Im getting some 6.5 component speakers for my 02 explorer sport. The thing is the original openings for my speakers are 5x7, if i just drilled my new speakers into the same holes without buying or making adapters would the extra open space on each side of the speakers affect the sound quality of the speakers? would it be noticeably worse quality or not?

 

yes...they'll sound like crap...a speaker needs to have the front and rear separated and sealed from each other in order to produce sound properly. If you leave spaces like that, the front and rear sound waves will cancel each other and you'll get very little output in the lower midrange and bass regions...all you'll get is high frequencies. Make or buy adaptors!