Best 1-Ohm Stable Amplifier
The Planet Audio Tr3000.1d

The Best 1-Ohm Stable Amplifiers For True Power Audiophiles

If you need more power than what a regular 4 ohm or even 2-ohm amplifier can provide, then a 1-ohm unit is your only option. Because of the immense amount of current they produce, there’s a ton of potential for volatility. Fortunately, there are lots of stable 1-ohm amplifiers in the market as well, and this year I had the opportunity to try out about 12 of them.

In this article, I’m going to be reviewing my top five as well as reveal what I think is the overall best 1-ohm stable amp.

Best 1-Ohm Stable Amps

A Beginner’s Guide to Amplifiers

Buying the right amplifier isn’t easy as there many factors to consider first. In addition to finding a unit that serves your needs in terms of sound quality, you also need to make sure that it is compatible with your existing car audio setup. In order to do that, you need to be able to read and understand a few technical specifications, including class, frequency response, power output, number of channels, speaker sensitivity and impedance.

If you’re not familiar with these terms, don’t worry. I’ll be explaining what they are and why they’re important as we go along.


Amplifiers belong to different classes and the four main ones are A, B, A/B, and D. The main difference between them is efficiency, which is a measure of how much Alternating Current (AC) an amplifier can supply while consuming the least amount of Direct Current (DC) possible. Here’s a brief summary of how efficiency varies among the different amplifier classes.

Class A

Class A amplifiers have the simplest circuits and are also the least efficient. This is because they conduct electricity all the time and most of it goes unused by whatever component is connected to the amplifier. As a result, Class As typically have an efficiency of 30%. Another thing to note is that most of the wasted electricity is converted to heat energy, which means these amplifiers tend to overheat with prolonged use.

The biggest advantage of Class A amplifiers is that they provide the purest audio signal.

Class B

Class B amplifiers are more efficient (70%). This is largely because they only conduct electricity half the time when compared to Class A units. However, their circuits are known to add a little bit of distortion to the signal.

Class A/B

Class A/B circuits are a hybrid of Class A and Class B, combining the best of each. Thanks to biasing diodes in the Class B chain, you don’t have to deal with any distortion in the signal. As a result, you get the signal purity of Class A and the power efficiency of Class B in one unit.

Class D

Class D amplifiers typically boast an efficiency of 90% – 95%. This is largely due to the fact that when these amplifiers are off, they’re off. What I mean is that their output transistors retain no electricity at all when the unit is switched off. Hence there isn’t any lingering electricity that can be converted to heat.

You’ll note that a lot of 1 ohm-stable car amplifiers have Class D circuitry. I find this quite appropriate, considering that they deal with massive amounts of electricity.

Power Output

Essentially, amplifiers allow your speakers and subwoofers to be louder by supplying them with more power. So, if you’re like me and you love blasting your music regularly inside the car, then you’ll want to choose an amplifier with high power output. However, you need to consider the fact that there’s a limit to how much power you can direct to your speakers. Cross this limit and they may overheat and start to malfunction.

Fortunately, there are two specifications that tell us exactly how much power a speaker can handle: RMS and Peak Power. RMS indicates how much power (in watts) you can safely supply to a speaker on a regular basis while Peak Power sets the absolute limit for how much it can handle.

Similarly, amplifiers too have RMS and Peak Power ratings but they refer to power output instead of handling. Hence, when you’re buying an amp you must make sure that its RMS is equal to or lesser than that of your speaker. Otherwise, you’ll risk damage to the latter every time you crank up the volume really loud.

Speaker Sensitivity

Speaker sensitivity tells you how loud a speaker will be (in decibels) when you supply it with just one watt of power. For example, let’s say a speaker has a sensitivity of 85 dB. This basically means that if you were to power it with one watt, it would output music at a moderately loud level. For each additional watt, you add another dB to the volume.

A speaker’s sensitivity rating will tell you how much power you’ll actually need from an amplifier. The more sensitive a speaker is, the less power you’ll need to supply.

Frequency Response

Frequency response refers to the range of frequencies that an amplifier can handle. Amplifiers that can handle all frequencies within the human audible range (20 Hz to 20,000 Hz) are known as ‘full-range’. Those that are specifically designed to work with subwoofers typically have a frequency response of 20 Hz to 250 Hz, which is the bass range.

Most 1 ohm amplifiers are only designed to work with subwoofers. This is because they output massive amounts of power – way more than what regular speakers can handle.

The Number Of Channels

The number of speakers and subwoofers in your car’s setup will determine how many channels you need in your amplifier. For instance, if you’ve got three or four speakers and a subwoofer, then a 5-channel amp is probably the best option for you.


Impedance measures the internal resistance (in ohms) that an amplifier possesses. It determines how hard an amplifier has to work in order to supply current. The lower the impedance, the lower the load placed on the amplifier and the greater the amount of current that is supplied. Hence 1-ohm amplifiers supply the greatest amount of current.

You need to be a bit careful with low-impedance amplifiers because they can supply more power than what your speaker can handle. Hence, they’re more suited for subwoofers.

1 Ohm Stable Amps Reviews

Now that you’ve received a crash course on amplifiers in general (particularly what you need to look out for when purchasing one), let’s take a look at my top five 1 ohm stable amps for this year:

Skar Audio Rp-2000.1d

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Tons of Power

The Class D Skar Audio RP-2000.1D can be toggled between 4 ohms, 2 ohm and 1-ohm settings, providing more power as you go down. At 4 ohms and 2 ohms, the RMS is 800 watts and 1400 watts respectively which is already more than adequate for most high-powered subwoofers. However, if you do need more power, the 1-ohm setting will output 2000 watts RMS.

Variable Low-Pass Filter

Low-pass filters are EQ tools that allow you to set a cut-off frequency. Any signals that are higher in pitch will be blocked while those that are lower in pitch will be allowed to pass. Hence, low-pass filters are great for eliminating any unwanted distortion from the upper-bass region.

The filter that comes with the Skar Audio RP-2000.1D is variable which means you get to decide the cut off frequency between 50 Hz and 220 Hz.

Also read about the best RCA cables here.

Bass EQ Switch

If you feel like your subwoofer lacks a bit of attack in the sub-bass region, then having a Bass EQ switch is quite useful. It’s essentially a bass boost where you can crank up the low end by either adding 6dB or 12 dB to the volume. I found this quite handy whenever I was listening to EDM music and wanted the bass to sound a little bit deeper and be more prominent in the mix.

Subsonic Filter

High-pass filters are the opposite of low-pass filters. They block signals that are lower than the cut off frequency while letting those that are higher pass through. Subsonic filters are essentially high-pass filters that are restricted to the bass region. In the case of the Skar Audio RP-2000.1D, the cut off is set at 50 Hz.


  • High power output at each impedance setting
  • Comes with a variable low-pass filter and a subsonic filter
  • Bass EQ switch adds more ‘punch’ to the low end

  • It’s quite a long unit so your installation options are quite scant.

Pioneer GM-D8601



At the default impedance setting of 4 ohms, the Class D Pioneer GM-D8601’s single-channel has an RMS rating of 300 watts, which I found was quite adequate for my own subwoofer. However, when toggled down to 1 ohm, the RMS jumps up to 800 watts.

Variable Low-Pass Filter

The low-pass filter included in the Pioneer GM-D8601 is adjustable between 40 to 240 Hz. What I like to do is set the cut-off close to the upper limit and dial out any harshness from the upper-bass region.

Variable Bass Boost

This works similarly to the Bass EQ Switch found in the Skar Audio RP-2000.1D. It boosts all signals that have a frequency of 50 Hz by up to 18 dB. This can really help those deep, thumping sub-bass beats to have a more forward placement in the mix.

The GM-D8601 comes with a bass boost remote that allows you to control the level of the boost without having to fiddle with the actual dial.

Protection Control System

Things can get quite volatile at 1 ohm but fortunately, the GM-D8601 has a counter for this. The ‘Protection Control System’ in its circuit has sensors that measure the internal temperature of the unit at all times. It then automatically moderates the input level based on how high or low the temperature is.


With a width of 10 inches, a height of 2 and a depth of almost 8 inches, the GM-D8601 is fairly compact, especially when compared to other 1 ohm stable amplifiers.


  • High-powered, especially at the 1-ohm setting
  • Comes with a variable low-pass filter and a bass boost
  • Includes a bass boost remote
  • Built-in sensors monitor internal temperature at all times
  • Fairly compact

  • I’m having trouble thinking of any

Rockville RXD-M1

Rockville RXD-M1 2000 Watt Peak/500w @ 1 Ohm CEA RMS Mono Amplifier+Amp Kit
23 Reviews
Rockville RXD-M1 2000 Watt Peak/500w @ 1 Ohm CEA RMS Mono Amplifier+Amp Kit
  • Package Includes: (1) Rockville RXD-M1 500 Watt CEA Compliant Rating...
  • CEA Power Ratings (Rated at less than 1 % distortion) (Use these CEA...
  • RMS Power Ratings (Use these RMS ratings when comparing with great...
  • 4 Ohms: 1 x 1000 Watts. High-Speed MOSFET Power Supply. Optical...
  • Fully Adjustable 12dB Bass Equalizer. Mute and Delay Soft Start...
Very Powerful

The Rockville RXD-M1 offers three impedance settings: 4 ohms, 2 ohms, and 1 ohm. At 4 and 2 ohms, the Rockville RXD-M1 outputs 500 watts RMS and 700 watts RMS respectively. This is more than enough to power most subwoofers in the market. If you do need more, the amplifier will belt out 1000 watts RMS when you turn down the impedance to one watt.

Adjustable Low-Pass Filter

The Rockville RXD-M1’s low-pass filter allows you to set the ‘gate’ at any frequency between 50 Hz to 250 Hz. If your subwoofer can’t handle upper-bass frequencies too well, I recommend you set the cut off frequency quite high and get rid of any white noise in the mix.

Subsonic Filter

The subsonic filter has a range of 15 Hz to 55 Hz. If you notice a little distortion at the extreme low end (around the 20 Hz mark) then I suggest using the subsonic filter to dial that out.

Wide Frequency Response

Compared to most subwoofer-specific amplifiers, the Rockville RXD-M1 has a relatively wide frequency response, ranging from 10 Hz to 500 Hz, which ventures into the midrange area.

Bass EQ Control

If you feel a lack of bass when you’re listening to music or you simply want more of it, the Bass EQ control can help you target the sub-bass region and give it a boost of up to 12 dB.


  • Very powerful, even at the highest impedance setting
  • Comes with an adjustable low-pass filter and a subsonic filter
  • Has a wider frequency response than most 1-ohm amps
  • Bass EQ control adds more depth to the low end

  • It’s a little heavy to carry around

Planet Audio Tr3000.1d

Planet Audio TR3000.1D Class D Car Amplifier - 3000 Watts, 1 Ohm Stable, Digital, Monoblock, Mosfet...
937 Reviews
Planet Audio TR3000.1D Class D Car Amplifier - 3000 Watts, 1 Ohm Stable, Digital, Monoblock, Mosfet...
  • 3000 W MAX Power X 1, 2250 W X 1 RMS @ 1 ohm, 1125 W X 1 RMS @ 2 ohm,...
  • Monoblock Class D, MOSFET Power Supply
  • Low Level Inputs, RCA Pre-amp Outputs
  • Variable Low Pass Crossover, Variable Bass Boost, Variable Subsonic...
Maximum RMS Of 2250 Watts

Even at the default impedance setting of 4 ohms, this amplifier is capable of outputting 563 watts RMS, which is plenty for most subwoofers in the market. However, you can switch down to 2 ohms for 1125 watts and 1 ohm for 2250 watts. This makes the Class D Planet Audio TR3000.1D one of the most powerful amplifiers on the market.

Phase Control

Phase control helps you deal with absent bass notes. To put it simply, it makes sure that all the audio signals are ‘getting along with each other’ rather than canceling themselves out. With a little tweaking, the phase control can help you make sure all the details and nuance in the music are retained.

Variable Bass Boost

This feature lets you boost the low-end up to 18 dB. This is handy if the sub-bass frequencies tend to come out a bit muted through your subs.

Variable Low-Pass Filter And Gain Control

The Planet Audio TR3000.1D’s low-pass filter allows you to specify a cut off frequency between 50 to 250 Hz. The included gain control helps to ‘clean up’ the audio signal that is sent from the amp’s output to your sub’s input. Having too much gain can lead to unwanted distortion so this control helps you limit it.

Thermal Protection Circuit

The TR3000.1D’s circuit contains thermal sensors that are constantly monitoring the internal temperature. The instant it gets too hot, the amplifier will be automatically turned off and allowed to cool. The circuit will also cut the amplifier’s output if an electrical short is detected due to a speaker failure.


  • Very powerful
  • Phase control helps prevent absent bass notes
  • Bass boost for adding more ‘presence’ to the low-end
  • Variable low-pass filter and gain control helps clean up distortion
  • Thermal protection circuit prevents heat damage and damage due to electrical shortage

  • Not the most compact amplifier

Taramp’s HD 3000

Taramp's HD 3000 1 Ohm Class D Full Range Mono Amplifier
733 Reviews
Taramp's HD 3000 1 Ohm Class D Full Range Mono Amplifier
  • Excellent for voice as well as bass
  • 1 ohm
  • 3000 watts
  • Mono
  • Bass boost
Maximum RMS of 3575 W

The Taramp’s HD 3000 is easily the most powerful amplifier on this list. At the 4-ohm settings, the HD 3000 outputs a maximum RMS of 1365 W which is already enough to drive a really powerful subwoofer. When switched to 2 ohms, the RMS climbs to 2355 W and 1-ohm gives you 3575 W maximum.


The Taramp’s HD 3000’s frequency response ranges from 20 Hz to 20,000 Hz making it the only full-range amplifier on this list. This means that the amplifier is compatible with both regular speakers and subwoofers.

High- And Low-Pass Filters

The HD 3000 features adjustable high and low-pass filters, allowing you to dial out any unwanted distortion. The high-pass filter allows you to set the cut off frequency between 10 Hz to 80 Hz while the low-pass filter’s range extends from 80 Hz all the way up to 20 kHz.

Bass Boost

The HD 3000 allows you to target all signals at 50 Hz and give them a boost of up to 10 dB. While this isn’t as big a boost as what you might find in other amplifiers on the list, I found it was more than enough to give the low-end a bit more focus.


With a width of 9 inches and a depth of 7, this amplifier is quite compact for a 1-ohm stable unit.


  • The most powerful amplifier on this list
  • Can handle the full range of frequencies from sub-bass to upper-treble
  • Comes with high and low-pass filters for shaping the tone
  • Bass boost gives more power to the low-end

  • Not sure there are any

The Best Overall 1-Ohm Stable Amplifier

The most difficult part of this process was choosing my overall favourite of the top five. There wasn’t really a clear winner as they’re all excellent and have tons of similarities. For instance, each one of these filters has at least a low-pass filter on them. However, after much deliberation, I finally decided on the Planet Audio TR3000.1D.

Planet Audio TR3000.1D Class D Car Amplifier - 3000 Watts, 1 Ohm Stable, Digital, Monoblock, Mosfet...
937 Reviews
Planet Audio TR3000.1D Class D Car Amplifier - 3000 Watts, 1 Ohm Stable, Digital, Monoblock, Mosfet...
  • 3000 W MAX Power X 1, 2250 W X 1 RMS @ 1 ohm, 1125 W X 1 RMS @ 2 ohm,...
  • Monoblock Class D, MOSFET Power Supply
  • Low Level Inputs, RCA Pre-amp Outputs
  • Variable Low Pass Crossover, Variable Bass Boost, Variable Subsonic...

Here are my reasons:

First of all, this amplifier comes packed with a ton of features, from a phaser control to variable gain control. Being an audiophile I found this quite useful as I always try to get the tone to sound better. Another feature I loved about this amplifier is the thermal protection circuit. This always gave me peace of mind whenever I switch the impedance level to 1 ohm.

1-Ohm Stable Amps FAQ

What Amps Are Best For Subs?

I find that 1 ohm-stable amplifiers are generally the best for high-powered subs since they provide the most power. However, if you have a sub with a lower RMS, you may also go with a 2-ohm or 4-ohm amplifier that can output at least 150 watts RMS.

Does Impedance Affect Sound Quality?

What it affects is the amount of current that an amplifier can supply and how much stress is placed on it. However, if the impedance is too high, the speakers may not receive enough power, causing the sound output to sound weak and muted.

How Many Ohms Can My Amp Handle?

Typically, car amplifiers have a default impedance of 4 ohms. This ensures that it can output a decent amount of power without being overworked. However, as this article, clearly demonstrates, there are plenty of amplifiers that can handle having their impedance dropped to 1 ohm. This information should be available in the product information section or the manual of your amplifier.

What Are The Dangers Of Running Your Amp At 1 Ohm?

The great thing about a 1 ohm-stable amplifier is that there really aren’t any risks. Most are equipped with some kind of thermal protection feature in their circuit that switches the unit off when things get too hot.

The products featured on this page were last updated on 2021-03-22 at 11:39 /. Affiliate links / Images from Amazon Product Advertising API.

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