520 replies to this topic

[fecupe2001]

Results so far!!

Gain:
- 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

Lost
- 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



New score:


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!!
New score:



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, 29 July 2011 - 11:57 PM.

[fecupe2001]

I always wanted to try taking out the boot of the sub, i saw a guy saying it raised his score 0.2 dbs , of course i wasn´t gonna pass the oportunity of trying this:





Next step was getting the box bigger, i raised the internal space from 1.3 cubic feet to 1.5 cubic feet with an external 4" PVC tube 12" long, this gave me around 39 hz, what i learned about this truck is that, no matter what you do, the thing likes to peak between 52 and 53 hz no matter where i tuned the box, of course the box was small so it was one of the reasons, here we go:



New score:



After this, i retuned my port from 39 hz to 42 hz trying to raise the tuning up for a better score, i was amazed of the result, honestly i thought i would raise a few tenths but i dropped to this:



So, i cut another piece of PVC and retuned to 39 hz again and my score got to 137.7 dbs again!!

The pictures about the scores END here, i honestly got bored of taking them, if you believe the scores nice, if not, then don´t bother to read the topic anymore

Anyways, i changed the DD 2512 because the box was to small for it and the power was stupid small, so i installed a Crossfire BMF 12" wich is 375 watts, i raised 0.3 dbs by doing this, so, i went from 137.7 dbs to 138.0 dbs @ 53 hz.

[fecupe2001]

There are TONS of people on this forum wondering how much you can gain by running a negative wire from the front battery to the amplifier instead of grounding it to the car, so , i disconnected the ground from the amplifier to the car and connected one of my negative runs that comes from the front battery to see how much a single negative run add to this application, went from 138.0 dbs to 138.3 dbs!!

Then, i connected my 2 batteries on the back and the other pos and neg runs, so i went from a single batt with 1 pos and 1 neg to 3 batts with 2 pos and 2 neg, my score raised from 138.3 dbs to 138.5 dbs!!

So this means, that the 2 batts on the back were giving me 0.2 dbs on this application, if you are wondering why i got a small gain about having 3 batts instead of a single batt, it´s because this amplifier is so small that it doesn´t need too much power, In other words, going from a single battery without a negative run to the back , to 3 batts and 2 + and 2 - gives me 0.5 dbs on this application!!

Ok, i´ve ALWAYS wanted to try something different than the resin because it´s a pain in the ass to work with , and besides that, it´s expensive!!! Said that, we all know that the most of the time, you gain some by getting the surface of the box smooth as hell, since i have a printing supplies company, i took one my my PRINTING VINYLS and installed this thing inside of the box, if you guys wanna try this it´s way cheaper than the resin, also, i didn´t pay too much attention on details and ended up with a few scratches:







Looking thru the port:


New Score:



As you can see, the dumb ideas sometimes WORK!! there aren´t bad or stupid ideas on SPL, you have to try everything that comes across your mind, you never know what´s gonna happen!!

[Rebel4055]

Taking the boot of the sub was pretty interesting.. And finally someone confirmed the ground haha!

[StrongmanDesigns]

This is awesome man keep it going. I've been trying to find time to do testing like this myself.

[fecupe2001]

So far so good, we went from 134.6 dbs to 138.9 dbs on a single afternoon!!!

Anyways, it was time to move on to the 45´s , since i had A LOT of pvc, i prefered to try rounding the corners instead of building some wood 45´s , after this test i learned something IMPORTANT, this are the most crucial and dangerous things you can install inside of a box!!!!!!!!!!!!!!!!!

How come?? oh well, here are the pics:
I striped a 4" pvc tube on 4 pieces, first i installed some vertical round overs:






Guess what??? i went from 138.9 dbs to 138.6 dbs by installing those things

After the 0.3 dbs lost, i took them out to confirm my last score and got a 138.9 dbs again!!

So, the next step, was to install a single horizontal round over!!



New Score: 139.1 dbs

Then, i installed a second horizontal round over close to the port:


This one dropped my score to 138.7 , took it out and got to 139.1 dbs once again.

[fecupe2001]

Taking the boot of the sub was pretty interesting.. And finally someone confirmed the ground haha!

Yeah man, that helped a lot hehe, well, glad i could confirm something, tons of new updates in a few minutes!

This is awesome man keep it going. I've been trying to find time to do testing like this myself.

Thanks a lot hommie, yes sir there´s more coming up!!

[fecupe2001]

I have to go now, i´ll update this topic tonight

[cracker]

i like this thread already

[Tebo]

great post!

[Ford302Redneck]

I tested my Honda Accord one day, and I gained 2dBs just by moving seats, visors, and other stuff in the car.

Ductape around the sub usually gains .1 or so. There is soooo many little things to do to gain. If you start at 145 with a plain install, a 148-9 is easily reachable in most cases. Just by doing little stuff.

I love doing tricks like this to gain SPL. I hope to buy a TL this spring just to test and have something to do.

I have a lot I want to myths I want to test, and a lot of things people say makes a difference I just don't believe.

[Forevrbumpn]

now try the carpeted box trick, how it lowers by like 0.3db+

[memphisBred]

Good stuff cupe. It's nice to have info like this for those are learning and those who enjoy reading about other ideas/tips.

[Ford302Redneck]

now try the carpeted box trick, how it lowers by like 0.3db+

Good one.

[StrongmanDesigns]

I was just about to ask if you were gonna try 45's but then you beat me to it. lol

I was pretty surprised that the pvc corners lowered your score.

[Alex K]

More!!!

[Hugh G. Rection]

i see alot deebeez in there that you havent found yet........

[fecupe2001]

Thanks for the input guys, YES, carpet lower your score (at least that´s what happened to me in the past)!!

Hugh, yes i know there is a lot more debeezzzz, so here we go

Ok, i ended with a 139.1 dbs @ 53 hz on my last post, after that, i installed a PVC to round the external edge of the box, something i saw jacob from sundown and tons of other people trying, like this:



This little thing dropped my score to 139.0 dbs, so i took it out, burped again and saw my 139.1 dbs.

Then, i knew my port was way to small for this box, i mean, 8 SQ per cubic feet it´s small as hell, i wanted to get a bigger port but i only had 4" PVC around, i wanted to try a single 5" pvc port but i don´t want to spend money on this little "project" , SO, i went from a single 4" port to a couple of them, with this, i could have an idea of how much i would have gained with a 5" pvc port, i thought that, if i dropped my score 1 db or something like that by switching to 2 4´s , then with a 5" i would have gained A LOT!!! But, they are only assumptions, so, i got the 2 4"´s :



I went from 139.1 dbs to 138.5 dbs with this things, I´m SURE that, with a single 5" port i would have raised at least a full db

Anyways, i closed the hole of that port as good as i could without spending ANY money or wood, i did it with a little square of mdf that i had on the floor, my score went from 139.1 dbs to 138.5 dbs, this means that this hole took 0.6 dbs from my score

Then, it was time to do some flares, i had a metalic bowl laying around, BUT, it was way too small, i tried to find another one but didn´t get any luck, so , i had to do the job by getting hot the tube on the small bowl and push the fucking tube down to a piece of wood i had, they end up looking like SHIT , i didn´t think i was gonna gain ANY with this been so badly heated, BUT :

Went from a 12" pipe to a 14" pipe, only EXTERNAL flare:




139.4 dbs, that´s a HUGE gain if you ask me, take into account that i´ve already lost 0.6 dbs because of the hole of the second port!!

Then, i took out the sub and flared the other side of the port, i mounted thru the hole of the sub and attached them with cheap ass electrical tape, and what would you know?????







After this, i duct taped the holes of the box because remember that i raised the internal space by moving one of the walls, went from 140.7 dbs to 141 dbs.

THEN, i did my good old seats , central console and visors positioning, my two front seats all the way forward and folded vertically, visors vertically, center console empty and open:

Visors down: 141.5 dbs
Front seats forward: 142.2 dbs
Front seats folded vertically : 142.5 dbs
Center console empty and open : 142.7 dbs

IMPORTANT NOTE : Remember that i lost 0.6 dbs because of the second hole on the box, this means that i ended up with a 143.3 dbs @ 53 hz with a 375 watts sub and a cheap Almani amplifier.

After doing all this, i honestly called a done job because the box had way too many leaks, remember that i didn´t even glue it, small ass cone area for this car, smaller port that i would have wanted, etc etc etc etc!!!

I hope you guys enjoyed this short topic, i´m not a big expert on Burp boxes and there are TONS of other things that i couldn´t try on this little "project" , mostly because of the time, i have DB Drag finals this weekend and i have to work on the sexplorer and install everything again, BUT, the results are GOOD if you ask me!!!

I went from 134.2 dbs to 143.3 dbs in 2 days without spending a single dollar!!!

[AA98hoe]

what do you mean seats folded vertically? and did you try glove box open? and center console do you have a pic?

[fecupe2001]

what do you mean seats folded vertically? and did you try glove box open? and center console do you have a pic?

Remember that spanish is my main language so i might have said it wrong haha, is when you get where your back is and you move it, some cars score better all the way forward, others all the way back, my explorer scores A LOT better when i get them on a 90º positioning, understood me now? if not, i would have to take a pic to explain myself better!

Yes, i tried the glove box open and dropped 0.2 dbs, also, i tried to close the a/a vents and dropped 0.5 dbs, that one hurted!! i also want to try armour all on every spot of the dash and see if it gains anything, about the center console, no pic either, but is just the stock console emptied and opened