Reply to thread

Message

<blockquote data-quote="squeak9798" data-source="post: 945811" data-attributes="member: 555320">Just doing that doesn&#039;t actually tell you the res freq of the vehicle, since you aren&#039;t isolating the frequency response of the car from the frequency response of the box itself.Take a subwoofer (10&quot; or 12&quot; or whatever, doesn&#039;t matter) and put it in a sealed enclosure (NOT ported). Set the box somewhere in an open area (like your yard, NOT somewhere in your house). Play a set of frequencies (say, 40hz - 80hz at 2hz or 5hz intervals..the smaller the intervals the better, but the more time consuming) through the sub while in the open area, measure the output level of each frequency with your meter and record on a sheet of paper each frequency and it&#039;s output level. Now, take that same sealed box and place it in your car. Play the same set of frequencies now with the box in your car, and again record the output level of each frequency. Now you need to compare the output levels of each respective frequency between the open area and in-car enviornments. The frequency that has the greatest difference in output between the two measurements (in-car and open area) is the frequency that your vehicle peaks at.Or, you can do this method: <a href="http://www.bladeice.com/resfreq.htm" target="_blank">http://www.bladeice.com/resfreq.htm</a></blockquote>

[QUOTE="squeak9798, post: 945811, member: 555320"] [I]Just[/I] doing that doesn't actually tell you the res freq of the vehicle, since you aren't isolating the frequency response of the car from the frequency response of the box itself. Take a subwoofer (10" or 12" or whatever, doesn't matter) and put it in a sealed enclosure (NOT ported). Set the box somewhere in an open area (like your yard, NOT somewhere in your house). Play a set of frequencies (say, 40hz - 80hz at 2hz or 5hz intervals..the smaller the intervals the better, but the more time consuming) through the sub while in the open area, measure the output level of each frequency with your meter and record on a sheet of paper each frequency and it's output level. Now, take that same sealed box and place it in your car. Play the same set of frequencies now with the box in your car, and again record the output level of each frequency. Now you need to compare the output levels of each respective frequency between the open area and in-car enviornments. The frequency that has the greatest difference in output between the two measurements (in-car and open area) is the frequency that your vehicle peaks at. Or, you can do this method: [URL="http://www.bladeice.com/resfreq.htm"]http://www.bladeice.com/resfreq.htm[/URL] [/QUOTE]

Verification