ApexJr Ribbon Tweeter Frequency Response

The Black, Blue, & Red curves are John Schroeter's measurements done with Speaker Workshop. The data is unsmoothed and was measured at 1 meter w/ a 4 ms MLS window. The tweeter was mounted on a 24" square baffle with the center of the tweeter about 4' above the floor. The mic I used was a calibrated capsule from Kim Giradin, who also supplies the mics for the Wallin/Neal pre-amp kit. The correction (the mic capsule was +/- 0.5 db throughout) was incorporated into Speaker Workshop. No blocking cap used during measurement. No modifications were made to the tweeter. The tweeter has low hours on it.

The green curve is the one-third octave RTA from some initial play with Mac-the-Scope using a swept sine. The confidence level on this result is very low. Measurement is at 1 m with an Apple PlainTalk mic. This mic is a completely unknown beast in terms of its FR (but it let's me play). 13.3 mF blocking cap. The ribbon has had the metal grill (and the plastic grill holder) removed. Ribbon is mounted on the top of a pyramidal mini-monitor, at a height of about 3'.

Please feel free to e-me with more results.

[ Back to the TL Speaker Page | ApexJr Ribbon ]