When you take a ride in your car, which features do you value the most? Is it the plush, comfortable leather upholstery? Or do you prefer the latest head units with flip out touchscreens and Bluetooth? Well if you listen to music while driving the car, then you most likely should invest in a good set of car speakers, be it stereo or surround. However, most non-OEM car audio solutions will require the installation of an external amp. You can get a single 4-channel or 5-channel amp to power all of the speakers inside your automobile theater setup, or you can instead choose to get multiple mono-block amps for the same.

And if you have a big 12”/15” car subwoofer in there (possibly a dual sub setup), you must get a good 1-ohm stable amp to power the same. Subs require extra power, and the “cleanliness” or quality of power that is fed to a sub will determine the clarity and responsiveness of the driver towards a bass signal. There are many types of 1-ohm stable amps out there and most good ones allow you to bridge multiple output ports in order to generate extra power that will be fed to a high-powered sub driver.

Some other things that you need to focus on are- internal component shielding, coil and capacitor quality, I/O options, heat dissipation, etc. All of these factors have a pretty large impact on how “clean” (distortion-free) your sub is going to sound at both low as well as high volume levels. Internal circuitry can also determine the frequency response of an amp and will affect how well a driver that is connected to the amp reacts when you feed it with super-low frequency sounds. Also, check to see if your 1 Ohm mono-block amp has high pass filters if you wish to hook it up with your sub. And check the quality of the crossover circuitry.

In this article, we examined a total of 5 different 1-Ohm stable amps. All of these amps were cherry-picked from the hundreds of amps currently available on the market, based on the thorough analysis of customer reviews, as well as specifications and build quality.

Check out our list of best car amplifiers!

Our Pick: BOSS AUDIO PD5000 Phantom

This Boss Audio amp is our top choice for many reasons, primarily because of how much it offers for the price. While costlier and better options exist, they will charge a very high premium for a slight increase in performance, which most consumers and even audio enthusiasts will not need unless you’ve built your entire car around the audio system. For less than 200 bucks, you’re getting an extremely well-built class-D amp (single channel of course), with a whopping 3750 watts of output at 1 ohm, 1875 watts on 2-ohms, and 938 watts on 4

For less than 200 bucks, you’re getting an extremely well-built class-D amp (single channel of course), with a whopping 3750 watts of output at 1 ohm, 1875 watts at 2 ohms, and 938 watts at 4 ohms of resistance. With power like this, you’ll have no problems whatsoever while pushing the volume knobs up on your 12”, 15”, or even 18” sub/dual sub.

On top of the amazing power output, you’re also getting pre-amp outputs so you can connect this amp output to another mono amp without the need to run separate wires from different speaker to each separate amp. Low-level inputs are also present, along with variable crossovers and bass boost.

The subsonic filter will catch and chop off all the super-low subsonic frequencies that our ears are not capable of hearing. This will reduce power draw during operation, and make the whole sub run much more efficiently since it does not receive any signals that don’t matter. The one con regarding this amp is the fact that it tends to run pretty hot when you use it in 1-Ohm mode, and the power draw might get a little too high. For smaller cars, you will have to dim the lights unless you want to risk damaging your amp or speakers.

On the Budget: BOSS AUDIO R2400D Riot Monoblock

If you’re planning to get a budget mono channel amp with decent build quality and passable audio characteristics, then this might be a good choice for you. Still, exactly what are you getting for less than 100 bucks? Well, there is 1800 W of RMS power available at 1 ohm stable, and that number is halved at 2 ohms of resistance (Duh). At 4 ohms of resistance, it will fall down to 450 W and that is still more than enough for powering some low-mid end car subs. The package is completed with low-level inputs and RCA preamp outputs. Low-level speaker controls let you control the sub and speaker settings from the amp itself, and you can conveniently bridge multiple channels or even amps together (thanks to the built-in preamp outputs).

So what is lacking inside our budget champ? Well, it does not feature the best coils or capacitors, so there is a noticeable amount of distortion when you pump the subs up to max volume. The sub-par heatsink is not capable of keeping this unit cool under heavy loads and you may notice performance degradation during long drives. For regular urban commuting, though, it should not matter. Also, the back comes embossed with a really classy looking BOSS logo that features a blue backlight.

On the Budget: SOUND STORM EV4000D EVOLUTION Monoblock

Well, this is yet another budget amp. It costs nearly 40-50 % more than the R2400D from BOSS but makes up for that increase in price with superior build quality and better internal shielding. The audio quality is pretty good, and this should be all that you need if you’re interested in listening to some rock, electro, metal, etc. while taking a drive around the city in your brand new sedan. You get remote subwoofer control, switchable phase control, variable bass boost, and a whopping 3000 W of RMS power at 1 Ohm stable. One of the features that you’ll get on this amp, which is otherwise only found on more high-end amps, is the variable subsonic filter.

What is it that we don’t like about it? Well, at this price the amp is already offering so many goodies that it is rather hard to nitpick. However, some things COULD have been improved just a LITTLE bit- such as the terminals on this amp which only allow you to connect wires of thickness 4-guage and below. Also, it would have been super-great if Sound Storm found a way to decrease the size of this amp ever so slightly. If you are going to mount this amp in really tight spaces, the larger than conventional size could turn out to be an issue.

Also Great: Power Acoustik BAMF5500/1D 1700W Class D Mono Amplifier

This is a class D Mono 1 ohm stable amp, and it is in the “Worth Considering” category only because of its relatively underwhelming power output. Even though it is one of the most solidly built amps that we have ever tested, the 1700 W RMS power does tend to drag it back a little bit. Bridging synchronization, 4-way protection circuitry, and full PWM power supply comprise a few of the most notable strengths of this amp. The interiors are loaded with high-speed digital circuitry and feature high-quality chokes, capacitors, and coils so that the amp will respond immediately to volume changes. You will notice a smooth transition from low to high volume and vice versa, no matter how fast you turn the knob. The bass boost is clean and distortion free, with plenty of punch and well-defined notes even in the sub-100 Hz range.

The biggest con of this amp, of course, is the slightly limited RMS power, and the second con would be lacking proper heat dissipation owing to its super small form factor. However, there is one thing that must be noted over here- you’ll probably never feel the lack of heat dissipation unless you ALWAYS use this amp on maximum power, and that too for extended periods of time. The lower RMS power means that you’ll be totally fine in most usage scenarios as less power= less heat produced. We recommend strapping two of these amps together to make up for the shortage of RMS power.

Vincent T
*Any prices mentioned in the article were at the time of publishing and are subject to change. Any price and availability information displayed on Amazon.com or Amazon.co.uk at the time of purchase will apply to the purchase of this product.