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So what does the response graph look like above 100Hz? Below that, I wouldn't touch a thing - +-3dB is essentially perfect. Although, given what I do see above 100, it would appear that you are running the subs a little hot. Assuming the graph shows all speakers being driven of course.
That might be tough to get rid of. 540Hz has a wavelength of 2 feet. Typically you'd move the listening chair or shift the speakers, but that may screw up your <100Hz performance. Have you tried a blanket over the tv?
How do you do ETC with REW?
Under Impulse, choose Envelope (ETC) at the right bottom and remove all the others. Zoom in on the first 50-70ms. What comes after that is of no interest, since the reflections will been attenuated a great deal.Your waterfall shows that you have some troublesome resonances and a bit of a long decay.You might want to change the settings to 500 ms for both window and time.
I just read all four pages of your thread in AudioEnz. A fascinating and very informative/helpful read. It was fascinating to study your journey and the huge improvements you gained.Very few people document and explain their changes any where near as well as you have. I found it way more helpful than reading piles of documents on the theory of room setup.Thank you very much.Rod
Here's the ETC measurements; any help is most appreciated. Other than widening the room and adding a false wall behind the LP, should I treat anything else (diffusion, more bass traps, absorption)?
That peak at 540 Hz and 3.5KHz definitely shrinks if I move the mic to the left or right seat, as opposed to the center seat. It's prominent in both the L and R speaker measurements, though, so it must be room interaction, eh?
More than likely it is a room interaction, you've got a summing going on at that spot. What happens if you move the mic front or back?
You need to let the window only show the first 50-70 ms. You zoomed in, but you also moved the window to the right. We need see more details to say anything. Let 0 start at the far left.Pictures of the rear of the room would also be nice.
Something you could consider is setting up angled wall dividers that will redirect the energy to rear sidewalls where you have diffusors but will still pass the bass through.
Something I would consider in a room that's somewhat narrow is getting speaker with controlled dispersion. For example a good waveguide speaker. These will give less reflections from sidewalls and you don't need to dampen them as much and one can therefore avoid the headphone feeling which easily comes with much absorption on sidewalls. Here's some examples of that type of speaker:http://gedlee.com/Loudspeakers.htmhttp://www.jblpro.com/products/recording&broadcast/lsr6300/JBL.LSR6332.pdf
The JBL LSR6332 are actually wide dispersion but great linear on- and off-axis response. A better example of controlled dispersion would be the JBL Project Array series, which have a higher directivity index for most of the frequency spectrum.
They are a fantastic speaker (objectively, as I've never heard them). I believe they are Harman's best measuring speaker, period. The fact that they use those instead of the Revel Salon2's is telling IMO. Or maybe it's because they play the nicest in a variety of rooms due to their superior polar and sound power response. My speakers have a very good polar response, but not that good; I don't think many speakers measure that well, actually.
Post 47 has been updated with ETC measurements within the specified window.
I attached a (crappy) picture. The DVD rack has since been moved, but other than that the layout is the same. Obviously I am limited in what I can do, but the speakers fire down the long dimension and are about 7.5 feet apart (flanked by dual subs) and just over 2 feet from the side walls; they are 4 feet from the wall behind them. The listening position is 10.5 feet from the speakers. As you can see I have a first reflection absorption panel at the lateral walls, and a pair of bass traps in the corners. The room isn't dedicated and extends well beyond the couch (passed where I was standing when I took the picture), which then becomes the children's play area (lots of toy boxes, toys and various kiddy stuff everywhere). The room then L's around and open to another 12x15 section (complete opposite end of the TV and speaker system). Obviously it's not an ideal setup, and my plan is to expand the right wall another 5 feet (the laundry room is way too big), and perhaps use wall dividers like you mentioned behind the listening position.Anyway, do you have an suggestions? And yes, I want an accurate listening environment (as much as I can get with this crappy room). My apologies to the OP - don't mean to hijack the thread. I didn't want to start another one, though, since I am pondering adding diffusion myself. Thanks for letting me post in your thread.
