Denon AVR: No bass mgmt if no .1 signal comes in

[The Bright Side]

[EDIT: I thought at first this was a problem with both my surround systems, but it's only the Denon]

Hey guys! I realized something completely bewildering the other day.

I have a Linux Mint PC hooked up to my 7.1 sound system (Denon AVR-X1400H receiver) via an HDMI cable running from the PCs' Nvidia graphics card to the AVR's HDMI-in. The AVR is set to send frequencies below 80Hz to the subwoofer.

If I play back 4-channel or 5-channel files, like Dark Side of the Moon or David Elias' "Crossing" album, there's no LFE! Even though the AVR should send low frequencies there.

What's even crazier: As soon as I add silent (!!) LFE channels to the FLACs, bass management starts working. I'm completely mystified about this. Does anybody have any idea why this is happening!? Any inkling would be greatly appreciated.

I'm currently in the process of converting all my 4.0 and 5.0 files to add silent LFEs, which is a crazy amount of work... But the increase in sound quality makes it really worth it. I used to think Dark Side of the Moon, the Santana SACDs or the Doobie Quadio box just had bad bass, but damn they sound incredible once the bass management actually works.

 

[The Bright Side]

UPDATE. I looked at this more closely and put my hand on the subwoofer while playing back the 4-channel and 6-channel files. It actually feel like the sub response is the same. It's just that when playing back 6-channel files (with silent LFE or silent C and LFE in case of quad), there's much more bass overall. So I guess the extra bass is coming from the fronts. So weird!

 

[shokhead]

In your listening position if you can tell the bass for music is coming from the sub then it's not set up right.

 

[The Bright Side]

Hmm, it's really difficult to tell. I can say this much, as soon as I make 6-channel files out of my 4-channel files, everything sounds more awesome. I think the added bass is coming from the FL and FR speakers. I'm almost through converting and checking my entire collection.

 

[par4ken]

I'm currently in the process of converting all my 4.0 and 5.0 files to add silent LFEs, which is a crazy amount of work... But the increase in sound quality makes it really worth it. I used to think Dark Side of the Moon, the Santana SACDs or the Doobie Quadio box just had bad bass, but damn they sound incredible once the bass management actually works.

Glad that you have it sorted out! I could never understand those reports of week bass.