determining vehicle interior resonance frequency

[quackhead 10+ year member]

The first advice given in designing a system is to determine your vehicle's resonance freq. I have an '02 Suburban w/ 3rd row seats...How do I determine this vehicle's resonance frequency?

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[iDesignBoxes 10+ year member]

You've got to build a box with a Qtc of .707, play test tones, from 30-60Hz. Every frequency in that range needs to be played and needs to be metered and recorded. You will notice a certain frequency with a significant increase in decibels compared to the other frequencies. This will be your vehicle's resonance frequency.

 

[SeanDub 10+ year member]

You've got to build a box with a Qtc of .707, play test tones, from 30-60Hz. Every frequency in that range needs to be played and needs to be metered and recorded. You will notice a certain frequency with a significant increase in decibels compared to the other frequencies. This will be your vehicle's resonance frequency.

And how do you do that?

 

[lilmaniac2 5,000+ posts]

but even then , that may not be the peak for spl numbers. as it gets louder it sometimes will shift.

Also you have to take into account for the box volume you will be using and make a dummy box to take up that room //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[audioholic 5,000+ posts]

Find a friend with an RTA.

 

[DBDRAGGUY 10+ year member]

I assume you are wamting to do a comp setup. From my experience those trucks do best in the 38-45hz range. Pm me and i can get you going in the right direction.

 

[quackhead 10+ year member]

Thanks to all of you. I really appreciate the input.

 

[Immacomputer 10+ year member]

You've got to build a box with a Qtc of .707, play test tones, from 30-60Hz. Every frequency in that range needs to be played and needs to be metered and recorded. You will notice a certain frequency with a significant increase in decibels compared to the other frequencies. This will be your vehicle's resonance frequency.

That's not always true. You need to measure the response of the sub in an anechoic environment and then subtract the two measurements from one another. That will give you the actual transfer function of the vehicle. From there, you can find the area that will give the most gain. But you get into issues for the amount of air in the cabin if you change box sizes. That will shift the resonance point. The weight will also affect the actual point of resonance.