I tried to find an English manual for a model that is close to the model numbers in mfabien's post and the manual for the VR-6070 mentions subwoofer remix:
ftp://docs.kenwoodusa.com/manuals/OM-VR-6070-2002-KUSA.pdf
From the manual in Preparing for Surround Sound - speaker settings - page 23:
4 Use the MULTI CONTROL knob or Joystick to select the appropriate front speakers setting.
1 FRNT LARGE : Large front speakers are connected to the receiver.
2 FRNT NML/THX : Average size front speakers are connected to the receiver. 'Small' speakers for receivers that follow the bass mgmt naming conventions.
• For “FRNT LARGE” selection, no sound will be heard from subwoofer speaker even when it is set to ON. However, if you select “SW RE-MIX ON” when subwoofer is selected, you will be able to hear sound from the subwoofer. When in STEREO mode, the sound goes directly to front speaker.
So it looks like with 'subwoofer remix' set to on, the sub will be active for those channels set to Large. It doesn't mention exactly *what* will be sent to the sub. I would assume it is LFE only (and thus equivalent to LFE+MAIN (Denon), Plus (Pioneer), or Double Bass (Onkyo) settings) because it does say that in Stereo only the fronts will get the bass.
It is yet another example of manufacturers using non-standard terminology thus making an already confusing topic (bass mgmt) even more so. Reminds me of the Onkyo 501 where Onkyo also invented their own terminology. Rather than the typical Small vs Large and Subwoofer=yes or no, the 501 required you to choose Subwoofer mode=1,2, or 3. Mode 1 was equivalent to all speakers Small and Sub=yes, Mode 2 = Fronts Large, Center and Surrounds = Small, and Sub = yes and Mode 3 = All speakers Large and Sub=no. That was just plain dumb and Onkyo saw the light and went with the standard terminology for the x02 models. Maybe Kenwood will similarly see the light someday...