Joined
·
1,423 Posts
FAQ: Denon 2500, Panasonic DMP-BD10, Panasonic DMP-BD30 "LFE Bug"
Update:Issue is resolved on DMP-BD30 ONLY with firmware v1.6.
There is currently no resolution for Denon 2500 or DMP-BD10.
What is the issue?
The LFE channel (the .1 in 5.1 or 7.1) for PCM output over HDMI is 5db lower than it should. This applies to any tracks internally decoded to PCM or native PCM track on the disc.
What is a LFE?
The LFE or Low Frequency Effect is channel that contains frequencies below 120Hz. It is the ".1" in 5.1 or 7.1 tracks. It contains sounds designed to go exclusively to the sub woofer.
Is analog affected?
No. Analog does not appear to be affected. The output leaving the mixer is -5db but the LFE channel is amplified 5db after DAC (digital to analog conversion) so it is at the proper level.
Is SPDIF (digital out, optical out) affected?
No. This only affect PCM output on the LFE channel. PCM is limited to 2 channels (Left & right) over SPDIF. There is no LFE output to be affected.
Is bitstream output affected?
No. Bitstream output which is sending the raw compressed track is not affected. DD, DTS, DD+, TrueHD, DTS-HD, DTS-HD MA tracks are NOT affected if the player output is bitstream. Regardless of the player settings LPCM tracks are always sent as PCM so LPCM tracks on a BD disc output over HDMI will always be affected.
So if I have player set to bitstream to a compatible receiver (Onkyo-705) I am not affected?
No. LPCM tracks on the disc are output as PCM regardless of player settings. Since they are output as PCM they will be affected. There is currently no player setting to bypass the issue when playing a PCM track.
Can't I just boost the LFE channel +5db on my AVR (receiver)?
Virtually all AVR only allow lowering the LFE channel not raising it. If you AVR has a +5db setting it could compensate but I am not aware of any AVR that has such a setting. This is not the same thing as boosting the sub (see next questions).
Can't I just boost the subwoofer output +5db on my AVR (receiver)?
Not if you are using any bass management. Most HT setups redirect bass below a certain cutoff (40Hz, 60Hz, 80Hz) from main speakers to the subwoofer. Boosting the sub +5db will make the LFE channel have proper level but now the redirected bass from other 5 or 7 channels is now running "+5db too hot".
I am not using any bass management (speakers set to "large"). Can I boost subwoofer output +5db?
Yes. If the AVR is not applying ANY bass management then all bass from main channels goes to main speakers. There is no redirected bass, only the LFE channel goes to the subwoofer. The sub should be raised +5db for LPCM tracks and set to normal on all other tracks. For bass management to be turned off all speakers must be able to handle full range as main channels routinely have bass
Update:Issue is resolved on DMP-BD30 ONLY with firmware v1.6.
There is currently no resolution for Denon 2500 or DMP-BD10.
What is the issue?
The LFE channel (the .1 in 5.1 or 7.1) for PCM output over HDMI is 5db lower than it should. This applies to any tracks internally decoded to PCM or native PCM track on the disc.
What is a LFE?
The LFE or Low Frequency Effect is channel that contains frequencies below 120Hz. It is the ".1" in 5.1 or 7.1 tracks. It contains sounds designed to go exclusively to the sub woofer.
Is analog affected?
No. Analog does not appear to be affected. The output leaving the mixer is -5db but the LFE channel is amplified 5db after DAC (digital to analog conversion) so it is at the proper level.
Is SPDIF (digital out, optical out) affected?
No. This only affect PCM output on the LFE channel. PCM is limited to 2 channels (Left & right) over SPDIF. There is no LFE output to be affected.
Is bitstream output affected?
No. Bitstream output which is sending the raw compressed track is not affected. DD, DTS, DD+, TrueHD, DTS-HD, DTS-HD MA tracks are NOT affected if the player output is bitstream. Regardless of the player settings LPCM tracks are always sent as PCM so LPCM tracks on a BD disc output over HDMI will always be affected.
So if I have player set to bitstream to a compatible receiver (Onkyo-705) I am not affected?
No. LPCM tracks on the disc are output as PCM regardless of player settings. Since they are output as PCM they will be affected. There is currently no player setting to bypass the issue when playing a PCM track.
Can't I just boost the LFE channel +5db on my AVR (receiver)?
Virtually all AVR only allow lowering the LFE channel not raising it. If you AVR has a +5db setting it could compensate but I am not aware of any AVR that has such a setting. This is not the same thing as boosting the sub (see next questions).
Can't I just boost the subwoofer output +5db on my AVR (receiver)?
Not if you are using any bass management. Most HT setups redirect bass below a certain cutoff (40Hz, 60Hz, 80Hz) from main speakers to the subwoofer. Boosting the sub +5db will make the LFE channel have proper level but now the redirected bass from other 5 or 7 channels is now running "+5db too hot".
I am not using any bass management (speakers set to "large"). Can I boost subwoofer output +5db?
Yes. If the AVR is not applying ANY bass management then all bass from main channels goes to main speakers. There is no redirected bass, only the LFE channel goes to the subwoofer. The sub should be raised +5db for LPCM tracks and set to normal on all other tracks. For bass management to be turned off all speakers must be able to handle full range as main channels routinely have bass