@rauliruegas wrote: "The main reason to integrates a pair of self sealed ( not vented ) powered subs in true stereo fashion along any passive main speaker in a home audio system is to reduce IMD in the speaker/system and you can achieve that main target only through a high pass filter ( teflon cap. ) like the one @bdp24 advise."
I think that what works best depends on the specific situation.
And in particular regarding vented vs sealed subs, again imo it depends on the specifics. I can go into detail if you’d like.
"According with a scientific JBL studies the ideal number of subs in a home system is four subs and at least two. The number of subs makes evenly the room/system bass frequency range response."
Yes, I’m quite familiar with Todd Welti’s study. I manufacture a four-piece subwoofer system called the Swarm, and in my setup guidelines I include Welti’s recommendations along with several asymmetrical suggestions. Welti did not investigate asymmetrical placements but Earl Geddes has.
Briefly, the in-room smoothness goes up as the number of intelligently-distributed subs goes up, and smooth bass is "fast" bass. So two subs are twice as smooth as one, and four subs are twice as smooth as two, and eight subs are grounds for a divorce. So four subs is probably ideal!
Duke
