Music Intrusment Reviews

Mackie Big Knob Passive Monitor Controller - Recording

Mackie Big Knob Passive Monitor Controller - Recording







Feature Reviews

Recording Reviews: Mackie Big Knob Passive Monitor Controller - Recording



Mackie Big Knob Passive Monitor Controller

Sometimes taking the passive approach is the way to go




by Phil O'Keefe




bkpassive3qtrleft-854a393c.thumb.jpg.52eb174d76ac6f6a9a1d0b78b47f8c31.jpgWhat You Need To Know

  • The Mackie Big Knob Passive is a tabletop monitor controller that measures only 5.4" W x 5.6" D x 3.1" H, so it takes up relatively little space on your desktop. It has some heft to it that helps keep it stationary - it weighs 2.2 pounds. The Big Knob Passive is decidedly sturdy, with a black powder coated metal housing - no plastic here.


  • Because it is entirely passive, no power supply is supplied - or needed.
  • The Mackie Big Knob Passive is a 2 x 2 monitor controller. It can accept signals from up to two stereo line level sources and outputs signal to one or two pairs of studio monitors.


  • All of the connections are found on the rear panel. There are two pairs of 1/4" jacks that accept balanced or unbalanced 1/4" plugs from two input sources - labeled A and B.


  • In addition, there is also a 1/8" (3.5 mm) TRS jack for Input B that you can use instead of the 1/4" inputs if you wish.


  • Two pairs of 1/4" output jacks are provided for connecting your monitor speakers to the Big Knob Passive. As with the inputs, either unbalanced or balanced (TS or TRS) cables can be used.


  • The user interface on the top of the unit is sparse, yet ergonomically laid out and simple to use.


  • There are five pushbutton switches near the bottom of the angled front panel.


  • The Source Select switch allows you to choose between input Sources A and B. Since Source B has both 1/4" L/R inputs as well as a stereo 1/8" TRS input, you'll probably want to save that for a secondary source and use Source A for the Monitor Outputs from your DAW computer's audio interface. That way, you can quickly select between your mix, and something like a reference mix that's playing back over your smartphone in order to, well, A/B them.


  • On the far right is the Monitor Select button. This lets you quickly switch between two sets of monitors. Most people will probably have this set up for their main speakers and their nearfield monitors, or possibly some other auxiliary pair of speakers. Again, this lets you quickly switch between two different sets of speakers for quick and easy comparisons.


  • In between those two crucial switches are three very useful switches that provide additional functionality beyond just basic monitor and source switching.


  • The Mono switch does exactly what you think it does - it sums the left and right input signals to mono output - this is a crucial tool for both tracking / mic placement and mixdown to check for mono compatibility and make sure that you don't have any phase cancellation issues.  


  • Have a phone call coming in and need to turn everything off for a minute? Hit the Mute switch and everything goes silent instantly.


  • Don't want to kill the sound completely, but still want it to drop dramatically so you can have a brief conversation in the control room without having to raise your voice? That's what the handy Dim switch is for. When pressed, it lowers the output level by 20 dB. 


  • The obligatory Big Knob is in the center of the front panel, directly above the five switches. It's large and has some weight to it, which helps give it a nice feel when you turn it. It allows you to smoothly control the volume level of the connected monitors.




  • There's some signal loss - about 6-7 dB or so. That's basic physics folks, and it's an unavoidable consequence of using passive electronics. On the positive side, you also get no added noise or distortion - both of which are unavoidable with active electronics.


  • Because this is a totally passive device, there are no headphone amps or any other headphone monitoring provisions.  


  • You can not use both the 1/4" and 1/8" inputs for Source B simultaneously - connecting to the 1/8" input automatically disconnects the 1/4" inputs.


  • Since there are no trim or level controls for the two pairs of monitor outputs, any playback level matching you may want to do between two sets of monitors will need to be done by trimming the controls on the monitor amps.





It's great that Mackie is now offering people three different monitor controllers, because not everyone needs the same features. This way, you can get the unit with the features that best match your own needs without having to pay more, or worse yet, make due with something that doesn't quite do everything you want it to. Out of the three new Big Knob series monitor controllers, the Mackie Big Knob Passive has the least amount of features, but for some users it may be the perfect fit. If your system is used primarily for playback, you probably don't need a built-in talkback system. Ditto that if you work alone. And while being able to monitor on headphones is something that many of us need to do, you probably already have a headphone jack and level control built into your audio interface.



For switching between two input sources and two sets of monitors and controlling their playback level, the Mackie Big Knob Passive has all the features you need. I like the fact that an 1/8" stereo input is included for use with portable audio devices. The Source and Monitor Select buttons operate with a slight mechanical click that lets you know you've engaged them but they don't cause any audible clicks in the signal path and they seem to be reliable and consistent in use. The Mono, Mute and Dim switches also work as they should and the Big Knob itself is heavy and smooth both physically and in terms of its taper and attenuation, with no weird phase issues or wandering of the stereo image as you turn it down. You'll want to keep your cable lengths reasonably short in order to avoid signal loss and interference, but if you do, other than a bit of level drop (which you can probably compensate for elsewhere, such as by turning up the level on your powered monitors), the sound that comes out is the same as what goes in, with no added distortion or noise.



If a 2x2 monitor controller is enough for you and you have other ways of handling headphones and talkback, the Mackie Big Knob Passive may just be perfect for your needs. The Mackie Big Knob Passive will do the job inexpensively, reliably, cleanly, and with a minimum of fuss. If you have more than two sources that you want to switch between, or more than two stereo pairs of monitors, you should probably consider something else, such as one of Mackie's other Big Knob monitor controllers. Yes, we'll be covering those too - stay tuned for a review of the Big Knob Studio + monitor controller. While the Big Knob Passive is a little light on features to use as my main studio monitor controller, it's perfect for the setup I have in a second room, and I'm so pleased with its performance there that I'll be purchasing the review unit. -HC-




Have questions or comments about the Mackie Big Knob Passive? Then be sure to click over to this thread in the Studio Trenches forum right here on Harmony Central and join in the discussion!





Mackie Big Knob Passive Monitor Controller ($89.99 MSRP, $69.99 "street")


Mackie's product web page    



You can purchase the Mackie Big Knob Passive Monitor Controller from:




Guitar Center    


B&H Photo Video   


Musician's Friend    

















Phil O'Keefe is a multi-instrumentalist, recording engineer / producer and the Senior Editor of Harmony Central. He has engineered, produced and performed on countless recording sessions in a diverse range of styles, with artists such as Alien Ant Farm, Jules Day, Voodoo Glow Skulls, John McGill, Michael Knott and Alexa's Wish. He is a former featured monthly columnist for EQ magazine, and his articles and product reviews have also appeared in Keyboard, Electronic Musician and Guitar Player magazines.  



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