Bravo, I'm not sure how to interpert your measurements. Are you saying that (1) the right channel at 100 hz is +6db over a 1K tone measured on the R speaker or a 1K tone measured on both speakers, or (2) 6db over the L speaker output?
One thing to consider in making measurments/adjustments in the mid-lower bass response is that much (but by no means all) of the info there is mono. Rather than focusing on the difference between each speakers output below 200 hz I would look at the summed output of both speakers. Also, consider that most of the balance issues are more apparent from tones in the mid range and highs, so while your might have an imbalance in the lows (between speakers)if the summed output is balanced with the upper frequencies you might never hear it.
In general the corresponding node and null at 100 and 150 hz suggests to me a problem which might be curable by altering the speakers or listening position, however if this ratio is close to the same no matter where you place your speakers and/or chair it is a room problem. You would want to fix this either by using appropriate bass traps or a good parametric equalizer. A 12 db swing is going to be very audible. BTW this could be a result of your rooms construction.
That 12db rise at 15kz is not likely to be related to your room - it could be the equipment used to make your tests or it could be a problem with your electronics or speaker. You could easily check this out by using a process of elimination in switching electronics and speakers one piece at a time.
What are the other measurements between 1k and 15k for the right speaker and for the left speaker? IMHO, your balance problem is more likely because of disparate speaker response, or untreated reflection points, some where between 500hz and 5000hz than anywhere else.
One thing to consider in making measurments/adjustments in the mid-lower bass response is that much (but by no means all) of the info there is mono. Rather than focusing on the difference between each speakers output below 200 hz I would look at the summed output of both speakers. Also, consider that most of the balance issues are more apparent from tones in the mid range and highs, so while your might have an imbalance in the lows (between speakers)if the summed output is balanced with the upper frequencies you might never hear it.
In general the corresponding node and null at 100 and 150 hz suggests to me a problem which might be curable by altering the speakers or listening position, however if this ratio is close to the same no matter where you place your speakers and/or chair it is a room problem. You would want to fix this either by using appropriate bass traps or a good parametric equalizer. A 12 db swing is going to be very audible. BTW this could be a result of your rooms construction.
That 12db rise at 15kz is not likely to be related to your room - it could be the equipment used to make your tests or it could be a problem with your electronics or speaker. You could easily check this out by using a process of elimination in switching electronics and speakers one piece at a time.
What are the other measurements between 1k and 15k for the right speaker and for the left speaker? IMHO, your balance problem is more likely because of disparate speaker response, or untreated reflection points, some where between 500hz and 5000hz than anywhere else.