4 replies to this topic

[OEG50]

I have recently moved my tweets onto my pillars and after my last comp have been told my stage rainbows. How does this occur? and how is it eliminated? My tweets are now in their fixed position so moving them is not an option. they are halfway between facing each other and on axis and also have a slight upward angle.

thanks in advance for the info!

[mooingchicken]

i wouldnt of though that they wouldnt raindow up on the pillar's, my tweeters rainbow from being down in my door pods, but i can change my mounting cups to angled cup's which im going to try.

maby try playing with a few things suggested in this thread http://www.mobileelectronics.com.au/forums...showtopic=82933

[Winno]

Tweets and mids/mid bass drivers up high with angle adjust for best width, depth and imaging.
Most people shy away from dash modification though even though they go to town on their door trims.

That's very strongly influencing my equipment and instal in the next car right now.

Edited by Winno, 30 April 2007 - 07:10 PM.

[abmolech]

Quote

How does this occur? and how is it eliminated?

It occurs because of a drivers off axis (or lack of it) response. A driver is effectively a sum of "infinite" points, each one radiating a wave. When the frequency length matches the cone diameter (or below) the points create interference patterns. This is normally expressed as "combing", so called because the real time analysis looks like a comb on the screen (represented frequency response in bars).



Point

These patterns reduce off axis response, and the higher the frequency the poorer the response. This is often called "beaming".



Larger diameter drivers are more prone to beaming than smaller diameter cones. Your expected frequency bandwidth versus the cone diameter is the PRIMARY determiner of off axis response.(The cone or dome shape accounts for practically no difference)



Use three way sets, or preferably arrays, horns or wave guides for the best performance.



If your using limited number of drivers (two way) and large diameter cones or domes, consider on axis listening as mandatory.



I would use wave guides to eliminate this problem in your case.

[mooingchicken]

ok i think i got that. so the higher the freq the more they drop off towards the point source (driver)?

and what is wave guides?

Edited by mooingchicken, 30 April 2007 - 08:33 PM.