How to smear your imaging.
03-16-2004, 05:25 PM
#1
1000 Watt CAFz'r
Thread Starter
Join Date: Oct 2003
Posts: 1,783
This is easy. Run your mids above where on and off axis response is uniform.
I'll give an example:
Imagine having your mids mounted in the kick panels angled towards the center of the car. As long as your head stays dead center of the car (yeah right) you will get uniform response from both drivers at all frequencies. But, as you move your ears to the left of center, the higher frequencies on the left driver get rolled off,(due to off axis response) while the right driver is still pretty much "on-axis" with your ears. The result is that the right driver sounds louder than the left driver despite the fact that you are closer to the left driver. Imaging wise, a voice will be shifted more towards the right of the car in upper frequencies(due to increased high frequency intensity vs. the left side) and the midrange frequencies will dwell more towards the center.
This will confuse the heck out of your ears. Imagine Mark Knopler playing guitar. You've got him playing in the center, but his fingers are sliding up and down the strings to the far right.
When you run a driver within it's uniform on and off axis response range, image smear is greatly reduced.
Adam
I'll give an example:
Imagine having your mids mounted in the kick panels angled towards the center of the car. As long as your head stays dead center of the car (yeah right) you will get uniform response from both drivers at all frequencies. But, as you move your ears to the left of center, the higher frequencies on the left driver get rolled off,(due to off axis response) while the right driver is still pretty much "on-axis" with your ears. The result is that the right driver sounds louder than the left driver despite the fact that you are closer to the left driver. Imaging wise, a voice will be shifted more towards the right of the car in upper frequencies(due to increased high frequency intensity vs. the left side) and the midrange frequencies will dwell more towards the center.
This will confuse the heck out of your ears. Imagine Mark Knopler playing guitar. You've got him playing in the center, but his fingers are sliding up and down the strings to the far right.
When you run a driver within it's uniform on and off axis response range, image smear is greatly reduced.
Adam
03-17-2004, 09:59 PM
#4
500 Watt CAFz'r
Join Date: Jul 2003
Posts: 756
Damn off-axis, my nemesis! [img]smile.gif[/img]
Adam: I have also noticed the phenomenon you are describing. I've been working on my tweeter imaging, and experimenting with some different positions over the last few days (until it dumped 20cm of snow yesterday) [img]smile.gif[/img] Are you currently using your tweeters in kicks or on the a-pillar?
Adam: I have also noticed the phenomenon you are describing. I've been working on my tweeter imaging, and experimenting with some different positions over the last few days (until it dumped 20cm of snow yesterday) [img]smile.gif[/img] Are you currently using your tweeters in kicks or on the a-pillar?
03-18-2004, 12:05 AM
#5
Guest
Posts: n/a
So what happens if a person runs both drivers totally off axis? Usually the degredation from 0-30degrees is way worse(and more radically progressive) than from 30-60degrees and even farther out.
I think some people have discovered this and it is why you see some KP mounted mids pointing at the back of the headunit area or even more off axis
Now whether they understand the reasoning or just played around until it sounded good is anyones guess [img]graemlins/dunno.gif[/img]
Of course you listen more to reflected sound than direct sound but it's the result that is important, not the process [img]smile.gif[/img]
I think some people have discovered this and it is why you see some KP mounted mids pointing at the back of the headunit area or even more off axis
Now whether they understand the reasoning or just played around until it sounded good is anyones guess [img]graemlins/dunno.gif[/img] Of course you listen more to reflected sound than direct sound but it's the result that is important, not the process [img]smile.gif[/img]
03-18-2004, 06:17 AM
#6
1000 Watt CAFz'r
Thread Starter
Join Date: Oct 2003
Posts: 1,783
I think you can run the X.O. points on midbasses, and midranges to help eliminate drivers running outside of their sweet spot. But...you can't really do that on a tweeter, after all there's nothing above it. The more listening I do to tweeters, the more convinced I am that intensity and positioning are more important than phase and frequency.
Adam
Adam
03-18-2004, 03:41 PM
#8
Sounds like you are talking about 'beaming' and how kick panels can suffer from that especially if you have the mid and tweet aimed directly on-axis to the opposite person. I very much agree that intensity and position are key items with tweeters. Mids are more about pathlengths than axis.
03-19-2004, 09:48 AM
#9
1000 Watt CAFz'r
Thread Starter
Join Date: Oct 2003
Posts: 1,783
"Mids are more about pathlengths than axis."
I wish I knew that last September. Front stage build #1 had the midbass and midranges in the doors.
I'm learning though...you guys keep helping me along [img]smile.gif[/img]
Adam
I wish I knew that last September. Front stage build #1 had the midbass and midranges in the doors.
I'm learning though...you guys keep helping me along [img]smile.gif[/img]
Adam
Thread
Thread Starter
Forum
Replies
Last Post
