What say you? I have heard some say it doesn't matter and some say it can mess up your front sound stage.

For simplicity's sake, let's assume these are aftermarket tweeters that accompany an component set with 6.5s mounted in the door's stock position.

Let the debate begin!

 

I mounted my Focals in the OEM location.
Took a little customization but worked out great.

 

I mounted my tweeters in the stock position as well. Fit just like OEM and the sound quality is a 100 times better.

 

The theoretical problem with mounting tweeters very far from the mid is that you get a phenomenon called "float" - where vocals and instruments sometimes seem to come from the tweeter and sometimes from the woofer depending on where they are at the upper or lower end of the register.

With the tweeters close to the bottom-of-the-door mids, where this issue is remedied by location, you get a different issue in the car - a huge hole in the center of the soundstage. You get far left, far right, or both, but no front middle.

The way around this is to move the tweeter up and forward, AND to use as low a xover point as you can. But most car speakers don't use a low tweeter xover point. They use 5000 or so. If you use a kit with a 2000-2500 tweeter xover, you get the best of both worlds.

 

What about keeping the tweeters in the stock location but lowering the xover point to 2-2.5khz?

What's the solution if the kit xover point is 5khz? I would assume xovers are not exactly swappable from kit to kit across brands etc.

What is the xover point for the DLS UP6? It seems like it's 4000 but I'm not sure.

 

The UP6 xover point is 2200, as I recall. : )

The xover point of a tweeter is usually dictated by its meacnical characterstics. Everything - every speaker, and every other physical body - has a resonant frequency - a note that it "wants" to vibrate at louder than any other note.

As a rule you want to cross over a tweeter at least one octave above its mechanical resonance. Two if you're using a lot of watts.

So if your tweeter has a resonance at 900, you can cross it over at 1800 Hz or above without exacerbated risk. If you have a mechanical resonance of 1750 (like, say, the Diamonds) you can't cross them over below 3500 without risk. (I think they are at 4K).

The typical Focal or Quart xover point is at 4000-4500. Morel, a/d/s/, Dynaudio, and DLS are companies that aim for a lower xover point than that (2000-2500).

 

Of course if you've got a mid driver that has a flat response through 7 octaves (like the Diamond Audio Hex series), then you can afford to bump that xover up a little, eh?

 

Well, since you mention it, no.

The larger a piston surface is, and the higher note that frequency vibrates at, the worse its off-axis dispersion characteristics are. The math that describes this shows it as a function of the radius of the piston.

This is why 5.25"s play better mid in a car than 6.5" - at the listener's ear.

So what you describe about the Hexes are the same characteristics that get Focal in trouble in cars - "beaming" in the upper midrange freqs. The cone driver must be pointing directly at you for this upper response to be effective. With most 6" cone drivers, above 500 Hz or so the 60-degree off-axis response starts to take a nose dive relative to the 0-degree off axis (or ON axis) response. The tweeter is essentially omnidirectional at these frequencies (it takes a dive in off-axis response at the top of ITS range). This is not a design thing- it's the laws of physics, captain.

Here's a chart (a bad one) of a Via 6.5" midwoofer. Look at the graph: http://www.madisound.com/pdf/vifa/P17WG00-06.pdf

I have a friend that says that the top of the line Diamonds sound great - in kick panels - but he dislikes their sound in doors. He prefers the D6 in doors.

In home speakers, this works out fine - but not in cars.