Good. It must be this one. MPT-165 Monacor similar on the outside to the Motorola 1165. (but)They don't come even close. (http://www.monacor.com/en/produktseite_stageline.php?artid=5353&spr=EN&typ=u). Are you using it with or without a piezo filter? Do you have the same SPL on the speakers? I just made one with a 5db attenuation@20KHz following Wayne's rule of thumb "Pi implementations of quartz piezoelectric tweeters". Regards