Every car is different when it comes to being loud for spl. I've tested car's that range as much as 4db, power for power box for box tune for tune. Some vehicles are loud but have low resident frequencies (explorers, 01 and up VW golfs) and that isn't good for getting really loud. Those cars are great for street beating spl not pure spl.

So what you'll be looking for is hatchback or extended cab truck with no back seats with a resident frequency above 55hz. Typically cars with thicker metal have lower resident frequencies vs cars with thinner metal. Proven pretty loud cars besides crx, pandas are Yaris, VW golf 01+ models, Yugos. I've always wondered about for rangers or any smaller extended cab truck. They have a lot of potential.

There are so many factors for a car being loud but hope this gets you in the right direction.

 

yeah i have an extended cab truck with those small little fold down back seats, im really hopeing i can pull out some good numbers after i start testing.

how do you find the resident frequency and how does that factor to box size and tunning the port?

 

I kinda agree.... however if you talk to some ppl on here about resonant frequency, they will say B.S your car will hit at what you tune your box for it to hit! I have changed what frequency I hit at using my port, and as I moved my frequency up, it got louder aka 52hz in my neon, and yet my resonant is tested to be 46-49!

 

so how do you find the resonant?

 

you can do pink runs in your car or just race me for your pink slip and ill show you how to find your resonant frequency for the truck!!!

 

I'll also agree with that to an extent. I can get any car to play at any hz I want but that doesn't mean it'll be loud. I would love my car to play in 70hz range and I have made it do it but it's only 8db quieter than what my car likes at 56-58hz. I can even get it to peak in the 40hz but it's till 3-4db quieter than my peak hz. That's my point to saying you tune the box to the resident frequency of the car. At least this is what you do for Street Class.