As far as I can tell a Kelton Subwoofer seems to be a bizarre, bandpass, passive radiator system offering no benefits that couldn't be achieved by a bigger driver.
Thoughts?
Thoughts?
At a glance it appears to basically be RCA's Harry Olson's isobaric driver variant, i.e. uses a PR in lieu of a second driver, so a larger and/or higher Xmax driver with a tiny Vas spec could work just as well.
GM
GM
Looks like a bandpass subwoofer that's tuned with a PR instead of a vent. There are some significant advantages to doing so, including smaller box size (no extra space required for a vent) and a reduction in out of band resonance peaks (no "organ pipe" vent effects). Also, with no vent to worry about, you've got a lot more options available concerning the physical layout of the box.
The disadvantage of course is that this comes at an extra cost - PRs usually cost more than vents. And PRs will distort more than vents when both are in their linear range of operation. For subwoofers however that distortion is likely to be unnoticeable.
Using PRs instead of vents for a bandpass subwoofer is a viable alternative - see link below for a good example of one in use for a commercial speaker system.
Elac Adante AF-61 loudspeaker | Stereophile.com
The disadvantage of course is that this comes at an extra cost - PRs usually cost more than vents. And PRs will distort more than vents when both are in their linear range of operation. For subwoofers however that distortion is likely to be unnoticeable.
Using PRs instead of vents for a bandpass subwoofer is a viable alternative - see link below for a good example of one in use for a commercial speaker system.
Elac Adante AF-61 loudspeaker | Stereophile.com
I've just looked at the specs on a commercial Panasonic system. They are the worst I've ever seen.
6.5" sub 10" radiator.
Frequency response. 35Hz to 200Hz - 16db
SPL. 78db!
6.5" sub 10" radiator.
Frequency response. 35Hz to 200Hz - 16db
SPL. 78db!