Splitter and new HD TVs

Question

I haven't called Verison yet; I wanted to research. I have a 5-port splitter (1in, 4out) where FiOS comes into the house. One of the ports goes to the attic where I have another splitter for multiple TVs. We had no problems until recently when we moved a 2nd HD TV upstairs (fed from the attic). With one HD TV and no splitter upstairs all is fine. As soon as I add the splitter, channels 570 and 574 start to pixilate. I though the splitter had gone bad so I ordered a new one from FiOS. It had no effect.
What can be done? We have four outlets fed from the attic. Once our daughter moves out, 2 will of the TVs will be HD but cable is run to all 4 outlets.
I read that an amp is not the answer since its not compatible.
Relaxdad

Answer 1

It's probable that you simply have too much signal loss.  First, you should only have as many split outputs as you have STB's -- additional splits add additional loss and additional points for interference to enter.  Any outputs which don't have an STB on them if they can't be eliminated entirely should have a terminator on them so that no signal leakage can occur.
Essentially, you want your network to be as flat as possible with as short as possible a run between each STB and the ONT and between each STB and the Router.
A two-way (one in, two out) splitter loses -3db at each output. 
A three-way splitter typically loses -3db on the leftmost output and -6db on the right two outputs (but I have seen cheap ones which lose -6db across every output)
A four-way splitter typically loses -6db across all outputs (but I have seen ones which lose -3db out the left most, -6db out the second, and -9db out the last two).
Most splitters usually show the loss for each output.
Try to think about how you would set this up if all you had were two-way splitters.  Then design it so that you can have the shortest path for each STB to the ONT and the Router.   Once you have that, you should be able to figure out where you could substitute in 3-way or 4-way splitters.
In particularly, I believe you need to start with a two-way splitter -- and send one output up to the attic before you split it again and the other to the downstairs areas.
If after you do this and reduce your splitter counts and remove any "open" coax outputs, you still have pixelization, then it's possible that Verizon may need to provide some amplification (there are amps available, but you can't use the ones you pickup at the typical electronics store).