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MB Quart ONX4.125

1000W RMS ONYX Series 4-Channel Amplifier (ONX-4.125)

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MB Quart ONX4.125

1000W RMS ONYX Series 4-Channel Amplifier (ONX-4.125)

$129.99

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Success is a Measurement of Quality and Power

The success of any car audio amplifier depends on system quality and construction, ease of installation and configuration, and sound enhancing features. MB Quart engineers built the all new Onyx series amplifiers from the ground up to be an affordable amplifier with the audiophile and performance enthusiast in mind. This series is composed of value-packed class A/B amplifiers that boast affordability without sacrifice to power or quality. All Onyx Amplifiers come clothed in a beautiful new age piano black finish which accents interiors and brings a whole new level of sophistication to swallow. To match, the line of Onyx Speakers shows off the same piano black finish applied to their polypropylene cone woofers. It’s a perfect match every time.

Speaking of features, Onyx amplifiers bring the full tuning spectrum to your fingertips with variable high-pass, low-pass and subsonic filters built-in. To increase endurance, MB Quart designed Onyx amplifiers with military grade printed circuit boards and built-in system diagnostics that keep these amps running strong. High speed MOSFET output devices are used in the power supply to give you the best watts-per-dollar ratio. It’s not hard to see how success has been written all over these amplifiers, though with a piano finish that looks that good, we know you will be staring.

  • ONYX Series 4-Channel Class A/B Car Amplifier
  • RMS Power Rating:
    • 4 ohms: 125 watts x 4 chan.
    • 2 ohms: 250 watts x 4 chan.
    • Bridged, 4 ohms: 500 watts x 2 chan.
  • CEA-2006 compliant amplifier
  • Peak Power Handling: 2000 Watts
  • PWM (Pulse Width Modulated) MOSFET power supply
  • LED power (green) and protect (red) indicators
  • Variable Bass Boost (0 to +12 dB bass boost at 45 Hz
  • 4/3/2 channel operation
  • Unbalanced RCA input jack
  • Preamp RCA outputs to daisy chain multiple amps
  • 4-Way System Protection circuitry (DC, thermal, overload, and speaker short protection)
  • Piano black gloss finish with illuminated logo
  • Heavy duty aluminum alloy convection heatsink for superb heat dissipation
  • Silver-plated RCA level inputs
  • Silver-plated screw terminals
  • Input sensitivity:
    • Low level: 200mV-6V
  • Variable high-pass filter (60-13,000 Hz, 24 dB/octave)
  • Variable low-pass filter (30-250 Hz, 24 dB/octave)
  • Damping factor: >180
  • Frequency response: 10-45,000 Hz
  • Dimensions: 20"L x 9"W x 2-1/2"H
  • 4-gauge power and ground wiring is required for installation. Contact us for information regarding a discount on select amplifier kits when purchased together with this amplifier.
  • Authorized Internet Dealer
  • 1-year Manufacturer's warranty

Power Specifications - Full Range Channels

RMS Power @ 4 ohms

The RMS power rating is the measure of continuous power that an amplifier can output, or a speaker can handle. It is the most accurate depiction of real, continuous power that the industry has so far.

If the final impedance of your speakers or subwoofers equals 4 ohms, this is how much power this amplifier will supply at that ohm level. The higher the RMS wattage, the more clean and loud your music will sound.

125 watts x 4 channels
RMS Power @ 2 ohms

The RMS power rating is the measure of continuous power that an amplifier can output, or a speaker can handle. It is the most accurate depiction of real, continuous power that the industry has so far.

If the final impedance of your speakers or subwoofers equals 2 ohms, this is how much power this amplifier will supply at that ohm level. The higher the RMS wattage, the more clean and loud your music will sound.

250 watts x 4 channels
Bridged RMS Power

Bridging refers to combining two channels on an amplifier to create one channel with double the voltage and an increased power output. A 2-channel amplifier will bridge down to 1-channel and a 4-channel amplifier can bridge to create 2-channels. An amplifier is most commonly bridged to drive a subwoofer.

Remember, once you bridge two channels down to one its final impedance will be 4 ohms unless otherwise specified. This rating lists the RMS power created once an amplifier is bridged.

500 watts x 2 channels

Power Specifications - Full Range Channels

Peak Power @ 4 ohms
This form of power rating refers to the maximum amount of power an electronic device can handle or output in an instant without damage occurring. Often times this maximum is achieved during a brief musical burst, such as a drum accent, or low bass hit.

Some manufacturers display peak power ratings on the face of their products to increase the appeal to consumers. The RMS power rating is more accurate, and we recommend using it for product comparison. However, some manufacture's do not provide an RMS figure and therefore one cannot be advertised.

Peak Power @ 2 ohms
This form of power rating refers to the maximum amount of power an electronic device can handle or output in an instant without damage occurring. Often times this maximum is achieved during a brief musical burst, such as a drum accent, or low bass hit.

Some manufacturers display peak power ratings on the face of their products to increase the appeal to consumers. The RMS power rating is more accurate, and we recommend using it for product comparison. However, some manufacture's do not provide an RMS figure and therefore one cannot be advertised.

Peak Power @ 1 ohm
This form of power rating refers to the maximum amount of power an electronic device can handle or output in an instant without damage occurring. Often times this maximum is achieved during a brief musical burst, such as a drum accent, or low bass hit.

Some manufacturers display peak power ratings on the face of their products to increase the appeal to consumers. The RMS power rating is more accurate, and we recommend using it for product comparison. However, some manufacture's do not provide an RMS figure and therefore one cannot be advertised.

Bridged Peak/Max Power

Bridging refers to combining two channels on an amplifier to create one channel with double the voltage and an increased power output. A 2-channel amplifier will bridge down to 1-channel and a 4-channel amplifier can bridge to create 2-channels. An amplifier is most commonly bridged to drive a subwoofer.

Remember, once you bridge two channels down to one its final impedance will be 4 ohms unless otherwise specified. This rating lists the Peak/Max power created once an amplifier is bridged.

Power Specifications - Subwoofer Channel

Peak Power @ 4 ohm
This form of power rating refers to the maximum amount of power an electronic device can handle or output in an instant without damage occurring. Often times this maximum is achieved during a brief musical burst, such as a drum accent, or low bass hit.

Some manufacturers display peak power ratings on the face of their products to increase the appeal to consumers. The RMS power rating is more accurate, and we recommend using it for product comparison. However, some manufacture's do not provide an RMS figure and therefore one cannot be advertised.

Peak Power @ 2 ohms
This form of power rating refers to the maximum amount of power an electronic device can handle or output in an instant without damage occurring. Often times this maximum is achieved during a brief musical burst, such as a drum accent, or low bass hit.

Some manufacturers display peak power ratings on the face of their products to increase the appeal to consumers. The RMS power rating is more accurate, and we recommend using it for product comparison. However, some manufacture's do not provide an RMS figure and therefore one cannot be advertised.

Peak Power @ 1 ohm
This form of power rating refers to the maximum amount of power an electronic device can handle or output in an instant without damage occurring. Often times this maximum is achieved during a brief musical burst, such as a drum accent, or low bass hit.

Some manufacturers display peak power ratings on the face of their products to increase the appeal to consumers. The RMS power rating is more accurate, and we recommend using it for product comparison. However, some manufacture's do not provide an RMS figure and therefore one cannot be advertised.

Amplifier Specifications

Amplifier Series
This designates the series of the amplifier. Many amps are available in a litany of different wattage and channel configurations, but maintain consistent features throughout the product line.
Amplifier Class

An amplifier increases the power of the signal being fed to it by taking energy from its power supply and matching the signal but increasing its amplitude. Amplifiers use many different methods for converting these electrical signals and have been categorized into classes.

Class A/B: Greater than 50% of the input signal is amplified while the other percentage is “off”. These amplifiers have a small amount of current flowing through the output transistors all the time which almost eliminates crossover distortion. Class A/B has great sound quality but is not as efficient as class D. These amps are most commonly used to drive speakers.

Class D: Also known as switching amplifiers, class D amps have output transistors that are completely turned “on” or “off”. This means that when the transistors are on, there is almost no voltage across them but when they are off there is significant voltage but no current flowing through it which makes these amplifiers very efficient at the cost of sound quality. These amps are most commonly used to drive subwoofers.

Other Classes: You may see classes such as GH, bD, X, FD, etc. by some manufactures. These amplifiers tend to be either class A/B, D or a hybrid of the two but with improvements to their designs that can make them more efficient or offer better sound quality.

AB
Number of Channels
Each channel on an amplifier will power one speaker using a positive and negative cable. There are various types of amplifiers, each designed to power a certain number of speakers. Monoblock amplifiers, also known as single channel, are designed to power one or more subwoofers. These amplifiers often have very high power ratings. On the other hand, multi-channel amplifiers power multiple speakers, usually at lower power ratings. 2-Channel and 4-Channel amplifiers can power car speakers or low powered subwoofers. Occasionally you might see a 5 or 6-channel amplifier that can power speakers and subwoofers at the same time. The most common setup is a monoblock amp to run subwoofers and a 4-channel amp to run door speakers. Check out our Knowledge Base for more information.
4
Total Peak Power Output
The total peak power output is measured as the wattage per channel multiplied by the number of channels, and is calculated at the lowest level of operating impedance.

It is measured during a brief musical burst, such as a sudden drum accent. Some manufacturers display peak power ratings on the face of their products to increase the appeal.

The RMS power rating is more accurate, and we recommend using it for product comparison.

2000 watts
Total RMS Power Output
Total RMS power is measured by multiplying RMS power per channel by the number of channels, and is calculated at the lowest level of operating impedance.

RMS power is the amount of continuous power, measured in watts, that an amplifier produces is called RMS power. The higher the RMS figure, the louder and cleaner your music sounds.

The RMS output figure is much more accurate than the peak rating when comparing products.

1000 watts
Maximum Input Gauge Size
This is the largest gauge wire that will fit into the power and ground terminals of this device. The lower the gauge number, the thicker the wire is. For example, a 4 gauge wire is thicker than an 8 gauge wire and thus has higher current carrying capacity. Always do your best to get this size wire to reduce the risk of damage to your components.
4 AWG
Minimum Impedance Unbridged
The lowest impedance the amplifier will handle when it is not bridged.
2 ohms
Minimum Impedance Bridged
The lowest impedance the amplifier will handle when it is bridged.
4 ohms
THD at Rated RMS Power
The amount of change in harmonic content of the signal as it is amplified. A lower figure indicates less change and a more accurate amp. THD below 0.10% is inaudible.
0.05%
Speaker Level Inputs
Speaker level inputs are commonly referred to as high-level inputs and vice versa. This input type allows you to get your audio signal directly from the speaker wire in your vehicle, instead of using RCA cables. The advantage of this is factory integration, as most stock radios do not have RCA outputs to run amplifiers.
No
Preamp Outputs
Many amplifiers are equipped with RCA preamp outputs which pass the original music signal from the source to additional amplifiers. This is known as daisy chaining because the source connects to the first amp, and the first amp connects to the second amp, etc. The advantage to daisy chaining is you only need one 2-channel RCA cable to transfer the signal from the head-unit to the amplifier, and then one additional cable for each amp being daisy chained.
1 pair
Built-in Crossover

A crossover is a type of filtering system that permits only certain frequencies to play. A Low-Pass (LP) crossover allows only frequencies below its setting to get through which is good in the case of some subwoofers. A High-Pass(HP) filter allows frequencies above its setting to pass through, this is normally used on speakers.

When a crossover is set to FULL it means no filtering is added and the full frequency spectrum is allowed through the amplifier. Filtering is important because feeding a speaker frequencies it cannot reproduce effectively creates distortion.

Low-Pass (LP)
High-Pass (HP)
Full (AP)
High-Pass Crossover Frequency
The high-pass crossover frequency can be a fixed crossover point or a variable crossover range. A variable high-pass crossover allows you to select a specific crossover point which allows frequencies above the set crossover point to pass, while making frequencies below the set point gently or harshly roll-off, depending on the steepness of the slope.

The steepness of the roll-off slope is measured in dB/octave and refers to the rate of attenuation (lowering of volume) outside their pass bands.

60 - 13,000 Hz
Low-Pass Crossover Frequency
The low-pass crossover frequency is typically used for subwoofers. It can be a fixed crossover point or a variable crossover range. A variable low-pass crossover allows you to select a specific crossover point which allows frequencies below the set crossover point to pass, while making frequencies above the set point gently or harshly roll-off, depending on the steepness of the slope.

The steepness of the roll-off slope is measured in dB/octave and refers to the rate of attenuation (lowering of volume) outside their pass bands.

30 - 250 Hz
Signal-to-Noise Ratio
This spec compares the strength of the signal to the level of background noise. A higher value indicates less background noise.
>92 dB
Channel Separation
Also referred to as crosstalk. The amount of interference on one stereo channel caused by the leaking of the other stereo channel. The higher the rating in decibels (dB), the better the Channel Separation.
>80 dB
Bass Boost
The objective of the bass boost is to get more kick out of your subwoofer. It is a circuit that emphasizes the lower frequencies at a given point. The bass boost should always be set first before setting the gain. This feature is known for destroying subwoofers and is commonly used incorrectly, so be cautious.
0 - 12 dB
Bass/Gain Remote
If the amp comes with a bass/gain remote you will be able to control the level of your bass from your dashboard. Typically bass remotes also include a 16-20 ft. wire for installation.
No
Fan Cooled
A great feature to have if an amp generates a large amount of heat. Cooling fans can help regulate the temperature to prevent the amp from overheating (burning).
No
Fuse Rating
The amperage and the number of fuse(s) an amp requires.
40A x 3 
CEA-2006 Compliant
Amplifiers that have been tested to meet specific standards. When a car amplifier meets these standards, you can be sure that it will be able to produce the amount of power specified by the official CEA-2006 rating. Usually, these rating consist of the following items:
  • RMS Power
  • Signal-to-Noise Ratio

This rating applies to both external car amplifiers, as well as the amplifiers inside of in-dash stereos.

Yes
Sonic Certified Amplifier
Sonic Certified amplifiers have been tested by the experts at Sonic Electronix to meet or exceed the wattage ratings provided by the manufacturer. If this is marked as Yes, then you can trust the wattage ratings. If marked as No, then we have tested the amplifier and it did not meet the advertised wattage ratings. If marked as Not Tested, then the Sonic Electronix experts have not yet been able to test the amp.
Amp Bluetooth Connectivity
This feature will tell you if the amplifier has the capability to connect to a Bluetooth device.
Hi-Res Audio Compatible
This feature refers to if the product is capable of Hi-Res Audio (HRA) playback.

Specials with this Item

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Warranty and Return Policy

Parts Warranty Duration
1 year
Labor Warranty Duration
1 year
Warranty Provider
Manufacturer

Summary of Customer Ratings & Reviews

Rating Distribution

5 Star
74%
4 Star
15%
3 Star
0%
2 Star
4%
1 Star
7%

Average Attribution Rating

Durability
4.3
Value
4.6
Features
4.4
Design
4.3
Usability
4.7
Sean

Eagle Lake, FL

Overall
Durability
Value
Features
Design
Usability
AMAZING!!

May 18, 2011

The other reviews are correct. This amp is awesome and powerful and a steal for the price. I also owned the DSC4125 and I didn't notice as big of a difference as they are but it is a extremely powerful amp.

35 of 41 found this helpful

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paul

las vegas, nv

Overall
Durability
Value
Features
Design
Usability
why discontinue all the good stuff?!!!

January 21, 2015

I am still using this amp years later without fail, baaaaangin!!

33 of 39 found this helpful

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MadGuitar07

HARTFORD, CT

Overall
Durability
Value
Features
Design
Usability
Best Voice amp i EVER!!!! HAD

November 23, 2011

This 4 channel amp give off mad!!! Power, Its the best voice amp i ever had, its Kinda Big, but its well worth it in the end. Does not get hot, it fact i wonder if it ever will because i play it so hard.
Get this amp you wont be disappointed.

30 of 35 found this helpful

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Robert

Alton, TX

Overall
Durability
Value
Features
Design
Usability
Great!!!!

November 27, 2012

I connected this amp, never imagined the power and the sound quality you don't even need to adjust amp level too high. I recommend this product you would not regret it having one.

29 of 35 found this helpful

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SilveradoZ71

Columbia, MO

Overall
Durability
Value
Features
Design
Usability
Decent Power Per Dollar

May 19, 2012

Got this amp despite knowing it is not known for quality, because of the reviews. First, are a few notes. It claims it has three 40 amp fuses. However the picture and amp I got have three 35 amp fuses. The manual also recommends 2 gauge wire, although it will only accept as large as 4 gauge (that's what I ran). Also, the plastic on the housing feels cheap, although it's still functional. I'm only using two channels to power a pair of Hertz HSK 165 speakers. Both are rated at 125w rms so it seemed perfect. They get very loud and are very clear, and together overpower a single Alpine Type-R (on a seperate amp). I have no other full range amps to compare to, but the signal is fairly clear. This amp gets the speakers VERY loud and the gain is still fairly low, and I have yet to hear it clip. I temporarily hooked up another sub to make sure all channels worked and at least at that time they all did. I'd love to hook two Type-R's up to it to hear what it would do to for bass, but the budget has yet to allow it. Overall, it's a good amp for the money, it has a lot of features, but don't expect first rate quality.

29 of 35 found this helpful

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Dubbin

Sumter, SC

Overall
Durability
Value
Features
Design
Usability
Surprising

May 3, 2012

Surprised with the kick for the price. Kinda big, but definitely thinking about purchasing another.

29 of 35 found this helpful

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kyle

ogden, UT

Overall
Durability
Value
Features
Design
Usability
Great amp

March 22, 2012

Installed now for a few days and its really surprised me, very loud.

29 of 35 found this helpful

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Ben

Fort Walton Beach, FL

Overall
Durability
Value
Features
Design
Usability
Times a changing

June 20, 2011

I have always considered the old school US amps to be uncomparable in sound. I was wrong the new manufacturing of today's technology far out weighs the past. The amp does the job extremely well, Doesn't get hot and the dynamic headroom is as good or undetectable against my a/d/s of the past that I paid 10 times more than this. Time to upgrade everything. This amp is worth every dollar.

29 of 35 found this helpful

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Shane

Ks

Overall
Durability
Value
Features
Design
Usability
Defective

March 11, 2012

Bought this amp to power some Polk db6501's and CDT full range speakers and it was defective. Only channels 3&4 work on this amp when used as a 4 channel setup, however channels 1&2 work if you are using it as a 2 channel setup. Waste of time, energy, money, etc. I do not recommend this amplifier.

26 of 30 found this helpful

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Eric

Thomasville, Ga

Overall
Durability
Value
Features
Design
Usability
Good amp for price

January 17, 2012

I bought this amp to use for a new set of components I purchased at the same time a few months back and it is pretty rad. This amp is easy to use, had a very sleek and nice design, and is in unbeatable for the price. It pushes what it says and is very efficient. I use it to push a set of Rockford T2 components and some pioneers (temporary) and it does amazing. It has popped a couple tweeters sadly but at least I know it's powerful. Overall I would recommend this to anyone on a budget and looking for some power. I will most likely purchase another for my new rebuild.

28 of 34 found this helpful

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chris

spring, TX

Overall
Durability
Value
Features
Design
Usability
Best 4 channel ive ever used!

November 7, 2011

Mb quarts onyx 4.125 amp is so amazing! Im running 6 rockford 6 1/2s and 10 tweets on this amp and it handles them like nothing! The amp gets warm but never hot! It even comes with a cleaning cloth to wipe it down! If ur looking for a 4 channel amp thats gonna be a goood buy and perform awsome buy this one I promise you wont regret it!

28 of 34 found this helpful

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eric

Lemont, IL

Overall
Durability
Value
Features
Design
Usability
very large but also very strong

November 14, 2012

theres nothing special about this amplifier except that its very strong. it is very large for the wattage.

28 of 35 found this helpful

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josh

olive branch MS

Overall
Durability
Value
Features
Design
Usability
best dollar per watt that produces clean power

August 14, 2012

I love this amp, the quality of the sound is great, it actually produces the power it claims, and doesn't run hot, I'd recommend it to anyone, pushes my crescendo pwxs excellently.
Only con is the amps size, it easily dwarfs my aq 2200

26 of 32 found this helpful

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Mannu

Country Club Hills, IL

Overall
Durability
Value
Features
Design
Usability
Great Amp

August 2, 2012

I have this amp powering my two 15 in subs and this amp is way under rated it actually puts out 850w RMS I tested this with a digital multi meter and test tones to prove it. I have had this amp for about 2 months and have not had a single problem with it and its extremely clear at every frequency.

26 of 32 found this helpful

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Jean

Sacramento, CA

Overall
Durability
Value
Features
Design
Usability
Impressive amp for the cost!

November 30, 2011

For the cost I don't think you'll be able to find another amp with these features and power. Currently I am using this to power an older set of two ohm Image Dynamics Chameleon CXS52 components and a single Polk db 12" sub (probably the weakest link in the system). Headunit is a CDA-105, and set of 6ch stinger flat rca cables for expandability.

No turn on/off thump, no noise that I can hear, and it can get plenty loud while still sounding very clean. I love having extra power and headroom, so no chance in clipping the speakers if you set it up right and want to play it loud from time to time.

I give it 4 out 5, only because the case could be a little better vs parts of it being plastic.

26 of 32 found this helpful

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Lkncomputer

Huntersville NC

Overall
Durability
Value
Features
Design
Usability
owner

November 9, 2012

I have been running this amp for a good wile now and it has proven to be up to any task i ask of it, driving 2 ohms or 4 x 4 nothing stops this amp and it does it with style and awesome audio too, power is right on par with my meters right to the end of its range heat was their but cool down was fast, well done MB Quart!!!

25 of 31 found this helpful

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YOSLO

San Luis Obispo

Overall
Durability
Value
Features
Design
Usability
Crazy!

May 23, 2011

How in the world is this a 165 bucks?!?! I have owned a LOT of amps, and this one is hands down the best bang for your buck I have ever seen. Clean, Loud, and Purdy! Its a big amp so be prepared, but it has an awesome glossy black finish and plenty of controls. I have it pushing a pair of Polk MM6501s and this thing pushes them perfectly. Subs are in the mail, but I can only imagine that this thing will just pound.

I almost missed this amp when searching for a new one and I am so glad that I found it. There is nothing even remotely close in price that is even almost close in specs.

Definitely would buy again.

24 of 29 found this helpful

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muss

Australia

Overall
Durability
Value
Features
Design
Usability
great value

February 20, 2011

running 4 JBL P963 6x9's at 2 ohms and it does not break a sweat

24 of 30 found this helpful

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LoudNLow

Tullahoma, TN

Overall
Durability
Value
Features
Design
Usability
Great Product!

November 2, 2011

If you are looking for an amp thats cheap (price), puts out alot of power and sounds good this is the amp for you! I am using this amp to power 4 sets of Image Dynamics components and it does it with ease and sounds amazing! I would recommend this amp to anyone looking for a 4 channel.

23 of 29 found this helpful

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baceman

pulaski, VA

Overall
Durability
Value
Features
Design
Usability
What a Beast

September 22, 2011

I ordered this amp after purchasing the ONX4.80 hoping that this amp would be like 2 old school phoenix Gold M-100s strapped together and it is just that! I got it running my whole system right now 125x2 to my highs and 500x1 to 4-12" in a wall in my 95 Geo Metro. I have 13 trophies for SPL comps guys, so I know amps and have used many different brands and i will say I can't wait to buy a couple of ONX1500.1 for my vehicles. The ONX 4.60 is the same size as the ONX1000.1 and the ONX4.80 is the same size as the ONX1500.1 for those who like to match things up. This amp is VERY powerful and is definately more than enough for the average listener...as a matter of fact if you are an average listener then this amp is not for you. Go with a smaller amp. This amp is for someone who is very serious about their cars system. I am going to be using this amp for highs and midbass once I buy the ONX1500.1 or a pair of ONX1000.1s. I still can't believe that this amp is only $179! Where were you back in the mid 90's? BTW, I used to own 4 Phoenix Gold M-100's 3 M-50's and an M-25. I also used to own a whole slew of Memphis amps any where from 50x2, 75x4,150x2, 1000D etc. These MB Quart amps fall right in line with the power and sound quality of those amps. You won't be disappointed.

22 of 27 found this helpful

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christian

Orlando, FL

Overall
Durability
Value
Features
Design
Usability
KUDOS to Sonicelectronix

January 6, 2011

First off I ordered this amp on a Monday Morning at 12am, by Wednesday,1pm, the amp was @ my front door in Florida!!!!! I intially purchased this amp for my front stage for all the controls-The amp looks nice, and even comes w/a red mb quart cloth for cleaning-now im an old skool Phoenix Gold guy, so I am usually very critical of SQ-I played w/this amp active, passive on my front stage,bridged to subs& now am going to use this amp bridged mono to my 2 dvc2ohm subs, thats how it sounds best to me, and the price point was worth it, as a front stage amp the seperation was excellent and clean(better sounding passive, than active, which surprised me)-personally class a/b amps still have a little more "punch, quicker response" to my ear than class D, for the 200 bux and free shipping, its worth the purchase!!!

22 of 27 found this helpful

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nismos14

Edison

Overall
Durability
Value
Features
Design
Usability
Even better than the DSC4125!

December 23, 2010

I replaced the DSC4125 I has from MB Quart with this ONX4.125 in my buddies car. The ONX is even better than the DSC4125. It's got more detail, more power, and overall better fit and finish. The sound drastically changed and has opened up the front stage dramatically. It also is pushing the subs even better than the DSC4125 did. Overall I rate this amp a 10/10 for price/performance and overall value.

21 of 25 found this helpful

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Parag

Edison, NJ

Overall
Durability
Value
Features
Design
Usability
Bigger, but better...

January 25, 2011

The ONX series essentially replaces the DSC amps and let me tell you although this amp is bigger, it sounds cleaner, less distortion, and more powerful than the DSC. Although the DSC put out a TON of power, this amp puts out even more, cleaner power. I am very impressed by this amp and would recommend it to anyone especially at the prices I've seen them at sometimes. Amp is large, but that's a manageable trade off when considering the amount of power and good clean output you get from this amp.

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goodyearjason

Labadieville, La

Overall
Durability
Value
Features
Design
Usability
was impressed, for a month

February 13, 2012

I purchased this amp from Sonic a few months back. It seemed like a steal for the price. I had the amp on one set of mm6501's and all was well while running it as a 2 channel. 3 weeks ago i added a second set of mm6501's. Within 2 days the front channels stopped working. By the third day the rear channel was filled with static. All of this happened with the gain turned all the way down. Just buy a better amp to start with.

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Marcel

Amarillo, TX

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Durability
Value
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Design
Usability
awesome amp!!

November 17, 2012

very sturdy amp it is very solid!! heavy and it is HUGE , hasnt got hot on me just warm but very nice

19 of 24 found this helpful

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Drew

Chicago, IL

Overall
Durability
Value
Features
Design
Usability
Incredible Value

October 15, 2011

The characteristics of this amplifier would be natural mids and highs, smooth midbass, and a seamless blend from the sub to the mids and highs. I am currently using this amp as a 3 channel set up with Hertz High Energy 3 ways in the front and bridged RF P3 10" at 4ohm. I have not heard such great fidelity and clarity from even some high end amplifers. I have had Stegs, JL, Alpine and many more brands of amps and this amplifier by far reproduces the most accurate sound I have heard. I am at awe how low the price is for this amp. I guess the only downsize is the size of the amp. As along as you have the space to mount the amp and let it breathe, you will not be disappointed. Audiophile sound indeed! Thanks Sonic. I'm considering buying a second one. It's that good!

19 of 24 found this helpful

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bogturtle1

oklahoma city

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Durability
Value
Features
Design
Usability
not happy

June 27, 2011

well thought i was dreaming at first cause of the size but after hooking it up i found that with channels 1&2 just hooked up sounds fine and then hook up 3&4 and put the switch to 4 and they barely have sound over the front unplug the front and they are normal with sound level not happy cause now that it has been open and don't work right can't just send it back for refund with out paying why should i pay again for something that should work when i got it. that is the bad part cause shipping was great and faster then projected date just hope i can have it fixed or replaced for no cost or very little.

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Accessory Tools and Products

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Why did you choose this?
Sonic Electronix Store
I own 2 already. VERY good amplifier. Puts out true 125x4 OR 500x2. Got this one for $119. I would buy them all day long at this price!
jeremy w on Nov 26, 2014

Product Summary

Manufacturer

Model Number

ONX4.125

UPC

806576217046

Weight

16.00lbs

Internal SKU

onx4125

Internal Product ID

27474

Sonic Electronix Wiring Guide

Wiring Diagram Legend

Warning: The image depicted shows the resistance change when wiring multiple subwoofer terminals. Please refer to your subwoofer's owner's manual for the proper wiring of its terminals. Sonic Electronix, Inc. is not responsible for damage caused to your audio system or vehicle due to improper installation. Please call tech support at 1-877-289-7664 if you require additional assistance.

Product Name: MB Quart ONX4.125