[elee532]

Anyone have any recommendations on acoustical treatment for the room where I have my SongTowers? (FYI, they are part of a 4.1 system that will be used 75% for music, including a lot of hi-rez surround music)

95% of what I have read recommends absorption at the first reflection point. However, I just started reading Floyd Tool's Book, "The Acoustics and Psychoacoustics of Loudspeakers and Rooms." Most of the book is over my head, but it does seem to call into question the notion of first reflection absorption in a small room.

Now, on top of this, I recently saw someone mention that "early reflections are not necessarily bad. They are not good if the off axis response of your speakers is poor...then you want to absorb... If the off axis response is good, then you'd be looking for diffusion."

Now, it is my understanding that the SongTower's have excellent off-axis response. Correct?

I had literally already started purchasing my absorption panels when I started coming across these contradictory bits of info. Any insight greatly appreciated!

[fishinbob]

I suppose some more info on the room layout would be nice for someone to best inform you, and you would be more likely to encounter these opinions in the acoustic circle.
As for the off axis response of the SongTowers I would say your info is correct in that regard.
I for one was forced by room constraints to put my STs diagonally and thereby put the first (wall)reflection behind me. I may eventually put some absorption as it is within four feet of my listening position but I plan to look at bass modes first.

I think the Cardas placement is almost laughable in most enviorns unless you are fortunate enough to have a dedicated space or maybe live alone. I have mine at a 45 degree layout in the corner of a 16 X 22 ft room with my display in between. Imaging and depth of field are excellent and as a bonus it has given my little HT sort of a cozy feeling and works very nicely for conversing as well. I would recommend to anyone to give it a try if the layout permits. You may use all that money you save on treatments to buy some more music. 

Check out this piece
http://www.decware.com/paper14.htm
 Bob

Surrounds could be problematic with this layout though.

[oneinthepipe]

I don't think that diffusers have much effect in a very small room.  What are your room's dimensions? 

Ideally, I think that is important to place 1) bass traps in the corners, floor to ceiling, if possible, and 2) absorption panels behind the speakers, 3) behind the listener, 4) along the first and second reflection points on the walls, and 5) along the first reflection points on the ceiling.   

Every bit of properly-placed absorption improves the sound.  The more properly-placed absorption that is placed, the better the sound.  In my room, after I installed bass traps in the corners and panels behind the listener and speakers and along the side walls, the biggest improvement came from absorption on the ceiling.  I still need to deaden the corners more.  The bass traps are 48" tall and are mounted in the corners mid-wall to ceiling, but when I clap my hands below the traps, I can still hear some ringing.

You can contact Sal @ acoustimac.  Sal won't try to over-sell his acoustic treatments.  If anything, he might underestimate what is needed, but he has a good product at a good price, and he knows audio.

Regarding the off-axis issue, the SongTower have good off-axis response, but I think the issue is the location of the listening position(s).  There is a difference between treating a room for listening in specific locations and treating a room for listening from any location in the room.  Regardless, the bass traps are a must, IMO.  You might not be able to plan the whole room out at the same time, either.  When I was getting started with my room treatments, I contacted Sal several times.  At one point, he stated, "Isn't it funny how moving one panel can change the sound so much?" or something very similar.  I didn't think it was funny at all, but it was quite amazing.

[elee532]

FYI, I have already installed superchunk bass traps floor to ceiling in 3 of the 4 corners (fourth corner has a door in the way). I also placed one the entire width of the room along the front wall-ceiling corner and I plan to do the same along the back wall-ceiling corner.

Since you asked about room layout... 

I'm actually in the process of trying to determine optimal placement options. My room is about 9.5' wide by 17' deep. I'm somewhat limited in the placement of my surround speakers... I can place them at about 9.5' into the room or about 13.5' into the room give or take a foot in each direction. I'm leaning towards the 13.5' location. I'm still not sure exactly where to place the SongTowers or the listening seat. Any thoughts?

Also, oneinthepipe, your suggestions re: absorption pretty much reflect what I had been reading in other places. However, this approach seems somewhat at odds with the Floyd Toole book plus the off-axis response of the SongTowers.

Ugh, this stuff is not easy to sort out! 

[oneinthepipe]

My room is about 9.5' wide by 17' deep. I'm somewhat limited in the placement of my surround speakers... I can place them at about 9.5' into the room or about 13.5' into the room give or take a foot in each direction. I'm leaning towards the 13.5' location. I'm still not sure exactly where to place the SongTowers or the listening seat. Any thoughts?

That doesn't give you much width.  If the ST were 3' from the front wall and 1.5' from the side walls, the speakers would be about 6.5' apart.  You could sit 9.5' from the front wall, leaving 7.5' behind you, putting your surrounds about 4' behind you.  I think that setup would be OK for two channel stereo, although it would be better if you had more width.  I don't know about the surrounds.

I was just reading Floyd Toole's white paper: http://www.sound-thinking.org/index.php?s=2bbc5c9d0a672e1f75d9399b20ca641b&act=Attach&type=post&id=30223  In a section, he says that wide dispersion coupled with heavy absorption is wasteful, but it didn't seem to me that he was saying that absorption wouldn't work. Actually, he said that absorption would work, but it was wasteful to turns sound waves into heat.  In one of the diagrams, he has diffusers to the sides on the back wall and absorption in the center.  I don't think diffusion can hurt, however.  Maybe you should post this in the acoustic forum.   But let me know how it turns out.  If you go with diffusers, and they help, I'll get some too.    

[elee532]

Thanks for the quick reply! I'm gonna try to give your layout suggestion a try tonight.

When you suggest 3' from the front wall, should I measure from the wall or the bass trap?

I haven't read the whitepaper you referenced, but it sounds like think Toole's opinion on room treatment may be a bit different in his 2008 book.

One suggestion that was made to me was a new diffusor/absorber panel by Quest called the PerfSorber. However, the price I was quoted was almost $200 for a 2' x 2' panel before adding a fabric cover. A little steep for me right now - but I definitely hope to give 'em a try someday.

[oneinthepipe]

When you suggest 3' from the front wall, should I measure from the wall or the bass trap?

I was referring to the wall, and Jim recommends a minimum of 18", IIRC.  There are other members that are much more knowledgeable than me about speaker placement and room treatment.  I suspect that other members will respond.

[Nuance]

Anyone have any recommendations on acoustical treatment for the room where I have my SongTowers? (FYI, they are part of a 4.1 system that will be used 75% for music, including a lot of hi-rez surround music)

95% of what I have read recommends absorption at the first reflection point. However, I just started reading Floyd Tool's Book, "The Acoustics and Psychoacoustics of Loudspeakers and Rooms." Most of the book is over my head, but it does seem to call into question the notion of first reflection absorption in a small room.

Now, on top of this, I recently saw someone mention that "early reflections are not necessarily bad. They are not good if the off axis response of your speakers is poor...then you want to absorb... If the off axis response is good, then you'd be looking for diffusion."

Now, it is my understanding that the SongTower's have excellent off-axis response. Correct?

I had literally already started purchasing my absorption panels when I started coming across these contradictory bits of info. Any insight greatly appreciated!

I am with Toole and recommend starting with a panel behind each speaker.  At least for me, this netted the most gain. 

[elee532]

Thanks Nuance. I'm still trying to plow through the Toole book... 95% of it is over my head. Where behind your speakers did you position the panels? Would this change at all in a surround setup vs. a stereo setup? In addition to the bass traps that I already built, I've got two 2' x 4' x 2" panels from ATS Acoustics. I'm trying to determine the best use of just two panels until I can save up cash to get more. Placement of panels on my front and left side walls is complicatd by a 6" ledge about half way up the wall.

Thanks for any thoughts!

[Nuance]

elee -

Directly behind each front speaker is what worked best for me.  You can experiment with the two panels you have to find what works best.  I used quilts as I didn't have room treatments on hand.  This helped me decide where to put them when I purchase or make more.  Since you have those two, experiment when you have some free time. 

[fluke242]

Thanks Nuance. I'm still trying to plow through the Toole book... 95% of it is over my head. Where behind your speakers did you position the panels? Would this change at all in a surround setup vs. a stereo setup? In addition to the bass traps that I already built, I've got two 2' x 4' x 2" panels from ATS Acoustics. I'm trying to determine the best use of just two panels until I can save up cash to get more. Placement of panels on my front and left side walls is complicatd by a 6" ledge about half way up the wall.

Thanks for any thoughts!

I use ATS in my setup - great $ to performance.  As ATS points out, just getting the panels up anywhere will make a difference.  But 1st reflection points, directly behind front speakers, and room corners have the most impact.