Can Someone help Explain to me what AVR Crossover setting do to each pair involved in the crossover

[rimmi2002]

Hi,


Sorry, this might be a very newbie question, but I still don't have a clear understanding of what happens at the Crossover Frequency for the subwoofer vs speakers in an AVR. For example, I have the Onkyo NR7100.


It has a crossover point and LPF (Low-Pass Filter) for LFE settings (set at 120 Hz).


Hypothetically speaking:


If a 5.1 system has a crossover point of 80 Hz and LFE of 120 Hz, does this mean:


Below 80 Hz:

• Speakers are rolling off at 12 or 24 dB/octave and gradually play at full capacity at 80 Hz?
• Subwoofer is playing at full strength up to 80 Hz?

At 80 Hz and above:
a) The subwoofer starts to roll off at 12 or 24 dB/octave. If this is true, then what is the purpose of the LFE Low-Pass (LP) setting?


or


b) Does the subwoofer keep playing until the LFE Low-Pass setting of 120 Hz for my system, and then roll off? If this is true, then what happens if you set the crossover above the LPF of LFE setting of 120 Hz, say crossover at 150 Hz with LPF of LFE at 120hz?


Thanks for your help!

 

[antisuck]

Pretty sure the "LFE LPF" only affects the actual LFE signal, the "point 1" in a 5.1 surround signal. That tells the sub the highest frequency it should bother with on explosions and dinosaur footsteps etc. Normally leave this at the default 120 hz.

The other crossover setting is about bass management, where below the crossover point bass is redirected from your other speakers and handed to the sub to take care of.

So your sub ends up playing the proper LFE signal in movies and such, and on top of that plays whatever excess bass below 80 hz (for example) that you decide to send over from your main speakers.

 

[rimmi2002]

Pretty sure the "LFE LPF" only affects the actual LFE signal, the "point 1" in a 5.1 surround signal. That tells the sub the highest frequency it should bother with on explosions and dinosaur footsteps etc. Normally leave this at the default 120 hz.

The other crossover setting is about bass management, where below the crossover point bass is redirected from your other speakers and handed to the sub to take care of.

So your sub ends up playing the proper LFE signal in movies and such, and on top of that plays whatever excess bass below 80 hz (for example) that you decide to send over from your main speakers.

Thanks that explanation really helps and make sense as to why I have seen many people recommend tower speakers over bookshelf even with good subwoofers.

I thought for some reason when you set the crossover to a certain frequency for example 40hz or 80hz then all the bass above at frequency did not go to the subwoofer at all. But good to know the ".1" channel has its own source of bass that it plays.

Two follow up questions:
1. Since LPF channel plays its own bass up to the LPF if you are sending it bass from the ".1" feed avd if it is also getting bass signal from the speakers below the crossover frequency how does it handle both signals and keep it clean (or are the two signal expected to be identical and now the sub is playing it instead of the speakers)

2. For my movies all audio sources are high quality multichannel audio, but now days I end up watching a lot of music videos and other stuff on YT and various other streaming services. The signal is 2.0 and my AVR (Onkyo NR7100) upconverts that to multichannel "5.1".....Does this mean the AVR is using some algorithm to determine what goes where when change 2.0 to 5.1 and in this case the AVR hardware plays a key role in how that sound comes out in addition to the speakers?