I'm looking for the best crossover for my HT.
LPF on LFE : 120Hz
What would be the best setting?
Hi and welcome to AVS,
First you should run Audyssey. Then check how the AVR set the crossovers for each speaker. Set each crossover to 80 Hz if they are lower, but leave them "as is" if higher.
LPF on LFE @120 Hz is OK.
Klipsch RF-62II, RC-500, RS-400, SVS PC12+,
Def Tech SC8000
Harman Kardon AVR 1600
PS3, Apple TV, Sharp 70" Qattron
Your Onkyo 626 is a modern AVR. That means it has a Bass Management system inside. What does that mean?
The subwoofer output sums up two input signals.
1. The LFE (Low Frequency Effect) signal carried by the .1 channel,
2. The bass signals redirected from all speakers below the crossover point provided the speakers are set to "small" in the AVR.
The LFE channel's LPF (Low Pass Filter) should not be set to anything else than 120 Hz. That's the max. frequency that is recorded into the .1 channel.
The 80 Hz crossover recommendation is based on scientific experiments that have shown that the human ear practically looses its directionality clues at around and below that frequency, therefore it is best to let the subwoofer (aka Big Brother) take care of bass which needs a lot of energy/power to produce the required SPL (Sound Pressure Level).
There's a good read on the subject "Small vs. Large". Worth reading.
Hope this helps.
manufacturers ratings on spec sheets vs what speakers do in your room are two different things. you can experiment with higher crossovers to see if it sounds audibly better to you, but is really not necessary based on what the auto-cal and your receiver put them at.