Advanced SPL for Street Competitors
09-12-2009, 10:09 PM
#31
1000 Watt CAFz'r
Thread Starter
Join Date: Jan 2005
Posts: 1,151
I do not agree with double the amp power = 2.7-2.9 db. All the testing I have done usually only gains you .7-1.3 db. But your statement that the of the box rise etc. changing with power is absolutely true. I find that you have to test at 3/4+ power, because the box tuning and the voltage changes when burping at 1/2 to 3/4 testing. If your note was 54 hz at 1/2 testing, I find your note changes 1-4 hz at full power. Try it!
My two cents, good thread...
My two cents, good thread...
I don't mean doubling the amount of amps, I mean actual measured power output!
2000 watts to 4000 watts and see what you get
this is the true gain you should get before exceeding limitation of the woofers
Last edited by Lessy; 09-12-2009 at 10:13 PM.
11-18-2009, 02:21 PM
#35
50 Watt CAFz'r
Join Date: Jun 2007
Posts: 300
Since this thread just came back to life I have a question about loading. Is it the bottom of the sub that needs loading or does it just have to be all sides except one. ie. all 4 side, but leave bottom open.
Also when loaidng is there a magic distance/ amount of space that is needed?
Also when loaidng is there a magic distance/ amount of space that is needed?
11-18-2009, 07:20 PM
#36
Unloading is nondirectional, it's best to have the magnet 4+" from the back of the box, you want the air to hit the back and move around the entire box, if it's too close, the magnet will just get in the way of airflow. Think of pushing on a cone in a sealed box, it's slow to go back to it's original spot, when you port it, there is less pressure making it return to normal, so below tuning the x-max takes over and there is less support on the cone. If it's in a ported box the cone will return to it's original when pushed no matter how far the back of the box is from the magnet, but with a lot of power, it'll be the airforce that's reflecting off the back of the box back to the woofer. If it's too far than the cone won't stop moving and by the time the next note hits it's nonlinear.
