Advanced SPL for Street Competitors
09-09-2009, 01:51 PM
#21
more power - lower imp - higher spl - lower tuning - even higher spl
09-11-2009, 12:14 PM
#26
1000 Watt CAFz'r
Thread Starter
Join Date: Jan 2005
Posts: 1,151
Lesson 2
Every car with have its own peak or efficient frequency. Depending on port position and/or sub position that frequency will change.
eg. sub firing up will like 59hz, while sub firing to the side will like 60hz and so on
Key is to tune to the frequency the car would like to play. By tuning not only do i mean port tuning, but also box tuning. From experience, every frequnecy likes a certain box volume. Usually, higher frequency-smaller box volume, lower frequency-bigger box volume.
This is way pandas get away with such smaller boxes cause of the higher frequency the car like to play.
And vise versa. If your box is big, it will like want to play a lower frequency.
So key is to match box volume and the car's peak frequency.
Back in 04, My jetta peaked @ 44hz and like a box about 4.5 cubes
My Yaris peaks @ 60hz and like 1.4 cubes
eg. sub firing up will like 59hz, while sub firing to the side will like 60hz and so on
Key is to tune to the frequency the car would like to play. By tuning not only do i mean port tuning, but also box tuning. From experience, every frequnecy likes a certain box volume. Usually, higher frequency-smaller box volume, lower frequency-bigger box volume.
This is way pandas get away with such smaller boxes cause of the higher frequency the car like to play.
And vise versa. If your box is big, it will like want to play a lower frequency.
So key is to match box volume and the car's peak frequency.
Back in 04, My jetta peaked @ 44hz and like a box about 4.5 cubes
My Yaris peaks @ 60hz and like 1.4 cubes
09-12-2009, 12:47 PM
#27
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...
09-12-2009, 04:18 PM
#29
Theory is 3dB for twice the power, but this is for ideal condition.
The power compression and acoustical behavior inside the car will change that.
Each car has a math, I've seen numbers like 1.2 to 2dB for twice the power at higher levels.
The power compression and acoustical behavior inside the car will change that.
Each car has a math, I've seen numbers like 1.2 to 2dB for twice the power at higher levels.
09-12-2009, 10:06 PM
#30
1000 Watt CAFz'r
Thread Starter
Join Date: Jan 2005
Posts: 1,151
