Amp keeps going into protected mode.

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Amp keeps going into protected mode.

  • Ok so I've had a lot of problems lately with my system. It was all working fine for almost 8 months or so. I originally had two 12" Sony Xplod subwoofers hooked up to a monoblock Boss Audio amp. The amp was rated at 1350wrms and 3600 max. Then I decided to go and buy a pair of 15"s. They worked great for around 3 months. Then I decided to buy a new headunit and then that's when all my problems started.


    First my Boss Audio DD3600 stopped working. It then was making the subwoofers just flex in and out at a constant interval. So I assumed it was blown, ordered a new, higher power amp made by boss. It was rated at like 2200wrms and I think 4500 max, or 4000 max. And after a day of use that one had the exact same symptoms, so I returned it and they sent me back another one. After about 2 days of use that one had the exact same thing happen, then later that day the amp decided to make some popping noises and start smoking so that one obviously went bad. I had them switch me to a Power Acoustik amp that is rated at like 1700rms and 4000 max. This one stopped working, and then would start working again.


    So I figured that maybe the head unit was bad, so I switched back to my old one. I was still having problems so I started messing around with stuff and when I messed with the RCA cables, it started to work and then not work. So I figured those had gone bad since those have been in the truck for like 3 years, with constant plugging and unplugging the connections on the end were bad. Got a new pair and now finally my subwoofers are working. Sort of. Now if I try and turn it up at all the amp goes into protected mode. I don't get anywhere near the power of the old DD3600 amp that was rated at much less power (I was also thinking of maybe hooking the DD3600 back up to just see if the RCA cables was the only problem I was having with it).


    So now I have no idea what is going on and I would really appreciate any help that anyone can give me. Some extra specs:

    Subwoofers are Digital Audio, dual voice coil @ 4ohms, 1200rms and 2400max each.

    Amp is a Power Acoustik OVN1-4000D.

    Headunit is a JVC generic head unit. Just has auxiliary input and HD radio. Nothing fancy really.

    [edited by: J P at 11:44 AM (GMT -5) on Wed, Aug 4 2010] Changed to discussion.
  • Sounds like you have quite a mess. I see you're jumbling back on forth on specs and arn't comparing the same space from each amp.

    The BOSS DD3600 is rated as follows;

  • RMS Power @ 4-Ohm: 1350w x 1
  • RMS Power @ 2-Ohm: 1850w x 1
  • Remote subwoofer control
  • Line out (for system building)
  • Variable low pass crossover (24dB/oct)
  • Variable bass boost 0 to +18dB
  • Variable subsonic filter (24dB/oct)
  • Phase switch
  • Signal to Noise Ration: > 100 dB
  • The Max Power @ 1-Ohm: 3600w x 1 really doesn't mean much of anything. 

    The Power Acoustk OVN1-4000D is rated as follows;

    • Gothic Series Class D Monoblock Car Amplifier
    • RMS Power Rating:
      • 4 ohms: 1200 watts x 1 chan.
      • 2 ohms: 1700 watts x 1 chan.
      • 1 ohm: 2200 watts x 1 chan.
    • Max power output: 4000 watts
    • MOSFET power supply
    • Wired remote bass level control included
    • Bass Boost (0-18 dB bass boost at 45 Hz)
    • 180 Degree phase shift
    • Low level inputs (200mV-8V)
    • Variable low-pass filter (40-200 Hz, 12 dB/octave)
    • Subsonic Filter (12 dB at 20-50 Hz)
    • Frequency response: 15-150 Hz

    The PA amp is listed as being 1 ohm stable, but the BOSS amp only lists a PEAK output power at 1 ohm so I don't really trust it's 1 ohm capability, the amp giving out after 3 months doesn't reassure me any either. Your subs I'm having trouble finding, can you give us the model number? Being 4 ohm DVC subs you have to have them wired for either a 1 ohm or 4 ohm final load to the amp. I'm not sure how you had them wired to either amp. At 4 ohms each sub wouldn't get but 600-675RMS at best, but since I'm sure those amps are both over rated it'd be less that. At 1 ohm the Boss amp doesn't seem to have an RMS rating, however if it's RMS ratings hold true it would likely be rated around 2400RMS@1 ohm, but again I'm not so sure it can handle being at 1 ohm for extended periods of time. The PA amp would put out no more than 2200RMS at best, but again it's an over rated spec. And again, I don't know if the subs are wired for 4 ohms or 1 ohm on the PA amp.

    Upon looking I found the owners manual for your BOSS amp and found a disappointing little bit of information I had suspected. Once you download the PDF file, which is just over halfway down the page, you'll see on page 6 that it specifically states that while the amp was designed to run at a minimum of 1 ohm it can result in damage to the circuitry which isn't covered under warranty. This is why I suspect the amp quit working, the new subs were likely wired to it at 1 ohm. As for the PA amp, they're not the most reliable amps either, but they are supposed to be stable at 1 ohm and I've heard of many who seem to not have any issues doing so. The reason I belive the amp goes into protection mode is likely from being over driven by having the gain too high. The subs are rated to handle 2400RMS, but that PA amp likely doesn't put out more than 1800RMS@1 ohm. Still that should be enough to get the subs to hit decent. However, the BOSS amp was rated higher than the PA amp, but it doesn't appear to be 1 ohm stable in truth.

    Not sure if that helped you any or not.

    Anyone else?

    [edited by: Weigel21 at 9:19 PM (GMT -5) on Tue, Jul 20 2010]
  • Sorry I was posting in a hurry to go out, but yes most of that seems correct. But my first thing to change to that was about the BA amp. It was actually in my truck for around a year or so. It was on the exact same settings the whole time. I would leave the gain nob, or bass boost, remote nob, whichever it was, turned almost all the way up all the time. Originally I had two 12"s that were only rated at 350wrms each and were single voice coil. And they worked fine and I never had a problem. Maybe it has to do with the way I wired the subwoofers then. Since, according to the RockFord website calculations, I have them wired to one ohm. I think. I have the wires from the amp running to the box. Inside the box I have the wires going into one voice coil, and from that voice coil transferring to the other voice coil. So like I said, from the RF website that seems to be a one ohm load. But on the other hand, I did have the 15"s hooked up for about a 3 month period where they operated perfectly. And also like I said, I think one of my problems was the RCA cables having bad connections on the end. So I might throw the DD3600 amp back in to see if that might still work since that one I still have at my house.

    I went to my friends after posting the thread and the bass wasn't working at all. I tried messing with all the settings on the amp and it wouldn't put out any noise to the subwoofers period. The protection light was not on, and it seemed like the amp was fine other than the fact that it wouldn't play any sound.

    I'm trying to think of any other info that might be helpful. Let's see.... I have a 3 farad capacitor in line right before the amp. I recently redid the ground connections and power connections to the capacitor and amp but they were/are all securely screwed down on bare metal.

    What about the actual tuning of the amp as in LPF and HPF and gains and bass boost? Could I just be doing that SO wrong that I am messing up something? I have the HPF turned to somewhere between 25-30hz. And then I have the HPF tuned to around 90-100hz or so.

    Oh the subwoofers are... DA8015X. I also have a pair of Legacy Audio Red Series II laying around in case the subwoofers are bad or have some problem where they hate me and don't want me to use them, as it seems that's how my luck is with this stuff.

    Also a huge thank you to you Weigel. I am glad someone is definitely helping me out.

  • Let me get this straight, you had the BOSS amp wired up to two (2) 12 SVC 350RMS subs for a year without any issues. Well, that amp is rated (over rated) at putting out 1850RMS@2ohms. Now if that amp actually put that much power out then it'd have pretty much instantly blown your 350RMS as soon as you played any music(read bass) through them. The fact that they handled the power and didn't go out on you means that your BOSS amp couldn't possibly be putting out over 1000RMS@2ohms, if even that. Generally these type of budget brand amps really only put out half their claim power, which if that were the case it have fed around 900RMS to your 350RMS subs. If those subs were of reasonable quality that extra 100RMS apiece may not have done much damage, as far as reducing their lifespan. Now, you upgraded to subs that claim to handle 1200RMS, a combined power handling for both subs is 2400RMS. Being they are DVC 4 ohm subs you likely wired them like this presenting a 1 ohm load to the amp.

    Since that BOSS amp really wasn't meant to be ran at 1 ohm, even though it claim it can, it gave out in about 3 months. Well, this may not be true as you say you found other items (the RCA cables) you feel caused the failure. While I can't confirm or deny that was the sole problem it may easily have added to the ultimate failure of your system.

    Then after the BOSS amps failed you tried a Power Acoustik amp, which if you didn't change your wiring was still likely wired for a 1 ohm load. While the PA amp wouldn't put out it's claim power either, I don't beleive it'd have been as vastly over rated as the BOSS amp. Then again, I've never dealt with or known anyone with a BOSS amp. I have however been around PA amps and they, for the majority, seemed to perform reasonably decent for their cost.

    Now you say the subs aren't playing with the PA amp. Well, given they too were cheap equipment, no offense, they may not really handle their claimed power. However, if they had blown form being vastly overpowered by the PA amp, which I doubt, the protection light on the amp should light up indicating there's an issue. I'm having trouble visualizing your setup to try and pinpoint areas of concern. I think I'm going to request other well informed members to assist. The more members thinking about your setup and possible problems the better chance we'll get you fixed up right.

    Oh, and are the subs in a sealed or ported enclosure? Since you say the HPF (subsonic filter) is set from 25-30Hz I get the notion they may be. As for the LPF, having it set too high, like 200HZ, shouldn't cause any issues other than too much emphasis on the lower vocal range thus producing poor SQ in most peoples opinion. Having it set around 100HZ is not uncommon, although I believe 80Hz is generally given as the standard.

    As for your Legacy subs, I believe they are rated around 1200RMS and are DVC 4 ohm as well. Correct?

  • Okay let's see where I'm at now.... Yeah that's how I have the speakers hooked up currently. Also the subwoofers are in a sealed box that has 2.1 cubic feet per chamber. I had a busy day today so I couldn't get around to trying to hook the old DD3600 up, but that should hopefully be tomorrow after I get out of work.

    When driving through my friends neighborhood today though, I hit a speed bump and the subwoofers started working but very lightly and would go into protected mode if I turned up the radio past 1/2 way. Then after I started it up later it wasn't working again, then another bump and it was working. So obviously I have a loose connection somewhere. The whole time that the amp is in the car the light says it is powered though, so I'm going to assume it's not a power or ground or remote connection; though I could be wrong I'm not by any means an expert or anything, just a newbie so forgive my assumptions. Now I would think that it is possible speaker connections since I just replaced the RCA cables and they are securely held down. So I guess tomorrow I shall go on a witch hunt inside my subwoofer box to see if I have a bad connection in there or maybe on the outside of the box since the connections to the amp seem to be held in tightly. Also do you think while I have the subwoofers out I should wire the subwoofers differently to present a different load to the amp?  Thank you for continuing to stick with me on this. You've been a lot of help narrowing this down to what could be going wrong. I guess I had some bad karma way back with someone with a car audio problem and its coming back to haunt me :/

  • Yes, it's sounding more like a wiring issue with the subs than anything. While you have the subs out of the enclosure for inspection look and smell for burnt voice coils. Also, it wouldn't be a bad idea to wire each sub directly to the amp presenting a 2ohm load to see if ether can play without issues. The amp going into protect mode once the subs start playing if you turn them up could indicate your gain is set too high, which you did say you tend to do by stating the gain was maxed or close to it. The gain isn't a volume control. I need to leave for work soon, so I'll check back later on today.

  • I agree - at this point it seems like a wiring issue with the sub box.

    2002 Ford Focus JVC KD-A815 Sony CDX-GT410u Sony XT-100HD HD Tuner Stock speakers, no amp, no subs

  • So I finally spent a few minutes trying to mess around with my system. Backed into my driveway and at that time it was currently working. It was very low volume like it has been. Nothing compared to what it used to be. So I then started messing around with the bass boost and the gain settings. I would turn them up and it would go into protected mode. I turn it back down some and it would come back on.

    So I figured I would try and plug in the DD3600 and see what happens. Same thing that it was doing before; which was making a constant thumping of the subwoofers. So no luck there.

    Then I decided to go and pull out one of my subwoofers. So I went and unscrewed it, and everything was still connected perfectly. I tightened down anything that I could. I put it back in and plugged my PA amp in and only had one subwoofer attached. So I would assume that would present a 2 ohm load to the amp. Or 4 ohms? I'm not 100% sure but I figured it wouldn't be a 1ohm load. And it wasn't working. Great. So then I went and looked at my ground connections for my amp and capacitor. Both seemed fine, but I tightened them down like a 1/4 of a turn which was all the extra I could get. Still nothing.

    So I was wondering if maybe the power wire was loose somewhere down the line or something. I dunno I'm just throwing out wild ideas at this point. I'm soon going to message some of the Audio shops around here and see if they could hook me up with some help off the books or something for some cash. I'm desperate at this point. I have all this useless equipment in my trunk that's just sitting there now. Also I have an Explorer so I would assume that the amp wouldn't be overheating since it is in an open air environment and I always have my A/C on so that should help it some. I dunno at this point. Makes me feel like my truck is jinxed or something.

  • KSE rules
    So I would assume that would present a 2 ohm load to the amp. Or 4 ohms? I'm not 100% sure but I figured it wouldn't be a 1ohm load.

    2-ohms with only one sub connected.

    Did the PA amp do anything with only the other subwoofer connected? Did any of the amps do anything with only one sub connected?

    Could be a bad sub also, but I wouldn't think it would work sometimes and not others then.

    Hope This Helps!!!

    Anyone else have suggestions?

    2002 Ford Focus JVC KD-A815 Sony CDX-GT410u Sony XT-100HD HD Tuner Stock speakers, no amp, no subs

  • I tried one sub with both amps. The DD3600 did the flexing the subwoofer thing. The PA did nothing at all. But like I said, before I started connecting and disconnecting,both subwoofers were working perfectly fine, except quietly.

  • Perhaps you tried the "bad" sub with all the amps ...

    Just guessing at this point, though ...

    2002 Ford Focus JVC KD-A815 Sony CDX-GT410u Sony XT-100HD HD Tuner Stock speakers, no amp, no subs

  • Yeah that is very possible. I dunno anymore lol. I thought I had a decent hold on this stuff, but I suppose I had just been lucky up until now. I sent a message to a local shop to see what it would cost to help me out. I guess I'll just wait for them to reply and see if they can't help me out at all.

  • Do you have a DMM (Digital Multi-Meter)? if you do you could hook it to your subs and find what the ohm load really is. If it says 1 ohm with both subs wired up using set of wires to the amp then the subs should be fine. If the DMM reads for instance less than 1 ohm or more like 10 ohms then your subs may be messed up. If it reads 16 ohms then you probably have the subs wired in series completely, meaning the Voice coils wired in series and the subs in series to each other.

    Not sure if this helps any as I too am pretty much taking stabs.

  • Many shops will test your equipment for you for almost free.  It's somewhat in their best interest to do so.

    You have to be careful with that so you don't run into:

    <Shop guy>:  Sure, I'll just have our bench technician run a check on your amp.

    <Takes amp to rear of shop - it checks out fine>

    <Shop guy>: Yep, your amp was shot, we have a nice $500 one you could get to replace it.

    OTOH, they really don't want to sell you an amp and have you still have problems b/c your subs were bad, so you don't need to worry TOO much about this.

    And OTOOH, if your subs and amp check out fine and they have to troubleshoot an intermittent wiring fault - well that isn't fun for anyone.

    Hope This Helps!!!

    2002 Ford Focus JVC KD-A815 Sony CDX-GT410u Sony XT-100HD HD Tuner Stock speakers, no amp, no subs

  • I own the boss 3600 as well.  I have been very disappointed in this amp since new.  After a few weeks it started with a hum in the fan which was very irritating.  The amp stopped working so i decided to troubleshoot.  It initially blew the front large fuse off the battery.  Currently It  is in protection mode with nothing working.  I removed wires and tried new ground and seperate power wire coming off the battery.  All it is doing now is jumping from protect to green power for quick second which draws a large amount of power from the battery as all the lights dim out.  I am not sure what the problem is, but its not good.  I see i did make a mistake though perhaps yes, i did run 2 10" mtx for a short time which created the 1 ohm load, perhaps this was the beginning of the end.  The majority of the time i ran one 12" crankenstein in a bandpass.
    My old kenwood 240X1 did not push the subs as hard yes, but superior sound quality over it.

    Read forums, they help.  I should of done more myself.  Now i will buy a Kenwood.



    KENWOOD  is far superior, and i should of followed my instinct and gone for the  9000model