Klipsch Chorus II
Posted: Fri Sep 18, 2009 2:57 pm
I picked up a set of Chorus II a while back. There's more than couple references in this hijacked thread:
http://diytube.com/phpBB2/viewtopic.php ... c&start=37
One had a badly damaged passive radiator, so I fabricated a plug-in port tube replacement for it.
I had hoped to properly tune the port to match (or exceed) the performance of the factory PR, but things got real busy this summer. Only recently have I had the time time to spend on these speakers. I've built an impedance testing jig and plotted the curves for the Chorus II. The next images show the impedance plot for the left and right speakers, both with the passive radiator installed. I believe the trick is to trim the length of the port until the resonant peaks in the impedance curve (seen at approximately 29 Hz and 68 Hz in the plots below) are of equal magnitude. You can see that with the PRs installed, the tuning is correct. Next I need to mount my port assembly into one of the cabinets, and determine how far off it is. I intentionally left the port long, so I expect the port tuning frequency will be too low.
http://diytube.com/phpBB2/viewtopic.php ... c&start=37
One had a badly damaged passive radiator, so I fabricated a plug-in port tube replacement for it.
I had hoped to properly tune the port to match (or exceed) the performance of the factory PR, but things got real busy this summer. Only recently have I had the time time to spend on these speakers. I've built an impedance testing jig and plotted the curves for the Chorus II. The next images show the impedance plot for the left and right speakers, both with the passive radiator installed. I believe the trick is to trim the length of the port until the resonant peaks in the impedance curve (seen at approximately 29 Hz and 68 Hz in the plots below) are of equal magnitude. You can see that with the PRs installed, the tuning is correct. Next I need to mount my port assembly into one of the cabinets, and determine how far off it is. I intentionally left the port long, so I expect the port tuning frequency will be too low.