Panasonic DMP-BD80 Blu-ray Disc Player / Yamaha DSP-AX630SE - no LFE

[amanlikethat]

I recently upgraded my disc player from a Denon 1940 to the Panasonic BD80. I am delighted with the new player. The image and sound quality are truly excellent. However I have one problem. For some reason when connect to the Yamaha amp using the 5.1 analog outputs from the player, I am getting nothing through the subwoofer. My subwoofer is a Mordaunt Short Genie 409W.

I know that the connection between the amp and subwoofer is working as I can run a sound test from the amp and all 5.1 channels produce a test tone through each speaker.

The BD80 has an audio setup facility to test each channel too. When I run this test no test tone is sent to the subwoofer. Also when I play a blu-ray disc such as the wonderfully remastered '2001: A Space Odyssey', no LFE can be heard through the subwoofer. When I revert the set up back to the Denon 1940 DVD player and connect the audio from the Denon to the Amp using a SPDIF cable, 5.1 multi-channel sound works correctly for my DVDs.

Any suggestions? Am I missing something obvious?


Thanks.

[MrBoylan]

I recently upgraded my disc player from a Denon 1940 to the Panasonic BD80. I am delighted with the new player. The image and sound quality are truly excellent. However I have one problem. For some reason when connect to the Yamaha amp using the 5.1 analog outputs from the player, I am getting nothing through the subwoofer. My subwoofer is a Mordaunt Short Genie 409W.

I know that the connection between the amp and subwoofer is working as I can run a sound test from the amp and all 5.1 channels produce a test tone through each speaker.

The BD80 has an audio setup facility to test each channel too. When I run this test no test tone is sent to the subwoofer. Also when I play a blu-ray disc such as the wonderfully remastered '2001: A Space Odyssey', no LFE can be heard through the subwoofer. When I revert the set up back to the Denon 1940 DVD player and connect the audio from the Denon to the Amp using a SPDIF cable, 5.1 multi-channel sound works correctly for my DVDs.

Any suggestions? Am I missing something obvious?


Thanks.

You are missing something, but it's not obvious. First of all, the Panasonic player does not issue a test tone on the subwoofer in the speaker config. Weird but true.

Secondly, the subwoofer channel is actually stored/encoded on the software (DVD, Blu-ray, etc.) about 10 dB below where it "should" be. This is done so as to prevent overload of the subwoofer channel during analog transmission. Digital transmission systems compensate for this by automatically raising the subwoofer channel 10 dB at play back. So if you use fiberoptic or coax S/PDIF connections or HDMI, you'd never experience this issue because the receiver would compensate. But not so in the analog domain.

You need to raise the subwoofer channel 10 dB (if speakers are set to large) or 15 dB (if speakers are set to small, in the player) in order to get a correct blend of subwoofer channel to the other channels. Your receiver may have an adjustment for this (check the manual). If not, then you may need to lower the other channel levels to compensate, and also adjust the subwoofer level control itself (the knob on ths unit).

This is not something specific to the BD80 but if affects nearly all BD players with multi-channel analog outputs. AFAIK, only the Pioneer BDP-320 and the OPPO BD-P83 actually allow you to *raise* the subwoofer channel over multi-channel output. The Pioneer only allows +6dB which is insufficient. The OPPO allows either 10db or 12dB I think. But then you can run into other issues if you boost the levels too high in the player. A better solution is to have the receiver add the boost, so check your manual to see if this is an option.

Also, I'd recommend reading Peter O'Connell's tutorial on the subect. It's a quick read and invaluable if you're trying to do this kind of set-up:

How To Set up a Blu-ray Player Using Multi-Channel Analog Outputs... And Why: BigPictureBigSound

Good luck!

-Chris