Ported has alot to do with as well. Most ported JBL I have had just had an inch or 2 on all 6 pannels. All sealed boxes were full of foam or fibeglass or polly. Sealed Celestion for example uses foam and stuffs the box other than if there is a passive radiator. You need the airflow between the woofer and the radiator for it to work properly.
Anyone Damp the insides of your Speaker Cabinets?
Do most speakers sound best in cabinets that resonate as little as possible? Why or why not? Is there something any of you have applied to the inside of your speaker cabinets to keep them from resonating, and achieved a more pleasing sounding speaker?