Aux fed sub question

[cmchamp]

Yes, if you left the RH's crossover alone, you'd have a 20Hz frequency gap between 100 and 80Hz. The depth of the gap would depend on the steepness of the crossover filter.

Yes, you want to have the low pass on the subs and the high pass on the mains crossover point the same with the same filter slope.

[Brad Weber]

Originally Posted by cmchamp

Yes, if you left the RH's crossover alone, you'd have a 20Hz frequency gap between 100 and 80Hz. The depth of the gap would depend on the steepness of the crossover filter.

Yes, you want to have the low pass on the subs and the high pass on the mains crossover point the same with the same filter slope.

Not necessarily, in fact for the LS 700P 'High Frequency Cutoff Control' the manual states "This control should be set to the closest possible frequency to 20 Hz below the crossover point that the full range speakers processor uses as it's crossover point."

The LS 700P manual does not specify the slope or type of filter used, but since the control is limited to a 100-150Hz range and the low pass filter apparently cannot be defeated, using the integrated low pass in the LS 700P as the low pass for the system would apparently then limit the recommended high pass for the mains to a 120-170Hz corner frequency. Since you can't bypass the low pass filter in the sub then if you want a lower frequency cutoff for the mains it might be best to use lower frequency high and low pass cutoffs in the DR260 and set the LS 700P 'High Frequency Cutoff Control' as high as possible in order to try to minimize the effect on the lower frequency low pass in the processor.


I'll go back to the general point that you don't hear the result of the interaction between the two electrical signals (the inputs to the speakers) but rather the result of the interaction of two acoustical signals (the outputs of the speakers at the listening position). The response of the speakers, the effects of nearby boundaries, the effects of the room and so on can all impact how the signals arriving at a listener may differ from the signals going into the speaker and thus interact differently than the associated electrical signals. So how the electrical signals interact does not typically directly reflect the associated acoustical results.

Since a filter with a certain cutoff or corner frequency does not start to act at that frequency but rather is -3dB, or half power, at that frequency and since the shape of the 'knee' for a high or low pass filter varies based on the type and slope/order of the filter, one can vary the corner frequencies, slopes and types of filters for the low pass and high pass elements of a crossover to get different interactions through transition. For example, the responses of a main and sub along with their relative phase and level at the listeners may make something like a third order low pass and second order high pass with some gap between the corner frequencies the best solution for a specific situation, it all depends on the specifics of the individual components and situation. While this is getting into more advanced system tuning aspects, it reflects why one should not be fixated on just the electrical filter response of the crossover filters but rather on the results they create at the listener.


Looking at the picture and related information, the location of the subwoofer is almost certainly a factor. Not only is it behind the band, and thus the microphones, but being located sort of but not quite in a corner is going to result in natural acoustic gain at many frequencies due to boundary loading and natural cancellation at a few frequencies due to boundary cancellation. That's a technical way of saying that due to the location of the sub it will naturally have greater output in general but may have some notches in the response.

[rschultz]

Originally Posted by Brad Weber

Not necessarily, in fact for the LS 700P 'High Frequency Cutoff Control' the manual states "This control should be set to the closest possible frequency to 20 Hz below the crossover point that the full range speakers processor uses as it's crossover point."

Yes the manual states that but is assuming it is the ONLY crossover. If the DBX is used as a crossover lower than that (say 80 Hz), then the 700P crossover wouldn't be necessary and could be set anywhere. Right?

[rschultz]

Originally Posted by Brad Weber

Looking at the picture and related information, the location of the subwoofer is almost certainly a factor. Not only is it behind the band, and thus the microphones, but being located sort of but not quite in a corner is going to result in natural acoustic gain at many frequencies due to boundary loading and natural cancellation at a few frequencies due to boundary cancellation. That's a technical way of saying that due to the location of the sub it will naturally have greater output in general but may have some notches in the response.

Yes, good point. I believe that sort of thing has happened. Pushing it forward to the level of the mics is the practical solution, and we should try it. But aesthetically it is so big. Yeah, I know it's probably rather small compared to some larger (12-18") subs. Maybe we can put a viney plant on it, and the vines will grow and cover it up

[cmchamp]

"This control varies the frequency at which the LS700P rolls off the high frequencies. This provides part of a crossover function. This crossover function also combines with the natural low frequency roll off inherent of the full range cabinet (when the LS700P is not used with an élite processor). This control should be set to the closest possible frequency to 20 Hz below the crossover point that the full range speakers processor uses as it's crossover point. If an élite processor is used, set the high frequency cutoff to maximum (160 Hz)"

If an élite processor, or any other external crossover, is used, the control should be fully clockwise.

You can even contact Yorkville yourself and find out what the recommended processor settings are for the LS700p.

Last I spoke with Yorkville support, this is what they told me.

Yes, location will add to the level experienced in the room as Brad mentioned.

C.

[rschultz]

Originally Posted by cmchamp

If an élite processor, or any other external crossover, is used, the control should be fully clockwise.

Ah yes, thanks for pointing that out. I read that part in the manual earlier, but it didn't really click until you put it in BOLD.

Thanks.
Ryan

[rschultz]

We moved the sub up to the front of the stage, in line with the mics, during practice last night. Seemed to work. We'll give that a go on Sunday.