25-Nov-2024, 21:01
I assume you mean the "order" of the filter, 1st/2nd/3rd/4th order?
This relates to the steepness of the rolloff for the low-pass filter. So, as the frequency rises above the nominal "crossover frequency", how quickly - in decibels per octave - will the notes the subwoofer play get very quiet and then inaudible. The higher the order, the steeper the rolloff.
Generally you want a fairly steep rolloff, for two reasons 1) you don't want the sub to be playing any notes higher than it has to, in the mid-bass region, because your main speakers will be better at this and 2) your main speakers, especially if they are ported, will form a high-pass filter which will also roll off quite steeply. Thus, to create an even response in the crossover musical region you want a progressive handover from the main speakers to the subwoofer as the pitch descends. But RELs have their own low pass filter too, with - depending on the model - less flexibility on the order of the rolloff, and whether or not it is actually engaged on a particular input.
But the key is trial and testing. I find a signal generator, and a set of known tracks with substantial infra bass content, invaluable. One can literally go note by note in the bottom octave (16Hz - 32Hz). It takes a while to get it right for the room and for your tastes, but it's a fabulous thing when you get there and you can enjoy the results of your labours with every track.
This relates to the steepness of the rolloff for the low-pass filter. So, as the frequency rises above the nominal "crossover frequency", how quickly - in decibels per octave - will the notes the subwoofer play get very quiet and then inaudible. The higher the order, the steeper the rolloff.
Generally you want a fairly steep rolloff, for two reasons 1) you don't want the sub to be playing any notes higher than it has to, in the mid-bass region, because your main speakers will be better at this and 2) your main speakers, especially if they are ported, will form a high-pass filter which will also roll off quite steeply. Thus, to create an even response in the crossover musical region you want a progressive handover from the main speakers to the subwoofer as the pitch descends. But RELs have their own low pass filter too, with - depending on the model - less flexibility on the order of the rolloff, and whether or not it is actually engaged on a particular input.
But the key is trial and testing. I find a signal generator, and a set of known tracks with substantial infra bass content, invaluable. One can literally go note by note in the bottom octave (16Hz - 32Hz). It takes a while to get it right for the room and for your tastes, but it's a fabulous thing when you get there and you can enjoy the results of your labours with every track.
1000 Pro CI / Magico A5
440 Pro CI / Magico S1mkII / REL Studio III
440 Pro CI / Magico S1mkII / REL Studio III
