Sub 4 sale

shack

Originally posted by spasticpitbull
But still no Unfiltered LFE

Of course this is an ongoing topic regarding bass management. If you set the variable pass filter above any information being sent in the LFE signal is it still "filtered"? Some say there is no filtering effect whatsoever so it is unfiltered LFE. Others think that there is still some degradation of the signal resulting in "double" filtering. I guess I'm in the camp that doubts there is any information in a LFE signal above the max settings so it is basically unfiltered.

Airplay355

me 2 shack me 2

how can there be anything above that if your receiver takes out anything above 80 hz? ( or whatever u have it set to) my sub crossover goes up to 150, so i have plenty of room

glemay

I'm going to hold on to the sub a little longer. Going to try and sell it locally, won't have to deal with shipping. Thanks for your intrest Wallstreet, sorry it didn't work out.

Jerry

ramirezivan

your best price?

Dr. Spec

Of course this is an ongoing topic regarding bass management. If you set the variable pass filter above any information being sent in the LFE signal is it still "filtered"? Some say there is no filtering effect whatsoever so it is unfiltered LFE. Others think that there is still some degradation of the signal resulting in "double" filtering. I guess I'm in the camp that doubts there is any information in a LFE signal above the max settings so it is basically unfiltered.

These low pass filters are not brick walls. The low pass in the subwoofer is typically 2nd order (12 dB/octave). The low pass in the pre/pro is typically 4th order (twice as steep at 24 dB/octave).

If two low pass filters are overlapped (either partially or completely), the descriptive term is called "cascading" the filters.

If they overlap completely (i.e., are imposed at the same frequency), the combined effect is additive. So a 2nd order and a 4th order will combine to have a 6th order (36 dB/octave) effect.

If they overlap partially, (i.e., one starts at say 80 Hz, and the other starts at say 120 Hz) the combined effect is only additive above 120 Hz. So if you had a 4th order at 80 Hz, and a 2nd order at 120 Hz, the slope would steepen to 6th order starting at around 120 Hz.

You "might" be able to hear the effect of complete or partial cascading of the low pass filters as a reduced intensity in the mid bass region, as it would tend to produce a depression in the FR at this point.

If the sub has no unfiltered input, and you are doing the bass management at the pre/pro, then it is "generally" advisable to set the sub's low pass filter as high as it will go to minimize the region where the two filters will overlap.

Of course if you had a hump or a peak in the 80-100 Hz region (for whatever reason), cascading these two filters might be a GOOD idea and help reduce the peak.

The decision to deliberately cascade the low pass filters should only be made if you have the means to accurately measure the frequency response in the 60-120 Hz region.

Doc