4th order in a hatch?

[LosIsATool 5,000+ posts]

How do they work firing rear? Thinking about doing a 3:1 for my 12s with some plexi work.

Right now i got 36 wide, 13.5 high, and 34 deep. What I want to do is have the subs firing toward eachother with plexi on the sealed side. Do the experts think i have enough room? Would like to tune to 40hz.

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[Team Ampere 10+ year member]

If you graphed them at 1 cf each sealed, figure out what the rsonant freq of the sealed side would be and then tune the portedc chamber to that. It will normally peak a few hz lower than what its tuned at. 2 sealed and 6 ported would be 3:1. theres alot more to it than just this though

 

[fivepoints 10+ year member]

if you are any good at math you could pic up this book and figure out the formulas on fourth oders i got the book and it would take to long for me to type up the info and yess there is a lot mor then a 3:1 ratio i am thinking 40hz may still be a tad low depending on the subs most are tuned 50-80 hz for spl comps for sound quality they tune them around 40-60 if you did not have a hatch back throw the sub in a sealed box and cut some tube the length suggested by this book and put them in the rear deck ware the speaker go turns the trunk in to a band pass box but they got to be tuned high like 80-90 to do so casue of the area of the trunk is closer to a .75 to a 4 ratio with new trunks they got now. any ways back on subject if talking how close you can get them to face rear that's tricky. you got to design the box on paper then do the measurements then compare and see if the port is to close to the rear hood. if it is it will never play right if not to close like 8 inch from for a 4 inch port etc. also are you sure you want that weight on those shock's in the back a buddy of mines car bottoms out with a single 12 in it in a wrx hatch wagon.

Loudspeaker Design Cookbook 6th Edition | 9781882580330 | 1882580338

 

[CAT MAN 5,000+ posts]

derek you wll never be loud. just stop now lool......... or sub up aero back **** slots and octos

 

[Kangaroux 5,000+ posts]

If you graphed them at 1 cf each sealed, figure out what the rsonant freq of the sealed side would be and then tune the portedc chamber to that. It will normally peak a few hz lower than what its tuned at. 2 sealed and 6 ported would be 3:1. theres alot more to it than just this though

4th's dont always peak below their freq. Cabin gain has a lot to do with it and frankly they are pretty unpredictable. My 4th was tuned to 38 and peaked in the mid-high 20's (2:1)

 

[Team Ampere 10+ year member]

4th's dont always peak below their freq. Cabin gain has a lot to do with it and frankly they are pretty unpredictable. My 4th was tuned to 38 and peaked in the mid-high 20's (2:1)

If you graphed them at 1 cf each sealed, figure out what the rsonant freq of the sealed side would be and then tune the portedc chamber to that. It will normally peak a few hz lower than what its tuned at. 2 sealed and 6 ported would be 3:1. theres alot more to it than just this though[/QUOTE]
I know roux, that why i said therers a lot more to it than this.

But damm, tuned at 38 and peaking in the 20s!!!! holy low tuning batman!!

 

[Kangaroux 5,000+ posts]

If you graphed them at 1 cf each sealed, figure out what the rsonant freq of the sealed side would be and then tune the portedc chamber to that. It will normally peak a few hz lower than what its tuned at. 2 sealed and 6 ported would be 3:1. theres alot more to it than just this though[/QUOTE]
I know roux, that why i said therers a lot more to it than this.

But damm, tuned at 38 and peaking in the 20s!!!! holy low tuning batman!!

I was thinkin of going lower but it sounded good where it was lol

 

[Team Ampere 10+ year member]

I was thinkin of going lower but it sounded good where it was lol

lol. Was it beastly on teh lows?? Was there any force behind them?? I cant get any umpph from my lowend

 

[Kangaroux 5,000+ posts]

lol. Was it beastly on teh lows?? Was there any force behind them?? I cant get any umpph from my lowend

Runnin a single obsidian 12 off my 2200 was movin my whole door panel and shaking around my center console. Would whip around your shirt too if you opened the door all the way and stood there. Honestly it was a wicked nasty setup, sometimes I regret trading it off lol

 

[LosIsATool 5,000+ posts]

It was just wishfully thinking. I cant fit anywhere near that size. i hate this ******* car

 

[Team Ampere 10+ year member]

Runnin a single obsidian 12 off my 2200 was movin my whole door panel and shaking around my center console. Would whip around your shirt too if you opened the door all the way and stood there. Honestly it was a wicked nasty setup, sometimes I regret trading it off lol

Will you pm me sometime today and i will send you some pics of my setup. I need some help on this port. Everythinig i do either sounds like shitt, or decreases output so much i wanna choke this shitt outta something

 

[Team Ampere 10+ year member]

It was just wishfully thinking. I cant fit anywhere near that size. i hate this ******* car

I mean , you dont have to go w a huge artio. My 1.5:1 was beastly for what it was. 145 meca style off about 700 watts w/box rise

 

[Kangaroux 5,000+ posts]

Will you pm me sometime today and i will send you some pics of my setup. I need some help on this port. Everythinig i do either sounds like shitt, or decreases output so much i wanna choke this shitt outta something

Lol sure thing. So your low end is suffering?

EDIT: Just threw your box specs into winisd. It definitely looks like a loud setup but you get heavy rolloff from around 40hz down. If you drop your tuning down to 38-40 that will make a decent difference, but unfortunately you'll also be sacrificing some output. Honestly your box is gonna be pretty **** peaky unless you drop that ported section down to around 5-6 cubes

EDIT #2 : White is your current response, teal is the response if you just drop your tuning down to 40hz, and yellow is if you drop it down to 40 and lower your ported volume down to 5 cubes. If you don't mind it being too peaky you may just want to lower your tuning and see how that sounds. How much port area are you using right now?

 

[LosIsATool 5,000+ posts]

I cant even find 7 cubes gross. Its not going to happen. Im just going to wait and wall it. I dont know if you ever heard the name David Berger but thats who will be doing it. Hes doing Trippi's Hummer right now

 

[Phoenix Risen 10+ year member]

you could always pull the back seats and build a full floor...