Today I tried this idea just to see what happens. I have an AV Receiver and a set of 5.1 hifi speakers. With this setup, in Dirt Rally the codriver instructions are sent via the central speaker, but they are sometimes difficult to understand with the noise of the engine, etc. So, I got a audio jack cable, removed the male connector and attached the cables together with the ones that go to my central speaker on my AV receiver's output connector. The headphones I have tried are small in-ear and they sound quite loud so I have to beware not to use very high volume. In Dirt Rally I set the codriver volume to 10 or 20 and the rest to 80 or 100. So, while I can still enjoy the roar of the engine, surfaces, collisions, etc. at high volume from my speakers, I can hear clearly the codriver right on my ears. Best of all, this combo feels very realistic, because real drivers receive the instructions with the headphones integrated on their helmets. I'm going to order something like this (light, cheap and that doesn't isolate at all from outside sounds). Sound quality doesn't matter at all, because the voice coming from an intercom is supposed to sound like radio voice.
