Bear in mind that the room will affect the outcome. Even putting a fan in front of the car is no replacement for driving the car, all you are doing is moving warm air around the car. To get a true outcome you need a properly air-coned room that keeps the ambient temp down as well as simulating the moving air.
As others have said - the amount you are down is nothing to worry about.
BHP is not something to get hung up on. Get out, drive the car. If it feels good thats cool. If not then give it a good service and that should sort it out.
Also bear in mind that while some filters/ exhausts may sound better it does not mean you will get a bhp improvement - some will even loose you some.