I have 2 JL Audio Subwoofers in a ported box and the box is tuned to 34 Hz my amps subsonic filter can be set from 15 Hz to 40 Hz should I set the amps filter the same as the box's tuned frequency?
you can set the SSF to 20Hz for a sealed box. that will prevent power from being wasted trying to reproduce any signals below the range of hearing. Although in actuality most source material is filtered below 20Hz already.. CD is. MP3 is. Radio can't even reach 20Hz. Neither can tapes. you'd pretty much need a signal generator to go below 20Hz unless it's just harmonics of produced frequencies anyway.