Who makes quality sealed box speakers?

Very few. But if you want a very good used one The Avalon Radian and Radian HC are your ticket. In fact I prefer my Radian model to the older Eidolon model ( which is a modified port design), particularly the integration of the bass to the midrange.... very seductive!

Any even better question is:

Who makes a sealed active speaker?

Well, Vandersteen for one. The 2ce sig, 3a sig and 5a's are all sealed designs. The 1c is a tuned transmission line.

Bigtee, can a passive radiator design really be called sealed? I think technically it is not. But I'm sure someone will correct me if this is not correct.

supporting evidence #1

supporting evidence #2

VISION ACOUSTICS! I am not sure if they're still in business....

My SAP Quartettes.

Aroc, Vandersteen uses a very unique arrangement. That so called passive radiator is actively driven below 35hz. The 8" driver acts in a sealed enclosure. The Vandersteen is sealed and is designed for a Q of about .7.

klipsch heresy II....

According to what I have read, a PR system is fundamentally the same as a ported system, except it is more easily tuned by mass loading the PR instead of changing port dimensions. Also it avoids the port "wind" noise problem.

One interesting variation is to use a full driver (including magnet and voice coil) instead of a PR. Then you can tweek the system with inductors and capacitors across the coil, as well as by mass loading.

A final version, that I have played with is to actively drive the driver that functioning as a PR with a separate SW power amp that has frequency and phase control. If I had to give this scheme a name I would call it "Active Damped".

But, when all is said and done, my preference is for a Planar (or open baffle) system, with a sealed subwoofer.

Merlin TSM range

Source Technology does. They are awesome speakers

Pete

http://sourcespeaker.com/