Box Help

[Vizzo]

I recently rebuilt my box and have some questions about tuning. I started with low tuning and peaked at 42hz. I tried another port length that was about 10" shorter and peaked at 48hz and gained about .8 dB. My question is should I put the longer port back in and trim an inch at a time or keep trimming the much shorter port to raise the tuning even more? I don't know if I will gain somewhere in between or if I would be wasting my time. I understand the whole try it and see mentality, but I wanted to know if anyone else has an idea about what to do next. I have a 4 door Cobalt in Street A.

[Chuck]

Id say just start with trimming 1" at a time starting now. If you trim the first inch and lose dbs, you need to start at the original length and keep trimming until you find when it starts to go down.

[Vizzo]

That sounds right. Thank you.

[CalusaCustomConcepts]

It would help if you knew the resonant freq of the car.....

[Vizzo]

I have no clue and I can't tear my current box out and put in a sealed to experiment. 4 door Chevy Cobalt so I'm sure it isn't all that high. I would assume around 44-46hz but I am hoping to figure out how to make it work with the higher freq. If anyone knows the formula for figuring this out I will greatly appreciate any help you throw my way.

[Vizzo]

Can I set a sealed box on my back seat to try to figure out my resonant freq? My box fills my trunk and is sealed off very well.

[tunes002]

Bass mekanik V5.0 - its the 1 that has almas bronco on the cover - has a formula to calculate resonant frequency of your vehicle.

[CalusaCustomConcepts]

Can I set a sealed box on my back seat to try to figure out my resonant freq? My box fills my trunk and is sealed off very well.

Yes. You want to know what it is with your equipment in anyway. If the trunk were wide open it would change when you put in your current set up.

Meter the sealed sub at every frequency from 20 to 80 at the same volume and you'll see what your car does.

[Vizzo]

Thank you Buzz.

[Vizzo]

Found it! Now I need to get my box to peak at that note. Thank you for the help. We'll see how it does tomorrow in dB Drag.