I recently did some quick preliminary measurements of my room to determine the best listening position in an untreated space, and was wondering if anyone would be able to tell me which graph represents the most ideal theoretical listening position based on these measurements.
The tests were done with a Dayton Audio UMM-6 mic, pointed directly at the speakers at various distances from the speakers (no sub, speakers' range is 48Hz to 21kHz). The speakers remained stationary throughout the measurements, located as close to the front wall as possible, with the tweeters angled towards the listening position.
I just wanted to let you know that I'm not trying to achieve perfection, I'm simply trying to determine the best listening location with these tests – something that would be more accurate or scientific than just randomly selecting my listening position based on where I "think" it should be, or even at the suggested 38% distance.
Attached are some of the more "distinctive" graphs I picked (and their corresponding waterfall graphs), as well as the full REW .mdat file.
I looked at it quickly, but it seems the second test is the best to start with. Keep in mind that you really should be testing one speaker at a time and after you treat the room you may find that moving a bit will help.
Thank you for taking a look at those graphs. I'll do some more tests with one speaker at a time. In the meantime, just so I know what I'm looking for, would you be able to tell me why the second graph ( 67(38%).jpg ) is better than the third ( 85.jpg )? I personally thought that the third graph would be better, since while it has larger peaks, it seems to have less dips, and also doesn't have a peak around 47Hz like the other graphs.
Quite small changes in the response, perhaps because the speakers are so close to the front wall. Interesting. In the REW .mdat, the first measurements looks best to my eye.
Zoom to see LF fully, e.g. 30-300.
Try moving the speakers out from the wall in increments. They may well be at the best (least bad) location right now, but we need to know for sure. If a better Speaker location appears, then test for optimum listening position again.
I redid the tests, this time moving the speakers along with the mic to retain the equilateral triangle, and also testing L, R and then L+R speakers.
I took quite a few measurements, too many to fit into one .mdat file, in fact, so I had to separate the data between two files - one with individual L and R graphs and one with L+R.
This time around, I think the listening position closer to the middle of the room produced the best graphs (79-83), but I could be wrong, since I'm still not sure what to look for exactly in a FR graph. The biggest changes between graphs, however, were noticed around 46Hz, 76Hz, 84Hz, 96-106Hz, 147-167Hz, 203Hz and 222-242Hz.
I will definitely treat the room and then retest and reposition if necessary, however, as a starting point, could you please let me know which graph represents the optimal listening position currently, in an untreated room? I am simply trying to understand the FR graphs so I know what to look for in terms of problem areas. I realize that the graphs will most likely change once the room is treated, but for future reference, would you be able to tell me why, for instance, graph 61 is "better" than graph 79? Or is it not?
For example, is it less troublesome to have a larger peak in the 84Hz region, but have much smaller peaks between 147-167Hz (graph 61), OR would you "prefer" to have a much smaller peak in the 84Hz area, but have larger peaks around 149Hz and 165Hz? Hypothetically speaking, if the room was treated, and changing listening positions yielded these graphs, which one would represent a more ideal location? I don't know if I am making myself clear enough, but basically what I'm trying to determine is which of these graphs shows the least worst listening location (and why), regardless of whether the room is treated or not, simply based on the graph data.
Thanks for your patience and assistance once again!
The first position 61 still looks the best to my eye. Use zooming to see LF vividly. Use Waterfalls.
Using an equilateral triangle fixes the Width dimension and the Listening position.
This means that many positions remain unexplored.
You cannot simply fix one dimension and then move on to the next. They are interactive.
DanDan and Glenn, thank you so much for your feedback.
Glenn, just to make sure I understand correctly, it shouldn't be too difficult to eliminate or diminish that 84Hz spike, however, all other graphs show lack of lower frequencies (below 84Hz) which could present a problem and may not be fixed with room treatment. Is that the gist of it?
If I understood this correctly, would you say that graph 65 or 67 is "better" than graph 61 since the low frequency curve (between ~45 and 60Hz) is closer to 0db?
(I offset the graphs to bring down 1KHz point to 0dB with smoothing set to 1/1, as suggested in this post).