danieldl

Hi guys,

I've posted on another forum but now I really need someone that knows what he's saying and don't talkshit because I really don't want to spend $400 for nothing.

Here is my situation. I own a Toyota Yaris 2009 hatchback. I'm doing about 40 000 km per year, which is much, and I really appreciate listening to some bass when driving. I've changed the factory head unit for a JVC KD-R400. I've chosen this radio specifically because it can change his color and then fit my Yaris orange lights in the dash. It was also on sale in my local store and it has everything I need (aux, usb and 20W amp for speakers).

Then I took some gauge 8 around with a 60A rated fuse that I already had and pluggued in my PDX-1.1000 that I got for 300$ (only slightly used, really a good deal I think) and my 4+4 ohms Type-R (2nd gen) wired to 2 ohms. It sounds loud, which is what I want, but it also smells like in my car. I used it in a original first gen vented Alpine box.

It's still pounded a lot during about 6 months with the gain of my amp set to 1/2. But if finally died. I've got to tried another Type-R 2nd gen, this time DVC 2+2 ohms wired at 4 ohms and I can say that there were no more any bad smell or anything. But I've decided to upgrade anyway as I wanted to be sure to not blow another sub and I just wanted to change anyway.

As I was going for SPL only, I got a S12L7 (750W DVC 2+2 ohms) with a ported enclosure on audiosavings.com. Here are some pics of my setup:

http://webftp.dnll.net/dnLL/public/000.jpg
http://webftp.dnll.net/dnLL/public/111.jpg

I have more space in my trunk and the sound is going directly into the car, no problem with the trunk plastics, etc. Wired to 4 ohms total, I thought it wouldn't smell like . But after some hours, it smelled like burned clue or something. I raised my gain to almost 3/4. I've read a lot of times on forums that this sub was okay for 1000W anyway. It plays for 2 days. And then it stopped playing.

I've unpluggued everything and both coils are now at 1.4 ohms. If I plug them in series/parallel (it doesn't matter), it's still 1.4 ohms total. Sounds like the coils aren't anymore isolated. I've contacted audiosavings.com and they told me they would exchange it. It's okay. But now, before receiver my new one, I would like to know if I got a defective unit or if it's me.

I have a lot of questions. I already have bought some great knukonceptz.com gauge 4 (rated awg 2.83) wire kit for my amp, because I already knew that gauge 8 wasn't enough. It's actually on his way through UPS, I should get it before the new sub. ALL MY ELECTRICAL SYSTEM is stock in my car and I want it to stay like that (no upgrade on the alt or whatever, just my 1 farad cap in the back, that's it). I've still read a lot of times that my alt can take the 1000W of my PDX (this amp has a good efficiency).

So, now... is 1000W too much for this sub? Is there any chance that the sub was defective? Could it be the gauge 8 wire (why would it change anything)?

Last but not least, considering my amp can take either 2 ohms or 4 ohms load (same output wattage), am I really better using a DVC 2+2 ohms wired at 4 ohms with it? Is it better for the electrical system? And, finally, could a PDX-1.1000 in a long terme range damage my car stock electrical system?

Sorry for all the questions, I wouldn't even mind to pay a professional just to give me the right answers. I'm living in Quebec, more precisely in Chicoutimi and there is only one shop selling some car audio things and I cannot say they know a lot about it. By the way, sorry for my English, I'm a French canadian. Hopefully I will find someone that will give me good informations. It would be so much appreciated.

FYI, the enclosure is 18"x16"x14" external, I don't have any other specs on it but it's vented and 1" MDF thick.

Thank you in advance.
Daniel

jstoner22

iTrader: (1)

what exactly stopped playing?

has the amp gone into protect?

is the sub blown?


also, it sounds like your gains may be a little high. in addition to the gain, there is a switch to change gain controls from 0.1-1V or 1V-8V.
if you have it 3/4 up on the more sensitive settings, you could be sending some nasty clipped signals to the sub.
you also said your car smells from the sub you blew. another indictation.


those amps are regulated to the same power at 4 and 2 ohms. however they don't like to go below 2ohms. and seeing as impedance fluctuates, i'd be going with a 4ohm sub.


as far as the 750 watts on a 1000watt amp. it will be just fine if your gains are set proper. the amp will only put out 1000watts when playing a test tone and 1%thd (or whatever specs they happen to use). in the real world, the power its putting out will greatly vary, only coming close to that 1000 when pushed on on musical peaks. which the sub can handle on a peak, 750 continuously.

also, you should have no issue running that amp off of a stock alternator.
and it doesn't matter what amp you buy, any additional strain on the alternator, no matter how little, will shorten its life. to what extent will vary.

1)get your new wiring kit in
2)get someone to properly set the gains
3) and if you still aren't happy, address your box, as that will make more of a difference than anything.

danieldl

Yep, the amp goes into protect when I'm raising up the volume. The sub is still working (at 1.4 ohm lol) but at high power draw, the amp fails. Both coils at 1.4 ohms, pluggued or not, they are no more isolated (don't know how it can happens).

The sub looks new by the way. For the 0.1-1V or 1V-8V thing, it's at 0.1-1V, at 1-8V it wouldn't even play with my actual headunit (don't know if that is really the thing that matters). I also have the subsonic filter set to 30 Hz, it looks a lot easier for the sub.

And you asked when it happened... well, everything was fine, I ran up a bass test for 1 minute, then stopped the car because the voltage dropped to 9.6v on the cap at the back of the car, which is really low imo. With the multimeter, I measured 12.6v at the battery when running, then 12.4v around the fuse, so I've removed the fuse and put it back again after some cleaning (thee fuse was VERY hot, no way to hold it before 20 minutes). After this, I started getting problems everytime I raise the sound on my headunit. I've changed back the fuse to a brand new one, it didn't fix the problem. I've tried without the cap, with different wires, etc. and then I saw the 1.4 ohm measure on both coils pluggued/unpluggued (series or parellel, doesn't mind).

If it could matter, I'm also using a Pac LC-1 RCA bass controller with my head unit, it just acts as a bass remote so I can control a little bit more my bass (if features output and input for RCAs).

By the way, thank you really much for your reading and reply, your help is really appreciated.

jstoner22

iTrader: (1)

okay, well it sounds like your problems are simple.

you REALLY need bigger wiring.

the amp WILL shut down if your voltage drops that low.
(look into doing your big three upgrade, its cheap easy and effective)


if it happens not to be voltage drop, it sounds like you are simply pushing the amp too hard. having the gain that high is asking for alot of power off a weak signal, and when you go past what the amp can put out, it goes into protect.

so bottom line is you are suffering from two major things.
1) voltage drop
2) amp overload

thankfully your solutions are easy.
1)upgrade your wiring (which you say you are already doing, thats good)
2)upgrade your 'big three'
3)get someone to properly set your gains.



as far as the sub, i have no idea why that would present a 1.4ohm load when wired in both series and parallel.

regardless...make sure you are using the Multimeter correctly. unless there is something wrong with you car, you should be at 12.5V with the car off, and 13.8V with the car running.

danieldl

That's ok for the measurement of the coils, I still know how to use a multimeter ! Everything was working fine and stopped working when the impedence suddently changed. That is the problem, the sub is blown up, something is wrong. The bad smell wasn't obviously only glue. As I've said, when everything is unpluggued, whether I'm measuring coil 1 neg with coil 3 pos, or coil 1 pos with coil 1 neg doesn't matter at all, I'm always getting 1.4 ohms (and as far as I know, I should respectively get OL and 2 ohms in these cases). Same when it's pluggued (either series/parallel), 1.4 ohms on the enclosure. I remember getting a 3.8 ohms load on the enclosure when I've first set up my sub. Now I get 1.4 ohms and nothing has changed...

13.8v with the car running yeah, it's okay, but I took my measures when the sub was playing obviously as I wanted to know where was all that voltage drop (because as I've said, 9.6v on the cap is too low).

For the gain, just one thing I would like to know. I do own an oscilloscope and everything, I've read a lot about clipping and etc. My gain was set to 1/2 on my Type-R and it playing great and loud; when plugging my L7, at the same gain it was playing exactly the same way (well let's say with some more SQ of course, even if it's square, it sounds a lot better than a Type-R imo). I thought that giving the amp a 750W sub instead of 500W would allow me to raise up a little bit the gain from 1/2 to about 3/4. I know this have nothing to do with the wattage but I'm not sure neither to understand why a PDX would clip at a little less than 3/4 gain. If I've changed my Type-R, it was also to get a little louder, and raising the gain obviously pushes the sub a little more (I wouldn't have even tried with my Type-R, it was already so much overpowered).

jstoner22

iTrader: (1)

well a 2ohm rated sub will not always be 2ohm. you should be able to either wire that sub at 1ohm or 4ohm (give or take a little)

lol, and given the first sub fried in 6months, you probably already had it up enough for a more powerful sub.


remember you gain is simply to optimize your amps input sensitivity to match the output of the headunit.

if you have it too high, you will be maxing out that amp at 25/35 on a headunit. rendering the upper ten notches useless. (35 is just an example)

just because you keep turning up that gain, doesn't means its continually going to put out more power.

like a said though, you have two clear problems with cheap simple fixes.
1)voltage drop
2)amp overload (most likely)


the majority of the issues will be fixed with the new wiring kit.


(if you sub is now indeed presenting a 1.4ohm load as opposed to a 4ohm load, this will also contribute to a greater current draw from the amp)

follow the three steps i listed above, and get your sub checked out!
good luck!

danieldl

For the sub itself, I'm sending it back to the dealer for an exchange, it's obviously broken. It's DVC 2+2 ohms, both coils were around 1.9 ohms when received and pluggued to about 3.8 ohms; always getting 1.4 ohms isn't normal at all, it's just broken, something has melted and the coils merged. I don't really understand this part of the problem, but the fact the the coils are always at 1.4 ohms whether they're pluggued in series, parallels or not pluggued at all is a really good indication that the coils are now somehow pluggued in even when it's not. I probably pushed hit too much but I still think that a few hours is a short life for a 250$ subwoofer. That's why I will get a replacement.

I think I should just follow your advice concerning the gain. But I cannot say that raising the gain isn't going to put out more power, as it really gets A LOT louder at 3/4 than it is at 5/8 for example. Is there any way to know where exactly is the max gain I can set on the amp for that specific sub? I know we can see when a amp is clipping with an oscilloscope, but the fact that the sub is actually half-blown doesn't mean that the amp was clipping, right? I may just have pushed it a little bit too hard.

I will install my gauge 4 cables as soon as I get it (which will be before I got my sub replacement anyway). There's the big 3 like you said, I will see how are my voltages after this and I will see.

Dukk

To me it sounds like you are listening too loud for too long. Kicker used to publish power ratings by time which was really cool. JL did something like that too back in the day.

The sub may well handle 1000watts, but that's a lot of power and that power results in a lot of heat. That heat will kill the speaker sooner or later.

Look at it this way - the engine in your car is probably rated to 7000rpm but how long is it going to like running there? Would you pull out on the freeway and leave it in second gear and drive for an hour or two? Something to think about..

lpchouinard

my PDX 1000.1 went into protect often with different 2ohm drivers, I switched to w15gti (3ohms) and it never stopped again. The tiny PS of the PDX is not design for "low" 2 ohms load...

danieldl

It was actually a 4 ohms load but the sub went into protect when the impedence had dropped to 1.4 ohms.

For the rpm thing, I agree. Am i better to replace my pdx 1000 with a M6 or just leaving the gain lower (around 1/2) will do it?