Acoustic Research introduced sealed loudspeaker cabinets as a way to extend bass while reducing cabinet size. Indeed, a sealed cabinet’s bass rolls off at 12db per octave (compared to 24db for ported designs). But this comes at the expense of efficiency. There are always tradeoffs when it comes to loudspeaker design. I like the sound of sealed designs because they are less bloated and easier to integrate into rooms. I also have had better luck integrating sealed designs with powered subwoofers. Perhaps the milder slope helps blend the main speakers with the subwoofer? WinISD offers a great way to design sealed and ported loudspeakers for free. You can simulate the responses of both sealed and ported projects as you learn what sounds best to you.