Speaker grills affecting sound

[KEW]

I would be surprised if anyone could do a true blind listening test (having someone else take the grills on and off) and actually be able to correctly state whether they were on or off more than 50% of the time.

I appreciate this forum because it maintains a factual stance regarding many esoteric (and expensive) tweaks, etc.

Are there any studies of a few speakers with and without grills to establish that they are truly acoustically transparent in the high frequencies. I certainly do perceive a difference on some of my speakers (not all). However, I am human and this could well be more of a psychological phenomenon than an acoustical one. Certainly instruments could measure this better than any person could hear it.

It would be great if someone knows of some testing to determine this.
Like I said I cannot notice the difference on every speaker I have, but I cannot understand how grill cloth could be completely transparent. I would expect that all grill cloth would show a measurable effect, but that I can only perceive where the difference is audible to me.

 

[popotoys]

This would be easy to test on a system with auto correlation. Just run your room correction with the grills on, then write down the eq results. Now run the room correctin again with the grills off and compare the two results.

 

[KEW]

Okay, I did some research to see what I could find and came across the link below from an Audioholics pro review. The second graph shows the effect of the grill on the FR.

Note in the paragraph above this graph, the author states "A perfectly transparent grill cloth would have produced a ruler-flat line, centered at 0 dBr. As it is, the curve is very flat and better than some I have seen of systems costing far more than the Klipsch Ultra THX2."

http://www.audioholics.com/reviews/speakers/satellite/klipsch-thx-ultra2/page-5

This chart is impressive, but the fact that this grill cloth is being extolled as very good makes one wonder what else is out there. Consequently, I spent some more time with Google. There is not a whole lot out there that I could find. However here is the second graph I found. As you can see (scroll down for the graphs) the high frequencies drop significantly:

http://www.aecinfo.com/1/pdcnewsitem/00/90/15/index_1.html

The above data is for a video screen which may require compromises in sound transmission as compared to a simple grill fabric.

Any comments, corrections, etc. welcome!

 

[yepimonfire]

The question remains, at what SPL relative to 1 khz?

like with my headphones cranked to 3/4th of max. and let me tell you , you will get a headache for hours from listening to that.