Box for HDC3 10's.

[SPLluminator 10+ year member]

Im planing on getting into some comps this spring and want to start in street a. I bought some HDC3 10's. Now i need to design a box for spl. I am (barely)pushing them with an IA 20.1. Im not sure what the peak frequency of my car is(99 lumina). What is the best method of finding this out? Then, i will begin building a box around that.

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[kmanian 5,000+ posts]

Im planing on getting into some comps this spring and want to start in street a. I bought some HDC3 10's. Now i need to design a box for spl. I am (barely)pushing them with an IA 20.1. Im not sure what the peak frequency of my car is(99 lumina). What is the best method of finding this out? Then, i will begin building a box around that.

build a simple sealed box, run a sweep from 20hz-100hz . Using a meter you run the sweep at the same volume throughout, where ever the dBs are the highest is your res. freq for the car

I hope that helps

 

[SPLluminator 10+ year member]

build a simple sealed box, run a sweep from 20hz-100hz . Using a meter you run the sweep at the same volume throughout, where ever the dBs are the highest is your res. freq for the car
I hope that helps

Thanks for the quick reply

Ive heard people say that this method is bogus. Is that true? If not, then im gonna do it because ive got the wood for a sealed box just laying around. Ive gotta go to the local shop tho to get it metered

 

[bball09124 10+ year member]

build a simple sealed box, run a sweep from 20hz-100hz . Using a meter you run the sweep at the same volume throughout, where ever the dBs are the highest is your res. freq for the car
I hope that helps

After you do that, you meter the sealed box in an open air environment. You subtract the open air db from the in-car dbs and whichever frequency there is the largest difference is your resonant frequency.

I did a horrible job explaining that, if I wasn't clear I'll attempt to explain it again.

 

[SPLluminator 10+ year member]

Ok i think ive got that, but theres gotta be an easier way

 

[kmanian 5,000+ posts]

After you do that, you meter the sealed box in an open air environment. You subtract the open air db from the in-car dbs and whichever frequency there is the largest difference is your resonant frequency.
I did a horrible job explaining that, if I wasn't clear I'll attempt to explain it again.

Ok i think ive got that, but theres gotta be an easier way

he is correct, and secondly, there is an easier way, pick a number and build a box. then hope for the best. Truth be told, with the information you got from us, you will be in the ball park but you will still have to tune and tinker from there. It is definately an art!

good luck

 

[SPLluminator 10+ year member]

lol, im just gonna pick a #, im a newb anyways, im not gonna win, just wanna get into it. Ill prolly build a box tuned to 45-55hz and .8ft^3 each

 

[thorshammer1 10+ year member]

Wouldnt go any higher than 45-47. You won't be happy with 55. Try a slot port and make it big!



First box had a 7 in wide prt tuned to 47 and did 146.6 consistently.



Next box has a 10in wide port tuned again to 47 and gained 2.2 db to 148.8.

Hope this works or helps.

 

[SPLluminator 10+ year member]

Ok this is an old thread but i are bumping it. Im looking at different options for my trunk. Im running into space issues for a port that big(7-10"). The max dims. of my trunk are 34wx16h. Itll work but there is no space for sound to get into the car. Has anyone ever tried subs up port up/back in a trunk with good results? Jw. Ive got a Daily box that 2cubes @ 40hz but im not gonna get craxy #s with it. Any help would be appreciated.

 

[SPLluminator 10+ year member]

What are you guys thinking?

 

[SPLluminator 10+ year member]

You not thinking?

 

[basshedz06 10+ year member]

i would recommend smaller boxes is better in some cars subs up port back is good while in others its not, thats where testing coming into play, i know in my altima if i do ports back an subs to the side i am louder but i have to get some testing done also to see what it does

 

[GearGuy2001 10+ year member]

Can you fold your seats down?

The do subs/port forward and only play it when you fold your seats down

 

[SPLluminator 10+ year member]

Subs forward was actually 3dbs lower. I was just wondering if they were facing up if i would do better. The seat go down when i unscrew them(which i always have undone because im constantly changing things.

 

[RAM_Designs 5,000+ posts]

^^^what he said. Fire everything forward and seal the box off from the trunk.