REW measurements MPL with or without head

[RegD]

Hello,

I have performed an optimization of my listening position with REW and a convolution plugin. To calculate the EQ filters, I used some averaging of the MPL and other surrounding positions.
The result is quite decent for the MPL and positions close by.
Then I had the (terrible) idea to try to see what was the influence of my head. I measured (with the correction) leaving the mic at the same position with and without my head. The SPL spectra are very different in the mid and high frequencies. The results are not so great anymore.

=> Should all measurements (before applying filters and after to verify the effects) be performed with the mic right next to the user's ear (L and R sequentially)?
Can one trust measurements done without the head next to the mic?

Many thanks!
Cheers,

 

[ddude003]

Maybe your looking for something from https://www.bksv.com/en/transducers/simulators/head-and-torso... Everything in a signal chain matters... Everything in a room matters... Are you sure your cat didn't move during a signal sample? Just how picky are you going to be and at what cost?

 

[RegD]

Hey ddude003,
Thanks for the reply. I was not planning on buying anything extra...
What is everybody doing? Do you all use Bkvs stuff?
But no, nothing changed between those two measurements except myself.

 

[ddude003]

Hey ddude003,
Thanks for the reply. I was not planning on buying anything extra...
What is everybody doing? Do you all use Bkvs stuff?
But no, nothing changed between those two measurements except myself.

I was mostly teasing in my above post... Am am pretty sure there are a few here on AVNirvana that do use BKSV equipment... I use a UMK1... And It seems that there is a two mic rig that some here use with REW... My real point, although I see now that I was a bit off the cuff, is/was that everything matters... Even the slightest movement of your head, speakers, stuff in the room... And at what point is one satisfied with the sound of ones system?

 

[John Mulcahy]

The presence of your head changes the response. Your brain knows that, and what the effects are. It has become quite accustomed to where it lives, and uses the response changes to help understand things like source direction, for example. The sound needs to be correct before your head intrudes, stay away from the mic.

 

[RegD]

Right! Thanks John! That's good to hear.
I am so lucky that my brain knows stuff (and that I don't have to buy more equipment).

 

[ddude003]

The sound needs to be correct before your head intrudes, stay away from the mic.

Mic drop...

 

[RegD]

Along these lines ... it got me thinking:
For each listening position, does it make sense to make 2 position-separated measurements for L and R speakers off by one's ear-distance? Or just the two measurements at the virtual middle between where the two ears would be? (I have always assumed and carried out the latter).
Many thanks

 

[FargateOne]

IMO it depends what you are searching for. In my amateur experience, if you want to equalize and find the filters, it is better to use the mmm method

Room correction with REW using PEQ

mehlau.net

https://www.ohl.to/audio/downloads/MMM-moving-mic-measurement.pdf

 

[RegD]

Thanks FargateOne. That's interesting.
I am just searching to have a faithful reproduction of the sound played in my music studio (correcting peaks and dips in the SPL spectrum for each of the mains around the main listening position).
In the MMM method, how critical is it to place the mic at 90°? I have only a 0° calibration file for my mic (not a Umik-1).

 

[FargateOne]

I saw a video (don't recall where) where the person was holding the mic horizontally to move it. So go with your cal.file spec are for.