The amplifier is an essential component that drives power into the speakers. If you want your music to be loud and crystal clear, amplifiers are definitely part of the picture. However, it’s important to find the right mounting location for the amp to maximize its advantages.
No hard and fast rules exist that say exactly where an amplifier should be mounted inside the car – it’s a matter of space, function and preference.
As long as the amplifier has adequate ventilation, and enough space to ‘breathe’ – since it could run the risk of overheating if it’s in a nook that’s too cramped – you can basically mount it anywhere inside the car.
We will explore Five different car amp mounting ideas, from underneath the front seat to the spare tire area, to even an amp rack. The last item is a unit or case that serves as an amp holder. All of the options have their pros and cons — you be the judge.
4 Reasons You Shouldn’t Mount an Amp Over a Sub box
Mounting your amplifier over a subwoofer box has always been a topic of heated debate in the car audio community.
Generally speaking, mounting your amps on a sub box is not recommended at all. Nonetheless, so many people have been doing it for a very long time with no problems whatsoever, probably because those people build very good enclosures from 3/4″ (or thicker) MDF with extensive bracing.
Others (especially impatient greenhorns) are too lazy to do that and build un-braced enclosures from thin MDF or even worse plywood. These enclosures aren’t strong enough and will easily flex more than a well-built enclosure and will likely cause early amp failure if the amp is mounted to the enclosure.
There are a lot of things in life you can get by without any major problem. That does not mean by any means that it is a good idea, or that it should be done.
1. Damage to Amp’s Internal Components
The reason why car amp prematurely fail when mounted to a subwoofer box is because of vibration-induced failures (also known as vibration fatigue), which is one of the main mechanisms that causes the failures of electronic devices.
It goes without saying that electronics are subjected to vibrational stresses, and car amplifiers are no exception.
I mean, when the subwoofer is pounding hard, the material making up the box flexes and therefore causes the sides of the box to vibrate. These vibrations are then transmitted to the amplifier mounted to the box; specifically to the electrical components through the electrical leads which are soldered into the PCB (circuit board). This wreaks havoc through the solder joints and electrical leads which are soldered into the circuit board, causing the components to break loose, which eventually leads to early amplifier failure.
Vibrations are liable to cause early amp failure in different ways. Being subjected to vibrations for an extended period of time causes:
- The solder joints to crack
- The pins of the semiconductors to break (which causes amplifier failure).
- The capacitors to crack and break off of the PCB (which can cause catastrophic amplifier failure).
- The solder joints to break on the semiconductors mounted to the heat sink.
- Transformer windings to grind into one another (which causes lots of smoke and burning smell to come out of your amplifier).
Keep in mind that the vibrations won’t negatively impact your amplifier immediately but over the long run.
Also, this depends to a great extent on power. I mean, a well-built box housing a 200 watts RMS subwoofer is unlikely to cause an issue.
Furthermore, it must be noted that some amps are more prone to vibration-induced failures than others.
2. Risk of Theft
If you frequent any of the popular car audio forums, you’ll notice that “subwoofer box theft” comes up quite a bit.
In fact, we’ve come across several posts on car audio forums and social media where people have been victims of theft of their subwoofer boxes and are asking for how to secure subs to prevent that from happening again.
Mounting your amplifier on a subwoofer box means presenting an all inclusive package to potential thieves on a silver platter.
The theft thing is the best reason not to mount it all together since it would be much easier for a thief to snatch it all at once.
3. Amp Overheating
If your amplifier is mounted flush against the subwoofer box with no air circulation on the bottom, it’ll easily heat up. This is especially true if the subwoofer box is mounted in sedan’s trunk.
It should be noted that lack of airflow is one of the most common cause of amp overheating.
4. More Work Taking the Box Out
Another reason to not mount your amp to a subwoofer box is because it limits your ability to disconnect that subwoofer box if you need to remove it to make extra room for cargo. This also holds true when you’re swapping out boxes.
Tips For Mounting An Amp On A Sub Box
If you have to mount your amplifier on a subwoofer box for whatever reason, there are a few precautions you need to take to ensure your investment will last for many years to come.
1. Double or triple baffle the sub box
The mounting surface you attach the woofers to is susceptible to excessive and severe vibrations. Doubling or tripling its thickness makes it stronger and allows it to absorb some of the energy waves generated by the sub(s). This allows for less box flex and cuts down the amount of vibration that’s transmitted to the amplifier.
2. Make sure to brace your enclosure
Bracing is the KEY to a well-built subwoofer enclosure. It’s a technique used to prevent unwanted physical stress (from panel flex and vibration) to the amplifier.
If your enclosure is built with inferior or too thin materials, or if it’s just generally poorly built with no bracing, you’re probably going to get a lot of flex in the box, which will then be transferred to the amplifier causing damage to its circuit board.
3. Use rubber washers on amp’s feet
Another tip to consider when mounting an amp on a sub box is to put like 4-6 rubber washers at each foot of the amp.
Doing this kills two birds with one stone. The rubber washers will give the amplifier some cushion which will significantly dampen the vibrations, and at the same time get the amp about 1/2″ off the box which will allow it to “breathe”.
5 Best Locations to Mount a Car Amplifier
Now that we’ve explained why mounting an amp to a subwoofer box is a bad idea, and what you should do if you had to, it’s time to tackle the ways of doing it correctly.
Down below, we’ve listed some great car amp mounting ideas for different vehicles.
Underneath The Front Seat
Mounting your car amplifier underneath the seat is the most preferred choice option among car audio fanatics.
The main advantage to mounting the amplifier underneath the seat is that you get to use shorter signal and patch cables.
If you’re installing a 4-channel car amplifier to power your door speakers, by mounting it under your seat you will have a central location to route all of your speaker wires.
On a related note, it’s worth noting that car audio cables are unbalanced cables. And because unbalanced cables can pick up noise as a signal is sent along the cable, they’re more suitable for short distances, like connecting a head unit to an external amp. This minimizes the risk of unwanted noise and signal degradation.
Additionally, another reason to consider this amplifier mounting option is because it’s a great way to hide your amplifier out of sight.
The downside, however, is that your amplifier might keep overheating due to lack of airflow being mounted in a confined space such as underneath the seat. This is especially true if you live in a hot area, or if you have a cheaply made amplifier that tends to get hot easily.
Moreover, it can be difficult to easily tune an amplifier mounted underneath the seat since you can’t reach it easily without sliding the seat.
It must be noted that not all cars have enough space under the seats to accommodate an amp. This is especially true when the amp is too long or too tall. So, before attempting to mount your amp underneath the seat, you need to measure it to ensure it’ll fit in there.
You’ll also need to consider the clearance of the seat when it moves (stick it under the seat and move the seat back and forth to see if it will fit properly under there), if people’s feet will hit it while in the back, if there is a floor vent under it (in colder climates the amp would be blasted with heat from your AC), not to mention if the amp is accessible if necessary.
When it comes to mounting a car amp underneath the seat, one of the biggest problems is the wide variety of amp sizes. Generally speaking, only small car amplifiers are suitable for being mounted in there. However, sometimes depending on your car, you may also be able to fit a mid-sized or even a large amplifier underneath the seat.
It goes without saying that you always need to make sure the amp’s case is isolated from the chassis of the vehicle. This is to prevent ground loop and noise problems.
One of the best ways to achieve that is to mount your amplifier to a wooden mounting board then bolt that piece of wood to the metal floor of the car. If you don’t want to drill holes into the car’s body, you can simply glue the board to the metal floor using construction adhesive.
To keep the amplifier running cool, use standoff screws to raise the amplifier a bit off the wood so there is air space under the amplifier allowing good ventilation.
Another easy way to hold an amplifier into place under the seat is to use heavy-duty industrial strength velcro tapes.
- You get to use shorter signal and patch cables as the amp is close to the speakers and headunit.
- The amplifier is out of sight, thus it’s unlikely to be stolen.
- No cargo space is sacrificed.
- This makes wiring easier due to the fact that you are ripping up far less materials to hide your installation wires.
- This also allows you to adjust your setting easily without getting out of your car, especially if the amp is installed in a position that allows easy access to the amplifier controls.
- You have the added cooling of your internal cabin during hot summer months.
- You may have to remove the seat to do the installation.
- Lack of air flow and cooling, especially on class A/B amplifiers.
- Unless you have amazing clearance down there, the amp will get scratched up pretty bad.
- The feet of any back seat passengers might damage the amp depending on how it’s mounted.
- If you have a large amplifier, it’s likely to stick out and be right at the back passengers feet.
Behind the Seats / Trunk
The other common way to mount a car amplifier is to attach it directly onto the back of the seats. This actually makes perfect sense if you have multiple amplifiers, or an amp and a crossover/equalizer.
The biggest advantage to mounting a car amplifier behind the seat besides being out of sight is that it affords you easy access and space to easily tweak and fine tune the amplifier. This is not to mention efficient ventilation, especially in SUVs and trucks.
It should be noted, however, that this might not be a great car amp mounting idea in sedans due to the lack of airflow in the trunk, which can cause the amp to overheat after a little while of loud playing.
I mean, sedans’ trunks generally don’t have much ventilation, so air is not circulated away from the amps area as fast as it’s heated up. And although car amplifiers are built to operate at hot temperatures, sometimes non-fan cooled amps might overheat in the summer.
Another downside to mounting amps behind the seats or trunk is the cost of the extra wiring. This is not to mention the fact that the wires can pick up noise and interference as they are run from the front of the car back into trunk.
An easy way to mount your amplifier and any other component behind the seats is to mount everything to a piece of wood (plywood or MDF), then secure that piece of wood to the back of seats (consider carpeting your car amplifier mounting board to make it match the trunk and more cosmetically pleasing).P.S: If the back of the seats is wood and is solid enough, then you can secure the amp directly to it. However, if it’s metal, don’t mount the amp directly to it. Use a mounting board instead.
One thing to watch out for when mounting an amp behind the seats is not to forget to leave a few extra inches on each wire in case you need to fold the seats down.
- Easy mounting (especially if you mount the amp directly to back of the seats).
- Great mounting option if you have multiple amps, or an amp and another component such as crossover or equalizer.
- Enough room to mount and adjust amp settings.
- There is a slight risk of RCA wires picking up noise and interference and more chances to run into pinched lines if not careful.
- Lack of airflow in sedans’ trunks.
- The cost of the extra wiring and the mounting board.
In The Spare Tire Area
If you’re looking for a car amp mounting idea, and want to keep as much space as possible, or don’t have enough space in the car to begin with, then mounting the amplifier in the spare tire area might be a decent option to consider.
Depending on how much clearance you have down there, and how big your spare tire is, you may be able to mount your amplifier to a round wooden cutout that fits inside the spare tire (after taking out the foam inserts of course). This will allow you to easily remove the amp and the wood cutout and access the spare tire should you need it.
If your amplifier can’t fit inside the spare tire, then you’ll need to pull out the spare tire and the tool kit altogether, which is not recommended at all. You don’t want to be the driver who is caught off guard and stranded in the middle of nowhere when one of the regular tires goes flat.
The biggest advantage to having your amp mounted in the spare tire location, aside from not taking up valuable space, is that it’s completely hidden out of sight.
The main downfall to mounting an amplifier in the spare tire area is the lack of airflow, which could make the amplifier overheat especially during summer. Thus, you may want to add a small fan in there to help circulate the air.
Usually, a class D amplifier that’s set properly shouldn’t have any overheating issues, but some class A/B amps will likely need some air flow.
- Amp is completely hidden out of sight.
- Amp is out of the way and isn’t taking up any valuable space.
- Lack of air flow. So, it’s not a great mounting option if you have multiple amps.
- If you have a tall amplifier, it’s likely to raise the trunk liner a bit unless you have amazing clearance down there.
- Amplifier not easy to reach and fine tune.
- Risk of being stranded in the middle of nowhere if you swap the spare tire for the amp.
- The cost of the extra wiring.
- Depending on where you run the wires, they can pick up interference from other wires you have run close to them.
In the rear quarter panel
Having your amplifier tucked way in the rear quarter panel (or in between the taillights and the strut tower) is another great car amp mounting spot to keep it out of the way, and allow you to use the entire trunk space, while effectively hiding the amp. This spot is typically used to mount car subwoofers in the trunk and it’s referred to as “corner loading”.
Generally speaking, mounting the amplifier somewhere in the trunk is most commonly done with subwoofer amplifiers, as it allows you to keep the length of the speaker wire leading to your subwoofer down to a minimum.
It should be noted, however, that due to the limited space in that spot, you’ll only be able to fit in a small car amplifier.
Keep in mind that if you have a vehicle where you can see into the trunk area, mounting your amp in the rear quarter panel may not be the best location.
- Keeps the amplifier out of the way
- No cargo space is sacrificed
- It can be hard to mount a mid size or large amp in the rear quarter panel
- Not enough room to adjust amp settings
- Not a good mounting location in some vehicles where you can see into the trunk area
Using An Amp Rack
The most professional way to mount amplifiers in a car is to use an amp rack. An amplifier rack can be anything (unit, case, holder …etc) that you’ve built to hold one or multiple amps in place. It can be of almost any design, shape or size.
In fact, you can build an amp rack and mount it in any suitable locations like those mentioned above. If you do build a rack for your amplifier, make sure it has lots of ventilation as it will get hot.
An amp rack is practically a mounting board. As a matter of fact, if you frequent any of the popular car audio forums, you’ll notice that car amplifier mounting board and amp rack are two terms that are often used interchangeably.
If an amp rack is properly designed and well placed, it’ll look pretty cool and you’ll get a ton of compliments on it.