: Amp/Subs kick off when volume/bass is too high.



fiXXXer
11-22-06, 09:29 AM
I got a Sony Xplod 1200 Watt amp, to replace my previous, much cheaper, amp, that caught fire.

So, I installed the amp, and reconnected the fuse - no fire.

Everything was working, so I turned up the volume, and wham, the amp/subs cut off. The other speakers kept working, but not the subs/amp.

I turned off the head unit, which is connected to the amp via the remote wire, off, then back on, and the subs/amp are again working.

Turned up the volume again, and wham - cuts off. I checked all of the fuses (two on amp, one on power wire from battery), and none of them are blown.
The light on the amp stays on, even after the bass cuts off.

I turned on the low-pass filter, turned down the level and the bass boost, and all of that.

What could cause this to keep happening? It also happened with my previous amp.

CadillacSTS42005
11-22-06, 09:34 AM
you new amp cant handel the ohm level of your subs.

fiXXXer
11-22-06, 09:44 AM
Arrgh!
I think the subs (3 12"s) tested at 1.5 ohm.
Does that mean the amp should be higher or lower than 1.5 ohm?

CadillacSTS42005
11-22-06, 12:16 PM
rofl
that sony amp MAY be 2 ohm stable
in bridged mode its probably 4 ohm stable
dude you gotta rewire your subs, that ohm load youll blow another amp

fiXXXer
11-22-06, 02:05 PM
Could you go into some more detail with that?
I'd ask some questions, but I do not know what to ask.

And.... Could you recommend any sites that give the basics of all of this stuff?

CadillacSTS42005
11-22-06, 02:12 PM
your subs are operating at 1.5 ohms
your amp (idk wat amp you have so i cant go into more detail) is more than likly 4 ohm stable bridged (aka you used the pos teminal from the left speaker output and the right neg output)
when your running your amp at 1.5 ohms it cant handle that so it shuts off to not damage it, your amp cannot handle subs at that low of a a resistance so you MUST REWIRE YOUR SUBS TO REACH 4 OHMS OR MORE
look up ohms law for an explanation for that, i could go on for days about it, again i dont kno what amp model your have heck i dont even know what subs you have (1 ohm 2 ohm 3 ohm etc etc etc single voice coil, dual voice coil etc...) but when you tell me your subs are 1.5 ohm and you have a SONY amp (sony amps are crappy they cant handle below 2 ohms period) then i know your operating your subs at too low an ohm

the727kid
11-23-06, 07:50 PM
What type subs you got?

cl1986
11-25-06, 05:46 PM
as long as your talking about ohms here......i still cant figure out the dual voice coil thing...

Isnt it if you have two single voice coil subs say at 4 ohms each if you wire them parallel then you get 2 ohms....now if you wire then series you get 8 ohm but they will cancel each others bass out and you would need to put one sub facing out of box and one sub facing in the box??NOT???

Okay now on a dual voice coil wouldnt they still cancel out bass if wired in series to create 8 ohm load?? this is where im confused.....

the727kid
11-26-06, 02:23 PM
Subs only cancel out when you place them weird. Face them both towards the rear and no cancellation.

cl1986
11-26-06, 03:13 PM
i dont think u understand...

in a normal sealed box....if you wire a speaker on L channel and one on R cahnnel with opposite polairty to the coil they will cancel each other no matter what and you will have no bass at all......

Same goes with your high end.....if you wire one speaker backwards it fights the other 3.....

not sure ive never done 2 speakers on one channel....is that somehow different?....

fiXXXer
11-26-06, 04:18 PM
OK, here are the specs:

Subs: 3X PMW122FDVC; 4 ohm; Dual Voice Coil. They can take 500W, or 750W with Liquid Cooling (which the back of the subs say that they have), but are recommended at 100W-500W.

Amp: 1X XM-2200GTX; 1200 watts max power; 200 watts x 2 RMS into 4 ohms; 500 watts x 1 RMS into 4 ohms. All of the info can be found at http://www.amazon.com/SONY-XM-2200GTX-XPLOD-Channel-Amplifier/dp/B0001YEYKM

So if I need to rewire my subs, can you show me a diagram that would work?

--Kyle

MachX
11-26-06, 04:40 PM
3 subs on one amp, eh. That's bad. Unless you wire them in series, which is to go from the positive on your amp to the positive on the first sub, then from the negative on sub 1 to the positive on sub 2, then from the negative on sub 2 to the positive on sub 3. Then from the negative on sub 3 to the negative of the amp. Or just use 2 subs and quit with the overkill.

fiXXXer
11-26-06, 05:15 PM
Would it be better to wire them in series, or to go with 2 in bridged mode, or whatever?

cl1986
11-26-06, 08:11 PM
Ok man.....i think your amp aint up to it...

go to this site and find the first diagram that has 3 and only 3 speakers in it....it the 13th pic on the page

http://www.bcae1.com/spkrmlti.htm

you can try this but it would put a 2.6666 ohm load on your amp and your amp states that when bridged it should be 4 or 8....

If that doesnt work your going to have to do only 2 subs (keep them wired the same as the pic just eliminate one) and get another amp for the third one.....this will put a 4 ohm load on your amp when bridged....

You do know what bridged means right?? You would have only two speaker wires coming from the amp.....one on the + of the right channel and one on the - of the left channel......

cl1986
11-26-06, 08:17 PM
Oh....and it states that that amp will draw 48 amps.....so use at least a 4 guage power wire....2 would be better....

fiXXXer
11-26-06, 10:50 PM
cl1986: Done. I knew what bridged was, and it is all done, too.

I don't have anything to seal the enclosure with, so I'll have to buy some after work, tomorrow, then seal it, then test it.


Can I still expect the amp to cut off when I turn the volume high?
Imagining that I had an amplifier of sufficient power, how much of a difference would I notice between using two and three sub woofers?
Currently, would it be better (bass output, safety, etc) to run the amp with two or three of the sub woofers??


Thank you for the help,
Kyle

cl1986
11-27-06, 03:22 PM
the amp should not cut out at all if only using 2 subs...

you can try 3 and see what happens....if it does cut out either live with it and dont crank it up all the way or go back to 2 subs...

Ive never had more than 2 subs but a second amp for just the 3rd sub would probrably be quite an improvement over just 2 subs

Also your gonna need some air ports through the rear deck to let some air move into the cabin.....you can test by removing your 6x9's and see how good it sounds....this is what i have currently and it makes a 70% improvement in loudness....im only running one 12.1 kappa perfect though....

MachX
11-28-06, 05:58 AM
For the frequencies that a sub is *supposed* to be used for, air ports aren't necessary as the sound will pass through the back seat. One sub isn't enough because you will be running it at 3 db less than the rest of the frequency range. Not good when low frequencies are the hardest to hear. You need at least two and a decent amp and a head unit that puts out at least 2 volts into its preamp, preferably 4v. Another sound piece of advice is to run your rear deck speakers 3 db lower than your fronts. This will give you a better front sound stage and greater stereo seperation. The easiest way to do this is run 4 ohm speaks up front and 8 ohms for the rear deck and run your two subs on a mono amp at 2 ohms. You'll get plenty of bass without running your amp too hard. Stay away from junk like Sony. The 3 and 4 way speakers may LOOK fancy but you'll get too many peaks and midrange bias. Use a good two way component system for your front stage and ONLY two way 6x9's in the rear. You'll notice that all the sweet sounding show cars use simple components in the cabin and oodles of subs. A good resource demonstrating system design can be found here http://www.rockfordfosgate.com/scripts/rightnow.cfg/php.exe/enduser/std_adp.php?p_sid=5ZxewNni&p_lva=&p_faqid=175&p_created=1059712885&p_sp=cF9zcmNoPSZwX2dyaWRzb3J0PSZwX3Jvd19jbnQ9MjM2J nBfcGFnZT0x&p_li=

cl1986
11-28-06, 08:18 AM
do you have a 92+ eldo or seville??? you need an air passage....like i said its 70% louder.....maybe cause i have one sub....but its still 70% louder do a search.....

the back seats on these are like a bomb shelter wall......

the727kid
11-28-06, 07:03 PM
For the frequencies that a sub is *supposed* to be used for, air ports aren't necessary as the sound will pass through the back seat. One sub isn't enough because you will be running it at 3 db less than the rest of the frequency range. Not good when low frequencies are the hardest to hear. You need at least two and a decent amp and a head unit that puts out at least 2 volts into its preamp, preferably 4v. Another sound piece of advice is to run your rear deck speakers 3 db lower than your fronts. This will give you a better front sound stage and greater stereo seperation. The easiest way to do this is run 4 ohm speaks up front and 8 ohms for the rear deck and run your two subs on a mono amp at 2 ohms. You'll get plenty of bass without running your amp too hard. Stay away from junk like Sony. The 3 and 4 way speakers may LOOK fancy but you'll get too many peaks and midrange bias. Use a good two way component system for your front stage and ONLY two way 6x9's in the rear. You'll notice that all the sweet sounding show cars use simple components in the cabin and oodles of subs. A good resource demonstrating system design can be found here http://www.rockfordfosgate.com/scripts/rightnow.cfg/php.exe/enduser/std_adp.php?p_sid=5ZxewNni&p_lva=&p_faqid=175&p_created=1059712885&p_sp=cF9zcmNoPSZwX2dyaWRzb3J0PSZwX3Jvd19jbnQ9MjM2J nBfcGFnZT0x&p_li=

Wow this is a mixed post true stuff and some BS.

Anyways, airports are never neccesary but will not make a huge difference. Unless of course your going from a sealed to ported box.

Secondly, one sub can easily be enough. My 1 12 sounded like 4. You can't hear the low frequencies for a reason, they are low, the human ear can't hear below like 20hz. All do you is feel shake alot harder.

Thirdly, prevolt outage means abosultely nothing. All it means is you get to set your gains a little lower on your amp.

Fourthly (Is that a word?) Running your rears at a lower volume doesn't matter too much. The only thing that gives you a better sound stage in the front is good speakers, imagine and installation (seal that door up!). I don't run any rear speakers and imaging is very good. All you need is a very good solid component set up front, good install and some power you will have more than enough frontstage.

MachX
11-29-06, 06:29 AM
He's talking about air ports in the rear deck to allow 'more air'. What this does is more or less create a bandpass box situation. The problem is that if all you want is more noise, go for it. But if you don't use your trunk volume and other factors of the speaker and a properly tuned port, you end up colouring the sound with peaks and it doesn't sound as clean ESPECIALLY if you have a ported sub box already. And pre out voltage is very important because the lower the gain setting on your amp, the lower the S/N ratio and less distortion you will get. And running your rears at an equal level to your fronts will give you more 'warparound' effect, but it degrades your stereo seperation. You said that you don't run any rears which is why you HAVE a good image. But most people prefer some rear ambience (more realistic) which is why you run the rears 3 db lower so they don't kill your stereo imaging. And if you run two front channels, does it not make sense to run 2 subwoofers to get the same output all throughout the frequency range and not work your amp as hard? Higher input voltage and lower impedance means higher clean output. There's a REASON amplifiers have seperate gain and bass boost controls that you are intended to set according to the output voltage of your source unit, the amplifer runs at peak efficiency this way. The link I gave can perhaps explain these things better than I can. Nothing I said is BS. It comes from years of research and is the fundamentals for a well balanced system in a poor accoustical environment.

cl1986
11-29-06, 10:24 AM
well....im not sure the air ports in the rear deck create a bandpass.....

but i do know that the sub (12.1 kappa perfect in sealed 1.0 cuft box) will just about rattle your teeth out when i had it center in my garage placed on a 3' high stand....
i thought wow!! then i put it in my car and it sounded like a 5" speaker for the amount of bass i was getting....opening the trunk brought back the tooth rattling bass.....then i finally figured out that taking out the rear 6x9's let some air movement i got about 70% of the tooth rattle back when doing this....

I really dont think i would call this a bandpass.....in a caddy trunk its just starved for air and if there is no air to move u get no sound.....

either way i havent heard a kappa perfect sound bad.....even if it is a bandpass encloser...

I just gotta say i LOVE the accuracy and tightness of the Kappa perfect and am very pleased with it......

the727kid
11-29-06, 04:03 PM
He's talking about air ports in the rear deck to allow 'more air'. What this does is more or less create a bandpass box situation. The problem is that if all you want is more noise, go for it. But if you don't use your trunk volume and other factors of the speaker and a properly tuned port, you end up colouring the sound with peaks and it doesn't sound as clean ESPECIALLY if you have a ported sub box already. And pre out voltage is very important because the lower the gain setting on your amp, the lower the S/N ratio and less distortion you will get. And running your rears at an equal level to your fronts will give you more 'warparound' effect, but it degrades your stereo seperation. You said that you don't run any rears which is why you HAVE a good image. But most people prefer some rear ambience (more realistic) which is why you run the rears 3 db lower so they don't kill your stereo imaging. And if you run two front channels, does it not make sense to run 2 subwoofers to get the same output all throughout the frequency range and not work your amp as hard? Higher input voltage and lower impedance means higher clean output. There's a REASON amplifiers have seperate gain and bass boost controls that you are intended to set according to the output voltage of your source unit, the amplifer runs at peak efficiency this way. The link I gave can perhaps explain these things better than I can. Nothing I said is BS. It comes from years of research and is the fundamentals for a well balanced system in a poor accoustical environment.

I don't even know why I bother responding to this.

Anyways, a "wraparound" sound? If anything the sound is coming from the center of the car and sounds a lil heavy in the back, depending on the car. Some cars you can't even hear them, hence my car I used to have 6x9s in it, I could a full fade to to the front and not hear a difference.

Why are you mixing input voltage and impendance, that is two compltely different things. Anyways, higher input voltage means you keep your gains lower on your amp. This does not mean a higher cleaner output or whatever you just said. Some of the best SQ decks ever made have 2volt preouts, all Alpines are 2volt preouts.

This is true: There's a REASON amplifiers have seperate gain and bass boost controls that you are intended to set according to the output voltage of your source unit, the amplifer runs at peak efficiency this way.

To that statement, higher pre-out, lower the gain, lower pre-out higher the gain. Either way if you use the ohms law to set your gain with a DMM you will end up at the same voltage, which if you set according to the paper RMS of the amp, odds are you are far from the clipping threshhold.

But, if you know how to set your gains properly, it never ever matters pre-out voltage. If you ever get distoration when setting gains, that is when you turn it down. Maybe if your years of research still haven't taught you how to use an O-scope, or even a DMM than a higher pre-out is important. But in the end, if you know how to properly set your gains, pre-out voltage means jack shit.

MachX
12-01-06, 07:40 AM
well....im not sure the air ports in the rear deck create a bandpass.....

but i do know that the sub (12.1 kappa perfect in sealed 1.0 cuft box) will just about rattle your teeth out when i had it center in my garage placed on a 3' high stand....
i thought wow!! then i put it in my car and it sounded like a 5" speaker for the amount of bass i was getting....opening the trunk brought back the tooth rattling bass.....then i finally figured out that taking out the rear 6x9's let some air movement i got about 70% of the tooth rattle back when doing this....

I really dont think i would call this a bandpass.....in a caddy trunk its just starved for air and if there is no air to move u get no sound.....

either way i havent heard a kappa perfect sound bad.....even if it is a bandpass encloser...

I just gotta say i LOVE the accuracy and tightness of the Kappa perfect and am very pleased with it......

When you leave holes in your rear deck you are, in effect, creating 'ports' like what you see in bandpass boxes. But if they aren't the correct diameter you risk colouring your bass response. Since you are running only one sub, your bass output is 3 db lower for the same voltage as your two front stage speakers. (assuming the impedances and speaker sensitivities are all the same) simply adding another sub adds 3 db which is the same as a 100% gain in volume. Since subs are usually 3 db less sensitive than mids/tweets, you actually need FOUR subs to get everything to match at the same voltage. I don't have any vents, and my amp's gain only needs to be set half way up to get my two subs to match my two fronts. Air movement isn't the issue as bass waves have no trouble passing through the rear seatbacks if the voltage is right. The air tightness will only serve to tighten up your bass by balancing the external dampening of the driver with the internal dampening of the box so that the driver oscillation is equal in both directions. This is the same as the argument of ported boxes vs sealed boxes. Ported boxes give higher output and lower frequencies while sealed boxes give tighter, more accurate bass. It's all about preference. I truly apologize if I seemed condescending, I was just trying to illustrate the best way to create an accurate sound balance in your car.

the727kid
12-01-06, 03:19 PM
When you leave holes in your rear deck you are, in effect, creating 'ports' like what you see in bandpass boxes. But if they aren't the correct diameter you risk colouring your bass response. Since you are running only one sub, your bass output is 3 db lower for the same voltage as your two front stage speakers. (assuming the impedances and speaker sensitivities are all the same) simply adding another sub adds 3 db which is the same as a 100% gain in volume. Since subs are usually 3 db less sensitive than mids/tweets, you actually need FOUR subs to get everything to match at the same voltage. I don't have any vents, and my amp's gain only needs to be set half way up to get my two subs to match my two fronts. Air movement isn't the issue as bass waves have no trouble passing through the rear seatbacks if the voltage is right. The air tightness will only serve to tighten up your bass by balancing the external dampening of the driver with the internal dampening of the box so that the driver oscillation is equal in both directions. This is the same as the argument of ported boxes vs sealed boxes. Ported boxes give higher output and lower frequencies while sealed boxes give tighter, more accurate bass. It's all about preference. I truly apologize if I seemed condescending, I was just trying to illustrate the best way to create an accurate sound balance in your car.

You match your mids and highs you need to set your gains right. Setting your gains halfway doesn't mean they are louder. I have the gains on my 300/4 at maybe 1/4 if that and my speakers are LOUD. I have 2 subs and the the speakers and subs are matched evenly even at full tilt.

heavymetals
12-01-06, 05:12 PM
Subs only cancel out when you place them weird. Face them both towards the rear and no cancellation.


It is called phase.

the727kid
12-02-06, 12:27 PM
It is called phase.

I know, but if I would of said that they probally wouldn't understand.

cl1986
12-02-06, 01:46 PM
I know, but if I would of said that they probally wouldn't understand.

obviosly you dont know.....how u position the subs wont cause phase cancellation....its the out of phase that does this....happens when one speaker is + to + and - to - and the other sub is + to - and - to + terminal and each on different channel of the amp......for single voice coil subs that is.......it does matter where u point ur sub even in hometheatre but has nothing to due with phase.....

I was asking how the dvc works....but obvoisly when hooking up two subs on the same channel they dont phase cancel.....thats all i was looking for and no one has said that yet......

I remember when the forums were full of useful info instead of just a bunch of posts about nothing.....seems to be that way around here now......

sorry to be so rude but it gets annoying after awhile...