Bass management--high/low pass filtering

Many subs have active high pass crossovers.  Lots of people use this configuration.

My setup has a separate preamp/amps....I split the preamp output signal and sent part of the signal to an active low pass crossover set at 63hz that then feeds the line level inputs of an integrated amp.  The speaker outputs of the integrated amp feed the 8" woofer of my main speakers, plus it feeds the high level inputs of my active subwoofer, and I set the low pass of the sub at 50hz with reverse phase. 

The other side of the preamp output feeds my monoblock tube amps....there is a 10nF silver mica capacitor that acts as a high pass inline filter that restricts low bass < 63hz to the tube amps, and passes everything else to the 5-1/4 midbass and tweeter that use a passive crossover.

I ran the above configuration without the inline high pass crossover (10nF cap) to the tube amps for a while, and I thought it made a notable improvement once installing it, but every situation is different so it may or may not be a good solution for  you.  I know it sounds complicated from a glance, but it’s not bad, and this setup evolved over time... it made sense in my case and has worked out extremely well for me.

You can start out inexpensive with Harrison Labs in line filters. If it works for you can decide on more expensive solutions like Marchand or JL Audio. I high pass me mains at 50 Hz before the amp. It really helps the sub integration.

There are a couple of options for you. The JL Audio Crossover is an excellent choice.  Another option is the SPL Crossover which I use. Both units allow you to adjust the low and high crossover points on the fly. This does require a separate power amp for the subs, but most subs today have their own built in power amps. The benefit is reducing the demand on the primary speakers allowing them to focus on rest of the music.

+1 @avanti1960 !

I agree with running your speakers full range.  I have the option of setting both the low and high pass filters in my main system.  I find I like the sound better running the speakers full range and now full range out to my subs using the preouts.  I even switched off the low pass filter on my subs.  You need to have a room that is well setup acoustically and I dial in the volume on the bass but it works for me.  I’m a bass guy which is a good thing because only my dog can hear the high end anymore.  Suggest experimenting with your settings and find what you like best.  It’s a fun part of this hobby for this old guy.