If the cables are short and there isn't any hum, then using "half" of the balanced output to an unbalanced input is the best solution. I am planning a home theater with four subwoofers, using four outputs from the sound processor. The previous generation SVS PB-2000 is on sale and will do nicely, but it has an unbalanced input. I like the common mode noise reduction a balanced wire provides over a longer distance, so balanced cables will be pulled. First, I will test by using one side of the balanced cable to verify that there is no undesirable noise. If there is noise, then a raw Jensen transformer will cost about $75 per sub. Seeing as an engineer from Jensen participated in the design of the chip in the Sparkfun THAT 1206 kit, it could provide similar results to the Jensen transformer and would be cheaper. Power for the boards could be provided by using two JAMECO RELIAPRO DDU050100M2270 to supply positive and negative 5 VDC for all four boards. All told, that's about the cost of one transformer. There is no perfect and it seems that moderate distortion from either transformers or added electronics is easier to tolerate in a sub than in full range speakers.