@erik_squires put it very well and very succinctly: "The thing that makes a bigger difference is matching the room."
Lacking Erik’s gift of succinctability, here’s my take, from the perspective of a designer:
In my opinion where the speaker is likely to be placed in the room makes a great deal of difference.
Sealed box design doesn’t offer the designer very many degrees of freedom. Once the woofer and box size have been chosen, the shape of the frequency response curve (not counting room interaction) is virtually carved in stone. Increasing the box size beyond optimum will raise the -3 dB frequency but lower the - 6 dB frequency, while decreasing the box size below optimum will have the inverse effect. And the theoretical "optimum" box size isn’t necessarily optimum for a given application.
Vented box design allows the designer more flexibility but imo requires more care. Assuming the woofer and box size have been chosen, different tuning frequencies result in significantly different frequency response curves. So if I have a pretty good idea of where the speakers will be placed, I can take anticipated boundary reinforcement into account in choosing what the frequency response curve should look like. Also, having multiple pluggable ports allows the end user to somewhat tailor the speaker’s low-end response to his room situation.
Note that the "boominess" often attributed to vented boxes includes the room interaction. Take the same speaker outdoors and it will NOT sound boomy... point being, it is the net in-room frequency response, not the speaker’s inherent low frequency time-domain response, which dominates our perception.
One drawback of ported boxes is this: As a note near the tuning frequency decays, its pitch can actually shift in the direction of the tuning frequency. This makes sealed boxes generally more suitable for small studio monitors than vented boxes; with large studio monitors, the tuning frequency can often be made low enough that pitch-shift is not an issue.
Personally I tend to prefer use ported boxes in my designs for three reasons:
1. Greater room-adaptation flexibility, assuming pluggable ports are part of the design.
2. In general woofers which work well in ported boxes have more powerful magnets and/or lighter cones, both of which imo contribute to midrange articulation.
3. In a series of blind tests intended to sort out the best internal damping material for a sealed box with the priority on midrange sound quality, I accidentally found that a ported box could have better midrange sound quality.
Duke
