Tough measuring

[Jay Barracato]

Here are some measurements I recently took in a venue. These were taken with the system in place, including all the problems associated with that.

A couple of things:
1. These are not my system settings, but the ones in use on a nightly basis.
2. Regardless of the way it measures, I consider this a good sounding system.
3. I took these on a run and gun basis, having about an hour before load in. The mic was ear level for a seated patron.
4. The L/R mains were taken in a T pattern: close, medium far, left, right. The subs were measured centered on the stage. None of the fills are shown exccept the center fill was on during the last all in measurement.

So the first is my freeform art project:







































Since this was all the measurements of the L speakers, here is the same coherence averaged:







































I am seeing plenty of evidence of reflections, which matches what I see in the room. The floor is at two different levels, and the ceiling (fairly low) is also two different levels. The room is also on the small side with plenty of hard flat surfaces. In addition:




Here are the subs which are on an aux:






































With a little smoothing:








































Here is everything on together:








































And with some smoothing:







































I think I figured out why I never turn the sub channel all the way up to unity.

Let me know what you think/see and then I will post some of the questions I posed and hopefully answered with the measurements. Once again, this was not a system optimization, it was more "preshow see what you got"

 

[Jay Barracato]

Here is a photo from my phone which I couldn't load into the original message

 

[Bennett Prescott]

Re: Tough measuring

Jay,

I almost always use 1/12 octave smoothing on the phase, trends are all that matters there. On the magnitude, the lowest level of smoothing (1/48?) is more normal, almost never more than that since it makes it difficult to read for me which peaks and dips matter.

 

[Jay Barracato]

Re: Tough measuring

Jay,

I almost always use 1/12 octave smoothing on the phase, trends are all that matters there. On the magnitude, the lowest level of smoothing (1/48?) is more normal, almost never more than that since it makes it difficult to read for me which peaks and dips matter.

I tend to look for broader trends on the magnitude as well, hence I think I like to see a little more smoothing, but I do usually look at the lower level of smoothing also. The 1/12 octave seems to be a nice compromise for me. I remember Jamie talking about looking for broader trends in the magnitude, even if he did suggest that he prefered less smoothing. I am not sure if it really is a usual practice, but while everything is in place, I like to take the broader pits shown at 1/12 octave and change the eq to see how the measurements responds (over the entire range, over part of the range, or not at all). I think that helps me, determine if I am looking at a meadurement/room artifact or something that can be helped by eq.

For example, in this set, I see the same 300, 500, and 3K dips in both the average of the tops, and the mains plus the subs. Those would be my first candidates for a little tweaking.

In addition, when I look at the side by side configuration of the mains, I can estimate where I expect to see the combing, and smooth that out to see more general trends.

 

[Kip Conner]

Re: Tough measuring

In that room located at 33 West St, I usually only measure at one spot due to time constraints. I put my measurement mic about 3 tables over from the mix position towards house right and then cross the aisle so I'm at the back of "lower level" listening area. Basically in front of the other cabinets not pictures. I also put the foam from the back of my work box on the table to try to absorb some of the table bounce.

That room is full of reflective surfaces that can taint the TF measurement, but I would say your coherence looks great for that room.

 

[Jay Barracato]

Re: Tough measuring

In that room located at 33 West St, I usually only measure at one spot due to time constraints. I put my measurement mic about 3 tables over from the mix position towards house right and then cross the aisle so I'm at the back of "lower level" listening area. Basically in front of the other cabinets not pictures. I also put the foam from the back of my work box on the table to try to absorb some of the table bounce.

That room is full of reflective surfaces that can taint the TF measurement, but I would say your coherence looks great for that room.

Kip, that corner in the ceiling right above your measuring point plays hell with the measurement, I was getting a better sense from the left speakers. You basically described the middle measurement of my "T".

The thing is, the room is so small that no where you go has all that big of a difference in arrival times from the paired speakers. I can measure combing, but in general I can't hear it.