When the Xbox Series X was first unveiled, many were left somewhat disgruntled after finding out that ports such as the HDMI in and optical audio port would not feature on Xbox's next generation of hardware. Phil Spencer has now clarified why the decision was taken to not include the optical audio port, and it mainly comes down to both price and form factor.In a recent interview with IGN , Spencer said that along with space considerations to factor in, the cost of components is important when designing a new console. If a part costs one or two dollars, you have to plan for how many consoles you're going to sell. That component's price becomes significant when planning on selling millions of consoles. "We frankly know how many people use [the optical audio port] today on the console. And we do the math of having to put a part in every console that x-per cent of the people uses — is there a better place for us to spend that money if we can support it in a different way?"The decision about HDMI in, Kinect port, IR blaster on the front — all of these decisions that we think through very deeply and try to figure out where the plans are. And I know with everything that we don't do — that we used to do — there is going to be somebody who's disappointed. It's not the funnest part of the job, but I think we have to plan for the future."For more on the Xbox Series X and how it compares to Sony's PS5 , check out our comparison of the two consoles and our full Series X specs reveal.