POST new line in JSON for _msearch in ElasticSearch

I'm trying to do a _msearch using ElasticSearch from a browser, and can't figure out how to replicate this CURL command.

curl -XPOST http://localhost.com:9200/ratecards/_msearch -d '

{}
{"query":{"term":{"_id": "1"} }}'

Notice the presence of the new line. That's what I want to replicate.

This is the JavaScript I'm using, it's using Angular's $http which is just a thin wrapper around jQuery's ajax commands.

      if (routing) {
        address += '?routing=' + routing;
      }

      var data = '\n';

      _.each(payloads, function addPayload(payload) {
        data += '{}\n' + JSON.stringify(payload);
      })

      var config = { data: data, method: 'POST', url: address };
      $http(config).success(doStuff);