amplifier overheating

[Smokin' Rubber]

Soo I had to get rid of my old amplifier because while my friend was removing my sub box (which its attached to) from the car he dropped the box on the amp side and crushed my amp (doh!). So I got a new cheap amp from ebay that is supposedly 1800W as well. Problem is that now whenever I turn it up "too loud" the amp get the overheat and offset lights and it definitely isn't putting out 1800W before it overheats. Something I could have fudged that could be causing that? I am no audio expert so someone enlighten me.

[Pablo1669]

was the amp new or used? (I almost asked what brand, but then I rechecked your signature)

[Jahntassa]

Does it actually have an 'overheat' light, or just 'protect'?Is it a monoblock amplifier, or a two-channel? What gauge wire do you have going to it? What size fuses do you have?Also, if you're overpowering the subs, you might be over-extending them, and causing random shorts... Or, it might not be connected at the right ratings...

[Smokin' Rubber]

I got a new one pablo, no longer the MTX one (thats the one my friend cracked) Jahn- It actually has a light that says "overheat" altho it might do the same thing as protect since it cuts the signal to the subs when it happens. Its a dual channel I believe with a 4 gauge wire running from the battery to the amp. I have an 5AG 80Amp waterproof fuse less than a foot off the battery. Not sure about the amp's fuse itself but I would guess about 60 amps. Overpowering the subs i highly doubt since they are rated at 1000W a piece and I bought them from a friend who had them in his car and I saw the cones moving ALOT more in his (meaning that I don't think they are reaching their wattage peak in my car).

[drunkenmaxx]

well, what brand?chances are that if youve never heard of it, it's a POS

[Jahntassa]

So you have a two channel amplifier that has one sub connected to each channel... It may actually be overheating, how hot does it get?And the other problem is, you're speaking in peak wattages, not RMS which is the "true" output. Those Rockfords might only take 300w RMS, and that 1800w amp is probably very over-rated. It might be able to hit that 1800w at some point in it's life...but not on standard.. What's the brand/model on the amp?

[Smokin' Rubber]

Well not quite the subs are basically one unit so it only receive one input. As far as I can tell it doesn't get hot at all to the touch.Root mean squared I love sine waves lolI'll go check what the RMS output for the subs is but from what I have seen it looks like they can put out more than they are right now. Its some off brand rip off like Xblod instead of Xplod, think actually buying a new amp will help (I never had the problem with my MTX, but i never cranked it up really high on my MTX either)

[Jahntassa]

Are they wired to 2 Ohm? 4 Ohm? You can check it with a multimeter. If they're wired too low for the amp to take, that'll definitely cause an overheat situation. If they're dual-voice-coil subs, they might be wired to 1 Ohm, which only certain amplifiers can take..

[Smokin' Rubber]

Hmm ok I'll check sometime this week as i usually don't have access to my car since I live on a university campus and my car is at my house which is 20ish minutes away (driving).Which do you think it should be though, 2 or 4 Ohms? I'm checking the subs online manual tonight to see what the specs are can't check amp till later tho.*EDIT* Ok I looked over the stats for the newer ones since mine are slightly older since, but the newer ones are 500W RMS and 1000W peak, on some of the ones i saw the dual voice coil thing was listed others not, what does that mean? and what would I need?

[Jahntassa]

You need to know the exact model of the subs. You might not be able to know if they're dual-voice coil or not. Only way to tell for sure is to pull one out of the box, or use a multimeter to find out the Ohm reading.Dual voice coil means there're two voice coils instead of one. So instead of having just one set of contacts (+/-) there're two, and both are usually rated at 2 Ohm, 4, or 8 Ohm apiece.Then, there're different ways to wire it to tell how it's hooked up. That, and newer model subs may or may not be rated the same as older models. Judging from the way Rockford subs have been the last few years, i'll say they're probably different from the newer ones..What you have will determine what you need to do for the amp..until we know exactly what subs we're dealing with..it's hard to say.

[Smokin' Rubber]

If I found you a picture could you fiure out what kind they are?Rockford Fosgate Punch HX2'sHere is a pic of my subs.http://memimage.cardomain.net/...l.jpg

[Jahntassa]

Is that the amp you're using on the side of the box right there?Also, it's hard to tell from just HX2, because they come in a lot of configurations.. It could be anywhere from a single voice coil 4 Ohm, to a dual-voice coil 2 Ohm...Major differences.. They really don't make it easy.

[Smokin' Rubber]

Going home today to check the subs

[Smokin' Rubber]

Ok so on the back it said it was dual 4 ohms and had model number RFD1212, here is the descrption with all the stats: http://www.cardomain.com/item/ROCRFD1212

[Jahntassa]

So you need an amplifier capable of 500w RMS x2 at 2 Ohms.Which is a two-channel amplifier that can support two channels at 2 Ohms per channel. Otherwise, the amplifier will go into protect, which is what yours is probably doing. You don't have enough amplifier for the subs, and it's shutting down. You can rewire the subs so they appear to be 8 Ohms, but then you'll lose power overall. If you have two subs, you can wire it to show up as one 4 Ohm sub, so you can get a monoblock (1 channel) amplifier that supports something like 500-600w RMS @ 4 Ohms.For examples:Alpine MRD-M1005 (http://www.crutchfield.com/S-pLcnmhNlx3 ... 500MRDM105)2 Channel amps will be more expensive.. Plus, for amps like that, you need at least 4 ga wire running back to the amplifier...

[Smokin' Rubber]

Well let me tell you how its wired right now and you tell me if its set up mono or dual channel as it is. So both amplifiers are wired to the same input. Like its hooked up so that all the cables from the subs (excluding the ones that go between the two coils) go to only one positive peg and one negative peg on the outside of the box.Would this amp work for the application?http://www.rockfordfosgate.com...fiersAnd I already have 4 ga wire from the battery to the amp

[Jahntassa]

That would work, and it depends more on how the wires are connected to the back of the speakers, not the amplifiers.There are two methods for hooking up DVC subwoofers like yours.Parallel: The inputs are combined, so red from one coil connects to red to the other, same with black, and then to the amplifier. In your situation, this would give you 2 Ohms per speaker.Series: If you connect one black and one red to the amplifier, and then connect the other black and red together. So, connect the red from one side to the black on the other, then the remaining two go to the amplifier. This would give you 8 Ohm.You need it in parallel. So inside the box, both the red (positive) terminals should connect together, and both the black (negative) terminals should connect together. In order to work correctly with that amplifier, one speaker (in parallel) needs to connect to one output on the amplifier, and the other needs to be connected to the second output. You can't connect them both to one output or you'll overload the amplifier.

[Smokin' Rubber]

Quote, originally posted by Jahntassa »In order to work correctly with that amplifier, one speaker (in parallel) needs to connect to one output on the amplifier, and the other needs to be connected to the second output. You can't connect them both to one output or you'll overload the amplifier.Ok, so since the box only has one input (one pair of terminals for positive and negative) I would need to get a monoblock amp?

[Jahntassa]

We'd need to know exactly how they're hooked up before we can determine that. Subs can be wired in a box in any number of ways, and without knowing exactly what's hooked where, or finding out what the Ohm rating is with a multimeter, we can't determine what kind of amplifier will work best.Alternative to that, get another terminal cup and put that in the box... Because you have DVC subs, there're just too many variables without having more information..

[Smokin' Rubber]

I just went and looked they are hooked up in parallel

[Jahntassa]

So then your speakers are connected at a 1Ohm rating. Which means you need to find an 1 Ohm stable monoblock amplifier that is capable of at least 600w RMS

[Smokin' Rubber]

So with a parallel setup I need to get a monoblock, but why the 600 w RMS shouldn't it be like 500 or 1000?Would this amp be good or too strong?http://www.cardomain.com/item/ROCT10001BD1000w RMS at 1 ohm

[Jahntassa]

The RMS value on the sub says how much power it can take on average. So, even if you have two subs hooked together, the sub can still only handle 500w. By connecting them together, it simply means that they run more efficiantly.I suggest 600w because you want an amplifier slightly more powerful than the RMS of the subs, so the amplifier doesn't have to work as hard to do what you need it to do.That 1000w amp will work with the subs, but you're going to have to make sure it's tuned right so it doesn't blow the subs. Plus, you'll have to make sure you have 2 ga wiring to the battery, and probably at least 2-4 farads worth of capacitor. Maybe even upgrade your battery and alternator.These amplifiers take a lot of power, and they have to be wired right. If they aren't, you'll have a lot of problems, including frying your wiring system, or melting your car when the wiring fails and catches fire..

[Smokin' Rubber]

Lol that sounds pleasant, 600w it is thanks Jahn, any opinions one what I should get (since 1000w RMS is apparently WAY to much lol)

[Jahntassa]

Names you know are great. More or less:- MTX- Audiobahn- Infinity- JL- PolkThere are a few others...old school Rockfords are great, and the newer are good. So if you can get a Rockford, you can do that too.Don't get:- Phoenix Gold- Pioneer - Just not enough power- Bazooka (heat issues)- Sony (heat issues)- American Standard (flea market)