In Reply to: Notch filter for TAD TD4001 posted by fatbottle on February 16, 2007 at 08:05:29:
FatbottleI don't know what the frequency response of the TAD looks like but if it resembles at all the jbl 244x series drivers (or any 2" exit driver for that matter) it would probably start falling off around the 600hz mark at about 12db/octave. You 're using a 2nd order electrical filter that would result in a 24db/octave acoustic roll-off if my assumption is right. Since most likely the woofer's response is still flat at that frequency, the acoustic roll-off is the same as the electrical roll-off at only 12db/octave so when the two responses sum they would create a peak.
Also because of the assymetry there should its possible that there are phase tracking anomalies that affect the off axis response as well. Without measurement capability it would be a difficult task to get the FR to sum flat but someone below had a good suggestion when he mentioned the -6db thing. At least you could try it by using cheap parts at first to see if you get anywhere.Cheers
G
This post is made possible by the generous support of people like you and our sponsors:
Follow Ups
- Re: Notch filter for TAD TD4001 - sonicboom 18:07:53 02/18/07 (0)