Axiom Home Page Forums General Discussion Home Theater An LFE question – I’m confused, again.

Mike, if you leave all speakers set to large in the player (disabling bass management in the player) then there is no issue. Since your reciever is capable of processing the analog inputs you can then apply your crossover settings at your receiver with no worries.

The issue only bites you if you are using analog inputs on a receiver that can't convert the analog to digital in order to apply bass management/xover and surround mode processing. Most receivers on the market can't do this. When you can't apply bass management settings with the receiver you are forced to use the bass management of the player.

Using the player's bass management causes the player to mix redirected bass from the speakers setup as small into the sub out channel along with the LFE. The 5dB attenuation is by design because adding the bass signals from up to 5 simultaneous channels on top of the LFE channel can overdrive the analog input on any receiver. The attenuation itself is really not the problem. The issue is that by design the LFE channel recorded on DVDs/Blu-ray/HD-DVD is 10 dB below the reference level. The reason the LFE is recorded 10dB low is for the same reason as before, the signal level would be "too hot" for use with analog inputs/outputs. It is the surround processors job to apply a 10dB boost to the LFE (but not the other channels) to give it the impact originally intended.

If the player mixes in redirected bass from the speakers setup as small, this and the LFE are now sharing a single analog path into your receiver. There is no way for the receiver to apply the 10dB boost to the LFE and not also the redirected bass from the other channels. Thus throwing off the intended level balance.

Again, if your receiver is capable of sampling the analog inputs and applying bass management / surround processing- just leave the players bass management off by setting all speakers large. Then the analog output for the sub does not contain anything but LFE, and your receiver can boost it correctly, and handle the crossover settings for your other channels by mixing in the redirected bass to your sub.