Results so far!!
- Moving box around the trunk until i found the sweet spot: 0.5 dbs
- Changing box size until i found the best one: 2.2 dbs
- Removing sub´s boot: 0.1 dbs
- Negative wire run from battery to amp instead of grounding it to the car: 0.3 dbs
- 2 extra batteries: 0.2 dbs (depend on the application, i was using SMALL power).
- Printing Vinyl inside the box to make it smooth: 0.4 dbs
- PVC round over on the pressure point of the box: 0.2 dbs
- Extertnal flare on an aeroport: 0.9 dbs
- Internal flare on an aeroport: 0.7 dbs
- Duct taped old screws holes on the box: 0.3 dbs
- Sunvisors folded down: 0.5 dbs
- Moving front seats all the way forward: 0.7 dbs
- Taking out floor mats: 0.1 dbs
- Front seats vertically: 0.3 dbs
- Center console empty and open: 0.2 dbs
- Covering the sub´s pole vent hole: 0.14 dbs
- Duct tape around the sub: 0.25 dbs
- Using 8 gauge from sub to amp instead of a POS wire: 0.22 dbs
- Cooling the cabin with the a/a: 0.45 dbs
- Rounding the sub hole: 0.28 dbs
- Rounding the external edges of the box: 0.17 dbs
- Armor all the whole interior of the car: 0.06 dbs
- OFC vs CCA vs Welding vs electrical wires: 0.1 - 0.2 dbs difference only!!
- Grounding battery to chassis : 0.3 dbs
- Routing the mouth of the port : 0.15 dbs (only 1/2" , should be higher with a bigger jig")
- Raising tuning: 0.3 dbs, this depends entirely on the car!!
- Installing 45´s on non pressure points of the box: 0.4 dbs
- Steering wheel at lowest position: 0.2 dbs
- Having 2 round ports with different sizes: 0.5 dbs
- Printing vinyl outside the box: 0.3 dbs
- PVC roundover outside the box: 0.2 dbs
- Opening the glove box: 0.2 dbs
- Closing a/a vents: 0.5 dbs
- Inverting the sub´s polarity: 0.3 dbs
- Changing from PVC roundover to mdf 45´s : 0.2 dbs
Hey guys, just wanted to post a couple of things i tried this week, i had some 3/4" MDF in my garage and said, what the heck! I built a sealed box to show people how you can find the resonant frequency of a car:
After that, i started some nice trials and mostly errors haha, but here are some tips, advices, gains, scoring drops, etc etc , i started taking pictures but i got bored of taking them, this is my 99 Ford Explorer wich is a "big" SUV and i tried a very SMALL cone area for it, testing was at the beggining with one of my 2512´s but sub barely moved because of the small power i was using and the tiny little box, so i changed to a crossfire BMF 375 watts sub, i was using an Almani 1500 watts amplifier wich i don´think it´s even a 1000 watts amplifier, but who cares,once again, this topic is not meant for braking any world record, i don´t care if the number sucks, this topic is only to show you guys a few tips on how you can gain some debeezzzz!!!!
Said all that, let´s start with the box, i did it this way because i wanted to try 3 different box sizes with this thing, see how much i could raise or drop by getting it bigger, also ,remember that raising or shrinking the internal space changes the tuning frequency, so yes i had to retune this box each time i changed the internal space, i had A LOT of 4" pvc pipe in my garage so i didn´t care, this is the box:
Sealed box , 1.1 cubic feet after sub displacement:
Score with the sealed box:
After this, i drilled a hole for a single 4" PVC tube and got this box ported with an external port, this means that the box remained 1.1 cubic feet after sub displacement, i tuned this box to 42 hz
After this, i tried box positioning, and found out that this box scored WAY BETTER by facing the sub to the driver side and the port to the back!!
This score was at 55 hz, so i knew box was way to small and i needed to raise the internal space, to be able to do it, i didn´t glue the box so i could open the box a few times without any problems, anyways, i raised the internal space from 1.1 cubic feet to 1.3 cubic feet.
New score at 53 hz:
Edited by fecupe2001, 08 August 2013 - 12:26 PM.