Resonant Frequency

[mhuck123]

Quick question, I need to get my system tuned properly but like everyone else I want to do it on a budget if possible. :01nocomment8so: Soooo I had an idea, I don't have access to a Meter so I thought the next best thing would be something like the audio control unit (don't know the model) with the SPL meter. My thought was along the lines of a body fat monitoring scale. It may not be very accurate as to the level but if it changes from 1 DB level to another it should be right on, at least that is what doctors tell me about the scales; may not be accurate as to exact body fat but if it goes down a percent your down a percent.

Also I believe the proper procedure is a sealed box in as close to the exact location of the build along with a test tone CD and run through the spectrum and mark it on a graph. The highest frequency is your resonant frequency and what your box needs to be tuned at or around.

Chime in guys and let me know

[mhuck123]

BUMP!

[brewer_brewer]

BUMP!

you have a sealed box?

if so you can't CHANGE your tuning. your resonant frequency will be based on the sub and cabin gain.

[BJD3]

you have a sealed box?

if so you can't CHANGE your tuning. your resonant frequency will be based on the sub and cabin gain.

I'm pretty sure he's referring to changing the frequency of the sound waves from the source and using that figure to build/tune his ported box.

Edited July 20, 2009 by BJD3

[Lowroll]

you have a sealed box?

if so you can't CHANGE your tuning. your resonant frequency will be based on the sub and cabin gain.

You technically can change the tuning by adding fill to the box and or using bricks & stuff to change the internal volume.

But, its my understanding that a 1x1x1 sealed box is used to determine your tuning frequency.

[brewer_brewer]

^^^^sorry. i misunderstood his post. it was late.

[mhuck123]

you have a sealed box?

if so you can't CHANGE your tuning. your resonant frequency will be based on the sub and cabin gain.

Yeah I have a ported box in the car but it was built to the manufacturers specs not my cars. I was planning on using the sealed box to find the frequency of the car and then build a new ported box to those specifications.

You technically can change the tuning by adding fill to the box and or using bricks & stuff to change the internal volume.

But, its my understanding that a 1x1x1 sealed box is used to determine your tuning frequency.

Yes sir, at least that is what I also heard and was trying to check here. I gues just run a test CD that blows through the freq. range and record what I hit. The issue is that I dont have a meter so I was hoping something like the Epicenter 160 with the SPL mic could at least let me know what freq. are higher or lower.

Anyone else got an idea if my Bodyfat scale/Epicenter analogy is correct?

[Lowroll]

I wanna know how this goes bc I built a box for 2 RE 15's based on RE's specs which was 36 hz. Both time the truck has been metered it peaked at 41 hz. So wouldnt a 41 hz box be louder since it matches the trucks resonant frequency?

[Eric B]

I wanna know how this goes bc I built a box for 2 RE 15's based on RE's specs which was 36 hz. Both time the truck has been metered it peaked at 41 hz. So wouldnt a 41 hz box be louder since it matches the trucks resonant frequency?

No thats wat ur current box is peakin at.. change the tuning and your peak will change..

[HHR Ed]

Well we have been doing this for years and years.

Build an enclosure with a flat response. A nice sealed box would do the trick.

Play varying frequencies, dB Drag CDs have sweeps you can use.

Use an SPL meter with a peak hold and whatever frequency hits the peak, is what you want to tune to.

The Term Lab meter will be your best meter of choice since it reads the most consistantly and varying air temps do not effect at what frequency it will read more sensitive at.

Also, the TL has an Oscope that will tell you at exactly what frequency was the highest SPL.

This is really a 20 year old technique, and it still works well to this day.