Rear fill gone, now a few questions.

[sjv13 10+ year member]

On axis just means the speaker is pointed at your head or as close as possible. Most tweeters/drivers perform best directly on axis and start to wane in wide-range FR the further off axis they go. Here's an example using the FR curve of the Vifa XT-25 ring radiator tweeter(courtesy of Madisound):

Axis response is color-coded, so the black line is directly on-axis, purple is 15 degrees off axis, and red is 30 or 45 degrees off axis. Obviously the more off axis you get, the more attenuated the upper range will be even though they all play consistenly until about 2K.

Ok. Thanks. So since my tweeters bounce off my windshield they'd be considered 90 degrees off axis? Or is it different when bouncing the sound is the idea in the first place?

 

[neo_styles 10+ year member]

Ok. Thanks. So since my tweeters bounce off my windshield they'd be considered 90 degrees off axis? Or is it different when bouncing the sound is the idea in the first place?

Bouncing off the windshield is a different beast, entirely. To make things easy, it would be more of an on-axis setup, but I wouldn't recommend doing that since reflections are pretty much the source for all that sibilance and harshness we try to remove from our tweeters. If your new speakers come with an angle-mount cup, that'll mitigate a bunch of reflection issues. If you want to go hardcore, invest in a dashmat as well. The difference is pretty remarkable.

 

[sjv13 10+ year member]

Bouncing off the windshield is a different beast, entirely. To make things easy, it would be more of an on-axis setup, but I wouldn't recommend doing that since reflections are pretty much the source for all that sibilance and harshness we try to remove from our tweeters. If your new speakers come with an angle-mount cup, that'll mitigate a bunch of reflection issues. If you want to go hardcore, invest in a dashmat as well. The difference is pretty remarkable.

Interesting. My tweeters are just in the stock location. What's a dashmat? How much are they? And where do I buy one?

 

[neo_styles 10+ year member]

DashMat | America's #1 Dashboard Covers

Price depends on your vehicle. I got a 40-dollar quote for my Passat, so they're really a low expense. Yeah, it looks weird driving with a dashmat like your grandpappy would, but it should be high up on the list for deadening treatments for any SQ nerd.

 

[calebkhill 10+ year member]

Bouncing off the windshield is a different beast, entirely. To make things easy, it would be more of an on-axis setup, but I wouldn't recommend doing that since reflections are pretty much the source for all that sibilance and harshness we try to remove from our tweeters. If your new speakers come with an angle-mount cup, that'll mitigate a bunch of reflection issues. If you want to go hardcore, invest in a dashmat as well. The difference is pretty remarkable.

Mine are in the dash too and I had harshness. But I found that ALOT of attenuation and scooting back about 6" cleared it up. They sound great now

Edit: Setting the levels properly on the door speakers helped too.

 

[calebkhill 10+ year member]

[quote name='ciaonzo'] excursion and power handling relative to those frequencies. Add to that, power response (on and off axis), filter poles (shallow to steep), phase and time coherency [/QUOTE]
@ciaonzo; Would you mind explaining these concepts? Or post a few links? Would like to read up on some of this. Especially how excursion and power handling are related to frequencies, I'm not sure if I completely understand what your saying here.