Advent Heritage Dual Woofers or Not?

[VinceBob]

I pulled the crossover to replace the caps on my Advent Heritage's and noticed the bandpasses for the 2 "woofers" are different -- coil and cap pairs are different sizes for the 2 woofers.
I have to conclude that the 2 cover different frequency ranges, but the mystery (to me) is that they share the same space in the enclosure, i.e. they are not isolated from each other (and of course they're open-back elements). How can this possibly work? Why dont they interfere with each other moving air at different frequencies at the same time? -- tks

[markw]

I don't know your particular speakers, but there's such a thing as "two and a half way" speakers.

Generally, the way these operate is that they will have a tweeter and two mid/bass drivers. One of those two will run pretty much full range so it covers both the bass and mid-range. The second one will have it's top end limited even more so that it acts as a true woofer. This gives the system a bit more bass than it would if it were just a two way system,

From your description, this sounds like a possibility.

[bfalls]

MARKW sounds right on. Because xovers overlap depending on how steep their slopes are, a speaker commonly has two or more drivers covering parts of the same freq range simultaneously. Although not ideal for an 8" driver to cover the mid-range, it happens all the time in a 2-way design, where the woofer is asked to go a little higher and the tweeter a little lower than ideal. I believe the overlap is called coloration and effects the overall frequency balance of the speaker.