Seeking advice on skyline diffuser size and placement


I’m in the process of improving the acoustics in my listening/living room and would appreciate some guidance from those with experience.

I’ve ordered cork panels for the TV wall and the light grey wall behind my left speaker, and now I’m focusing on building skyline diffusers for the dark grey wall directly behind each speaker. I’m uncertain about the optimal dimensions for these diffusers. For context, you can view my virtual system.

My setup is in an open space where my living room, kitchen, and dining area are all one room. My listening position is ~14’ from the TV / speakers. I already have GIK Acoustics 4" Impression Pro Series Bass Trap Diffuser/Absorbers hung at the first reflection points (or as close as possible given the limitations of the room).

Specific questions:

  1. What would be an appropriate height for skyline diffusers that will be ~24 inches wide?
  2. Should the skyline diffusers extend beyond the height of the speakers, or is it sufficient to align with them?
  3. Would I get better results using shorter skyline diffusers (~24" tall) in combination with other acoustic treatments directly behind the speakers? If so, what complementary treatments would you recommend?

Thanks in advance for any insights!

sandrodg73

Thanks for the advice all.  I'm using a BBC patern for the skyline. It's a big time commitment. I am reaching back out TO GIK too.  I know that there is alot of experience and knowledge on this site so that's why I ask here also

I've found diffusers  on front wall behind speakers to be effective, generally middle front wall, helps to give dimension to sound stage and images. First reflection points good, remember ceiling. My issue with off the shelf diffusers is the size, 2' x 2' seems to standard size, I've cut my Skylines into half and/or quarters and spaced them out, standard size sometimes has too great an effect for me. For instance I may want a little more focus vs diffusion at certain reflection points, cutting diffusers into smaller pieces allows me to fine tune for this. Also, keep in mind the materials diffusers made of will have affect, ie, wood will be more reflective than a foam product.

- Absorption is the correct treatment right behind the speakers for sbir, etc. Put some floorstanding GIK 244 or Acoustic Fields ACDA right behind where the woofers are. Other places for absorption.... directly in front of you, directly behind, directly to each side, and directly above mlp (which would help with the strongest lengthwise and width wise, heightwise room mode).

- I assume you like the ’aesthetic’of the skyline diffuser. But QRD quadratic is predictable and sounds better. Acoustic Fields sells all their formulae in a book for 50 bucks or so. Get that book and start cutting wood, glue, nails, etc for all your diffusive needs. There needs to be a min distance between listener and diffusion panel. Side walls between speakers and listener would qualify (ipsilateral and contralateral reflexive spots), back wall if you meet the distance threshold...any spot that’s not directly behind or directly to the side or above, reserved for absorption as noted above.

- Considering the 14ft distance between speakers and mlp, that area rug in front of you is a bit inadequate. You could get a open cell foam type of absorption at specific spots on floor that absorbs lower frequencies than your rug, upon which anyone can still walk on, etc

I’m pretty sure you’re the one that needs to be giving us the advice. That’s some pretty sweet equipment you have. 

Thanks for your response and knowledge.  Great looking set up!

We are trying to maximize a multi use room that's odd shaped without it looking like a recording studio.  We have abosorbers/diffusers at 1st reflection on the right.  On the left is kitchen so no can do.  From the research I've done, diffusers behind a speaker may allow for them to be a bit closer to the wall and a bit closer together while improving imaging at the same time. Maybe split the length behind the speakers in thirds?absorption/diffusion/absorption? My room is on the lively side and base in areas is boomy

Diffusers placed behind front firing speakers will result in very minimal improvements at best. Back wall and rear of sidewalls placements would result in better results. Key for diffusion is to place at points of reflections. Behind front firing speakers is one of the last place you will experience reflection. If your room is overly deadened, place diffusers on first reflection points. If lively enough as is, place them on back wall. See my system with multiple pics showing my acoustic setup. The key to room acoustics starts with what your goals are, liveling up your room with diffusers, or deadening it with absorbers. Only you know. The key is usually a little of both until you get it right.