in need of advanced subwoofer tuning help

[Dirtrider4eva 10+ year member]

to try and calculate the peak tones of my Car,

i derrived the equation

2(distance between face of woofer to kick)*3.280 = Frequency (hz) in feet.

then a second equation to determine the size of a wave:

say you want to know the length of a 50 hz wave?

3.280(340/x) = length of frequency in feet.

i got this by applying the two factors (hz = cycles per second)

and the second (speed of sound at sea level =340 MPS)

by doing so, this is going to give me the hz tone that my car will hit best, for this is when the wave just peaks and is on its maximum downfall. am i correct?

in addition, is it fair to assume that there are multiple tones that will work 1 1/2 wavelength, or even 2 1/2?

Click to read more...

 

[Buck 5,000+ posts]

Why don't you get a meter and figure out what your peak is? That's the only way to do it. Theory will only take you so far in audio. You have to take into account things such as flexing. It might be a good start, but the best think is to test.

 

[Kangaroux 5,000+ posts]

Why are you using the speed of light lol. You use the speed of sound

 

[Dirtrider4eva 10+ year member]

theres a meter for this?

and that makes life easier //content.invisioncic.com/y282845/emoticons/thumbsupwink.gif.129404938effda6ad9cca39e7f4b58a3.gif

 

[Buck 5,000+ posts]

TL dawg //content.invisioncic.com/y282845/emoticons/fyi.gif.9f1f679348da7204ce960cfc74bca8e0.gif

 

[Dirtrider4eva 10+ year member]

Why are you using the speed of light lol. You use the speed of sound

i had the number correct, just wrote in the wrong unit.

it is the SOS at sea level.

 

[Kangaroux 5,000+ posts]

Yeah set the meter to peak hold and just do like a 100-20hz sweep, doesn't even have to be loud just enough to get your peak

 

[Dirtrider4eva 10+ year member]

TL dawg //content.invisioncic.com/y282845/emoticons/fyi.gif.9f1f679348da7204ce960cfc74bca8e0.gif

yeah... dont have 500+ sittin around. ill see what i can figure out from a buddy perhaps.

 

[Buck 5,000+ posts]

Yeah set the meter to peak hold and just do like a 100-20hz sweep, doesn't even have to be loud just enough to get your peak

That's a good starting point, but absolute peak will need to be measured at full volume.

 

[Dirtrider4eva 10+ year member]

ive heard of vehicles having 1 -3 peak sub tones,

is that true?

 

[Buck 5,000+ posts]

ive heard of vehicles having 1 -3 peak sub tones,is that true?

Yes, but there is one louder usually.

 

[Dirtrider4eva 10+ year member]

thanks.

 

[akheathen Premium Member]

you know, i just go down to a shop and use theirs. imho, it would be best to use a sealed enclosure with the flattest response to get your vehicle's rf, even taking a reading at xdistance fired into the free-air outside for comparison, so you know what the drop-offs may be.

 

[Dirtrider4eva 10+ year member]

well i have an extra 8" laying around...

should i hook it up Free air where the other sub would be? or created a sealed box?

my usual sub is a 15" HDC3.

i just want to get a peak.

 

[Kangaroux 5,000+ posts]

That's a good starting point, but absolute peak will need to be measured at full volume.

True however I don't think it would be very necessary unless you have some serious flexing issues or are into advanced SPL competitions.