XTZ Room Analyzer II Pro

[chessman]

Originally Posted by jdandy

Randy.......How much elevation did you gain with the spikes? I see the 7K dip has disappeared.

Dan, it is a quarter inch or less higher than the spikes. I think the difference in where the null is occurring is probably small variances in mic placement (missing or hitting the soffit edge).

[Manbient]

This thread is fun. I'm about to start a journey with some treatments, might chronicle the same way you have. Who knows, might help the next guy understand a bit better what happens with treatments!

[Detroitrock]

I need to go back to college.

[chessman]

As most know, I simulate true full range speakers by using small towers and a pair of subwoofers via an active cross-over. These measurements measure the output of my resulting "full range" mains. I measured first the right, then the left, superimposed the two curves and got this:



Then I took a measurement with both mains on at the same time and got this:



Looks to me like a perfect example of room induced comb filtering at the high end and a most unfortunate pair of nulls at 240 H. I took various readings around the listening position and I can make the null change frequency. So I conclude the listening position is badly placed vis a vis 240 H. Oh just move the chair you say? Well since it is also a home theater and since the accursed pole holding up the ceiling is to my immediate right, I cannot move as a practical matter. It would put the pole between me and the right main and block my view of the screen. Oh well, first world problems.

[chessman]

My conclusion of comb filtering may have been hasty. It occurs to me that as to the two "flat" curves the mic was pointed straight at first one, then the other, tweeter, while the combined curve was with the mic pointed at the center point between the speakers. The mic is directional above 5,000 H, so maybe my pilot error just introduced an artificial off-axis reading?

The RTA results show no such nulls at the listening position, just a gentle roll off in the upper frequencies that I attribute to a low ceiling. I wish this kit explained how to intepret the results.

[antipop]

Originally Posted by chessman

The RTA results show no such nulls at the listening position, just a gentle roll off in the upper frequencies that I attribute to a low ceiling. I wish this kit explained how to intepret the results.

Taking measurements is the easy part, understanding the results is the tough one. Sadly I'm no better than you and it's not easy to have someone who explain clearly what you see.