resonant frequency

[plyhammer 10+ year member]

Does anyone know of a site that has resonant frequencies of vehicles? I am trying to find the freq of a 98 dodge ram quad cab.

Click to read more...

 

[tRiGgEr 5,000+ posts]

ghetto way to do it...

put in a sealed box and play frequencys. Get the one that reads the loudest. And there you have it.

 

[squeak9798 5,000+ posts]

Does anyone know of a site that has resonant frequencies of vehicles? I am trying to find the freq of a 98 dodge ram quad cab.

It will change vehicle to vehicle anyways (even same make/model)......so, yeah, only way to find it is to measure it yourself //content.invisioncic.com/y282845/emoticons/thumbsupwink.gif.129404938effda6ad9cca39e7f4b58a3.gif

 

[80INCHES 5,000+ posts]

ok i'm alot rusty but i think u have 2 measure from the floor to the roof and then from door 2 door...and then from the rear deck to the dash board...u mutliply them...and the u divide by 1130..and then u divide by 2....(i think i'm not sure its been 10 years (15 years old) since i measured incar freq.)

i.e. 2005 dodge quadcab ...floor to roof 40.4inches, door to door 66.9inches..from rear to front is 77.7inches..allthis adds up to 210004.452 cubic inches...then divide that number by 1130..and u will get 185.84..then divide that number by 4 and 46.46hz is your res. frequecy

for that truck ...

now let take a different truck

2005 cevy tahoe

floor to roof is 39.1inches..from door to door is 64.9inches...from front to rear is 107.2inches..and this up and u get 272029.648 cubic inches..divide that number by 1130..and u get 240.73..divide that by 4 and u get 60hz

so u see freq changes in different trucks

80

again these are not concreate freq...the measurements of the inside of both trucks are correct..i got them from the dealer...but as far as calculating the res freq..i'm not sure if i did it the right way...if i am right i'll be shocked as hell...but i dout if i am right

 

[negativezeroz 5,000+ posts]

where would the "rear deck" be in a '95 300ZX? since its all open into the trunk theres no way to really measure unless i went to the latch in the hatch area where my W10GTi is

 

[80INCHES 5,000+ posts]

i guess u measure from the back of the hatch to the windshield

80

 

[squeak9798 5,000+ posts]

ok i'm alot rusty but i think u have 2 measure from the floor to the roof and then from door 2 door...and then from the rear deck to the dash board...u mutliply them...and the u divide by 1130..and then u divide by 2....(i think i'm not sure its been 10 years (15 years old) since i measured incar freq.)i.e. 2005 dodge quadcab ...floor to roof 40.4inches, door to door 66.9inches..from rear to front is 77.7inches..allthis adds up to 210004.452 cubic inches...then divide that number by 1130..and u will get 185.84..then divide that number by 4 and 46.46hz is your res. frequecy

for that truck ...

now let take a different truck

2005 cevy tahoe

floor to roof is 39.1inches..from door to door is 64.9inches...from front to rear is 107.2inches..and this up and u get 272029.648 cubic inches..divide that number by 1130..and u get 240.73..divide that by 4 and u get 60hz

so u see freq changes in different trucks

80

again these are not concreate freq...the measurements of the inside of both trucks are correct..i got them from the dealer...but as far as calculating the res freq..i'm not sure if i did it the right way...if i am right i'll be shocked as hell...but i dout if i am right

The best way to measure:

http://www.bladeice.com/resfreq.htm

 

[yischrax 10+ year member]

ok don't get me wrong but you can't really do it that way lol I mean for a guess yes. but the meterial of the interior, the angle of difrent things and just about everything comes into play for a room in a house yeah you could more or less go pretty good about that but for the time you spent and what it will cost you to build a sealed box and go get it metered will be much more acurate and you will have maltiple standing waves that will come into play but tipacly your RF for a vehicle will be between what is it like 120-170 or so. I think thats about right I forgot what it is. so you need to make sure that your gain is set high enough for it to play up to around 200 to be sure.

 

[ANeonRider 10+ year member]

ok don't get me wrong but you can't really do it that way lol I mean for a guess yes. but the meterial of the interior, the angle of difrent things and just about everything comes into play for a room in a house yeah you could more or less go pretty good about that but for the time you spent and what it will cost you to build a sealed box and go get it metered will be much more acurate and you will have maltiple standing waves that will come into play but tipacly your RF for a vehicle will be between what is it like 120-170 or so. I think thats about right I forgot what it is. so you need to make sure that your gain is set high enough for it to play up to around 200 to be sure.

Wrong.

Most vehicles' resonant frequency is between 30-70 Hz. Since when does gain have anything to do your vehicle's resonant frequency? lol

And squeek's link is the BEST way of measuring it.