I was also thinking about your idea for the housing for the front speakers. As I was a stereo installer previously I think if you were to put the mid bass speakers in a small housing such as a headlamp or similiar you will lose lower end frequency response from the speaker. The speakers were designed to play in a door cavity or something of similar size just like a sub is designed to play in a certain sized box.
A sealed enclosure for them is however a great idea. The size of such could be determined by using a computer program with the speaker parameters. Or you could ask the Focal distributer in Australia. he's a great bloke and i'm sure would be more than happy to help if you were using one of his speakers. I guess the appropriate size would be somewhat like 3 to 6 litres, probably the larger the better.
If you were to use the three way system the mid range speakers would not need to be housed in such a large enclosure at all as the frequency range they play is much higher.
A sealed enclosure for them is however a great idea. The size of such could be determined by using a computer program with the speaker parameters. Or you could ask the Focal distributer in Australia. he's a great bloke and i'm sure would be more than happy to help if you were using one of his speakers. I guess the appropriate size would be somewhat like 3 to 6 litres, probably the larger the better.
If you were to use the three way system the mid range speakers would not need to be housed in such a large enclosure at all as the frequency range they play is much higher.