RJ11 vs RJ14
RJ11 and RJ14 are two wiring standards that are used mostly in connecting telephone handsets. The main difference between the two is in the number of wires that are used in the connection. With RJ11, there are only two wires used while RJ14 uses 4 wires.
With telephones, you need a pair of wires for each unit. The wires are twisted at a certain rate to optimize performance and are often referred to as a twisted pair. Because the RJ11 standard uses two wires, it can only accommodate a single telephone unit. With RJ14, the connection is able to accommodate up to two telephone units. RJ14 is often used when you have multiple lines leading to a single phone unit. It is also common to have an RJ14 connection that goes through a junction box and is then split into two RJ11 connections that lead to two separate telephone units.
RJ11 and RJ14 use the same sized connectors, so it is rather easy to mistake one for the other. Actually, there are a number of different connectors that can be used. There’s the 6P6C, 6P4C, and 6P2C. The first number indicates the number of positions in the connector. So the first connector has all slots with contact points while the last one only has two contact points. Because of the differing number of contact points, you can use any of those connectors for an RJ11 wiring. But for an RJ14 wiring, you can use all the connectors aside from the 6P2C as it lacks the necessary contact points.
If you will be installing telephone systems that use both RJ11 and RJ14 connections, it is better to get 6P4C connectors and cables that have two twisted pairs. It may cost you slightly more, but you gain the flexibility of having the right equipment for both wiring standards. It may also be worth it to pre-wire your house or establishment with RJ14, even if your plan is to just use a single phone, so that you would not to rewire again once you decide to add another unit or line to your current set-up.
Summary:
1.RJ11 only uses 2 wires while RJ14 uses 4 wires
2.RJ11 only accommodates a single phone while RJ14 can accommodate 2
3.RJ11 can use both 6P4C and 6P2C while RJ14 can only use 6P4C connectors