How do I set the crossover for 2 channel listening on my HT system?


My system consists of a Denon HT receiver powering a pair of B&W 805S speakers (and, unrelated to this question, B&W center channel and surround speakers) with a vintage M&K MX-350 THX subwoofer fed through the receiver’s LFE output via single subwoofer cable. In 2- channel mode the receiver is set for L/R front and subwoofer play only, using the Denon’s “Direct/Stereo” play mode. The signal is fed to the receiver via RCA interconnects from a stand-alone streamer (Bluesound Node 2i) and DAC (Topping D90).

The 805S speakers have an advertised frequency range of 49Hz–22kHz ±3dB. The subwoofer has a variable low pass filter adjustment ranging from 40 to 100Hz. The receiver’s speaker set-up settings allow a crossover setting in steps from 40 to 250Hz. The subwoofer’s phase adjustment has been properly set.

I understand a subwoofer crossover should roughly match a speaker’s low frequency capability, i.e., in my situation the M&K low pass should be set at approximately 49Hz. (I say roughly because the subwoofer crossover frequency is listed at +-6db whereas the speakers is at +-3db). But what effect is the crossover setting on the receiver having and where should it be set for 2-channel listening in my situation? Is the HT receiver’s subwoofer crossover setting controlling the signal to the subwoofer and either cancelling out or somehow multiplying the subwoofer’s independent crossover setting.   

sadbird

Showing 3 responses by sadbird

Thanks to all. To oldhvymec4: The front speakers are indeed set to Large in the speaker set up of the Denon AVR-2807. I thus understand the crossover setting on the Denon is irrelevant and the low pass filter setting in the M&K will control. On the other hand audiorusty appears to say the low pass filter on the M&K is irrelevant-- yet it is suggested I set the low pass on the M&K to its highest available, which in this case is 100Hz.  These seem contradictory.

Eric_squires: The 49Hz figure cited is the manufacturers spec for the 805S. I haven't any instrumentation to determine precisely. As indicated that figure is ±3dB and the M&K rating is ±6dB so there is a fractional difference where the blended frequency should be which I also cannot calculate and thus have used the speakers 49Hz as a "compromize". 

 

 

To bjp9738: Thank you for the clarification that the Denon crossover settings fo not apply to the LFE channel. I was concerned I was mutiplying or contradicting the settings if both the Denon's and M&K's were in play.

Based on what you said, if I am only listening to 2-channel stereo (thus only employing the FL/FR speakers and subwoofer and not the remaining surround sound speakers) there  apparently is no base management being used in the Denon. Under this circumstance I assume I should NOT set the low pass on the M&K to its highest setting but instead find an appropriate setting sounding best with the front speakers. Do I have this right?

(Also presumably when reverting to HT and using all speakers your advice to set the M&K high would then apply.)

bjp9738:

Thanks for beng so generous with your time and information. The fronts are set to large and I'll follow your guidance regarding the settings on the receiver and sub and--to take a line  from russ69 above--set the sub to its max and then make any slight  adjustment until it sounds right.

I appreciate everyone's input.