Mackie Big Knob Series, Passive 2x2 Studio Monitor Controller (Big KNOB Passive)

I have two different studio monitor sets: an old pair of iLoud Micro Monitors and a new pair of Kali LP-6's. Having both of them hooked up to this thing is a god-send versus having to open the routing software over and over again to switch between them during a recording or mixing session. It's also quite heavy and very sturdy, which is a good thing when you got several cables hanging out from behind the unit which could overcome units built more lightly if they are all hanging down from back back.The Mono button is great for checking mixes in mono and it also makes listening to old mono recorded songs (with the instruments in the left and right and not "stereo" from the get go) a breeze as well.The Dim button is great even at home as I can set the knob to a specific spot and then just use the button to lower the volume in an instant.As long as you have all the correct cables (I make sure to use TRS cables for the connection from my interface, you can use TS cables but YMMV) and read the manual to make sure everything is hooked up, it's a absolutely worthy buy for the home studio. I have cranked it up as well and I cannot perceive any additional line noise from either speaker, thanks to it being a well designed and fully passive circuit path.

What I wanted was a fully passive monitor control that switched two stereo inputs into two stereo outputs, AND offers a common subwoofer output regardless of the monitors chosen. I noticed this had some space in the rear panel once the 1/8” jack would be removed, so I got a slightly used one from Amazon warehouse and drilled and soldered. Pic attached. Works fine, although this is a bit of an advanced mod. I used the same 150ohm resistors on the sub outs used on the monitor outs, on both pins 2 and 3.Speaking of which, this unit runs only impedance balanced (it's passive, just using resistors, rather than active balancing or transformer balancing). Sure it accepts balanced connections, but pin 3 just runs 150ohms to ground both in and out, which will net fairly modest noise removal from the cable run. Otherwise they’d need a very fancy potentiometer double dual gang with very strict tolerances. Unbal to monitors with short cable runs not such a problem, but it is somewhat of a volume loss, beyond the loss this unit already has by design. Monitors are typically too loud anyway when driven at line level.There are also a pair of 10uF electrolytics…polarized commodity ones…between input and output. I shunted those off but most people should probably leave them, they don’t hurt the sound much. And 100pf ceramic caps avoiding RF interference coming down the line, perhaps bleeding off a touch of high end in the process. I left those.The next day (not shown in the photo) I also added an On-Off-On toggle under the logo on the back, that offers follow, mute, and solo for the subwoofer, handy for Room EQ Wizard or just hearing what your subs vs monitors are doing. The solo works in conjunction with the main mute button as a fast A/B.Anyway this did solve my problem after modding and the unit is heavy and the knob feels smooth and heavy like a hifi receiver. I improved the signal path a touch and the functionality a ton. I just wanted to show this mod is possible and is good enough to avoid spending more if you can hack it and that’s all you need.

Loving it so far. Very nice and sturdy. Works well for what it does. My only minor gripe is that the volume knob while big, has very little resistance when moving. By very little I mean almost none. It would be nice to have a little resistance for tactile feedback while moving, but as I said before, it's a small gripe. Using for multiple inputs and multiple outs in a recording studio. The dim button works well for alternating between a louder (checking bass and drums) setting and a quieter (balance and tone) listening environment. The mute button does what it says. The mono button is a fantastic tool for checking your mix for phasing issues and for (believe it or not) checking panning and how well everything sits in the mix. No coloration that would affect your mix to the sound as far as I can tell and test. Easy to set up in the studio and will hopefully last a long time.

Love this box for my home setup.I got this so I can switch my Yamaha studio speakers between my audio interface and my Tonex/HX Stomp XL so I dont need to have my PC running, I can just hit power on my pedalboard and speakers and hit source select and Im playing.

One of the channels is a little louder than the other. To verify this wasn't a problem at another stage I used multiple audio interfaces outputting mono collapsed mixes, and they all came out sounding with the left side a little louder than the right side. I was able to get around this issue by tweaking the gain on my monitors, but it was a hassle going back and forth tweaking things until set right, when before, when i had it connected directly to my interface I had my speakers set a fixed gain point provided by the manufacturer (yamaha, I own hs7s). Other than that. Audio quality is excellent because is transparent, Product is great because is built like a tank, built to last, very functional. Knob feels great. product looks great on my desk. I wish they make a rack version of this thing, would be great in my studio.

I acquired this as a solution in my studio to switch my nearfield monitors from an audio interface to a mixer's CR outs. I've also utilized the mini jack occasionally to run my computer's headphone out to the monitors which is a nice added feature. The mono. mute, and dim buttons work as expected. The only issue is it introduces noise as you increase the large volume knob beyond the mid-point. I have it set up with balanced TRS cables so I am not sure why it is introducing noise hiss other than it may be a flaw in it's passive circuit design.