Need quick amp help!

[Hartman]

Hey guys, I have a slight problem with my new amp. If I turn the gain up more than 1/4th of the way, the amp goes into protection. My subs (3) are wired to the amp at 2.67 ohms. The amp is supposed to be 2 ohm stable. Even when I'm at 1/4th on the gain, if I turn it up half way, it will go into protection. I'm not quite sure why, someone please give me some insight on this. Thanks.

 

[Cartman]

Couple of things to try;

1. First thing I'd try is hooking up just 2 of the subs, that would be a 4 ohm load and the amp is for sure stable at that. I can't remember what amp you got and if according to the manufacturer it is stable at 2ohm or if that was just the thought here.

2. are the correct channels bridged, usually it will say on the amp what channels to bridge.

3. Is the ground wire attached well and going to a good spot free of all paint, all other wires attached securely?

Thats all I can think of to try
Good luck

 

[Hartman]

Ground is definately not the problem. It is grounded to the frame on a bare metal spot. I'll try with the two subs, that seems like a good method to test it all.

 

[Hartman]

Ok I just found out something that does not make me very happy. I was looking in the manual, and it says the amp is stable at 2 ohms in stereo operation, but stable at 4 ohms in bridged operation. Correct me if I'm wrong, but that means I'm screwed because I'm running these subs at 2.67 ohms in bridged mode.

Someone PLEASE tell me that's not true.

 

[mhn3773]

does that amp say anything about mono operation? if it stable at 2ohm stereo it might not be stable and 2ohm mono..which is what u are trying to do


now im totaly not sure on this..but u could wire 2 subs to be 2ohm run them on one channel then one sub at 4ohm..run that on a different channel..would ballance out wouldnt it?

also what kind of amp do u have again? i cant remember

 

[Cartman]

Thats is what I was afraid of, the amp can't handle the 2.66 ohm load when it is bridged, there are a few more options

It may be possible to modify the amp to take handle the 2.66 ohm load - don't ask me how but it can be done but bye bye warranty if you do.

Get a 2nd amp for one of the subs and run the other 2 off this amp

Return amp and get a mono amp that would be stable at 2ohms.

 

[mhn3773]

id just return the amp if u can..much less of a hastle

 

[Hartman]

I talked to a professional and he says that the amp can handle 2.67 ohms bridged. He says he knows a guy that runs the same amp at 2 ohms mono. I'm going to check my wiring and make sure I didn't screw it up.

I can't really exchange the amp because my fiberglass enclosure is built around the dimensions of this amp. I have to use it.

 

[BBQ_HotDogs]

Oh my, when it rains it pours. Sorry to hear this.

 

[mhn3773]

I talked to a professional and he says that the amp can handle 2.67 ohms bridged. He says he knows a guy that runs the same amp at 2 ohms mono. I'm going to check my wiring and make sure I didn't screw it up.

I can't really exchange the amp because my fiberglass enclosure is built around the dimensions of this amp. I have to use it.

it has to be something mundane then..just sucks ur gunna have to take all the subs out to figure out whats wrong i saw in ur other post u have the kicker amp..i thought u did but couldnt remember i know those can do 2ohm mono also

 

[davesexplorer]

Just out of curiousity, try an ohmeter (multimeter) on the subs and see what kind of resistance that gives....

 

[Hartman]

I've been trying that but I can't seem to get a reading from them. I don't think I have my multimeter set right and I don't remember how to set it properly.

 

[mhn3773]

ok try this..connect just 2 subs and see if they will run...just dont blow em up =)

the ohm symble is a funky little symble an u should just have to click it to that to get the ohm reading..least on the ones i have used for the AC work

 

[mhn3773]

i was talking to drew and he thinks u should take each sub out and test each sub on each channel of the amp...just to rule out a VC or something

he said if one of the VCs was bad that would throw off the calculations..so the amp would see a different load then it should be..sending it into protect

 

[Redrig]

Here is what the OHM symbol looks like on the meter. I hope this is something simple, and not that you have the wrong VC subs. I know how much of a pain this kinda stuff is when it happens.

 

[davesexplorer]

Yeah try each sub individually, if ones v.c. is fried/shorted your amp will go into protect.

 

[hydroxy]

if the manufacturer says 4ohm stable when bridged, why would it actually be able to handle 2ohm?

 

[mhn3773]

sometimes they dont say it can handel 2ohm mono because that is kind of harsh on the amp..so the amp will heat up yadda yadda..they just do it to cover the butts

 

[Fhantazm]

Also, some high end amps can handle that low of an impedence, however it really depends on how "in spec" the amp is. The amp has an onboard microprocessor that detects the temperature of the output devices. Once they reach a certain point, the amp is shut down to prevent transistor burn. Since no amplifier is exaclty alike, the tolerences may vary from amplifier to amplifier and allow one amp to run a lower impedence (and hotter) without going into protect mode. Case in point, I have 2 Rockford amps. One of them can run a 2 ohm mono load all day (The Punch 180), but the PUnch 200 will cutout after about 30-45 mins of hard use. You may also want to check cooling. Theroetically the only thing that prevents an amp from reaching the lower impedence loads, is heat. Its very similar to overclocking a processor. The cooler you get the amp, the lower impedence loads you are able to run. Hope this helps.

 

[mhn3773]

i got a question about that 2nd wire on the amp..is it neccisary? i have never had to do that when bridging a 2 channel before..i dont understand what its there for

is it to complete a circuit or something??? im lost lol