800a2 running mono at 2 ohms
Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=114449
Printed Date: May 17, 2025 at 1:04 AM
Topic: 800a2 running mono at 2 ohms
Posted By: lotaimpalass
Subject: 800a2 running mono at 2 ohms
Date Posted: June 14, 2009 at 4:44 PM
OK I havn't seen the inside of my setup for several years, but I belive I am running 4 4OHM DVC 8"@2 ohms mono to my amp. From the search I did it sounds like the 800a2 is not made for it. So why am I not having any problems? I hit 132.8db at my pass seat two years ago with a box way too small. 4 DVC 4 ohm RE8" 800a2 or .2 I don't remember which OR is the amp actually able to do it, but not recommended OR did I just miss something and I am running it correct? I am a little confused as you can see any help would be great. Thanks Matt SHaw
Replies:
Posted By: i am an idiot
Date Posted: June 14, 2009 at 5:05 PM
The only thing I can figure is you are extremely lucky or you do not play it hard. When it does break, it will cost at least 200 dollars to repair the amp. It will take 5 IRF640 mosfet output transistors. 5 IRF9640 outpouts. 10 (.)1 ohm 2 watt resistors. and 8 IRF3205 mosfet power supply transistors. And they are all soldered to a mounting strip, there are not many places that will even attempt to repair that amp. Since they solder the transistors to the strip, if you run it hard at 2 ohm mono, the transistors heat up and the solder melts, this allows the transistor to move away from the thermal strip in which they were soldered to. When it comes off of the strip, the transistor will last about 2 seconds.
Posted By: lotaimpalass
Date Posted: June 14, 2009 at 9:05 PM
wow their is no way your and idiot. SO I am guessing you have seen the inside of these amps a time or two. The only issue I have had with the entier system is I lost my RCA outs on my head unit and I don't think it is related. because it did it on the 4 chan also. Thanks for the info so it sounds like I am playing with fire.
Posted By: i am an idiot
Date Posted: June 14, 2009 at 9:14 PM
Lost them, as in NO output, or noisy output? Is it a Pioneer radio? https://bcae1.com/images/rca/temporaryrcashieldrepair.html
Posted By: lotaimpalass
Date Posted: June 14, 2009 at 10:08 PM
no it is a eclipse and has no outputs on my RCA. It started of with having problems on the pass side loosing volume. I would have to turn the volume up and down then it would come back on. Then one day it just stoped. I just read some one else talking about the pioneer having problems wtih grounds causing noise??
Posted By: lotaimpalass
Date Posted: June 14, 2009 at 10:22 PM
I read the info you gave and it sounds like a short in a amp is this correct? If so I would assume that it is the amp that is connected to the speakers that started shutting down first. Or could it be just fed from the other amp and it just started at that location? THE more info you could shed on either unit would be great. all RCA are out sub, front and rear. front and rear on 400.4 and sub on 800a2 Thanks again.
Posted By: lotaimpalass
Date Posted: June 15, 2009 at 1:56 PM
As I can tell the d3 I purchased will not get favorable reviews. Since I already own it do you recommend I gust start off doing the grounding mod before installation?
Posted By: i am an idiot
Date Posted: June 15, 2009 at 2:14 PM
The D3 will be fine as long as you disconnect the negative terminal of the vehicle's battery before you perform any work on the system. You can check it as per instructions on the page I posted. If it reads near 0 ohms from shield to chassis of the radio, there is no need to do the repair. If you ever have any noise issues, don't be stubborn like some others. You get noise, check it again. If you do have to do the repair, it is a real pain to get to the board of that unit. However the RCA cables are stripped and separated right at the harness where they plug into the radio. If you strip the black insulation off of one of the cables, you can solder a ground wire right there. Are you refering to another topic? I thought you had an eclipse in this vehicle.
Posted By: lotaimpalass
Date Posted: June 15, 2009 at 4:24 PM
I have an eclipse in it that the RCA are not working on it. And just purchased the D3 to replace it for 325.00. The eclipse is model 7301 so it is an older unit. Any ideas what could be wrong with the eclipse off of the top of your head?
Posted By: i am an idiot
Date Posted: June 15, 2009 at 6:12 PM
Are the RCA jacks of the Eclipse mounted to the chassis of the radio? Possibly bad connections where the jacks are soldered to the circuit board. If the RCA jacks are on the end of cables coming from the back of the unit, they to go bad but usually they give plenty of warning before they go completely out.
Posted By: lotaimpalass
Date Posted: June 15, 2009 at 9:45 PM
They are soldered in. I used my fluke 23 and found that all outputs were .8-.9 Ohms on outside sheilding to body of hu. One input was 1.895 mOhm.
Posted By: i am an idiot
Date Posted: June 15, 2009 at 9:56 PM
I was concerned with the center conductors on that radio. If you still have it wired up in the car, plug an RCA in and try moving it around to see if you can make it make connection and begin playing.
Posted By: lotaimpalass
Date Posted: June 15, 2009 at 10:27 PM
I switched them all around and moved them all over the place and never got anything out of them. it did take several months of loosing the pass side before they all went out at once and never came back on. the unit is now out of the car.
Posted By: lotaimpalass
Date Posted: June 16, 2009 at 10:08 AM
So am I right to think that it is my HU
Posted By: i am an idiot
Date Posted: June 16, 2009 at 3:18 PM
If you installed the D3 and all is working, then yes it would have to be your head unit.
Posted By: lotaimpalass
Date Posted: June 17, 2009 at 11:03 AM
I have not put it in yet, but would hate to cause a problem with the D3 right off the bat. Is their anyway to check and make sure their isn't any other problems?
Posted By: i am an idiot
Date Posted: June 17, 2009 at 2:49 PM
The only things you need to do is: Disconnect the negative terminal of the battery any time you are working on the system. Especially if you are changing out an amp. That is a problem if you ever disconnect the ground wire from the amp while the RCA cable and power wire is still connected to the amp, the amp will try to find ground through the RCA jack. There goes the fuse inside the deck. Make sure the amp is properly mounted. If it is allowed to slide around the trunk, it could slide around and have the ground wire pulled out, and there goes the fuse. Only other way is for a power wire to actually touch the shield of the RCA cable. All of the above can be prevented, if you disconnect the battery any time yoiu are working on the system. That is also the first step in the installation instructions of any piece of audio equipment.
Posted By: lotaimpalass
Date Posted: June 18, 2009 at 8:43 PM
I have a nice fiberglass home for the amp so that shouldn't be a problem. I will definatly make sure I remove both cables when I work on it. Thanks for the help once again.
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