Top 20 MTX Thunder 801D Car Audio Amplifier Questions & Answers

Mtx 801

Do you have the remote power hooked up on the amp? Have you checked the fuses? or maybe the audio wires are bad.

if theres a switch on ur amp that says LPF Full or HPF put it on LPF for low pass frequencies

If you don't know if the amp is bridgeable, then I wouldnt do it. It could already be bridged internally and bridgeing it through the speaker terminals could be disatrous, i.e. the infamous blue smoke of death. The amp looks like a 2 channel amp fromt he pic and you have two speakers you are trying to power with it. So the safest bet would be to just unbridge your speakers and hook them each up to the amp as normal. No blue smoke. Good luck!

you might need to turn the amp down and get some better wires to carry the load. when at lot of juice is being tranfered you need good wires to hold it

I am guessing the bass control is just a potentiometer that you plug in. It could be open and that is why the bass dies. As far as the switch goes, I am not familiar with the amp but it sounds like a crossover between low frequency and subsonic frequency.

Looking at alot of the unsolved FixYa problems - I can see alot of "My amplifier is going into protect mode - How do I fix it?"

There is no catch all or simple answer. Troubleshooting steps must be taken to determine what is causing the problem.

It is one of 3 things....

1. Impedence under rated value or Thermal Protection.
2. Short to ground in wiring.
3. Internal Component Failure.


One of the more confusing things with a car stereo can be when the amplifier goes into protection mode. One minute it's working and the next minute it's not. Here's a brief troubleshooting method that will hopefully help you if your amplifiers ever go into protection.

1. Try to determine the cause. Amps can go into protection mode for several reasons. Knowing what happened before it cut out can help determine how to fix it.
Did the amp not work as soon as it was turned on?
Did it happen after blasting for hours (may be thermal overload and it needs to cool)?
Did it cut out after you hit a bump (a wire connection may have come loose)?

2. Tear it down. Get the amp down to it's most basic state. Remove all of the speaker wiring and RCA wiring and leave only the power, ground and remote leads connected. If you still have a problem in this state then either your amp is defective or you may have an installation problem such as the amp touching metal.

Remember that an amplifier should only be connected to the vehicle through the power and ground terminals. Mounting the amplifier to the metal of the vehicle, including putting the mounting screws into metal, can cause problems for your amplifier.

Always mount the amplifier to a non-conductive surface. An easy way to accomplish this is to mount the amplifier to a wood board and then mount the board to the vehicle.

3. If the amp is OK in this torn down state keep adding the other wires back on until you find what causes the problem.
Add the RCA cables first.
Then add the speaker wires one at a time.
If the speaker wires cause the problem then they are probably touching metal or have a blown voicecoil.
Check to make sure that a speaker wire isn't being pinched somewhere between the amp and the speaker.
Also check that the speaker wire or speaker terminals aren't touching the vehicle metal near the speaker opening.
Rear decks and door panels can easily touch unprotected speaker terminals if not properly installed.

If the problem starts occuring when you connect the subwoofer wires to the amplifier you may have your subwoofers wired at too low an impedence. First check the spec's on your amplifier to make sure what kind of loads it is stable under. Then check the wiring configuration to make sure that your load is not too low:

If you believe your amplifier is defective contact the manufacturer first. Many have flat repair rates that are very affordable and cover parts and labor.

However local repair shops may be cheaper if it is just a small repair.

Compare the manufacturer's repair rate to that of a local shop. If you don't know the reputation of the local shop it may be better to send it to the manufacturer who will have working knowledge of the amp and parts readily available.

Thanks for using FixYa - a 4 THUNMS rating is appreciated for answering your FREE question.

Hello chacha_loves,

Usually having to "wiggle" the equipment for it to work means there is a loose connection either on the external terminals or where the terminals are soldered to a circuit board. For it to power on OK, but not produce output seems to indicate the speaker connections or output transistor connections.

Check the external terminals and make sure that there's no "play" when you gently wiggle the attached wire. If it gives slightly, the solder connection inside may be defective. If no components are damaged, you can usually restore complete function simply by reheating the bad or loose solder connection. Use a low wattage soldering iron with a well-tinned tip or a controlled temperature soldering station. Don't overheat the connection and don't add more solder.

If there's still no output, it's probably a defective component.

Hope this helps.

there are already holes in the firewall, which exsisting cables run thru to the back of the dashboard, the holes have rubber grommet fillers in them, put ur cable thru one of these exsisting ones...
hope this was helpfull

ASSUMING that the amp is OK with a 2ohm load then you "set it up" by the configuration of the speakers you use. Two 4 ohm speakers if parallel will give you a 2 ohm load. However, if you are bridging the ouputs then a single 4 ohm speaker bridged between the two outputs will put a 2 ohm load on each channel. Be very careful if you are bridging the outputs that you know what you are doing. On average, when bridged wrong (too much load) the amp will last about one month before it fries. Get some help if you are bridging. Be sure not sorry.

It is too old for online manuals. Any colour light would show it has power and usually a red, green or blue LED. Red is sometimes reserved as a fault condition in conjunction with another power light. https://www.google.com/search?q=mtx+810d+amplifier+manual https://www.google.com/search?q=mtx+810d+amplifier ..

See if the videos help https://www.google.com/search?q=mtx+terminator+tna251+RCA+sockets ..

MTX will know that one. https://www.google.com/search?q=make+my+MTX+TERMINATOR+AMP+1+OHM+STABLE ..

What amp r u using

yes a higher voltage rating is OK lower voltage rating is not good.

If you have to ask, take it to a repair shop.

THE GREEN LIGHT SHOULD SHOW WHEN AMP IS POWER UP AN RED WHEN IN PROTECTION MODE

Try eBay Often available there from private sellers

I was having a similar issue. I checked every wire from the battery to stereo to amp, checked the ground, pulled the stereo to double check the wiring was all correct. Everything seemed good so I thought it had to be my battery not putting out enough power. Tested it and it was good. What it turned out to be was the connection from the power cord to the battery. It had a tiny bit of built up corrosion that was making the amp go into protect mode. Cleaned it up and hooked it back up and has been golden since.
The link attached is pretty straight up on what you need to check for different circumstances. I'm guessing it's a low voltage issue. Good luck