Digital Designs M4a Mono-Block Product Review

Usually when I do a review on a product I will run it in one of the work vehicles for a week or two testing out different settings and getting a general feeling of how it functions, sometimes I even push the items to its limits. Writing a product review on the Digital Designs M4a is slightly different in this case since I have been running two in ABTEC3 for about a year now and have used them for everything from SPL, Ground-Pounding to just playing Ordinary Everyday Music.

The build quality of the M4a is just flawless, not just aesthetically either but also in how it preforms too! Over the last year I have powered many Sub-Woofer setups with the M4a, including: 4 x DD-510-D4’s, 4 x DD-512-D4’s, 1 x DD-9518-D1, 1 x DD-z18 (the list goes on too) and has always provided plenty of power no matter what Ohms it was run at too!

As stated before I don’t just use a M4a for our SPL setup that has netted us 154.7dB Officially (We use 2 x M4a’s for this) but I Daily ABTEC3 driving a DD-9518-D1 with a M4a @ .5 Ohm and it absolutely loves it! Anybody that knows me knows I like my music LOUD, so LOUD that the windshield in the Toyota Vitz is usually flexing as I commute to and from ABTEC everyday!

As far as sound quality goes the M4a lives up to the Digital Designs motto of True To The Source! I do understand an amplifier can’t be judged on sound quality alone, but in my experience with the M4a and the Sub-Woofers I’ve used with it have produced beautiful sounding Bass. Even down to the low 40Hz-20Hz that I love the most!

What amazes me with the M4a is where most High-Output Amplifiers are rated at 14.4v or even higher, the M4a is still rated at 12-14.v which makes it ideal for everyday use. At 12v the M4a makes 5200w RMS @ 1 Ohm, at 14.4v it easily makes over 7000w RMS @ 1 Ohm and some people have even clamped their M4a’s at just under 8000w RMS @ .5 Ohm on 14.4v!


  • Bridged: NA
  • Channels: 1
  • Cont Power at 1 Ohm: 5,200W x 1 @ 12v
  • Damping Factor: >150
  • Dimensions (Inches): 27.625L x 9.13W x 2.5H
  • Dimensions (Metric): 702L x 232W x 63.5H
  • Dynamic Power: 9500W
  • Efficiency Thru Output: 87%
  • Input Sensitivity: 0.15v – 5v
  • Model: M4a
  • Shipping Weight: 36 lbs

Overall the M4a in my personal opinion is the ultimate amplifier for multiple uses, be it Ground pounding, SPL or even powering your daily SQ setup the M4a will have more than enough power for your setup. If some how you need more power just add another M4a and strap them together for double the power!

On an ending note I consider myself lucky that I get use not only one but two M4a’s in my daily, because here in New Zealand there isn’t that many people that drive around with an easy 10,000w RMS on a daily basis… Yet!


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