Every now and then We get e-mails from readers who like to rock out — really loud and hard. One recent one asked, “Can you recommend a great 1 ohm stable amp that doesn’t cost an arm and a leg?”
When it comes to amplifiers, Ohms represent the impedance on the audio signal from your amplifier to your speakers. So the lower the impedance, the more signal can travel from the amp to the speakers. Hence, an amplifier that provides 400 watts of power through a 4-ohm speaker, will deliver about twice that (800 watts) through a 2-ohm speaker, because it’s easier to push that reduced load.
The downside, however, is that a lower impedance means more stress on the amp. That’s the reason why amplifiers tend to overheat when their power output meets very little resistance (low impedance) or when they attempt to deliver more power than they were designed to produce. Therefore, choosing a good car amplifier that can drive as less as 1-ohm load safely is of paramount importance.
To help you make an informed buying decision, we’ve compiled a list of the best 1 ohm stable amps in the market.
Best 1 Ohm Stable Amplifiers — Reviews
1. Rockford Fosgate T1500-1bdCP
If you’ve ever taken any interest in car audio gear, Rockford Fosgate is a brand you likely recognize, and for good reason. It’s one of the most authoritative brands in the car audio industry.
Rockford Fosgate has gained a solid reputation throughout the years. It’s been in business for quite a long time and has mastered the art of making top-notch products. Their car amplifiers are no exception.
The T1500-1bdCP is one of the best 1 ohm stable amps that Rockford Fosgate has to offer, all things considered. This beast was designed from the ground up with quality in mind. It sits at the top of the car audio food chain, with proven durability and proprietary technologies that deliver unmatched performance than most of the competition.
This mono channel amp sports a remarkably compact chassis and is fitted with heavy-duty, state-of-the-art components. It uses a super efficient Class BD design to pump out up to 1,500 watts at 4 ohms to your subwoofer. It can also safely and effectively drive a 1-ohm load and deliver 1,500 watts, so you can get massive bass out of a wide variety of system designs with minimal strain on your vehicle’s electrical system.
To keep it running cool, this amplifier uses a cast alloy heatsink and a dynamic thermal management system that distributes heat evenly across entire amplifier heatsink for higher efficiency and lower distortion, and at the same time eliminating overheating and thermal shut-downs so your music keeps going strong without interruption.
2. Rockford Fosgate Punch P1000X1BD
Last update on 2020-12-23 / Affiliate links / Images from Amazon Product Advertising API
If you’re looking to scale down from the T1500-1bdCP (listed above), Rockford Fosgate has plenty of other choices available. One of the more popular options available is the P1000X1BD.
This beast can deliver up to 1000 watts RMS at 1 ohm load, giving you plenty of clean power, so you can drive multiple subs without any trouble.
Rockford Fosgate P1000X1BD uses class BD amplifier design known for being more efficient than typical class A/B amps, and has lower distortion than typical class D designs.
The best thing with this amp is that it’s featured with CLEAN (Calibrated Level Eliminates Audible Noise) technology which allows you to match the source unit’s output to the amp’s gain, and optimize the amp’s output. When your receiver is perfectly matched to your amp, you’ll get maximum clean power from your Punch amp.
This beast is featured with a low pass filter and a subsonic filter. The former keeps the high notes away from your sub, whilst the latter helps you rein in runaway boom. There’s also the Punch bass boost which lets you add some of that boom back into the mix when it’s needed.
As far as heat management is concerned, this amplifier uses Rockford Fosgate’s Dynamic Thermal Management system to shunt heat away from internal components through the high-mass heatsink for greater power output, long term durability, and enhanced thermal stability.
Rockford Fosgate’s proprietary MEHSA cooling process on the other hand maximizes the heat transfer from the MOSFET devices to the heatsink, allowing the heat to dissipate quickly, so the transistors stay cooler and work better.
3. Skar Audio RP-4500.1D
While Skar Audio might be one of the younger companies in the car audio industry, It has been able to make a name for itself as a viable competitor.
Skar Audio has gained a solid reputation throughout the years it’s been in business. The company offers everything from speakers and subwoofers to amplifiers and accessories.
The RP-4500.1D is one of Skar Audio’s best 1 ohm stable amp designed for the most serious audiophiles seeking extreme levels of power output. It uses class D circuit design, MOSFET power supply, and advanced PCB board layout making it able to produce up to 4,500 watts RMS at a 1-ohm load.
With that insane power output, it’s safe to say that this beast if by far one of the most affordable high-grade 1 ohm amps on the market when priced per watt. It’ll literally exceed your expectations when you hear it breath life into your subwoofers.
This amplifier uses oversized 1/0-gauge power and ground terminals for maximum current flow and therefore higher power output. It comes with the built-in user control panel, featuring variable adjustment tunings for gain level, bass EQ (0-9 dB), subsonic filter (10-50 Hz), low-pass filter (35-250 Hz), and phase filter (0-180 Degrees).
Additionally, this amplifier comes with a remote subwoofer level control (bass knob) that you can mount in the dash allowing you to have full control over the bass from the driver’s seat.
In addition to all the features mentioned above, this amplifier features 4-way protection circuitry, which will give you the peace of mind knowing your amp is protected against electrical shortage, overheating, low voltage, and more.
4. Taramps MD 5000.1
Last update on 2021-01-05 / Affiliate links / Images from Amazon Product Advertising API
Taramps is a Brazilian company that’s been in business since 1999. It offers a wide selection of car amplifiers of different types, sizes, and performance.
While Taramp isn’t as well known as some brands, their MD 5000.1 monoblock amplifier seems to hit the sweet spot for a lot of guys, for good reason.
This amplifiers relies on class D circuitry design and can produce up to 5,000 watts RMS, running at a 1-ohm impedance. It boasts over 90dB signal to noise ratio and can operate on all frequencies in the right measure.
For consistent performance and long term reliability, Taramps MD 5000.1 amplifier is fitted with protection circuitry for thermal overload, high- and low supply voltage, short-circuit to output, and low impedance at output.
5. Audiopipe APCLE-15001D
Last update on 2021-01-05 / Affiliate links / Images from Amazon Product Advertising API
On a budget but still want that insane power output? Check out the Audiopipe APCLE-15001D monoblock amp. It’s not expensive, but you still get a lot for the money.
The amplifier at hand is one of the cheapest 1 ohm stable amplifiers in the market. For the price, the Audiopipe APCLE-15001D offers a great mix of power and quality.
This amplifier uses class D design and is fitted with beefy components making it stable down to 1 ohm. And to ensure long term performance and reliability, this amplifier is fitted with a high quality aluminum heat sink with cooling fins running along each side and grills embedded in the top plate, allowing heat to dissipate away from the transistors, thereby preventing unwanted heat related shutdowns.
To further enhance its reliability, this amp uses electronic protection circuitry to protect it against harmful short circuits, thermal overloads and overheating.
The Audiopipe APCLE-15001D amplifier is designed for compatibility with 16V vehicle electrical systems. Because it can accept a higher voltage than the standard 12V amplifier, this amp is able to produce much more power. Speaking of which, this Audiopipe amp can deliver up to 1,500 watts of power on continuous basis at 1-ohm impedance load.
6. Soundstream T1.6000DL
Soundstream is a brand we haven’t come across very much on our website. They’re a company known for their long tradition of making budget-friendly products. However, Soundstream occasionally has a reputation for hit-or-miss quality. So how does their T1.6000DL amplifier measure up?
Soundstream T1.6000DL is a class D monoblock amplifier fitted with MOSFET power supply and high-grade IRTM transistors. It’s capable of pumping up to 2,500 watts RMS at 1 ohm load.
Similarly to most 1 ohm amps we listed here, this Soundstream amplifier has direct short, thermal, and overload protection circuits. It comes with high level and low level RCA inputs, as well as a variable 12dB high- and low- pass filter, and subsonic crossovers. There’s also a 12dB bass boost. On top of everything else, this amplifier features a multi-color RGB LED illumination accent lighting.
Why Class D Amps are Preferable?
If you’ve ever taken any interest in car audio stuff, you’d know that amplifiers are classified according to their circuit design and the way their output stages are powered. Typically denoted by a letter or two (A, A/B, D, G, and H), each class has its own set of strengths and weaknesses.
Power dissipation (in the form of heat) and distortion of the audio signal are two key factors in determining an amp’s efficiency and fidelity.
In the table below, we summarized all the the primary pros and cons of each car amplifier class.
|Car Amplifier Class||Pros||Cons|
|Class A||Clean Output|
|Energy inefficient |
Generate a lot of heat
|Class B||Energy efficient|
Generate less heat
|Potential sound distortion at high frequencies|
|Class AB||Excellent high-frequency sound reproduction|
Energy efficient; low operating temperatures;
More efficient than class A
Less distortion than class B
|Slightly lower peak performance than class A amps |
Less efficient than class B
More distortion than class A
|Class D||Energy efficient|
Low operating temperatures
Superb low-frequency sound reproduction
|Very poor high-frequency sound reproduction + Distortion at high frequencies|
Class D amplifiers have become much popular because they represent the zenith of amplifier efficiency. They’re also smaller, lighter, and run cooler than the other classes of amplifiers with the same amount of power. That’s the reason why you should consider a class D amplifier if you’re looking for a powerhouse that’s stable at 1 ohm load.
On the debit side, class D amps tend to distort a bit due to their transistors being rapidly switched on and off at least twice during every signal cycle. However, this distortion occurs at frequencies above hearing, and is easily cut down using a low-pass filter.P.S: Class bd Amps are also quite good. They offer the best of both world; they’re more efficient than typical class AB and have lower distortion than class D designs.
What is Speaker Impedance?
Technically, speaker impedance (measured in ohms and symbolized as Ω) refers to the amount of resistance applied by an electric circuit to the flow of alternating current supplied by an amplifier. In other words, a speaker impedance affects how much current is drawn from the amplifier – The lower the impedance in ohms, the more power the speaker will draw from your amplifier.
To give you a visual explanation, think of your amplifier as a pump, the speakers/subs as a water hose and the audio signal as water flowing through the hose. The wider the hose, the less impedance there is for the water to flow through it. For that reason, a 4 ohm speaker is considered more “power hungry” and will tax your amplifier more than a 6 or 8 ohm speaker.
Although car audio manufacturers label the impedance of most car speakers at 4-ohms, the impedance of a speaker is constantly changing – It changes as the sound goes up and down in pitch (or frequency) and can vary greatly. Therefore, rather than stating a speaker impedance for every frequency, speaker manufacturers state the “nominal” impedance.
In the car audio industry, 4-ohms is the standard impedance. However, this standard is more of an average impedance for speakers and amps when driven within the part of the audio spectrum for which they are designed.
Why Does Speaker Impedance Matter?
As we’ve mentioned above, a speaker with a lower impedance lets more electrical signal through and allows it to flow more easily. In other words, the lower the impedance, the higher the load on the amp.
In a nutshell:
- Low impedance → more current → greater load → increased power
- High impedance → less current → smaller load → decreased power
It’s worth mentioning that unless you have a powerful brand name amplifier, lowering the impedance of your amp to increase its power output will put a lot of strain on your amplifier. If the latter isn’t designed to handle that strain, its fuse will blow, or its protection circuit will kick in and turn the amp off to prevent it from blowing out.
With all of that being said, the capability of an amplifier should be considered before applying a load to it (hooking up a speaker). Most amp manufacturers indicate an amp’s minimum impedance requirements. Almost all car amplifier on the market today can drive a 4-ohm load. Most amps can work with 2-ohm loads on each channel, but not in bridge mode. Some amplifiers are also stable at 1 ohm load.
What is The Difference Between 4Ω Vs 8Ω?
Now that you know what impedance is, the difference between 4 ohm, 8 ohm, and 16 ohm is pretty self explanatory, as it refers to the level of impedance. Each one of these settings offers a different impedance path for your speakers to connect to your amplifier.
Some modern car amplifiers are featured with an impedance switch on the back that you can use to easily switch between ohm settings. That’s not to say that you can only connect a 4 Ohm speaker to a 4 Ohm amplifier. Although an amplifier will perform at its best (maximum power to the speaker) when all impedance is matched evenly, an 8 ohm speaker can be connected to a 4 ohm amplifier as well, and vice versa. However, this should be taken with caution, as hooking a 4-ohm speaker up to an 8-ohm amplifier will overtax the latter, and you risk blowing your amp.
Parallel and Series Wiring
Parallel and series wiring are two terms that refer to two ways of routing the speaker wires to your amplifier to properly manage the overall impedance load.
Series wiring means that the impedance rating of each speaker is added together to find their total impedance. In other words, two 4-ohm speakers wired in series have a total impedance of 8 ohms.
Due to the way the speakers are wired in series wiring setup, if one of the speakers goes out, the others will as well.
Parallel wiring on the other hand means that the connection ends of each speaker are connected to the same things — plus to plus, and minus to minus. This way, only the failed speaker will stop producing sound, and will not affect the other speakers.
Adding additional speakers in parallel decreases the overall resistance of the circuit. As resistance drops, the current must increase according to Ohms Law.
So, each time a Speaker with the same impedance is added to the parallel circuit, the current draw on the amp increases. The amp must be able to handle this increase in current at the reduced resistance.
The total impedance of a couple of speakers wired in parallel (as long as their impedance is the same), is equal to their impedance value divided by the total number of speakers. For example: four 4-ohm speakers wired in parallel have a total impedance of 1 ohm.