I understand that the THX standard crossover setting is 80hz, i have a question, if i have a good mid bass in my front loudspeakers, then, i dun need to set the crossover higher, coz i dun have to compensate for mid bass loss, since i can depend on the 2 front loudspeakers, therefore, my question is will setting the crossover as low as 40hz be better than 80hz for LFE in my subwoofer? will there be more bass projected in the subwoofer?

If you don't mind a layman's opinion, I think if you can get hold of the response graph of both speakers, it may give you better opinion.

If your front speakers' response started to taper off at around 60Hz, you may need subwoofer's assistance from that level on wards.

I think unless its of higher end sub, otherwise most sub started to taper off at around 35hz as well. So if you can set from 40hz crossover, your sub's usefulness seems to be quite redundant in this case.

If you can't really get hold of the audio response graph of both speakers, maybe only your ear will tell you your own answer.

Please any audiophile here can rebuke me on this, just my own opinion.

try different settings and follow what your ears tell u..

Most would set the x'over at 80 Hz and let the subwoofer take over the energy sapping bass work load.
This will free up the amp to drive the other speakers.

I have tried setting the x'over at a lower point and find the bass to be less controlled and a tad boomy with the front speakers.
It really sounds cleaner and more controlled if set at 80 Hz. IMHO

Correct me if I am wrong, I suspect you may have confused LFE with the normal crossover frequency. For LFE, you would like to set it as high as possible so that the full spectrum of the LFE channel is available for your listening pleasure through the sub. The LFE channel is independent from the audio that gets sent to your sub when the frequency is below the crossover frequency, typically around 80Hz (for THX).

If i have set the crossover frequency at 80hz in the Amplifier, then, frequency from 0hz to 80hz will be sent to the subwoofer, however, what about the high-cut/frequency adjustment in the subwoofer, shall i set it to 80 hz as well?(the subwoofer also has a high-cut frequency control).

If you have oledi set the cut off at 80hz in the amp....there is no need to cut another 80hz on the Sub itself...unless..you are using satellites directly connected to the Subs

If you can, disable it. If not, turn the control to max / highest freq.

some expensive subwoofers have additional LFE input, is this LFE input better than the normal Mono (L + R) input in subwoofer?

As far as i know, if we input using the LFE jack, the High-Cut Frequency control from the subwoofer will take no effect on any further adjustment.




This post has been edited by LoonFay: Oct 11 2010, 12:20 PM

Do you mean 'Balanced / XLR' inputs?

Not the balanced cables used for stereo amp, i'm referring on the LFE input in the subwoofer, coz i believe LFE input will exist on high quality subwoofers together along with the usual Mono input, so i believe connecting subwoofer preout from the Amplifier straight to the LFE will be better, and with this connection , the High-cut frequency control in the woofer will not take effect anymore.