Harrison FMOD passive filters.
pearsall001
Posts: 5,068
I tried an experiment with these filters from ACI & Harrison. My first were hi-pass filters from ACI (65Hz & 85Hz). Since my NAD AVR has an optional "Enhanced Bass" setting (this setting allows you to set your speakers to large with the full range signal going to both my mains & the two subs). So with the mains set to large & the enhanced bass option turned on I player aroung with both filters on my two channel amp. The 65Hz hi-pass gave the best results. In fact I liked the performance of this passive filter over the AVR's XO with my mains set to small.
I liked the outcome so much that I went & ordered a few low-pass filters from Harrison to try out with my two subs http://store.hlabs.com/pk4/store.pl?view_product=9. I tried the 50Hz & 70Hz low-pass filters. With my crossover defeated on the subs I played around with both pairs of filters. The 70Hz low-pass filter really settled in & offered the best performance.
I was extremely happy with my setup using the AVR's XO along with the Velo subs XO's, but these filters have raised the bar even further.
The winning combo are the 65Hz hi-pass filter on my two channel amp (speakers set to large & the enhanced bass option turned on...full range signal is sent to my mains & also to the subs). And the 70Hz low-pass fliters on both subs (with the subs internal XO's defeated). My center & surrounds are still set to small.
As I stated before I was extremely happy with the performance in both HT & two channel using the AVR's XO along with the Velo's XO. But now that the XO's in both the AVR & the subs are bypassed these passive filters have raised the bar big time. If you want to experiment with these passive filters you might just find them to your liking also. Both are worth the price of admission.
I liked the outcome so much that I went & ordered a few low-pass filters from Harrison to try out with my two subs http://store.hlabs.com/pk4/store.pl?view_product=9. I tried the 50Hz & 70Hz low-pass filters. With my crossover defeated on the subs I played around with both pairs of filters. The 70Hz low-pass filter really settled in & offered the best performance.
I was extremely happy with my setup using the AVR's XO along with the Velo subs XO's, but these filters have raised the bar even further.
The winning combo are the 65Hz hi-pass filter on my two channel amp (speakers set to large & the enhanced bass option turned on...full range signal is sent to my mains & also to the subs). And the 70Hz low-pass fliters on both subs (with the subs internal XO's defeated). My center & surrounds are still set to small.
As I stated before I was extremely happy with the performance in both HT & two channel using the AVR's XO along with the Velo's XO. But now that the XO's in both the AVR & the subs are bypassed these passive filters have raised the bar big time. If you want to experiment with these passive filters you might just find them to your liking also. Both are worth the price of admission.
"2 Channel & 11.2 HT "Two Channel:Magnepan LRSSchiit Audio Freya S - SS preConsonance Ref 50 - Tube preParasound HALO A21+ 2 channel ampBluesound NODE 2i streameriFi NEO iDSD DAC Oppo BDP-93KEF KC62 sub Home Theater:Full blown 11.2 set up.
Post edited by pearsall001 on
Comments
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I also use a low-pass filter with my B&K Ref 5 pre-amp's sub-out. I think the non-adjustable x-over is set at 80HZ and that was too high, so I added the 70HZ filter and no longer get voices going to my sub.
I use a 50HZ filter on an older AVR in my theater to a NAD amp brdiged to mono for my SVS passive sub. That works exceptionally well to blend with my LS-90's.
One last use for the extra 70HZ filter was to use the pre-outs of an HK receiver to a small powered sub that didn't have a crossover. Matched that with a pair of Minimus 7's and had a pretty decent system that we gave to my daughter's friend.
BTW, Parts Express carries these, too. -
Another happy user here. Also great if you want to dip your toes in (sorta) active biamping. Instead of ripping out your existing crossovers, pick up a pair of these that's well outside your existing crossover range to filter some more extreme freq's and ease up the load on your amp.Gallo Ref 3.1 : Bryston 4b SST : Musical fidelity CD Pre : VPI HW-19
Gallo Ref AV, Frankengallo Ref 3, LC60i : Bryston 9b SST : Meridian 565
Jordan JX92s : MF X-T100 : Xray v8
Backburner:Krell KAV-300i -
Hey all,
I'm researching these inline filters and wondered if anybody is still using them, and if they're happy with the results.
I'm after upgrading my two-channel setup and am looking at tube or tube-hybrid preamps to replace my Emotiva USP-1. The problem is that I love the built-in high-pass/low-pass analog bass management feature in the Emotiva. Running LSA-1 Signature monitors and a Salk Songsub, high-passing the speakers at 50hZ and the low-passing sub at about 52hZ. This sounds worlds better than running the speakers full range and using the sub's crossover to blend it in, not because it's a more seamless blend, but because I have a horrid room peak at 40hZ and another at around 31hZ, and sending everything below 50hZ to the sub, where it can be equalized by my Anti-Mode 8033, makes for nice tight bass. Putting the peaks right back into the room, coming from the speakers, muddies everything up.
So, the thinking is: a 20Hz FMOD filter and a 30Hz stacked with a 3dB attenuator between them to make a 24dB/octave 50Hz high-pass filter for my speakers, placed between the preamp and amps, and a full range signal sent to the sub, which has a 24dB/octave variable crossover. Now I don't need the bass management feature of the Emotiva.
The concern is: Signal degradation.
Do these things pass the frequencies above their designated roll-off point cleanly with no loss of detail and/or dynamics? That is the question.
Anybody?
