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What would happen, i know i am probly gonna hear that it is a terrible idea, but why???

I am talking IN the dash, pointed up at the windshield.
 

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That would be interesting... not sure how it would work though. Something like the LCY's aren't really any different than a conventional dome, except that they have much wider off-axis dispersion in all directions.
 

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using a ribbon in the dash might be a good way to utalize its directivity to prevent unwanted reflections. If you can aim them at the glass, if you're off axis enough you'll get just the reflected sound and no (or very little) direct sound... it might work well enough to help prevent the comb filtering you typically get when sticking tweeters in your dash. There's a pretty informative thread on ECA right now pertaining to this.
 
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Jim85IROC said:
using a ribbon in the dash might be a good way to utalize its directivity to prevent unwanted reflections. If you can aim them at the glass, if you're off axis enough you'll get just the reflected sound and no (or very little) direct sound... it might work well enough to help prevent the comb filtering you typically get when sticking tweeters in your dash. There's a pretty informative thread on ECA right now pertaining to this.
My thoughts exactly :) When you break it down, reflections from the glass cause problems that can be broken down into a few simple categories. There's comb filtering, which is a frequency response problem resulting from a direct source combining with a reflected/delayed source of about the same magnitude. We can also put the "stage smear" or loss of focus, or loss of pinpoint localization, into this same category ... a reflected source of about the same magnitude as the direct (and arriving at approximately the same time), but coming from a different point in space (which we call the image). If you can reduce EITHER the direct or reflected source magnitude, the problems in this category tend to go away.

The other category is frequency response anomalies resulting from the frequency response of glass reflections. No multiple sources in this category, so no combinations or cancellations to worry about. However, some EQ may be necessary for good tonal balance.

I think ribbons pointed at the glass do present an interesting opportunity to address the first catgeory. Direct radiation along the long axis of the ribbon will be greatly reduced almost 90 degrees off axis, meaning the sound you hear will be dominated by the reflection or "image". In other words, it will seem as though the sound is simply coming from the reflection of the ribbon you see in the glass. Not a bad place to put a ribbon, I think ... standing up vertically, a few inches in front of the windshield ;)

It may very well be that ribbons are the ideal high frequency drivers to put in the dash, pointed up at the glass :)
 

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A couple things to add...

The listeners would be hearing both horizontal off-axis and on-axis in whatever radiation pattern a windshield creates, especially in the upper freq's. Although, on and off axis won't be nearly as significant with as with their dome counterparts, varying by design.

Directly radiated waves at the vertical limits of the ribbon will still be reflected from the windshields reflection pattern, because it would seem the projected radiation limits of the ribbon wouldn't match the size of the windshield.

The crossover would have to be altered, due to the newly reflected pass-band dispersion of the ribbon.
 

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werewolf said:
My thoughts exactly :) When you break it down, reflections from the glass cause problems that can be broken down into a few simple categories. There's comb filtering, which is a frequency response problem resulting from a direct source combining with a reflected/delayed source of about the same magnitude. We can also put the "stage smear" or loss of focus, or loss of pinpoint localization, into this same category ... a reflected source of about the same magnitude as the direct (and arriving at approximately the same time), but coming from a different point in space (which we call the image). If you can reduce EITHER the direct or reflected source magnitude, the problems in this category tend to go away.

The other category is frequency response anomalies resulting from the frequency response of glass reflections. No multiple sources in this category, so no combinations or cancellations to worry about. However, some EQ may be necessary for good tonal balance.

I think ribbons pointed at the glass do present an interesting opportunity to address the first catgeory. Direct radiation along the long axis of the ribbon will be greatly reduced almost 90 degrees off axis, meaning the sound you hear will be dominated by the reflection or "image". In other words, it will seem as though the sound is simply coming from the reflection of the ribbon you see in the glass. Not a bad place to put a ribbon, I think ... standing up vertically, a few inches in front of the windshield ;)

It may very well be that ribbons are the ideal high frequency drivers to put in the dash, pointed up at the glass :)
The big issue that I'm facing with positioning the ribbons, is how to do it so that it's asthetically pleasing (no big goofy things sitting on top of the dash), and secondly, how to do it so that I don't get any major reflections other than off the dash. I'm not sure that I've devised a mounting scheme that's acoustically optimized and still asthetically pleasing.
 
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Well if I'm even close to right, mounted (horizontal) flush into the dash, firing up at the windshield just might be the ticket. Equivalent to a vertical ribbon element a few inches on the opposite side of the windshield from the passengers. Think about where you'd ideally put the ribbons if there was no windshield at all ... vertical ribbon element, out on the cowl (in line with the wiper pivots) ? What I'm suggesting might be pretty close to the same thing ... without removing the windshield, of course ... and with no big ugly "pods" on the dash.

Imagine where you see the windshield relfection of the horizontal, flush-mounted ribbon. That will be the primary radiating point (line), especially since the direct sound from the ribbon itself is so attenuated off-axis.
 

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I think that once I get my kick panel issues straightened out that I might have to pull the trigger and experiment with a pair.
 
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