS component doing just that in the A pillar. Since molding or cutting my 'A' pillar can get expensive, I decided to ask my buddy to buy me a tweeter hanger overseas and try it myself.

At first, I mount the driver side tweeter off axis from me (obviously) as well as the passenger side tweeter. I found by doing so I lost some of the detail in the music. Then I try swiveling the passenger side to point slightly on the axis towards me, the detail is back. At the moment I really have nothing to tune since my amplifier is solely there to produce power thus no crossover or anything like that, just a gain pod and my HU doesn't have any tuning capability either.

Well I can tell that my staging is deeper and imaging improved considerably. The previous position for my tweeter is in the sail panel. I really love the set up and how it sounds right now. Besides few cables hanging around I think it's a cheap exercise and worth a try.
The tweeter hanger really come in handy and can swivel in any direction for future experimental .

Few pics

Driver side:
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Passenger side:
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Closer look of the tweeter + hanger:
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those things are pretty cool

Hey Reza - care to share where you got them from? I'd like to get a pair

My buddy bought them back in indo. Right now I only have a 4 inch tweeter hanger (think ScanSpeak tweeter), which I'm contemplating to sell since it will look ridiculous on my dash if I decided to go ahead with big tweeter. I'm not sure where you can get one in here, but if you can pm me with your tweeter mounting detail (photo might help) i might be able to get someone to buy it there, not promising anything but .

You're onto something

Thats the way I'm facing my tweeters now

I'm guessing mine will be similarly aimed, though maybe pointing up a little more as well.

I always though hitting the windscreen caused it to blur the sound?

omg i want some of them!!!

they would be perfect for mounting my tweets, cause i ost the moutning hardware!!!...

dang

I was of the impression that the tweeters were placed on the dash in order to direct the higher frequency sound directly towards the listener as sounds of these frequencies don't diffract much. Unless you're talking about receiving the rebounded waves off the windscreen but I admit that I don't understand what positive effect this would have.

PS. I'm new to car audio, just did a lot of physics last year. Hehe

It gives a deeper soundstage (like the band is playing on the bonnet) and with some playing around can give a much wider soundstage.

I'm so going to try this. my depth is crappeh - maybe it'll help a bit

I've played around with this before. As long as the reflection dominates the initial wave the result is equivalent to sitting the speaker where the visual reflection of the tweeter is.

That is it is on the other side of the windscreen.

By having a dominant reflected image you also avoid comb filtering of high frequencies off the glass which creates the harshness associated with many high mounted tweeters. (That is where the reflection and the direct wave cause comb filtering)

Can work, will still work with curved windscreens effectively as with all high mounted drivers its a trick to avoid separation of the mid/tweet freqs

But remember there will always be a small loss of focus/tonality if you cant have a dominant reflection.

This is where manual TA is at

Pulse-R: What do you mean by manual TA?? Does the reflection effectively lengthen the tweeter position or in other word lengthen the distance the sound wave need to travel??

most certainly, and so to keep the reflection as the dominant source, you need to adjust the TA accordingly - if the sound image is further away, you need the sound to arrive sooner, or it will no longer be dominant.

Important to reduce the level of the 'direct' sound as well, so the image is dominant - this is partly achieved by off-axis mounting.

Any time alignment you place on the tweeter will not actually change the reflection/direct wave placement in relation to itself.

But time alignment should be measured from the reflected image if this is the dominant image. Obviously ignoring the fact that our ears localise higher frequencies using changes in amplitude and not phase. Time Alignment will see best results with lower frequencies as the ear relies on phase cues for image placement/localisation.

bla bla blah

Gong to say the same thing myself. High frequency detection is Interaural Intensity Dependant, so adjust your GAINS to suit. Time Alignment wont be very effective above 4 kHz.

Plus by firing into the windscreen, be mindful of diffusion. If you can control it properly, you can get away with almost no losses in frequency response and detail. If not, you will find it will cause more problems then it solves.

Why does everyone say you can't hear TA above 4kHz - what a crock.
Have you tried it?
Bad phase alignment at ANY frequency causes blurring of stage depth. Especially when the harmonics of a voice or instrument are out of phase (out of time - same thing really) with its fundamental.

I never said you couldnt hear it, I said its not very effective. It still works, to a degree, but Intensity changes have the greatest effect on localisation. From what I can remember, its to do with the wavelengths of sound being smaller then the distance between both ears. Called the 'head shadow effect' or something along those lines (been a while, might have to dig up some notes).

Yeah, Ive tried TA, have it at the moment (no independant gains) but it is no-where near as effective as gain adjustment. Ive been trialling replacement amps for my mids/tweets, and one of them had independant gain per channel. When initially tuning, the actual effectiveness of changing gain is MASSIVE compared to TA. Image was sharper and didn't 'move' (as much - still have to work on that), Soundstage wasnt as 'cluttered' because images were more distinct, I was able to more accurately 'see' the instruments. Nothing else changed besides the amp (and some basic tuning).

as a simple guideline where should the tweet be placed eg. close to the windscreen etc, positioned so it fires and reflects directly at you or angled so it spreads the sound and what point on windsreen should it to fire at? i am very interested in doing this i just want to understand why and how it works to deepen and widen the stage so i'm not fidling and not getting anywhere because i dont understand the physics. thanks guys

Yes, as frequency increases, it's direction is influenced more by intensity (gain or balance) rather than phase (time alignment).

A good system will allow control of balance and still allow time alignment.

I'd also like to see a few more people moving their tweeters in from the A pillars to locations on top of the dash.

It can allow you to get a stronger central image and yet, still give good width if you apply the priciples of reflection in similar way to using the windscreen to reflect.
My NZ IASCA winning Subaru had the tweeters in nearly 100mm from the A pillars. I'd try this and even experiment with a little outward facing angle on the tweets...but just a tad mind you.

Like using the side windows to reflect some of the tweeters' image outside the car??

This will not always work, some cars are suited to it others arent, generally a flat windscreen will be much easier to work with. But as with anything there are tradeoffs.

To explain we'll look at it simply. Just imagine a speaker * aiming at a wall | with a listener #. And we'll only focus on the reflected wave.

*
...\....|
.....\..|
.......\|
......./|
...../..|
.../....|
#

We can see the sound wave / reflected off the wall and back onto the listener. From where the listener # is standing in terms of speaker location, the listener will 'see' the reflection only.... Which will appear to come from well behind the wall.

As below:
...............*
........|..../
........|../
........|/
......./|
...../..|
.../....|
#

This is how we get extra depth. In terms of width it gets tricky as width will usually be narrower, or alternatively if we aim into the side windscreens the image will be blurred as we get multiple points from the front and side windscreen. Make sure you dont make it too complicated as this all adds to a loss of focus.

create point of crosstalk/interference at point on windscreen - works well (works well on all speakers actually, people should point them away more often instead of directing to listeners lol.. Only problem is introduction of sibiliance..

I actually have to notch up the tweeter adjustment in the crossover to get the sound that i like. There's sibilance but only with few music.

in regards to tweeters on dash, i have been trying that for the last 2-3 days with little success, stage becomes very narrow and there is little to no centre image... what would you suggest??

1) whats equipment do you have?
2) what car
3) exactly what have you attempted?

basically these 3 facets will impact on the overall (of course you know that) but unless you specifically break down what you have or haven't done then no one can specifically tell you what you should try and will provide you generalised comments

so help us by telling us

ok its a saab 900

i got dls tweeters up on the dash and im currently running them passive along with the factory saab 4inchers ... there running off a kicker IX252 getting about 30rms each... ive tried having them facing me and next to the mids, then up on a-pillar facing window and then next to mids facing window ...

You'll more than likely need more than two to three days of tweeking to get things right so don't write off the idea just yet. Persevere.

And a good tweeter will still have a good off axis responce with little sibilance/distortion.
You could try a different tweeter if you had to.

the tweeters ability to give wide off-axis performance could determine position .Im running mine pararell to the the window near the A pillar atm, so because of the window curve they intersect middle window and ive tried the tweets nearer the glass and away........cors