Bass management--high/low pass filtering


A few days ago I posted to this forum seeking recommendations for a new subwoofer, and that discussion has turned out to be very enlightening, offering advice about subs and integrating them into my system. One reply mentioned the advantages of bass management for my main speakers (Ryan R-610 bookshelf speakers), but rather than sidetrack that discussion I thought I'd ask this separately:

It was suggested that I try cutting off the frequency response of the Ryans at 60 or 80Hz and letting the sub take over from there, thus relieving the mid/bass woofers of that substantial burden. On paper, this seems like a promising avenue to pursue, so I'm wondering if anybody has tried this and if there is a hardware device that can accomplish it. I'm certainly not an electrical engineer--far from it--so trying to design and build one is way beyond me. 

My integrated amp is a Modwright KWI200 and my previous sub (which is now dead and not repairable) was connected via speakon (speaker level) cable, though the Modwright does have a pre-out that can also be used to connect to a sub.

While pretty much all active subwoofers have adjustable low-pass filters, it appears that this would entail a high-pass filter somewhere in the chain. Is this something I can buy as an add-on? Couldn't find anything online, so I'm hoping that somebody may have some suggestions. Thanks.

cooper52

Hi OP,

Unfortunately I don't see an easy way for you to accomplish this.  Your integrated has preamp outs, so you can connect your sub's line level (RCA) inputs this way but there's no way to limit the amount of bass that reaches your speakers.  However, you can plug the ports, which I often recommend for 2-way speakers with subs.  This will somewhat reduce the excursion below the tuning frequency but reduce the output so you can turn the sub up higher.  this will make it easier to integrate the two.

If possible however an approach that did let you put a high pass filter in line with your main amplifier would improve upon that.   Maybe talk to MW and see if they have a suggestion? 

yes, my system has a DSP tool as the DAC/Pre/Streamer that also has subwoofer outs and a bass management system so integrating a subwoofer is less tasking with it. So, unless you're willing to change your system I guess others can chime in @cooper52 

That's pretty much what I figured after failing to find anything online. I'll just deal with things as they are and integrate the new sub (yet to be decided upon) accordingly. My previous sub, a REL S/2, worked seamlessly once I got the settings to my satisfaction. Don't really have any interest in doing a wholesale system change just for this. And anyway, I really like the Modwright and would be hard-pressed to find anything within my budget that I think I'd like half so well. 

@cooper52 

Your speakers have decent bass down to about 44Hz -3db.  You can add a subwoofer and set the low pass filter for 44Hz and no need to high pass the main speakers.  

You paid for decent bass from your speakers, why not use it? 

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.