In my article, The Stereo to Mono Summing Cable that No One Makes, I described how to build (or buy) a cable that will take a stereo unbalanced signal and sum it to mono for connection to a PA system (mixer, power amp, etc.). You can connect the output end of such a mono-summing cable directly to a regular line 1/4″ line input. If, however, you need a balanced signal for connection to an XLR mic input on a mixer, you’ll need to use a mono-summing cable in conjunction with a DI box. Since writing that article, there have been several DI boxes that have hit the market that do something similar to what the mono-summing-cable-plus-DI-box combo do, so I thought it might be good to provide a quick overview of some of them. I’ve decided to list these in the order of the selling price from least to greatest. (more…)

One of my most popular blog posts has been The Stereo to Mono Summing Cable that No One Makes. I get contacted pretty much on a weekly basis from someone who wants to buy or build that cable to connect their iPod, phone, laptop, etc. to their PA system. I decided to take the concept a step further and build a balanced, line-level stereo to mono summing box. Just like the mono-summing cable, it appears that there aren’t any readily-available, off-the-shelf products that do exactly what this box does. There are some mic combiners (e.g., Galaxy Audio’s JIB/C) that are made for connecting two microphones to a single input, but those use much lower-value resistors, making them unsuitable for line-level signals (I even contacted Galaxy about the JIB/C, and that’s what they told me). (more…)