28-Oct-2015, 07:45
Just to avoid confusion: the diagram completeluxury posted shows a low-pass filter, which would be applied to/in your sub. In your case I thought you were worried about loss of output from the mains when they were high-pass filtered.
If you mentally flip the diagram round (left-right) to make it look right for a high-pass filter you can see that the filter order doesn't have much effect on the output level within the pass band, that is above the corner frequency - in other words, in the part of the diagram covered by the light green block.
Put into your context: if you're setting the filter corner frequency to 25 Hz, it shouldn't have any audible effect at 100 Hz whether you use a 2nd or 4th order filter.
I'd suggest you should probably try to work out whether the high-pass filter is working correctly on the mains, and if not, fix it before trying to integrate the sub. The best way to do that will be to use some audio measurement software such as REW (other programs are available...). Otherwise I think you'll be chasing your tail.
It will quickly get more complicated once the sub is added and you start worrying about integrating it nicely. For example, you can read more about it (including a discussion about how to select filter orders) at these links:
What I learned from my reading on this topic is that there is no "one size fits all" set of right answers that you can just apply in all cases because the behaviour of each combination of main speakers, sub-woofer and placement in the room will be different. To get the best result in your set-up you need to invest time to experiment and listen carefully to (and preferably measure) the result of each changes you make.
If you mentally flip the diagram round (left-right) to make it look right for a high-pass filter you can see that the filter order doesn't have much effect on the output level within the pass band, that is above the corner frequency - in other words, in the part of the diagram covered by the light green block.
Put into your context: if you're setting the filter corner frequency to 25 Hz, it shouldn't have any audible effect at 100 Hz whether you use a 2nd or 4th order filter.
I'd suggest you should probably try to work out whether the high-pass filter is working correctly on the mains, and if not, fix it before trying to integrate the sub. The best way to do that will be to use some audio measurement software such as REW (other programs are available...). Otherwise I think you'll be chasing your tail.
It will quickly get more complicated once the sub is added and you start worrying about integrating it nicely. For example, you can read more about it (including a discussion about how to select filter orders) at these links:
What I learned from my reading on this topic is that there is no "one size fits all" set of right answers that you can just apply in all cases because the behaviour of each combination of main speakers, sub-woofer and placement in the room will be different. To get the best result in your set-up you need to invest time to experiment and listen carefully to (and preferably measure) the result of each changes you make.
Roon (Mac Mini), Wilson Benesch Full Circle, Expert 1000 Pro CI, Kaiser Chiara
Warwickshire, UK
