Gixxus Christ! Posted July 20, 2016 Report Share Posted July 20, 2016 Ok. I have a mild system in my car, design acoustic Gothic series 600 watt amp bridged to a single kicker comp 2 600 watt 12" woofer. Damn amp will not quit going into protection mode if I'm listening to something with a lot of bass for more than say, 15 min. Any suggestions? Quote Link to comment Share on other sites More sharing options...
TheBrown57 Posted July 20, 2016 Report Share Posted July 20, 2016 Did you set the gain properly? Sounds like amp is getting over loaded due to high demand. I'm no expert though but that is something I think might be contributing. Quote Link to comment Share on other sites More sharing options...
zx3vfr Posted July 20, 2016 Report Share Posted July 20, 2016 people still put aftermarket stereos in their cars? I didn't realize it was 2001 and Paul Walker was still alive.... 2 Quote Link to comment Share on other sites More sharing options...
Gixxus Christ! Posted July 20, 2016 Author Report Share Posted July 20, 2016 21 minutes ago, zx3vfr said: people still put aftermarket stereos in their cars? I didn't realize it was 2001 and Paul Walker was still alive.... Subaru base model stereos are junk. I'm gonna have this car a long time and I spend about an hour and a half per day commuting so I want a quality sound system. I also wanted Bluetooth and a backup camera and navigation, so I put in a Kenwood touchscreen that did all that stuff, replaced the junk door speakers with some decent infinity units and put a single sub in the trunk for low end. I like to enjoy my music. So now that you understand all this, fuck the fuck off out of my fucking thread you fuck. 2 Quote Link to comment Share on other sites More sharing options...
TimTheAzn Posted July 20, 2016 Report Share Posted July 20, 2016 55 minutes ago, TheBrown57 said: Did you set the gain properly? Sounds like amp is getting over loaded due to high demand. I'm no expert though but that is something I think might be contributing. Could be but I've had amps in the past that went into that mode, but it was right when they turned on before music even kicked on. (I ended up buying another amp.) Quote Link to comment Share on other sites More sharing options...
jporter12 Posted July 20, 2016 Report Share Posted July 20, 2016 What's the impedance of the speaker? What is the amp rated for impedance wise? If the amp is only stable at 2 ohms bridged, and the load it sees from the speaker is 1 ohm, that would be the problem. 2 Quote Link to comment Share on other sites More sharing options...
jporter12 Posted July 20, 2016 Report Share Posted July 20, 2016 54 minutes ago, zx3vfr said: people still put aftermarket stereos in their cars? I didn't realize it was 2001 and Paul Walker was still alive.... Some of us drive old beaters, from back when most OE stereos were crap. Quote Link to comment Share on other sites More sharing options...
Gixxus Christ! Posted July 20, 2016 Author Report Share Posted July 20, 2016 I have the gain set about in the middle and usually run my sub out level on the head unit between -3 and +3 depending on the music. It's not like I'm overdriving the speaker I don't think. Quote Link to comment Share on other sites More sharing options...
Gixxus Christ! Posted July 20, 2016 Author Report Share Posted July 20, 2016 2 minutes ago, jporter12 said: What's the impedance of the speaker? What is the amp rated for impedance wise? If the amp is only stable at 2 ohms bridged, and the load it sees from the speaker is 1 ohm, that would be the problem. Good question, I have no idea what the impedance of the speaker is, I've never taken it out of the enclosure. Pretty sure the amp bridges at 2 ohm stable. Quote Link to comment Share on other sites More sharing options...
TheBrown57 Posted July 20, 2016 Report Share Posted July 20, 2016 Definitely check the sub's impedance and check this video for setting gains with a voltmeter Quote Link to comment Share on other sites More sharing options...
Gixxus Christ! Posted July 20, 2016 Author Report Share Posted July 20, 2016 Ok so I multiply the claimed 240 watts RMS of the amp by whatever impedance the speaker is, get the square root of that and then adjust my gain to that ac voltage while playing a 50 htz tone? Quote Link to comment Share on other sites More sharing options...
TheBrown57 Posted July 20, 2016 Report Share Posted July 20, 2016 Correct, if you were closer I have a tool that is more precise you could use but that is how I used to tune my amp before I got it. I normally get it to match the meter then back it down just a tad to be safe. Same with the volume of the head unit, as an example my previous head unit went to 35 but I never went over 30. Quote Link to comment Share on other sites More sharing options...
o-no-moto Posted July 20, 2016 Report Share Posted July 20, 2016 Hell Back when my buddys ran bump in the trunk we ran a ground wire no longer than 12 inches and cranked the gain far as it would go. Usally ran a 4 channel briged down to 2 channels to who knows what kinda ohms. Wonder what damage we did?..lol Quote Link to comment Share on other sites More sharing options...
vf1000ride Posted July 20, 2016 Report Share Posted July 20, 2016 Could just be the amp doesn't have enough heat sinks built into its design. I have an older Orion amp from when I had the stereo in my VW. It would overheat in 15-20 minutes of full power. I had it fully tuned with an oscilloscope to be sure it didn't distort. The amp just ran really hot. I ended up putting fans on it to try and keep it cooler. Quote Link to comment Share on other sites More sharing options...
Gixxus Christ! Posted July 20, 2016 Author Report Share Posted July 20, 2016 I folded my back seat down with the ac on yesterday but it wasn't until I was almost home and didn't seem to make a difference. Maybe today will be different. Quote Link to comment Share on other sites More sharing options...
Helmutt Posted July 21, 2016 Report Share Posted July 21, 2016 I'm not up to par with todays tech, and far from educated in car audio....but years ago my old Rockford Punch100 would do this running 2x12 Audiophiles 2 ohms. Even with 2 huge heatsinks it got hot as hades. Only at night though, and only when it was wound out pretty loud. Figured out it was starving for juice, and crashed my alternator a couple times. A 2 farad capacitor cured my issue, kept plenty stored up for the amp to draw on. Not sure if your issue could be similar or not, but caps used to be fairly cheap ( $60ish for good ones ) 1 Quote Link to comment Share on other sites More sharing options...
Gixxus Christ! Posted July 21, 2016 Author Report Share Posted July 21, 2016 Already running a huge wolfenhagen cap. Quote Link to comment Share on other sites More sharing options...
OSUYZFR1 Posted July 21, 2016 Report Share Posted July 21, 2016 Is the sub dual or single voice coil? What ohms are the voice coil(s)? If dual VC how do you have them wired, series or parallel? What load is the amp stable to when ran mono? You need this info to see if the amp is seeing load it can't handle. Also check your ground and power connection. Are you running sufficient gauge wire for the amp? 1 Quote Link to comment Share on other sites More sharing options...
RCBS Posted July 21, 2016 Report Share Posted July 21, 2016 http://www.techlore.com/article/common-car-amplifier-problems-and-solutions Quote Link to comment Share on other sites More sharing options...
wolfeman28 Posted July 21, 2016 Report Share Posted July 21, 2016 Yeah it sounds like you are pulling too much of a load on the amplifier, and the cheaper the amp the quicker it will go into protection when it doesn't like the impedance mismatch. I'd look into the sub impedance and voice coil setup as stated above and compare it to what the amp can handle. Anything out of spec and all you will get is protection mode. I bought myself a nice Alpine headunit a few years back, with the imprint calibration hardware, and shelled out a few bucks for one of the Alpine monoblock PDX amps...... Man, talk about sound quality. Paired up with one of the 12" Dayton Audio Reference subs. I'll never need to buy car audio equipment again. 1 Quote Link to comment Share on other sites More sharing options...
Gixxus Christ! Posted July 21, 2016 Author Report Share Posted July 21, 2016 I'd happily trade the comp 2 in a truck box (used to have a truck) for something that doesnt take up so much space in my trunk. The impreza trunk is shaped funny with a step in the floor of it and the only place the box fits is dead in the middle. Quote Link to comment Share on other sites More sharing options...
wolfeman28 Posted July 21, 2016 Report Share Posted July 21, 2016 A little glass work and you can make anything fit wherever you want it Quote Link to comment Share on other sites More sharing options...
Gixxus Christ! Posted July 21, 2016 Author Report Share Posted July 21, 2016 Ok. Pulled the speaker out of the box and it's a single vc 4 ohm. So I did the calculation (square root of ohms times rms watts) and got ~62. Hooked my meter up, downloaded a 50 htz sine wave and couldn't get anything higher than 45 out of it! Wtf? Ready to dump this setup and go to two tens and a much better amp. Quote Link to comment Share on other sites More sharing options...
vf1000ride Posted July 22, 2016 Report Share Posted July 22, 2016 (edited) What numbers are you using, what is the amp model number? Assuming the 600W@4ohm the square root is 48.9V not 62V. If your amp is 600 Watts peak output you need to figure out the RMS output (lower) and use that number. Assuming the magic interwebs formulas hold true and your amp is 600 peak, it should be roughly 425 RMS, using the same math (sqrt of 425*4) it would put your Gain setting at 41.2V which falls inside the max output you could get from your amp. I have never used that method to set an amps output gain and the whole process is something I find interesting. When I figured it out using the numbers from my old system I should have set mine at 34.6V; 1200W@1ohm. I would not have figured a high output 1200W amp driving a 1ohm speaker load would use a lower output voltage than a lower power system but I guess it's possible. The method I always used and it is only because I had access to the equipment was to hook an oscilloscope to the head unit output, crank the head unit volume until the peaks in the waveform start to flatten out (IE clipping) and back it down a small amount. Then while the head unit was on max clean output I hook the oscilloscope up to the amps outputs and slowly increase the gain on the amp until the output from the amp started to clip also, same deal to just back it down a little bit to get it clean again. Take note of the max number on the head unit volume control at this point and don't go past it unless you wanted huge distortion. Edited July 22, 2016 by vf1000ride Quote Link to comment Share on other sites More sharing options...
Gixxus Christ! Posted July 22, 2016 Author Report Share Posted July 22, 2016 You use rms watts, not peak. Square root of (240x4) Just realized my cell phone calculator fucked me. Forgot to put in parentheses, target voltage was actually 30 vac. I have an oscope I built over the winter, will hook it up when it's not hot as balls. Til then I found the 10" sealed setup I want. Quote Link to comment Share on other sites More sharing options...
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