Bloated speakers/weight wise

Macrojack, my explanation applies to both sealed and non-sealed speakers. A port, if appropriately designed, offers a controlled path for pressure to escape the speaker cabinet. Ported speakers still have to address cabinet flex. If I got it right, doesn't your speaker have a very slick multi-layer cabinet design. And since when did 70 lbs. become a light weight speaker?

Hwy-

I think you are correct about the cabinet but I am not sure.
I think 70 lbs. is light in comparison to the behemoths being mentioned here. And the things are over 4 feet tall besides.

The aperture at the bottom is about 4 inches by 9 inches. I don't know how it is configured inside but I would imagine an opening that large would present little resistance and therefore minimal pressure. Is that correct?

Macrojack, How do you know that your cabinet does not produce any sound? How did you test for this?

After reading some of this thread I did a little experimenting. First I tried to feel vibration on the cabinet with my fingers and could not feel any, so I tried my lips and then my check (the one on my face), still nothing. Next I held a glass up against the cabinet, (you know, like holding a glass up to a door as to hear what is being said on the other side of the closed door), then I could hear something coming through the cabinet. But what worked even better is just to press your ear firmly up against the cabinet, by doing this I could hear even more. Don't forget to plug the other ear and cut the volume off on the other speaker.

Have you tried that? If not, how did you test?

Line-
I'll have to try your experiment later. I just took a break from painting the living room. The system is dismantled. What I've done so far was just feel it while it was playing. Didn't feel any resonance as I have in other products at times in the past. I concluded that if it wasn't obvious, it wasn't happening. Certainly if you must go to stethoscope extremes to detect resonance, it must be small enough to be overlooked, at least in post-amplification circumstances.

Macrojack: Naturally your speaker cabs do resonante -- all speaker cabs resonate. I'm surprised that you and Line say you can't feel any vibrations with your hand placed on the cabinet. This is true with any surface, at reasonably lifelike volumes, playing any music? As for rocking, most speakers won't do this to any detectable degree if well designed and anchored.

Even if they don't obviously vibrate a great amount, the large areas of the cabinet surfaces involved in making a 4 ft. high speaker means there will be sonically significant unwanted contributions from the cabinet. The effect is potentially worst with speaker constucted from flat panels (as most still are) -- speakers with curved cabinet surfaces have a theoretical leg up here, especially if we're also trying to keep weight down to sane levels.

No matter what you do with the bass, cabinet talk will exist if there's a cabinet involved, but obviously speakers that roll out on the bottom sooner than others will have lesss of a problem to deal with, and this I assume is a factor with your speakers. BTW, I agree that 70 lbs, which is what my own Thiels weigh (with their 1" panels, 2" baffle, and 5 internal cross-braces), is at most mid-weight for a 4 ft. floorstander.

I do have to admit to a lack of basic understanding in a technical aspect of what you're alluding to here though. John Atkinson has also commented in a few speaker reviews that higher sensivity should translate into less cabinet talk. I think I understand why this would be true with horns, because they work by concentrating the sound pressure in the direction of the listener, thus reducing the overall driver excursion needed to achieve equivalent perceived volume levels. What I don't understand is why this should hold true for direct-radiators like yours, because the amount of air that's required to be moved to achieve any given volume level is the same, no matter what the efficiency of this type of speaker. In other words, I understand that the required amount of watts of power needed to achieve that air movement will be less with a more efficient speaker, but not why, if it's making the same SPL in-room, there would be less excitation of the cabinet. Anybody enlighten me on this one?