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Hi guys,

I've taken measurement sweeps across 7 positions on my sofa for a 2.2 system of standmount speakers with two identical subs in opposite corners of the room. The combined mains' seat-to-seat variation is generally good, the exception being between ~60Hz-80Hz. You can also see their output peaks by about 10db at 40Hz with a 24db/oct slope either side. Note individually they measure much worse than shown but I'm guessing sweeping both together and using the combined measurement gives MSO less to think about(?)



Sub 1 (closest to the mains) has only a few db seat to seat variation from 15Hz-48Hz. Above 48Hz the seat-to-seat variation goes haywire. Given proximity to speakers I could probably set the LPF at 120Hz without its location becoming obvious.



Sub 2 is a mess below 40Hz (really highlights the difference room positioning makes) but above that, it's a little better behaved overall than sub 1 between 43Hz-120hz. Given proximity to the listening position I’ll need to set the LPF around 80-85Hz.



Referring back to the mains, they need help below 40Hz (although having said that if I set the target curve in Dirac to 75db at 20Hz, they might only need supplementing below 30Hz!. They also need some help reducing seat-to-seat variation between 60-80Hz. When I run MSO with the range to optimise being 60-80Hz it can sort the range out nicely but completely messes things up above and below the range. Setting a HPF on the mains and Sub 2 somewhere between 40-50Hz you would think allows the frequencies below this to be left to sub 1 and to remain flat but they become spikey. Am I missing something? any advice on a good approach to adopt to get the best out of MSo would be appreciated.

Thank,
Alex

Note individually they measure much worse than shown but I'm guessing sweeping both together and using the combined measurement gives MSO less to think about(?)

I think that would make it harder for it to optimize. Perhaps follow the miniDSP app note.

When I run MSO with the range to optimise being 60-80Hz it can sort the range out nicely but completely messes things up above and below the range. Setting a HPF on the mains and Sub 2 somewhere between 40-50Hz you would think allows the frequencies below this to be left to sub 1 and to remain flat but they become spikey. Am I missing something? any advice on a good approach to adopt to get the best out of MSo would be appreciated.

Those filters are not brickwall (and not linear phase). I think you need to actually run the optimizer over the full frequency range of interest.

Hi,
Since there are only shared filters on the mains why is it harder to optimise when the mains are measured running together as opposed to individually?
I don't doubt you, I tried with the combined mains but it kept throwing one of the listening positions way out. It was strange all but one were OK but the one that was off was REALLY off!

Understand the point about filters not being brick wall but what do you mean about them not being linear phase?
 

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Hi,
Why is it more difficult to optimize when the mains are monitored simultaneously as opposed to individually, given that there are only shared filters on the mains?
Don't get me wrong, I tried using the combined mains and it threw one of the listening spots completely off. It was strange that everyone, except for one, seemed to be in good working order.