Admit it, we all have a tendency to use large splitters when we could use small ones. Even though the large ones cost more, we put them in because we want to future-proof our systems. Since DIRECTV rolled out their SWiM system that allows the line to be split multiple ways, this has become even more common.
There’s a good reason not to split the line more than necessary: line loss. Even a properly terminated splitter loses signal. In fact, the loss from a single 1×8 splitter can be up to 10 times greater than a 1×2 splitter. This means that you’ll have problems on longer lines especially in areas where rain fade is common.
If you’re an installer, you generally don’t have a choice. In fact it’s a good idea to leave the customer with one unused port, just so they can do a little bit of the work themselves if they want. However, some installers have been known to put a 1×4 splitter after a 1×8 splitter just because it’s what they had in the truck. In this case it cost the customer another truck roll and a lost day of pay when the only problem was that the splitters were too much for the job.
If you’re a DIY’er think about the absolute minimum you’ll need to run the system you have. Put splitters where you can reach them later so that you can easily upgrade from a 1×2 to a 1×4 if you need. Home installations hardly ever need a 1×8 as they won’t have 8 receivers very often. More likely they will have DVRs which only need one line to run 2 tuners. In homes, a 1×4 will usually do just fine. If you plan on splitting the line after a long run, use a 1×2 close to the dish and another 1×2 (or 1×4) where you need it.
Our expert VOS writes:
SWiM has a useable loss between the SWiM and the farthest receiver of about 30 dB.
If you don’t use ANY splitters, this comes out to about 300′ of RG6.
Add ONE 2-way splitter and you’ve lost 50′, so you’re down to 250′.
Use ONE 4-way splitter and down another 50′, to 200′.
Use ONE 8-way splitter and you’ve down to 150′.
ONE 8-way splitter and having to add a 2-way down stream, leaves you only 100′ of total coax between the SWiM & the receiver.
Should you [foolishly] use ONE 8-way and a 4-way, you’re down to only 50′ of coax [loss] before the receiver starts showing loss of signal.
All used ports need to be terminated, but this just means you wasting signal into a 75Ω resistor, instead of sending it to a receiver.
Always try to use the best size splitter for the need. Better to be able to add a 2-way downstream, than waste all the signal power in an over-sized splitter with a lot of loads/terminations.
Splitter do give you the flexibility of distributing them where you need them, which can be more helpful than home runs to a multi-switch.
All splitters are built upon a 2-way, so: