So, two days ago I watched the following about the science of the room with Paul Hales after seeing a post with a link from Desertdome.
I saw that AVS had this same interview a while back but I didn't watch the whole thing. The part that really intrigued me was from 43:00 to 45:00 where he talks about a study where they put people in an anechoic chamber and had direct speakers and then other speakers that were meant to mimic the effect of a first reflection from a wall and they gave the participants a volume control to select the volume from the secondary speaker (the speaker that mimicked the first reflection) and the people in the study turned the volume of the reflection speaker as loud or louder than what a first reflection from a hard wall would be.
Now, I think the flaw with this is that music would sound extremely dead and lifeless in an anechoic chamber so any help you could get to mimic a reflection would be a good thing so I figured there may not be much merit to this experiment. I think a better experiment would be to have the speakers outside with the same setup, having the secondary speakers mimicking what would be a wall - or do the experiment in a well treated room and place the secondary speakers right in front of the first reflection panels.
However, I was curious enough to try removing some/all of my treatments and see what would happen with 2 channel music.
At first I took all of them down, both first and second reflections on each side wall and the first reflection of the ceiling panels. I have a total of 7 GIK panels, 2 on each side wall and 3 on the ceiling.
So, with all of the panels taken out I randomly surfed through my music trying out parts of a bunch of different songs. Right a way I didn't really like it as much with all of the panels taken down. Yes, I felt the soundstage was wider but at the same time it became harder to focus on specific instruments/voices etc. and I knew I didn't prefer music this way - which I wasn't surprised, because I remember thinking it was a nice improvement when I put all my treatments in (thanks to Luke Kamp who brought over a bunch of panels so I could test it out before buying a couple years ago).
So, I figured that what Paul Hales is talking about doesn't work in my room but I wanted to be sure. So, I next tried different combinations of panels to see if I liked anything better than my 7 panel setup. I tried the following:
1. Ceiling panels, no wall panels.
2. All wall panels, no ceiling panels.
3. First reflection panels only, nothing else.
4. Second reflection panels only, nothing else.
5. First reflection panels only, nothing else.
6. Ceiling panels and first reflection panels.
7. Ceiling panels and second reflection panels.
8. Finally, back to all 7 panels.
I went back and forth many times since Monday evening. I've been home sick yesterday and today to lots of time to experiment.
Here is what I found. I liked #7
by a significant margin!! So, using the secondary reflection panels and ceiling panels but NO first reflection panels is what my ears liked best.
Second place was #4
(secondary reflection panels up and nothing else) and 3rd place was #8
(all panels in place).
So it would seem in my room that the most important acoustic panel placement is the secondary reflections, in other words, the reflection on each side wall coming from the speaker from the other side of the room. However, even more important is NOT having first reflection panels!!!
The way I would describe the improvement with taking down the first reflection panels is that the soundstage gets bigger and the sound is more "exciting" and pleasing. I went back and forth SO many times with taking on and off the first reflection panel and that was the impression I got every time. Enough to know that I'm not ever using the first reflection panels for 2 channel music again.
So, I figure all is good and I can just take down my first reflection panels and live happily ever after. Not so fast my friend. I was up in the middle of the night last night (can't sleep, just cough like crazy when lying down) watching episodes of The Killing on Netflix. I've watched a bunch of episodes recently so I'm very familiar with how the show sounds. Last night for the first time I found myself straining to hear some of the dialogue in a couple scenes. Nothing major, but enough to notice. The speech intelligibility in my room is quite good for not having an AT setup (ha, as long as i don't recline... which sucks a bit...) but this was noticeably not great. So this morning I checked with my mirror and sure enough the first reflection point for the center channel is the exact same place on the side walls as it is for my mains so I'm wondering if the issue with speech from the center channel is because it's a longer reflection to the side walls from the center channel, enough to hurt intelligibility.
When I get around today to turning my projector on I'm going to run those scenes with the primary reflection panels in place and go back and forth and see if there is a difference. I bet at the end of the day I'll have to take off the panels for music and put them back for tv/movies and I'm ok with that.
Now, I am open to the fact that it could all be in my head. I've done enough blind tests to know that the brain can trick us very, very easily when doing comparisons like this. What I really need is someone to remove/add those first reflection panels and I keep my eyes closed so I can't be biased (for whatever reason).
Still, to me the difference for music seems pronounced enough (and I swear it's not i my head, haha) that I'm very curious what you guys think that have first reflection panels and listen to 2 channel music. Can some of you guys try this out and post your findings?
I'm very curious how 2 channel would be affected in your room with taking out the first reflection point panels but leaving up all the other treatments since you have the big GTG coming up.
I can't remember, do you have first reflection point panels in your room?
Andrew, I think the Yorkville's dispersion is similar to the 215's right? I'd be very interested to see what you think if you get a second to try it out. I know you must be crazy busy getting ready for the GTG though...
how about you? I know your room is very well treated. In the end it could just be my room/seating position etc. The edge of the outside baffle of my mains is 26" from the side walls and maybe that's just the right distance to benefit from the first reflection. Maybe the speakers are far enough that the reflection adds soundstage size and liveliness but not too far which could cause that reflection to clutter the sound???
I think your 2 rooms are the best sounding rooms I have been in and both are obviously very well treated. Is it even possible for you guys to remove ONLY the first reflection panels for 2 channel music? David if I remember right your first reflection panels have those slats in them (is that for diffusion?) so that right there might be taking care of the issue I have in my room with the first panel absorbing everything.
I'd love to get your thoughts too since it was your post and link that got me thinking about this and trying it out for myself.
Whatever the case I am really loving the lively (not bright, it's hard to describe) and larger soundstage so I don't think I'm going back. To be clear, music sounded good with all of the combinations of panels but I really believe I'm on to something, at least in my room. I'd ask my wife to do a blind test for me but I know better, haha.
After typing all this I tried it one more time and yep, I like it much better without the 2 first reflection panels.
If anyone else tries taking out the first reflection panels can you include how close your mains are to your side walls along with your impressions?
I'm tired of typing the words "first reflection panels".