Amp getting hot hot hot!

[Beandip 3]

Hey guys i have a question. i searched around (and having fun learning) in the amp section and only found one person having the same issue as me but the problem was not resolved.

so i will try to give as much info as i can so there will be no confusion.

First off, i am very mechanically/electrically inclined but for some reason this problem has me stumped which usually calls for faulty equipment.

second, this thread here is the problem i am having. it is on another forum but it is exactly what mine is doing.

http://www.*****.com/board/topic/61561-amp-problem/page__hl__m1000%20hot

so first off, my electrical.

Big 3 soldered with 4 gauge

Deka intimidator battery 9A78DT under the hood.

4 gauge all the way back to the amp

stock 105 amp alternator

equipment.

Deh-p5900ib HU

Alpine MRP-M1000 amp

Fi Q dual 1 ohm version wired in series to present a 2 ohm load(got it before all the fancy options)...also want to add the DMM reads 1.4 ohms when i connect it to the speaker leads...is this wrong? the RE: specs say .7 ohms per coil but i guess that is the DC resistance correct? if so is it simply getting hot because the amp is seeing 1.4 ohms instead of 2 ohms or what? I have heard the nominal impedance will be 1 ohm when a/c current is applied though the DC resistance shows .7 and that is normal...correct me if i am wrong please.

Sub is in a 2.43^ft sealed box, 2.24 after sub displacement.

Now what is happening. the voltage at full tilt drops down to 13.3 volts TO the amp. of course listening to a moderate level presents almost no voltage drop. also i tested the ground for resistance and that checked out good. so power and ground is good and my electrical is almost perfect except for the stock alt but since the voltage is not dropping excessively then i rate my electrical as decent but you guys tell me what you think.

gains are set correctly though the problem is not gain related. reason i say that is because the amp will get hot at a moderate volume. on a scale of 1-10, 10 being max volume the amp will get hot running at about 3 and in about 30 minutes or so running at 4 or half power, the amp gets hot enough to limit itself. gets about 160ºF when this happens. most of the time it just runs around the 110-120 range.

so my question to all you audio gurus is why is my amp getting hot? is it defective? I have read on here that if its not hot enough to cook an egg then its fine. also it has been this way ever since i unboxed it almost 2 years ago and i have no clue why....If the voltage is not dropping then what is causing the amp to get so hot? could it be the sub possibly? I do have a feeling it is the sub since it does show 1.4 ohms and the amp is having to work a little extra duty. also the bass boost is on zero on the amp. only the gain is turned up to .5 volts which is the RCA pre-out voltage. again it doesnt have to be full volume for the amp to get excessively hot which makes me think its more of an amp problem. If that is the case then i will probably get a sundown amp since i have heard nothing but good things from them...though they are a little pricy but their amps makes most of their power at 1 ohm...since i have a dual 1 ohm my options are limited since i have to get a sundown SAZ-2500D just to get 1000W @ 2 ohms.

Also here is a pic of the setup. super old pic since i have long gotten rid of that crappy fold down console in favor of a full 5 speed s10 blazer console. i might want to add this is in my sonoma.

Thanks for your time reading this and if you have any questions or want me to get DMM readings or whatever feel free to ask.

-Jonathan

[Tirefryr 1,742]

Now this is how ALL questions should be asked!

I personally don't see a problem here. Some amps naturally run hotter than others. If it's working fine and there are no issues, I don't see the temp being a problem. It seems to me like you WANT a new amp and you may be looking to justify the purchase, so if that's the case, just buy the new amp.

[Sir-Lancelot 216]

Does it cool off when the AC cools off the car?

Mine are hot as shit right now before i even turn them on.

[Beandip 3]

:edit: ^ well yes the amp is hot of course from the temp outside when sitting in the sun. in this case my truck was in my garage when i left for the trip. even if i turn on the a/c on my truck, blowing out 40ºF air, it is still not enough to cool the amp...i have to wait until it naturally cools itself off. even if i push the passenger seat forward and roll the passenger side window down it will not prevent it from overheating even with the added airflow from going 70 mph down the highway. kinda sucks since i can only enjoy the sub for 20-30 minutes in this heat before it gets too hot. in the winter time i really dont have much of a problem since the ambient air temps are down but i can still make it overheat listening to about 50% output volume (based on excursion).

Thanks, i honestly hate it when vague questions are posted asking for help when so much information is left out it is almost impossible to tell what is going on.

well the problem its having is once it reaches 155-160ºF the amp internally limits itself to 50% power, so me listening at a normal volume (just enough bass to fill the music in..hell you could build a house with a deck of cards on the sub.) the sub is basically absent and i have to either turn up the RCA output on the HU or wait until it cools down.

lately i went on an hour trip and it was 105ºF outside and the amp, listening at a very low volume got too hot and ended up limiting itself. well before then i was jamming to a song but after the song i turned it down then 5 minutes later the heat built up until it limited itself. kinda pissed me off since the amp was putting off less power than a walmart special amp whenever i turned it down, i am talking about maybe a mm of excursion lol.

but i may be in the market for a new amp because of this....i debating on what amp to get if i do get another and sell this one if i know its not defective. i called alpine and they said they can look at it and if it is a manufacture defect they will replace it even though its 2 years old. first i want to know if the amp could be the problem or is it the sub since my DMM reads 1.4 ohms so is that the load the amp is seeing causing it to overheat. if that were the case wouldnt a lot of people who use Fi subs have a similar problem? of course that could vary based on amp manufacturer.

Edited August 10, 2010 by beandip

[Tirefryr 1,742]

It could very well be that it is just touchy enough for the small drop to pose a problem. I don't see anything else that could be wrong other than a faulty amp or it's sensitivity to load characteristics. You don't by chance have another driver with the same nominal load you could swap out do you?

[Beandip 3]

It could very well be that it is just touchy enough for the small drop to pose a problem. I don't see anything else that could be wrong other than a faulty amp or it's sensitivity to load characteristics. You don't by chance have another driver with the same nominal load you could swap out do you?

No i do not. though i do have a friend with a 10" kicker comp. its 4 ohms so that should not present a problem. i can give it a 20 minute beating and see if it overheats. i may just send the amp in later. who knows how long that will take but i want to eliminate most of the possibilities before i go ahead and send it back....i do have a feeling the amp is the problem but the Fi sub ohm is also worrying me making me think its the sub causing it.

just want to add, the sub plays beautifully up until the point where it does overheat, whether its max volume or low volume.

Kinda weird, all the electrical is up to par yet a problem exists leaving me stumped...usually in those cases its faulty equipment arguing against my logic.

Edited August 10, 2010 by beandip

[Tirefryr 1,742]

Doing a Google search for reviews leads to many people with the same problem.

[tripslipfall 0]

My friend has the same amp, he ran it at 1 ohm pushing an RE SX 10", it worked fine, it got very hot, but I don't remember it ever limiting itself, he did say it shut off sometimes though, but that's understandable because he was running it lower than recommended, and he always pushed the amp pretty hard, he has since switched to a Sundown SAZ-1000D v2 and it pounds way harder, way cleaner, and never shuts off or even gets very warm.

[sefugi 166]

I agree that it is possibly the amp. If you were considering Sundown would 2-SAZ1000 strapped be a possibilty that would give you 1800@2ohm. Good Luck on your decision.

[Beandip 3]

Yeah i would really like to get sundown but then i have to get an amp basically twice as much as i need just to get the power i want at 2 ohms. or will the SAZ-1500D be enough? i know 800 RMS is plenty for me but i would like to use the sub to its capable power.

if the sub is causing the problem having a DC resistance of 1.4 ohms, then technically i should get more power out of the SAZ-1500D than originally thought because i am not quite running 1 ohm, or two...but more towards 1 ohm so if 1500 RMS is at 1 ohm and 800 RMS at 2 ohm, i guess its safe to say i will get at least 900-1100 watts running at 1.4 ohms correct? if so then the 1500D may be my new amp if the sub is causing the problem. i kinda hope so because i dont want to have a faulty amp and have to send it in..wait...blah blah you know. i would rather either sell it or keep it as a spare.

so, i will try to see if i can borrow a buddy's spare sub and see if i can get my amp warmer than it normally should. i will report back whenever i get the chance. but if you have any other comments on what may be the issue i am all ears.

[cobra93 47]

As I understand it, in a sealed enclosure your impedance will never go below your static ohm load (2ohm's). Only in a vented enclosure can it go below your static ohm load (according to a kicker rep I spoke to a long time ago).

Since you seem to understand the difference between D.C. resistance (1.4 ohm's) and the load the amp will see (A.C., 2 ohm's static and higher) I'd assume you realize you'll probably not see the rated power at your sub ever (listening to music).

There are allot of people on this forum that understand this better than I do and I'm sure they'll give you the answers you're looking for. I'd go bigger than the 2500d if I were you, I'd rather have more then I need than wish I had more than I'd bought.

Sorry I can't help with the alpine issue, but that's my 2 cents.

[Beandip 3]

As I understand it, in a sealed enclosure your impedance will never go below your static ohm load (2ohm's). Only in a vented enclosure can it go below your static ohm load (according to a kicker rep I spoke to a long time ago).

Since you seem to understand the difference between D.C. resistance (1.4 ohm's) and the load the amp will see (A.C., 2 ohm's static and higher) I'd assume you realize you'll probably not see the rated power at your sub ever (listening to music).

There are allot of people on this forum that understand this better than I do and I'm sure they'll give you the answers you're looking for. I'd go bigger than the 2500d if I were you, I'd rather have more then I need than wish I had more than I'd bought.

Sorry I can't help with the alpine issue, but that's my 2 cents.

True, headroom is always nice. The way i see it now, with the current amp putting out lets say at least 800 watts for argument sake, i am more than happy....now if i was truly running 1KW....i might like that lol. like i said, most of the time, 90% i am running it at 1/4 volume or less...every now and then i like to turn it up but that might change if i get a new amp. Still i will probably try out the 1500D. i still have to decide and i am in no rush but when i do i will bump this thread with my findings.

Thanks to all those that helped.

Guess the only thing to do now is to decide, but most importantly before that...research

Edited August 15, 2010 by beandip

[ulrisa 26]

Have you considered the Rockford Fosgate 1000-1BDCP? Its the constant power version of the 1000bd, and it does 1000 watts rms at 2 ohms I believe. I think Kicker amps are rated for 2 ohms mostly as well, might be worth it to take a look. Sundown is awesome though, just seems like it may be cheaper to consider some other options. Hope this helps.

[Beandip 3]

Have you considered the Rockford Fosgate 1000-1BDCP? Its the constant power version of the 1000bd, and it does 1000 watts rms at 2 ohms I believe. I think Kicker amps are rated for 2 ohms mostly as well, might be worth it to take a look. Sundown is awesome though, just seems like it may be cheaper to consider some other options. Hope this helps.

Not a fan of kicker at all...not really going to go into it but i dont care much about their products...not going to hate on someone getting/using kicker, just not going to buy it myself.

as far as cost...all i care about is quality. i could care less how much it costs (within reason). its the same principle on my truck, do it right or dont do it at all...its always the little things that makes the difference.

but between the RF and sundown, i think the sundown amp would match better in my truck than the RF..though either amp would do the job fine.

Edited August 16, 2010 by beandip

[ulrisa 26]

Have you considered the Rockford Fosgate 1000-1BDCP? Its the constant power version of the 1000bd, and it does 1000 watts rms at 2 ohms I believe. I think Kicker amps are rated for 2 ohms mostly as well, might be worth it to take a look. Sundown is awesome though, just seems like it may be cheaper to consider some other options. Hope this helps.

Not a fan of kicker at all...not really going to go into it but i dont care much about their products...not going to hate on someone getting/using kicker, just not going to buy it myself.

as far as cost...all i care about is quality. i could care less how much it costs (within reason). its the same principle on my truck, do it right or dont do it at all...its always the little things that makes the difference.

but between the RF and sundown, i think the sundown amp would match better in my truck than the RF..though either amp would do the job fine.

I'm not much of a kicker fan myself either. If you don't care about price then I'd go Sundown all the way, I wasn't sure if the budget was part of your concern. Good Luck with whatever you get!

[Frostedflakejake 148]

Good luck with the heating issue

I can also reccomend a Sundown Amplifier to you. Mine is in location with very little airflow and it never even gets warm. Ever.

Good luck!!

[Notorious97200 339]

I live in a hot Caribbean island, and my Sundown amps can get hot even without playing !

They get really hot, but we are at 30°C (86°F) all day long, in the shade. Under the sun, it's hotter!

My sub amp shut down only once : I was playing with the car off, at little volume, for a long time.

When I drive the car, with the wind (hatchback car) or the A/C : it does not get very hot at all.

remember 800 watts rms or 1000 on your sub : the additional power will not really be audible for your ears, maybe on a meter only.

Sell your amp and find a good one with the power you need !!!

Good luck !

[Beandip 3]

Well guys, a couple of days ago i went ahead and ordered myself a SAZ-1500D (thanks Jacob!!)

even though i am running it at 1.4 ohms this amp performs! i am kinda thinking of reconing the sub so i can wire it up to 1 ohm nominal and take almost full advantage of the amp. of course i will have to add the BP option though. but for now i will just beat the hell out of my Q.

Thanks for everyone's input. i always had an idea that the impedance was causing it but until i upgraded the electrical 100% i wasnt so sure. hell, now with this amp there is a less of a draw on my electrical too!

so far the new amp only gets to 110ºF...and that is with it being 99ºF outside. so i know i am barely making this amp work but it wouldnt hurt though also with the way it is now, i am more than happy and really not in a rush to recone it just yet, sure the Q can handle a bit more power, but for now i really dont need a few extra hundred watts.

anyways, enough talk, pics!!!

Got the amp on the 20th...yeah kinda delayed on this update, i was having too much fun with the amp.

Flipped the "Sundown" aluminum strip so it wont be upside down.

kinda an overview shot, i am not quite sure if i like those speaker wires being like that....i may hide them but for now its good...I've seen worse lol.

Ah, sorry about the crappy pics. i didnt feel like using my good camera, kinda lazy to upload to pc, then to photobucket lol. It matches much better than my old amp. I will try to get a better pic sometime later but you guys get the idea. Got the speaker wires covered in braided sleeving and capped off with heat shrink on the ends.

also for fun i decided to see what type of power my sub is getting @ what frequency. had fun doing this too. Its really interesting on the results. ohms law ftw!

Volume----Frequency-----AC voltage-----AC amperage------Ohms----------Watts

31---------------20--------------49.9----------------14.3------------3.489----------713.57

31---------------25--------------48.9----------------12.5------------3.912----------611.25

31---------------30--------------50.1----------------8.7--------------5.758---------435.87

31---------------35--------------50.8----------------4.8------------10.53-----------243.84

31---------------40--------------51.3----------------7.1--------------7.225---------364.23

31---------------45--------------51.2----------------14.1------------3.631---------721.92

31---------------50--------------50.6----------------16.4------------3.085---------829.84

31---------------55--------------49.5----------------17.6------------2.812---------871.2

31---------------60--------------48.1----------------17.7------------2.717---------851.37

31---------------65--------------49.5----------------16.7------------2.964---------826.65

31---------------70--------------42.2----------------15.2------------2.776---------641.44

31---------------75--------------36.4----------------12.8------------2.843---------465.92

31---------------80--------------31.1----------------10.7------------2.906---------332.77

Anyways, thanks for everyone's input! now off to search and learn more about box design. that is one area i am really lacking.

Edited August 27, 2010 by beandip

[DarkTinman 9]

Glad you got everything figured out! I was about to post about how i have a Kenwood 1800 watt amp and that thing always gets hot but plays like a champ. I do understand what you mean when you say limiter in the amp itself. But i am glad you got an amp you wanted and you could always look into get a DC amp

[Beandip 3]

Yeah a bit of a old thread bump but whatever.

so far i still love this sundown amp, always runs COLD, not cool lol. i have a hard time bringing the amp up to room temp. since then i rewired my stereo with 1/0 welding cable just because, not like i noticed a difference but good to know this amp is getting all the voltage/current i have. I kinda wish i had the dual 2 ohm so i could take advantage of this amp, but not like the stock Q could handle this amps full potential anyways.

Edited February 16, 2011 by beandip