. Sealed and Vented are the most commonly used form of enclosure by most DIYers or speaker manufactures. Here is very basic step by step design sequence to get you started with out getting to complicated .Other types of enclosures will be given a brief description at this stage and all types will be covered in more detail in The Speaker Design Guide Book 2.
Design 1 Vented 6" 2 way bookshelf
2 way crossover
speaker terminal cup
Step 1 Chose a bass mid driver with a sensitivity level dbspl of say 87dbspl to start with you can allow up to 88dbspl as this will allow for the losses induced by the xover circuit and box acoustics ., eg WES Daiichi sp6-50 50watt paper cone
Step 2 Chose a soft dome tweeter of say 88 to90 dbspl with a sensitivity around this level you can allow for level matching the tweeter to the bass mid eg WES Daiichi Dt-80 soft dome
Step 3 Chose the box and vent size from the SSS recommended "Speaker Box chart "for WES speaker drivers
Step 1 Choosing the right type of speaker driver .