Redirect a Subdomain to my main application

I have a solution in Visual Studio 2015 with multiple MVC projects, based on areas, working correctly and redirecting from Test1 which is the main project, but I need to use subdomains to obtain information depending on this. My project is like the following image:

Now to capture the subdomains I did a test with a project without areas with the following code that worked correctly:

SubdomainRoute

namespace Prueba1.App_Start
{
    public class SubdomainRoute : RouteBase
    {
        public override RouteData GetRouteData(HttpContextBase httpContext)
        {
            if (httpContext.Request == null || httpContext.Request.Url == null)
            {
                return null;
            }

            var host = httpContext.Request.Url.Host;
            var index = host.IndexOf(".");
            string[] segments = httpContext.Request.Url.PathAndQuery.TrimStart('/').Split('/');

            if (index < 0)
            {
                return null;
            }

            var subdomain = host.Substring(0, index);
            string[] blacklist = { "www", "admix", "mail" };

            if (blacklist.Contains(subdomain))
            {
                return null;
            }

            string controller = "Home";
            string action = "Index";

            var routeData = new RouteData(this, new MvcRouteHandler());

            routeData.Values.Add("controller", controller); //Goes to the relevant Controller  class
            routeData.Values.Add("action", action); //Goes to the relevant action method on the specified Controller
            routeData.Values.Add("id", ""); //pass subdomain as argument to action method

            return routeData;
        }

        public override VirtualPathData GetVirtualPath(RequestContext requestContext, RouteValueDictionary values)
        {
            return null;
        }
    }
}

RouteConfig

namespace Prueba1
{
    public class RouteConfig
    {
        public static void RegisterRoutes(RouteCollection routes)
        {
            routes.IgnoreRoute("{resource}.axd/{*pathInfo}");

            routes.Add(new SubdomainRoute());

            routes.MapRoute(
                name: "Default",
                url: "{controller}/{action}/{id}",
                defaults: new { controller = "Home", action = "Index", id = UrlParameter.Optional }
            );
        }
    }
}

But testing it with my new project structure based on areas gives me this error:

Error de servidor en la aplicación '/'.

Multiple types were found that match the controller named 'Home'. This can happen if the route that services this request does not specify namespaces to search for a controller that matches the request. If this is the case, register this route by calling an overload of the 'MapRoute' method that takes a 'namespaces' parameter.

The request for 'Home' has found the following matching controllers:
Proyecto2.Controllers.HomeController
Proyecto1.Controllers.HomeController
Prueba1.Controllers.HomeController

Descripción: Excepción no controlada al ejecutar la solicitud Web actual. Revise el seguimiento de la pila para obtener más información acerca del error y dónde se originó en el código. 

Detalles de la excepción: System.InvalidOperationException: Multiple types were found that match the controller named 'Home'. This can happen if the route that services this request does not specify namespaces to search for a controller that matches the request. If this is the case, register this route by calling an overload of the 'MapRoute' method that takes a 'namespaces' parameter.

The request for 'Home' has found the following matching controllers:
Proyecto2.Controllers.HomeController
Proyecto1.Controllers.HomeController
Prueba1.Controllers.HomeController

Error de código fuente: 

Se ha generado una excepción no controlada durante la ejecución de la solicitud Web actual. La información sobre el origen y la ubicación de la excepción pueden identificarse utilizando la excepción del seguimiento de la pila siguiente.

Seguimiento de la pila: 


[InvalidOperationException: Multiple types were found that match the controller named 'Home'. This can happen if the route that services this request does not specify namespaces to search for a controller that matches the request. If this is the case, register this route by calling an overload of the 'MapRoute' method that takes a 'namespaces' parameter.

The request for 'Home' has found the following matching controllers:
Proyecto2.Controllers.HomeController
Proyecto1.Controllers.HomeController
Prueba1.Controllers.HomeController]
   System.Web.Mvc.DefaultControllerFactory.GetControllerTypeWithinNamespaces(RouteBase route, String controllerName, HashSet'1 namespaces) +256
   System.Web.Mvc.DefaultControllerFactory.GetControllerType(RequestContext requestContext, String controllerName) +651
   System.Web.Mvc.DefaultControllerFactory.System.Web.Mvc.IControllerFactory.GetControllerSessionBehavior(RequestContext requestContext, String controllerName) +57
   System.Web.Mvc.MvcRouteHandler.GetSessionStateBehavior(RequestContext requestContext) +208
   System.Web.Mvc.MvcRouteHandler.GetHttpHandler(RequestContext requestContext) +45
   System.Web.Routing.UrlRoutingModule.PostResolveRequestCache(HttpContextBase context) +12040727
   System.Web.SyncEventExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +142
   System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +92

to get a better idea of the structure of my project can see the following link .

I know that the reference to the controllers of my main application is needed but I do not know how to put them to avoid the error.