shizzzon

that's what i'm gonna do... Although in spl testing, shrinking port area is a nono so it's a toss up to see what will happen. what effects spl more, wrong tuning or smaller port area... ill find out soon.

down. When keeping the same port area and length, increasing internal volume will lower tuning... so the more i cut off the port from here... the more polyfill that would be needed to maintain the same note peak.

i know lots of people use it to enhance their low end but it also does lower tuning which means that a sub actually performs like being in a larger enclosure. Well, it's time to quit speculating... I'm gonna try shrinking port area to reduce tuning to see if i can ever get louder by doing that then when that fails, i'll go get some polyfill.

well, of course polyfill physically takes up space but it doesnt appear to it installed loosely, but actually gains volume. Dont we wish some things in life just worked backwards, lol

well, i can keep it in the box, that's no problem. I NEED it to change tuning. Polyfill virtually increases internal volume... so by keeping the same port area and length, the more polyfill added, the lower tuning will go. From what i read about polyfill, polyfill will only start to consume internal volume if packed instead of loosely spread and secured.

cool cool. I dont know whats worse... Charging at 28v.... or Doin what Snoopdan did the other day and hooked up a battery bank that only needed a 30 min charge at 200A... somethin didnt quite set right and it RAN ALL NIGHT AT 200A! over 8hrs! While still in the vehicle! Woke up to sulfur... Lucky nothin exploded on him! but sulfur was trapped in his ride for a while!

Holy Jesus! I'm surprised the batts are still alive! Ok man, take the batts out and sit them down somewhere for a few hrs. I know in my car, when the car is shut off, they stay at 13.8v for about 3hrs then they are back where they should be 13-13.1v. They must rest for a while so dont use them until they return to normal. Once they do return to normal, i would hook them back up in the vehicle with the stock alt and do current draw demands that match your stock alts capability so u can get some action out of those batts to see if they are still performing properly. I would monitor their voltage drop during a demand of 100A or so and see what happens and make sure they still float around 13v or more. PS - u still plan on comin down soon or u gonna wait until u get all this resolved?

i know what the problem is... I can't prove it because well.. box building software lies in the car audio realm... I was looking at a response graph in WinISD and looking at how the box likes to peak... This was only true on the very first port i made, the initial port. All other ports after that i cut, it went way off... What is happening is my response in the car is actually louder right after tuning then what WinISD is saying... 20hz later... So, it went all crazy and thats why i was confused. So, what is happening is even though i am gaining volume by cutting off some of the port, it's still not enough to get it to peak at 50hz AND gain from it every time... By the time the port was tuned to peak at 54hz, i'm over here burping at 50hz and lost 0.4dbs! I stopped immediately since i knew not to cut anymore off. I'm gonna create another thread here because i need to go a different route to see if i can get louder another way so i can keep a new thread's topic on topic.

hmm.. take ur multimeter and measure somethin else like a AA battery (1.5v) or a wall socket (110-125v) and make sure it's not the meter first. Sounds like the regulator inside just died. Do NOT use it again if your meter comes back reading right. Also, check the ground on the alternator and power cable. If one of these cables lost a good connection, it "may" also sky-rocket the voltage. Somewhat similar to removing the battery from the equation.

u got a big engine so i doubt it's this but u might be losin too much horsepower... only way that's possible is if u already have mechanical problems.

well i can tell u dont buy any batteries from this moron... He just wants your soul...

good luck at autozone.... some of them dont even believe high output alts exists and then some of their machines cant read their output either... Autozone for testing alts is about as bad as asking a crackhead to do it, i'm serious. Don't let them take your ground cable off the batt either... I've seen them want to do that before too, i was ready to bitch-slap some automotive sense into them but i figured it was a waste of muscle.

get an ammeter and check and see if the alt is outputting what it suppose to be outputting at a given rpm. Due to lots of manufacturers rating idle at 2400rpm... newer vehicles will have idling alt issues if your vehicle idles below 800rpm which most new ones do anyway... I'm sayin this so if u meter alt current at idle, don't expect idle output ratings until u hit at least 800rpm engine. So, because of this, expect alt output range between 800-2600rpm. Anything higher is pointless and anything below 800 is just enough to run the car. My 250A alt i tested was putting out in between 47-69A at 1800rpm Alternator speed(600rpm engine) so just enough for the car.

thanks for the info. I would have to get in touch with some locals who compete and a judge i know so i can ask them what all can i do to the car's glass and exterior mods to prevent air leaks without putting me in a class higher than i want to be in. Unfortunately, it will be a while before i ask them this as i am still port tuning right now. Although... i had to stop doing port testing as of tonight because apparently... i have already found my freakin port length and am not happy with it! I gotta look over a lot of graphs i have layin around so i can compare my data that i collected today and see what i need to change to get louder. As of right now, it peaked a 152.82 tonight. and a 156+ at the kick.

take a wire, solder it to the outside ring of the rca, then secure it to an actual ground on the car. For a temporary resolution to see if it will work, secure wire to car then hold other end to outside ring of rca. If it cures it... then u know what to do. I do say though that doing this is only meant to be temporary regardless of which method you choose to do.

i know nothing about the car but i do know this from messing with cars- If the dash contours the whole dash and console area, start from the bottom and work your way up. Sometimes you gotta start loosening up pieces all the way at the e-brake if ur dash is made like that. Also, most newer cars just have their pieces popped into place and may feel as tight as a screw. I know u don't wanna break anything but i am saying that if u can pry a part away from the car, then it's likely just popped into place. All else fails, go to a BMW dealership and request a print out of how to remove the dash.

if u wanan stay cheap, u can pick up a brand new Audiopipe AP30001D amp. It's rated at 3,000w @ 2ohms bridged. If u do not know hwo to properly set gains, i wouldn't suggest you buy this amp, honestly, because with this much power to play with, i'm afraid users may end up killing subs like yours due to clipping, etc... A lower power alternative would be - Alpine PDX-1.1000 This baby may only be rated at 1,000w but it outputs consistent power over a larger range of ohm loads allowing it be a more powerful amp than others rated in it's class(those that do not have that technology).

ur best bet is to start searchin all the forums yourself. A new one is gonna be around $310 shipped. If u just cant find one, alternative is to buy a Deka 9A31. it's 100aH, floats a hair below the D3100 but is under $200 shipped brand new.

My probes on my oscope have been actin funny the last few days and now they dont work so i had to go out and buy another meter while i wait to order some new probes so i can keep on testin. I retested my score with the same setup and measured 152.3 at the MECA headrest position rather than 152.55 so i have been doin some port tuning... Using same port area, just changing length- 25.5" - 152.33dB 24.5" - 152.37dB 22.25" - 152.52dB (back where i was, lol) I'm suppose to be around 5-6" "theoretically" so i'll see when i get that small.

linear excursion disappears after around 1200w per sub. Loudness factor continues to rise all the way up to around 3,000w of power. Power compression will start to become a problem just after this as well.

you can't run a large amplifier with just a high output alternator. What happens is 2 things- 1 - voltage regulator does not react as fast as a battery does so first sense of a massive current draw will come from battery. If it's like a quick bass hit, it will pull out of battery then alt will attempt to charge batt back up. 2 - alternator has exceeded it's duty capacity. Like the first example, if a bass note came in that was more constant, it's first source would be the battery since it reacts first... Then the alt will try to take over but it has a problem. It must attempt to supply power to the 4000w amp AND recharge the batt at the same time so it splits it's current dispersion. What happens now is it runs out of capacity to keep the amp running straight off the alt and starts digging into the batt full force just as if the car was off! When this happens, the larger the current draw, the lower the voltage will dip and i mean severe dip. It is VERY BAD to try to run an amp of that power with just a high output alt and no batt(s) next to the amp to help. This is the reason your voltage drops so low. Now, onto what might happen soon... You will need to make sure that your starting battery is kept charged. If it's discharged, then the more current that is supplied to the battery, the lower the voltage will be. don't keep your batt in a discharged state if it is and stop wangin on it for the time being until u get some batts back there.

i'm sure he's talkin about this- and prob the one to the left of it as well-

well of course but with plenty of experience with these subs, they do not shine until you start sending loads of power to them.

i like to know how u got the sub to stay steady while mounting it on the wall? Did u have to use a knee or foot? hehe. I know when i had to mount some HD3s like that before (48.5lbs) by myself... i hated it!

It is wise to use as much port area as possible. How much? well, i cannot say for sure exactly on a given ratio but i can assure on what i've been testing recently, port area plays a LARGE factor on spl output. Also, if your port is very short on the length side, you will also lose potential spl. I am currently runnin 144sqin of port area and whenever i try to shrink it down just 8 sqin, my score does drop! There is a point where you can have too much port area. This is why you will need a meter to find out for sure. A good rule of thumb is never exceed the area of port to the cone area of subs you are using. Now, for me, i'm running 706 sqin of cone area at only 144 sqin of port. Not my choice, my car is only so big. I always like to think of designs that are almost impractical to do but still feasible... Without a port in my wall, i have 185.75 sq in. If i can construct a port using thinner material or submerge the port inside the box without taking up port area.. i can gain some port area back! This is coming from a design that cannot be altered so worse-case scenario. I have a few ideas if i choose to alter the existing port area if i want to reach a higher goal.... More testing to come soon.