One sub, a two channel system ,one HT reciever ??

The idea behind not running the signal through a crossover is that it represents an additional degradation of the signal before it has been amplified, a degradation here can never be recovered. The crossover inside speakers represent a division of frequencies of an ALREADY AMPLIFIED signal and has far less effect on the sound. I am unfamiliar with multichannel systems and so don't understand the purpose of setting the crossover at 120hz but in operation no sub should EVER be set this high. Anything operating in that range is not a sub but a woofer. I run my subs as low as possible, I never have the sub crossover set above 40hz. In this way the output of the sub is nondirectional and it supplements the bass of the main speakers instead of interfering with it. Again I am writing from the perspective of 2 channel sound and of someone who uses subs with response below 20hz. The Nelson Reed was specified to do 120db at 20hz and extend to 16hz. The REL and HSU will go almost as low but not nearly as loud; they don't have 8 12" Volt drivers as the Nelson Reed.

I am currently running Spendor SP-1/2s with a REL stadium 11 sub. I am using the speaker level inputs to the sub rather than the line level which would allow me to roll off the bass. Why. First, this is what REL recommends. Second , I have never had an active crossover I couldn't hear. Such may exist but they would be very expensive. A custom passive crossover would be the way I would go if I was inclined to use one. For me the critical factor it that running the main speakers full range is what they were designed for. Rolling off their bass may enable them to play louder but when I have tried it I found the benefits mostly theoretical and the drawbacks obvious. BUT, if I have learned anything in 45 wears in audio it is we all hear differently and listen to different things in music so it a personal choice.

Tcatman,

I agree with Shadorne's suggestion re high quality HT pre amp. Even my vintage Proceed PAV/PDSD pre/pro combination does a fine job managing the interface of my KEF 104/2s and Velodyne HGS-15, whether stereo or 5.1. I take the balanced LFE output from the PDSD to a Velodyne SMS-1 room-correction manager, then to the balanced input of the HGS-15. Crossover is set at the pre/pro to 80 Hz, the Velodyne crossover is switched out, and the speakers are set to small. I can adjust the level of any speaker with the PAV/PDSD remote, and I set them with a RS SPL meter using the white noise generated by the PAV.

I've tried variations of this setup, but this is the one I prefer. Experienced listeners tell me they are unaware of the sub as a separate source of sound.

db

Running the mains full range as Rel suggests, either works, or doesn't work...it has a lot to do with whats going on with the main speakers. The Kef's may work great...many smaller ported speakers may not, again....it depends.

No amount of gibberish by Rel, or anyone else, can change the facts.

If it works...thats great. If it doesn't work (and it won't always work)....you will need to fix it, or you won't be happy.

Dave