Amplifiers help boost the audio signal, giving speakers enough power to cut out annoying background noises that you have to deal with while your drive. Hence, they help you hear more details in your music that would otherwise be obscured, whether it’s a groovy bass line or a backup vocal section that’s a bit silent in the mix.
If you’ve got a setup involving multiple speakers and/or subwoofers, then you’re going to need to purchase a multi-channel amp. This year, I set out to find the best 5 channel amp for cars. So I rounded up around 15 different units and put them to the test. I then picked out my top five from the bunch and wrote a review for each of them, which you can read below.
Amplifier Buying Guide
Buying an amplifier is not something that should be rushed. There are several factors you need to consider in order to ensure that the unit you buy fulfills your audio needs and perhaps more importantly, is compatible with your existing setup.
Hence, in this section, I’m going to be discussing a few of the technical details you should be paying attention to, including class, power output, impedance, speaker sensitivity, and frequency response. If you’re not too familiar with these terms, don’t worry. I’m going to be breaking each term down in a way that’s easy for anyone to understand.
Amplifiers mainly come in four different classes: A, B, A/B, and D. They’re differentiated by how they’re circuits work: particularly, how efficient they are. Efficiency, in the context of amplifiers, is a measure of how much Alternating Current (AC) a unit can supply while consuming the least amount of Direct Current (DC). Here’s a brief overview of how efficiency varies between different classes of amplifiers:
Class-A circuits are set up in such a way that it causes amplifiers to conduct electricity 100% of the time. This leads to a lot of electricity wastage because a relatively small amount of current will be drawn by speakers and the remaining will be converted to heat. As a result, the efficiency of Class A amplifiers is quite low at 30% and they tend to overheat with prolonged use.
One benefit of Class A amplifiers is that they offer the greatest signal purity.
Class B amplifiers only conduct electricity about half the time. This leads to less wastage, resulting in greater efficiency (70%). However, Class B amplifiers are quite notorious for adding distortion to the signal.
Class A/B circuits combine Class A and Class B chains. The latter contains biasing diodes that work on eliminating the characteristic distortion you get from Class B circuits. Hence, Class A/B amplifiers have the best of both worlds: the signal purity of Class A combined with the efficiency of Class B.
Class D units are the most efficient type of amplifier. This is largely due to the fact that when they’re off they’re 100% off. Their output transistors don’t hold back any electricity when you turn the amplifier off, meaning that there isn’t any lingering electricity that can be converted to heat. As a result, a lot of Class D amplifiers boast an efficiency of around 95%.
One thing you’ll notice when shopping for 5 channel amplifiers is that there are a lot of Class A/B – Class D hybrids in the market. These combine the signal purity of Class A/B with the efficiency of Class D.
Amplifiers provide speakers with more power, allowing your music to be loud enough to cut through any background noise. If you’ve got a particularly quiet pair of speakers, having a powerful amplifier will allow you to blast your music on a daily basis. However, there’s a limit to how much power your speakers can handle.
Before purchasing an amplifier you need to find out what your speaker’s power-handling rating is. Two specifications, in particular, will tell you what you need to know: RMS and peak power. RMS will indicate the maximum amount of power (in watts) that an amplifier can handle regularly without suffering heat damage. Peak power sets the absolute limit as to how much power (in watts) is safe to direct to an amplifier.
Similarly, amplifiers have RMS and peak power ratings but these refer to how much power they can direct to the speakers. Ideally, your speaker’s power-handling should be equal to or greater than the amplifier’s power output. Otherwise, you’ll always run the risk of blowing out your speakers whenever you crank up the volume.
How much power do you actually need to get loud? That’s what speaker sensitivity will tell you. Speaker sensitivity is a measure of how loud a speaker will get (in decibels) when it is driven by just one watt of power. For instance, if your speaker has a sensitivity rating of 85 dB, that tells you it’s got to get moderately loud with just one watt. Each additional watt will drive up the volume by 3dB.
The lower your speaker’s sensitivity is, the more power you’ll need. If you’ve got a fairly sensitive speaker (above 85db) and don’t plan on listening at ear-splitting volumes, an amplifier with around 25 watts RMS will be quite adequate.
Impedance measures the internal resistance (in ohms) of an amplifier. The greater the resistance, the harder an amplifier has to work setup send current to a speaker. Low impedance ratings will put less stress on the amplifier and allow it to deliver more current. However, lower is not always better. You need to think about your speaker’s power-handling thresholds again.
If your amplifier’s impedance is too low, then it might end up supplying more power than what your speaker can tolerate. Most 5 channel speakers give you the ability to toggle between 4 ohms and 2 ohms. The latter causes the amplifier to output twice as much power so you should only switch to 2 ohms if you’re confident that your speaker can handle it.
Some amplifiers can be paired up with both regular speakers and subwoofers while some are specifically designed to work with the latter only. The frequency response will tell you which is which. The audible frequency range for humans is between 20 Hz to 20,000 Hz so any amplifier that captures this entire range will work with both regular speakers and subs. Bass frequencies are in the range of 20Hz to 250Hz so if an amplifier’s frequency response is limited to this spectrum, that means they are meant to work with subwoofers.
While size isn’t a technical specification, it’s still an important factor to consider. The more compact an amplifier is, the more options you’ll have when it comes to mounting. In the list below, I’ve made sure to pick amplifiers that can at least fit under most car seats.
Best 5 Channel Amplifiers
Now that you’ve received a crash course on what to consider when buying an amplifier, let’s take a look at my top five 5-channel amplifiers for this year:
- 50 Watts x 4 + 200 Watts x 1 @ 4-Ohm / 75 Watt x 4 + 300 Watts x 1 @...
- Accepts High Level & RCA Level Input; Remote PLC (Punch Level Control)...
- Cast aluminum heatsink with Top Mount Controls
- 12dB/octave crossover. MOSFET power supply
- 4 Gauge power/ground connectors. The R600X5 produces up to 75 Watts...
Wide Frequency Response
The Rockford Fosgate R600X5’s frequency response spans between 20 Hz to 20 kHz, which is the entire audible range. Hence, this amplifier can work with both regular speakers and subwoofers.
At the default 4 ohm setting, the R600X5’s has an RMS of 50 watts from each of its 4 regular channels and 200 watts from its 5th subwoofer channel. This is more than adequate for the average person as it’ll allow you to blast your music really loudly on a regular basis. If you need even more power, simply switch to 2 ohms and its first four channels will now be able to output a maximum of 75 watts, with the 5th having its RMS bumped up to 300 watts. I can’t think of many situations where you’ll actually need this much power!
Thanks to the presence of a dedicated subwoofer channel, you don’t actually have to bridge the unit if you just need to connect one sub.
Cast Alumnium Heat Sink
Heat-sinks are components that draw heat away from an amplifier’s internal components, preventing any damage. Alumnium is especially good at absorbing heat which means that you can use the amplifier for hours on end without worrying about it overheating and malfunctioning.
Class A/B and Class D
The Rockford Fosgate R600X5’s circuits combine the features of Class A/B and Class D amplifiers. You get the signal purity of Class AB combined with the high efficiency of Class D. Hence, it’s the best of both worlds.
Punch EQ Control
If you feel like your speakers lack low-end, then you can simply engage the R600X5’s. It boosts the bass frequencies, making them sound deeper and more prominent in the mix. People who listen to a lot of electronic dance music may find this feature quite handy.
Sub Gain Control
The R600X5 includes a subwoofer gain control that helps you to clean up the signal sent through the subwoofer channel. With some tweaking, you’ll be able to dial out any distortion and have your bass sounding as crisp and detailed as possible.
- Compatible with both speakers and subwoofers
- Dedicated subwoofer channel
- Aluminium Heat Sink protects internal components from heat damage
- Contains both Class A/B and Class D technology
- Punch EQ Control adds more punch to the bass
- Independent sub gain control
- May be too much power for some speakers to handle
- RMS Power @ 4 Ohms: 60 Watts x 4 + 200 Watts x 1
- RMS Power @ 2 Ohms: 90 Watt x 4 + 300 Watts x 1
- 4-Way Built-in Protection Circuitry: Thermal, Voltage, Speaker, DC
- LPF/HPF/Bass Boost Controls
- 4 Gauge Power and Ground Input Terminals
The Skar Audio RP-600.5 is a full-range amplifier meaning it handles all frequencies between 20 Hz and 20 kHz. That means all the frequencies in your music, from sub-bass all the way up to upper-treble will be boosted.
At 4 ohms, the regular 4 channels of RP-600.5 is able to output 60 watts RMS while the dedicated subwoofer channel outputs 200 watts. Toggle the impedance down to 2 ohms and these values will change to 90 watts and 300 watts respectively. So if you like listening to music really loud really often, then this amplifier could consistently provide the amount of power you need.
Durable Construction and Heat-Dissipation
The Skar Audio RP-600.5 features a thick all-metal outer shell which means that it can certainly take some damage. So if you’re someone who goes off-roading a lot, traversing through jagged and bumpy terrains, this amplifier might be well suited for you. In addition, this amplifier contains heat sinks which will keep the internal environment cool regardless of how long you use it for.
Class A/B and D Hybrid Circuits
Just like the Rockford Fosgate R600X5, the Skar Audio RP-600.5’s circuits combine Class A/B and Class D elements to create a high-quality pure signal path while making sure that power wastage is at the absolute minimum.
Variable High- and Low-Pass Filters
High and low-pass filters are essentially EQ tools. They set a cutoff frequency so that frequencies either lower or higher in pitch will be blocked. High-pass filters block frequencies lower than the cutoff frequency and let others pass. Low-pass filters do the exact opposite.
The RP-600.5 feature variable filters, which means that you can decide what the cutoff frequency is. The low-pass filter is adjustable between 50Hz – 500Hz while the low-pass filter’s range spans much wider between 20 Hz to 5000 Hz.
Variable Sub Sonic Filter
In addition to the above, the RP-600.5 also offers a subsonic filter that lets you shape the sub-bass region (10Hz – 50Hz). If you’ve got speakers that have trouble handling frequencies this low, then you can set the cut off quite high and prevent distortion in the low-end.
Bass EQ Switch
This works similarly to the Punch EQ found in the Rockford Fosgate R600X5. It allows you to boost the low end by up to 12 dB.
- Full-range amplifier
- Maximum 90 watts and 300 watts RMS for speakers and subwoofers respectively
- Solid construction
- Built-in heat sinks
- Class A/B and D Hybrid Circuits
- Variable high- low- and subsonic filters
- Bass Eq Switch
- I can’t think of any
- 2,000 Watts Max Power
- Block Terminal
- ariable High Pass and Low Pass Filters
- Equipped with A/B-SW Input Select
Compatible with Speakers and Subwoofers
The GM-D9705 is yet another 5-channel amplifier with a frequency response ranging from 20 Hz to 20 kHz. Hence, it can be paired with both regular speakers and subwoofers as well.
The four regular channels of the GM-D9705 have a maximum RMS of 75 watts at 4 ohms impedance, which was more than enough power to have my ears ringing after just fifteen minutes of blasting my music inside the car. The 5th channel, which is a dedicated subwoofer output, is rated at 350 watts. Hence, this is an amplifier that’ll pair extremely well with a high-powered audio set up.
When switched to 2 ohms, the RMS increases to 100 watts and 600 watts in the regular and subwoofer channels respectively.
Class D Circuit
The Pioneer GM-D9705 is a class D amplifier, so you can rest assured that it will be highly efficient. Hence, there will be less strain on your car’s battery.
Variable Low-Pass Filter
The GM-D9705’s low-pass filter allows you to set the cut-off frequency between 40 Hz to 240 Hz, which covers the entire bass spectrum. If you set it closer to 240 Hz, this low-pass filter can help cut out unwanted distortion from the upper-bass frequencies.
If you feel like your speaker’s low end could use a little bit more ‘punch’ then the GM-D9705’s bass boost can help. The boost focuses specifically on signals at the 50 Hz frequency (which is in the sub-bass range) and allows you to pump up the volume of these signals by up to 18 dB. Hence, it’ll help make those low, thumping beats in electronic dance music louder and more prominent in the mix.
With a width of 12.4 inches and a depth of 7.87 inches, this amplifier is a little bit on the bulky side. However, it’ll still fit under the seat of any vehicle.
- Wide frequency response
- Variable low-pass filter helps to clean up distortion in the upper-bass region
- Bass boost gives the low-end more ‘punch’
- A bit bulky
- Power - 300 watts max x 4 @2-Ohms plus 5th channel 600 watts max x 1...
- Class A/B Topology - Class ‘A’ amplifiers have enormous amount of...
- Full Range - With a Full Range amplifier you not only have the option...
- Mosfet Power Supply - A MOSFET is an electrical switch that allows the...
- Low & High Level Inputs - A low level (RCA) input is measured in...
Like all the other amplifiers on this list, the Planet Audio AC1800.5 is a full-range unit, handling all frequencies from bass to treble. Hence, you don’t need a couple of amplifiers to power your speakers and subwoofers.
When set to the default impedance of 4 ohms, the Planet Audio AC1800.5 outputs a maximum of 150 watts through its regular channels plus 300 watts through its dedicated subwoofer channel. When set to 2 ohms, the RMS doubles for each type of channel, making the outputs 300 watts and 600 watts respectively.
This amplifier features nickel-plated contacts, chrome-plated connections, and heavy-duty set-screw terminals, all of which makes it incredibly durable. In addition to these, the amplifier also features a 3-way System Protection Circuit which protects it from current overload, overheating and short-circuiting.
The Planet Audio AC1800.5 features a heavy-duty aluminum heat sink which is designed to draw heat away from its internal components.
Variable Bass Boost, High and Low-Pass Filters
The featured boost lets you increase the volume of just the low-end frequencies by up to 18dB. In addition, you get high and low-pass filters that let you set the cut off frequencies between 50 Hz to 500 Hz and 45 Hz to 90 Hz respectively.
- Highest RMS out of all the amplifiers on this list
- Solid build quality
- Comes with a variable bass boost and high- and low-pass filters.
- May be too much power for most speakers to handle.
- Sophisticated unit will withstand numerous elements it encounters...
- Stainless steel hardware throughout to prevent corrosion, short...
- High-speed MOSFET switching power
- Nickel-plated wire terminals and RCA connectors ensure maximum signal...
- Protection: Thermal, DC offset, reverse DC voltage and short circuit...
Wide Frequency Response
The Polk Audio PA D5000.5 has a frequency response ranging between 20 Hz to 20 kHz, which means that you can connect it to both speakers and subwoofers. Provided that your speakers are great at handling all frequencies, you’ll never miss out on any details in the music once it is amplified.
Tons Of Power
At the default 4 ohm setting, the PA D5000.5’s regular channels will have an RMS rating of 70 watts while the dedicated subwoofer output’s RMS will be 200 watts. When switched to 2 ohms, the RMS increases to 100 watts and 400 watts respectively. Hence, regardless of whether you’ve got highly sensitive speakers, you’ll be able to get really loud with this amplifier.
Stainless Steel Hardware
The Polk Audio PA D5000.5’s stainless steel hardware makes it corrosion-resistant and protects against short circuit issues. Hence, if you go on a lot of outdoor adventures on your vehicle or you live in an area where there’s lots of humidity, this amplifier might be well suited for you.
A Variety Of Filters
The Polk Audio PA D5000.5 offers a number of filters that can help you shape your tone. For the front channels in the amplifier, you get a variable gain control, a high-pass filter (40 Hz – 400 Hz) and a low-pass filter (80 – 40,000 Hz). The gain control allows you to ‘clean up’ the amplifier signal by reducing the amount of distortion present. With a little bit of tweaking, you can have the signal sounding as pure as possible.
The rear channels also have a variable gain and a high-pass filter (40 Hz – 4000 Hz) but lack a low-pass filter. Finally, the dedicated subwoofer channel features a variable gain, low-pass filter (40 Hz – 220 Hz) and a subsonic filter.
Remote Subwoofer Control
The Polk Audio PA D5000.5 includes a wired remote that allows you to control the subwoofer level from your seat. This is quite handy if you’ve got the amplifier placed in a hard-to-reach location.
- Compatible with both speakers and subwoofers
- Power output is very high even at the default impedance setting
- Contains short-circuit protection
- Comes with variable gain control, high- and low-pass filters and a Subsonic filter
- Comes with a remote subwoofer control
- Only compatible with very powerful speakers
The Best Overall 5-Channel Amplifier
If I had to choose just my overall favourite from the above top five, which one would it be? That’s not an easy question to answer, considering that each one of these amplifiers is nothing short of excellent. After a ton of deliberation, however, I chose the Skar Audio RP-600.5
My reasons were simple: It offered all the power I needed (nothing more; nothing less), featured a solid build, combined Class A/B and D circuitry and offered adjustable tone-shaping filters.
Frequently Asked Questions
Why Should I Go For A 5-Channel Amplifier?
5 channel amplifiers are appropriate if you have three or more speakers plus a subwoofer in your set up. Most 5 channel amplifiers have a dedicated subwoofer channel so you don’t need to bridge the unit in order to connect a sub.
Do Bigger Amps Sound Better?
It depends on how the larger space is utilized by the manufacturer. For instance, if a larger transformer and more heat sinks are installed in bigger amps, then it may have a tiny impact on the overall sound quality. However other factors like the quality of the components have a bigger impact.
How Many Speakers Can A 5 Channel Amp Power?
The most common configuration is four speakers and one subwoofer. However, with bridging you can change up the ratio of speakers to subwoofers by connecting more of the latter.
Can I Install A 5-Channel Amplifier Even Though I Have Less Than 4 Speakers In My Car Audio System?
Yes. If you have only three speakers, you can leave one channel unused and it won’t impact the amplifier in any way.
Which Are The Best Places To Install A 5-Channel Amp?
The two commonest storage places for amplifiers are the trunk and space under car seats. If your amplifier is too bulky, then the former might be your only option.
The products featured on this page were last updated on 2020-02-22 at 22:40 /. Affiliate links / Images from Amazon Product Advertising API.