Behringer Monitor1

I wanted to use the Monitor1 volume control as a safety between my Audient ID44 interface and IK MTM monitors, using Mogami 2534 cables. Its simplicity was quite promising and I tried it for almost a month until I finally gave up.

The good: It's a well built, pleasant looking device with a good feel to the enclosure, buttons and the volume knob. It does not come with any bells and whistles and makes a good down-to-earth impression.

The bad: Passive attenuators should be used at or near full volume, otherwise they will impact the sound signature. However, this one is quite disappointing in the entire volume range.
First, you lose quite a lot of sound resolution with this device. It has poor channel separation and the soundstage becomes small and flat, particularly at low volumes.
Second, as is common for passive attenuators, the tonal balance changes with the position of the volume knob. However, here I found no position that would sound good: as you turn the volume up, you get from quite dark to bright-ish but with an unpleasant sharpness in the highs. It can sound fine with some recordings, but the minute you bypass it in your audio chain, you will see how much it has taken away.

Ultimately it was replaced with an SPL Volume2 and although by no means transparent, it preserves most of the imaging and its colouring, although noticeable, is much less invasive.

The monitor controller takes 2x XLR or Balanced Jacks in and 2x out. Ive had it for about 2 years now and it holds up great. The mute function is particularly helpful when I want to turn synths or phantom on and off to prevent pops and loud sounds. I use the volume control extensively and it's very smooth and easy to reset to any position due to the markers. It's entirely passive so no need to power it. It also has stereo 3.5mm I/O which I haven't used that is designed for monitors - Behringer support advised me that the signal is too hot for headphones although I suppose if you have high impedance cans it might be OK.
It's built of solid metal (including the dial and I think the buttons) and is extremely sturdy. To this day I have had no problems with the build quality and it looks as good as the day I got it with no scratches or paint rubbing off.
The mono function is a great addition for checking mixes esp. regarding phase. I'm now looking to get some more monitors so will probably have to upgrade to a controller with more outputs, but at the time I didn't need one. Even so I don't regret the purchase as it's a great price and compact enough to fit in my setup when it was much smaller.

Moved from a tc electronic Level Pilot to this. I had been searching for a competent volume controller that would not break the bank and came across this one. I have to say, reviews here helped a lot in the decision making. That being said, the unit is built like a tank, buttons for mute and mono have a smooth and satisfying click to them as well as being immensely helpful, especially the mono button that is right there in front of you to use. I have the unit for a few weeks now, I can't hear any distortion or coloration or any of the other issues people have noted with other, more expensive units. Let's see if it holds up over time. So far, so good. Behringer, chapeau!