These are inexpensive and do what they need to do without introducing any noise of hum in the signal I am sending to two sub-woofers. I am using these with the Monoprice high-quality RCA cables (15 foot and 35 foot lengths - PID numbers 6306 and 3976) and I have ZERO hum or noise in the subs. Others have reported low build quality on these splitters. I ordered several of them and they all work perfect.
This are great for the price, however I really dislike how mono price ships them with everything else you buy. They just throw them in a box and you have to hunt for them and make sure you received them all. It would be nice if they through this smaller items all together in a zip lock bag or something.