I have a 93 ls 400 with a nakamichi system. I am thinking of replacing my front and back speakers but am unsure if there will be a depth issue. Would putting 5-1/4" in the front and 6-1/2" in the back cause any problems?

 

the speaker boxes are designed for 4". you can mod them, but the potential problem i've heard of from other sources is that the box itself was specifically designed for 4", and another size might change the physics within the box. but others on this forum don't seem to report such problems. i'm a big fan of image dynamics speakers. they have great clarity. the 4" only go down to 100hz, but the point of having a subwoofer is that it takes care of the bass. why have the smaller speakers trying to duplicate what they can't? its a waste of power and a distraction from clear mids and highs.