Audiopipe APSM-1500 Protection for a few seconds?

[Quick 10+ year member]

possibly something wrong with the amp at this point? Post internals

Sounds like it to me also. I bought it off of ebay from 3 kings audio, and they have a swap out within 60 days. I'm going to just call them tomorrow and tell them I think it's defective and if they don't see anything else I can do to it then I'm going to swap it out.. Anything I should avoid saying or something like that?

 

[rebelfromva 10+ year member]

tell them you always set it with an o scope lol

 

[hispls 5,000+ posts]

There's absolutely no way anyone who has "worked in electronics" for more than a day doesn't know how to use a dmm, lol. It's a very basic tool. Yes, they're about twenty. you will need a good test tone recording as well. find one that is 50 hz. Stereo System Test & Analysis Tones by Nino B. and Multimedia Loudspeaker test are acouple of sources of recordings. You will play the tone at 3/4 of your hu volume with the gain on the amp starting at the lowest. with the dmm hooked up, set on ac volts, turn the amp gain up slowly until you reach 44v ac. that is what your amp should be set at, at 2 ohms, to make 1000 watts. and put a ring terminal on the end of your ground, for christ's sake, lol.

Of course that amp probably won't make 1000W @ 2 ohms on a good day. As likely as not actual impedence he's driving at 50hz is completely different than when he tries to play 60hz or 28hz for example so when the amp actually sees close to or under nominal impedence he is over-driving the amp.

Alright so I'm reporting back with some updated news..
My volts at the lowest dropped to 13.15, but most of the time went to 13.5 is that really that bad of a drop? I figured it wasn't bad enough for the amp to go into protect.

After setting the amp with a dmm, I cranked it up to the 75% volume on the HU we used when testing, and the amp went into protect. We added temporary ground to all of the weaker ones that we thought of just to see if it was a weak ground, but still no results. While it was playing, it hit real hard and was shaking the whole inside of my car, was great. Soon after went into protect tho. //content.invisioncic.com/y282845/emoticons/frown.gif.a3531fa0534503350665a1e957861287.gif Ground isn't the problem nor is the voltage drop I don't think. So maybe a faulty amp? I wasn't clipping it because I set it at 41.5 volts and the voltage said to put it at 43.5 with the dmm, so I went safe and put it a little under.

For the meantime tho, I put the gain about halfway and it hasn't gone into protect yet. Still hits nice but I feel like it's not doing its full potential. Also, I can't crank it up 100% with my HU or it will go into protect, so I have to leave it at 75%. Example is at 21 is perfect on my HU before it starts distorting due to my crap speakers, but I have to keep it at 16 because it will go into protect any higher.

Everything is either at 0 or off. Treble, bass boost, etc.

Ground looked fine to me the first time, but I'd agree that bad power or ground connection can cause issues.

Using anything that sais + on a head unit (boost, bass, treble, etc.) is almost always a recipe for premature clipping and/or distortion. Avoid at all costs in future!

My thought is that you have just reached the limits of that amp. It's like telling the doctor "it hurts when I do this" and the answer is "stop doing that". You are pushing to the absolute limit and the amp is going into protect to tell you that is it's limit!

Keep the gain set so that you never or rarely put it into protect and you're fine, or just use the volume knob correctly so that you don't push it that hard. For what you paid for that amp even if you set it to what you think is "75%" you're getting good bang for your buck I'm sure. If you really feel you need to listen at 100% volume all the time start saving up for a bigger amp and an extra battery to feed it with. Running any audio equipment at its very limits constantly will generally give poor performance and early failure.

When you say amp is hot, do you mean warm, or you can't leave your hand on it? From my experience if amp is going into THERMAL protect it'll take a while before it'll play music again.

 

[av83 10+ year member]

View attachment 26533163View attachment 26533164View attachment 26533165
We sanded the hell out of them and still nothing. We added a EXTRA cord to the strut tower, so another ground which should give it more grounding right?? Still protects, and we have it lower gain then the 43.5 hz suggest. //content.invisioncic.com/y282845/emoticons/frown.gif.a3531fa0534503350665a1e957861287.gif

Yeah, they look fine. Sorry man. Defective products happen, but something still makes me think we're missing something here...

 

[rebelfromva 10+ year member]

Take gut shots!

 

[av83 10+ year member]

Of course that amp probably won't make 1000W @ 2 ohms on a good day. As likely as not actual impedence he's driving at 50hz is completely different than when he tries to play 60hz or 28hz for example so when the amp actually sees close to or under nominal impedence he is over-driving the amp.

The only reason I bought the amp was because research said that it did rated cleanly. And I'm just trying to help the kid. I don't know as much as a lot of people on here, but it didn't seem anyone else was going to try... I'm curious, how many volts should I set the same amp at, and at what hz, if I have it running at 2 ohms?

 

[hispls 5,000+ posts]

The only reason I bought the amp was because research said that it did rated cleanly. And I'm just trying to help the kid. I don't know as much as a lot of people on here, but it didn't seem anyone else was going to try... I'm curious, how many volts should I set the same amp at, and at what hz, if I have it running at 2 ohms?

We had a big thread about these amps... the consensus was they're good amps at a good price, but if you plan to push things to the limit they really don't do well.

Impedence is different at every frequency. Ideally you would set it to make desired power at whatever frequency was your least measured impedence. Without a clamp or more sophisticated measuring tool (WT3, LEAP, or similar) there's no telling. Also, there's so many variables in music IMO the whole thing is pointless unless you use an O-scope before each track you play. Frankly I always set gains by ear and don't really truck with a lot of these other methods. IMO they all have their shortcomings..... Sufficed to say if the amp is going into protect and you have no shorts, good voltage, and no thermal overload you are simply over-driving that amp, turn the **** down or buy a bigger amp if you still need louder.

 

[av83 10+ year member]

We had a big thread about these amps... the consensus was they're good amps at a good price, but if you plan to push things to the limit they really don't do well.
Impedence is different at every frequency. Ideally you would set it to make desired power at whatever frequency was your least measured impedence. Without a clamp or more sophisticated measuring tool (WT3, LEAP, or similar) there's no telling. Also, there's so many variables in music IMO the whole thing is pointless unless you use an O-scope before each track you play. Frankly I always set gains by ear and don't really truck with a lot of these other methods. IMO they all have their shortcomings..... Sufficed to say if the amp is going into protect and you have no shorts, good voltage, and no thermal overload you are simply over-driving that amp, turn the **** down or buy a bigger amp if you still need louder.

sounds right... i go back and forth between using a dmm and just setting it by ear (and sometimes smell, lol.) I also went with cheap sub gear just to have something to play/learn with, and not have to worry about losing a months income if it goes kaput. it's not bad for a $250 sub/amp combo....

 

[Quick 10+ year member]

Alright so another update! Now the amp is just going into protect for the sake of going into protect. This should really throw people off -.-.....

I see people say it's pushing to its max? Here's what happened.

I was on my home playing a eminem song, which had WEAK bass, and had the preout on +7, which is less than half of the +15 I was playing it on. I also had gain under halfway, and setting with a dmm made it go to about 3/4. It goes into protect. I didn't even have it cranked very loud. I use to be able to put it up to 21 and 22 would protect it, now I can only put it to 15 and 16 protects it. I don't understand, it was a **** *** song not hard hitting or anything, and everything was turned down really low. I feel like this is a defective amp. I'm going to call the ebay seller tomorrow and ask them wth is happening, and hopefully get a replacement.

I understand it may not actually put out 950watts @ 2 ohms, but even if it didn't I set it low enough on the voltage that it shouldn't have interfered. Even if it did tho, It REALLY shouldn't have at half the subwoofer level on my HU, and the gain under halfway. This just does not seem normal to me.

I ended up having to turn the subwoofer level on my HU to -15, and I don't even know if that stopped it from protecting, because I couldn't hear if it was cutting out or not.

Edit: Could my HU be the reasoning for the amp protecting, or my subwoofer? Both seem to be fine but I'm not sure what's going on. Maybe the amp just has a protection glitch? :\

 

[Quick 10+ year member]

Take gut shots!

I would but I don't want to void any type of warranty because I messed with it.

 

[Quick 10+ year member]

The only reason I bought the amp was because research said that it did rated cleanly. And I'm just trying to help the kid. I don't know as much as a lot of people on here, but it didn't seem anyone else was going to try... I'm curious, how many volts should I set the same amp at, and at what hz, if I have it running at 2 ohms?

Thank you so much for trying to help me out, you don't know how much I appreciate it. I know i'm not worth a lot of people's time on here and I really am happy you tried to help, and kept the thread alive for me. It would be dead right now if it wasn't for you. I would be stuck not knowing what to do, or who to discuss things with. Thanks again.

 

[av83 10+ year member]

Thank you so much for trying to help me out, you don't know how much I appreciate it. I know i'm not worth a lot of people's time on here and I really am happy you tried to help, and kept the thread alive for me. It would be dead right now if it wasn't for you. I would be stuck not knowing what to do, or who to discuss things with. Thanks again.

No biggie, man. You're welcome. Don't give up, either. See if someone local can pinpoint the problem for you. Btw, if you're hu has 2 volt rca outputs, the amp's gain shouldn't be past 1/2 way up, for sure. It's possible the amp was damaged form the factory, or was dropped during shipping, or even maybe something happened during the install that you didn't realize could have damaged it. Mine has worked great from day one, no issues at all.

 

[Quick 10+ year member]

No biggie, man. You're welcome. Don't give up, either. See if someone local can pinpoint the problem for you. Btw, if you're hu has 2 volt rca outputs, the amp's gain shouldn't be past 1/2 way up, for sure. It's possible the amp was damaged form the factory, or was dropped during shipping, or even maybe something happened during the install that you didn't realize could have damaged it. Mine has worked great from day one, no issues at all.

So it never went into protect when you set it with a dmm? Weird. It sounds like a got a defective, does it to you?

 

[av83 10+ year member]

So it never went into protect when you set it with a dmm? Weird. It sounds like a got a defective, does it to you?

Mine went into protect once, and it wasn't thermal. Shoot, it's never gotten all that hot... and I've played it at full tilt for hours. It was caused by two ring terminals that I forgot to grind the burrs off of after drilling them out. They weren't seated well, at all. It was a stupid thing to overlook, and it caused a bad electrical connection. Have you checked ALL of your electrical connections to make sure they're good and tight? It could be just one bad connection. That's all it takes. And if you play it hard with bad electrical, it can damage any amp..... Which may also have been what happened. Bad things happen when you you're learning how to do something as you are doing it, rather than before hand. Been there. Multiple times.

 

[hispls 5,000+ posts]

Alright so another update! Now the amp is just going into protect for the sake of going into protect. This should really throw people off -.-.....
I see people say it's pushing to its max? Here's what happened.

I was on my home playing a eminem song, which had WEAK bass, and had the preout on +7, which is less than half of the +15 I was playing it on. I also had gain under halfway, and setting with a dmm made it go to about 3/4. It goes into protect. I didn't even have it cranked very loud. I use to be able to put it up to 21 and 22 would protect it, now I can only put it to 15 and 16 protects it. I don't understand, it was a **** *** song not hard hitting or anything, and everything was turned down really low. I feel like this is a defective amp. I'm going to call the ebay seller tomorrow and ask them wth is happening, and hopefully get a replacement.

I understand it may not actually put out 950watts @ 2 ohms, but even if it didn't I set it low enough on the voltage that it shouldn't have interfered. Even if it did tho, It REALLY shouldn't have at half the subwoofer level on my HU, and the gain under halfway. This just does not seem normal to me.

I ended up having to turn the subwoofer level on my HU to -15, and I don't even know if that stopped it from protecting, because I couldn't hear if it was cutting out or not.

Edit: Could my HU be the reasoning for the amp protecting, or my subwoofer? Both seem to be fine but I'm not sure what's going on. Maybe the amp just has a protection glitch? :\

And this is where setting with a DMM at some arbitrary frequency fails. OP finds a song that has a bass note nowhere near resonance (hence not very loud to the ear) and the amp is now seeing a load at or possibly below DCR so he pushes it harder and into protect again.

Is car running when you are doing this? If your dad is an electrician does he have a "clamp" to check current?

Bass +7 on the head unit is a recipe for disaster IMO. +7db means it is trying to put out nearly 10X the voltage it would attempt to do at 0 so running into clipping FROM the head unit is very likely at half volume on your knob. Gain on the amp is NOT a volume knob, saying it's "half way" is meaningless and doesn't tell anyone anything.