Yea, i bought a kicker l7 12inch which is in a sealed box for now, and got my old alpine amp back from my friend [for free!!] Im just using it for now until i get a more powerful amp.

Neways the amp is an mrd 350, which pushes out 300 to 320 rms at 2 ohms.
My sub is a dvc 4 wired in parrallel to run at 2 ohms.

I ran everything off the rear sub using a hi low converter.

[ lol dont worry guys install is super clean this time i will post pix later]

When i first got the sub installed, the bass felt and hit really hard. Now it doesnt seem as hard. I mean the bass is there but it isnt deep as it used to be.

The gain is set at half way, which reads normal on the alpine amp, and bass boost is off or all the way down.

I dont think its me, but the bass definately doesnt hit as hard is it used to. I dont know if im used to the bass or what.

i dont play my music so loud to the point where there is clipping, but is it possilbe to damage a sub with too little power? I mean the sub is brand new.

I dont know if i should turn the gain up a notch more, or just go get a ported box.[I know Rich wants me to get a bigger amp first]. But i am using what i have.

I duno, sometimes the bass hits hard, sometimes it doesnt. All my power cables are heat shrunk, and connections are great. I dont know what it could be. Could a bad hi low converter be a problem? or it doesnt matter once its getting a signal?

 

o btw, the sub is about 2 to 3 weeks old, not even.

 

dude get a new amp, a line driver, a new box, a new user, or a new sub. I doubt you blew a coil but if you did, that would explain why you think it got quieter. make sure that tite box is sealed kid.

 

You can damage a sub by running to little of power to it. Most converters have adjusting screws on them, try that our but, I install amps off of converters all the time and am never happy with the way they sound.

 

Sure you werent clipping that amp?

 

double check all your connections Avi. Was it a gradual decrease or a sudden one?

 

haha i want pics i need a good laugh 2da max .

 

change some setting(s) on the HU by accident and forget? ive done that a few times.

if you're worried about a blown coil, take a MM to the the terminals, but i doubt thats it..

maybe you're just getting used to it

 

i think im getting used to it. btw sometimes the sub gets warm after long periods of play, thats normal right?

o btw, i figured out the problem!

The bass is only deep when i have the arm rest down

 

I bet you're just used to the bass. It always seems louder at first. And I'm calling on the whole You can't always hear the clipping. Alpine amps have a never shut-off feature to them. Doesn't mean they don't clip.

 

Um ya there's 300+ watts of power going through the coils don't ya think that would get pretty hot?!

 

post pix or GTFO.

 

i never blast/ or turn my volume **** more than 75% up so i dont have to worry about that.

my bass/trebble/midrange is all set on half way. I mean it cant really clip if i usually play it at low volumes.

since i cant get a hu, i was thinking of getting maybe one of those kicker 5 band eqs? or maybe a processor or some sort? any suggestions?

btw, my gain is on halfway right now.

Would be ok if i turn the gain to the one o clock position?

 

dude...just because the volume is not past 75% doesnt mean you can't clip. I can set my gains to clip at volume 25/62 if I really wanted to.

 

Just when ya thought it was save to go back to the Org...

Attack of the noobish Avi.

ftL

 

With only 300watts on a L7 and it getting hot I am betting that you are pushing the amp well into chipping. Volume setting and gain setting really are no way to judge anything about clipping or the output of your amp. Volume on a stock HU is only good for about 75-80% before clipping happen on average. Gain setting are not to limit the output of an amp or are any refferance to the amps output. Gains are there to match the output of the source (Head unit, processor, line level convertor....) to the input section of the amp.

I have done many systems using L712s running them in pairs on Kicker 1200.1s. That 600watts of power to each driver and have never had a single problem with the driver overheating and/or blowing. I have also done a few with Kicker 1200.1 on each driver. This is more then overkill but if pushed hard for only a short period of time they will take it.

I really am not a huge Kicker fan but out of all their subs the L7 is by far the best. For your sub to he heating up that much with only 300watts on it you are for sure pushing the amp into clipping. Drivers are designed to work with modulated AC voltage. Once the amp clipps its dumping straight DC, albit for a short period of time, into the driver. This creates lots of unwanted heat that the driver was just not ment to disapate. You can kill just about any speaker faster with too little of power vs having way to much power.

Bottom line.....BUY A BIGGER AMP. Forget about processors, linedrivers ( cant believe someone even sujected that one with only one amp) or anything else. Trust me from years of working with the exact driver you have the a bigger amp with make the sub sing. You will love it.

Rick

 

the line driver was a joke because I guarantee he doesn't know what it does. He knows he needs a new amp...he even admits in his 1st post I told him to get a new one. I think he is expecting a bit much from that small amp on an l7 in a sealed box in a cadillac.

 

Sorry if I dont get the joke. I dont think its cool to incorrectly advise folks that might not know quit as much as others. It only makes you look bad and may leave a bad taste in someones mouth about people that are more into this. Think it would have been better to just help this guy out and keep the jokes to yourself......but thats just. I would rather help as much as I can instead of confusing people. This is enough confused in car audio without adding to it.

Rick

 

I agree 100%. But I know him personally and have even spoken on the phone with him about prior installs. Plus, do a search on him and you will see it is easy to poke fun at him.

 

and then you put out incorrect information like this...

 

OK, then but all means ask just about anyone in the industry and see what they say.

 

Sorry man, I did not know he was a personal friend, that puts poking fun at him in a different catogory, LOL.

 

Rading some of 2 Da Max's posts have made me laugh outloud several times, as well as the joking that came afterwards .

 

yeah like the time he grounded his sony amp...to his amp. and he wondered why it started smoking lol.

 

no worries...if you stick around long enough you will see who to mess around with. your audio knowledge is more than welcome in here too.

 

He didn't say it burns up just gets warm.

 

from i recall as well running too little power to a sub/speaker can be potentially more damaging than running too much. don any input on this?

 

taken from bcae1.com

 

so..Gordon, wtf does that mean? lol

SQ maxima thanks for the info. I didnt realise that little power would cause the sub to get warm?

They say a sub in a ported box will make the voice coils be a little bit more cooler...so i may do that first

 

eh don't let a 4" port solve this issue...unless you want more bass without getting a new amp.

 

basically means a sub won't move as much when its seeing a clipped signal instead of a nice sine wave. the movement of the coil(s) and former draws in cooling air through the vent on the pole piece. if the coils aren't moving as much, yet fed the same amount of power, it'll overheat (from lack of cool air being drawn into that area).

 

so ill raise the gain so it will get a better signal?

 

r u joking avi???????

 

yes


neways i found my bass test cd, played it today and i definately need to go ported. the low end sound like its suffocating


Hey Don, dont worry i need new front speakers soon. The shop around my way only has entry line b.s. I definately need to step it up for the front stage. So ill be seeing you soon.
lol i know youve been hearing that for the past years, but this time im serious since i want to spend the money and do it right. I dont want to go the cheap way.

and yes Rich i am getting a zx amp, just waiting for the dude at CC to get his order so we could make one big purchase

 

I knew it...your box is too small also. what is the internal cuft of the box? also get a zx750.1.

 

It is NOT possible to hurt a sub by using too little power.

It is possible to hurt it by using too little power and clipping the hell out of the signal trying to get more out of the amp then it can put out.


The cone moves less in a ported setup (until you go below tuning freq) but upto that point the lower the sub plays the less it moves. So basically the mechanical powerhandling has been increased it doesnt mean the thermal ability of the sub has been increased, I doubt voice coils wont be cooling any quicker.


As much as I dont like using this, its a basic tutorial, so Click

 

Let me first start off by restating that comment. You can damage a speaker but running too little distorted power then with lots of clean power. I think it goes without saying that most people with an amp that is to small for a given job try to push the amp to hard and end up running it into clipping=bad.

That half right. When an amps clips the cone still moves. When the amp clips its putting straight DC from the power supply section of the amp to your speaker. Thing about taking a 9v battery and taping the speaker leads. That 9v battery is straight DC but the speaker still moves (yes it will stop but only because the speaker suspension resists the voltage potential, it will do that even if the amp is not clipping). When an amps clips its doing the same thing. Let me give you a theoretical example. Lets say an amp has a power supply section that puts out 50 volts. When the amp is not clipping but running at 100% power your speaker is only seeing that peak of 50 volts for a very very short period of time. Now start driving that same amp into clipping and now your speaker is seeing that 50 volts over a long period of time. This is were the heating get out of control. Just think how long you speaker would last with a 50 volt battery hook to it. In testing some amps I have actually been able to push amps till that are running at over 50% clipped signal on the outputs on a scope with little effect. So instead of that speaker only seeing a peak for less then 1% of the total signal now it has to deal with over 50%, yes that's over 50 times what the driver was meant to handle. Even if its at a fraction of its rated power its still more then it was designed to handle.

Now think that with today's cheaper but more powerful amps you can have more then 4 times that amount of voltage potential. Even some not so high powered amps like some McIntosh amps run over 120 volt power supply sections. Now you start putting that kind of voltage into the driver and things heat up even quicker. If I remember right from talking to the designer, Rockford's HUGE 12,000 watts amp runs dual 250 volt power supplies.

Here some more info that might help with the moving voice coil myth. If you take the same sub in put it in two sealed enclosures, one is 1ft2 and the other is 3ft2 the smaller enclosure with have more power handling potential even though the sub in the bigger enclosure with have more cone movement. Now take the same sub and put it in a ported enclosure where the sub will really be moving (at some frequencies anyway) compared to a sealed box. Will it be able to handle more power....nope, less actually. Now take the same sub and run it IB where it will REALLY REALLY be moving, will it be able to take more power.......nope again. In IB it will only be able to handle about 1/3 of the power or less before things go bad. Just goes to show that cone, voice coil and former movement is not the determining factor on power handling or weather or not your speaker will blow (in most of these cases its mechanical limits of the speaker that limit things).

Generally seal enclosures with have a smoother rollon slope meaning they play lower but ported are louder.

 

How about going with more power. Who installed this anyway? IF you say you then I think we figured out the issue.

 

That's the problem. A lot people in the industry have no idea what they are talking about. My 5 year old subwoofers are still working as if they were brand new and they are being underpowered (they can handle 1.3x more power than what I'm sending them)

Distortion doesn't cause speaker failure. You can send the most distorted signal to a speaker and it still will not blow. All the speaker can see is power. It can't see or tell whether or not a signal is "clean".

When an amplifier starts clipping there's a very little chance it will be doing straight dc. It will only give you straight dc if you give it straight dc signal. Connect an amplifier to an oscilloscope and see what it does yourself. An amplifier is only limited give out a certain amount of voltage potential according to its design. When clipping occurs what actually is happening is the peak of the wave gets clipped off because amplifier is limited to peak voltage potential. This will result in less cone movement over time. When you connect a battery to a speaker is moves once and stays there. It moves a certain distance according to voltage supplied. Reverse the polarity and it will move to the opposite position.

 

thanks guys, still alot to learn in car audio.