The socket.io is emitting to all rooms instead of the specified ones

I'm new to node and socket io. I'm trying to implement a realtime notification system for couple of my own apps. So, using node, express and socket io, the code is given below:

Server Side Code:

io.on('connection', function (socket) {

    socket.on('subscribe', function(room) {
        socket.join(room);
    });

    socket.on('unsubscribe', function(room) {
        socket.leave(room);
    });
});

Client Side Code:

var sio = io.connect('http://localhost:9000');

var ch1 = sio.emit('subscribe', 'channel1');

ch1.on('log', function (data) {
    console.log('channel1: ', data);
});

var ch2 = sio.emit('subscribe', 'channel2');

ch2.on('log', function (data) {
    console.log('channel2: ', data);
});

I'm firing/emitting the event from a route (express) for example:

app.get('/', function(req, res) {

    var data1 = {
        channel: 'channel1',
        evennt: 'log',
        message: 'Hello from channel1...'
    };

    io.to(data1.channel).emit(data1.event, data1);
});

When I'm hitting the route, the io.to(data1.channel).emit(data1.event, data1); is working but it sending the data to both rooms/channels but I was expecting to get the data only in ch1 because data1.channel contains channel1 so I was expecting the following handler will receive the data:

ch1.on('log', function (data) {
    console.log('channel1: ', data);
});

Notice that, both channels have same log event. Am I on the right track. Is it possible at all?