Hi, I am a cable technician. Anytime you split the signal with a 2way splitter you lose 3db. Also the signal is not scrambling. The reason your picture was pixelating is from a weak signal from your coax. If your old splitter was not rated at 5-1000 mhz or more that can affect signal quality. So if you have more splitters than you need remove them. If you need all the cable lines you have then you need an amplifier. If you want to do this yourself make sure the amplifier you buy is rated 5-1000 mhz or more. Also you need to install it before any splitters. It does no good to amplify the signal when it is already weak at the end of the chain. This also has the benefit of boosting the whole system instead of just one jack. I would just have the cable company install the amp for you because they only charge you $50 to do so and you own the amp afterward. Considering the amp will cost you $50 to buy yourself you can't beat it. Also if you have 4 or less outlets and need an amp Comcast will install it for free. I'm not sure what cable company you have but just ask them what their policy is.
Good luck
Sean
Good luck
Sean