This is a drawing of my room, and the planned acoustic treatments I am planning. All of the Rocksilk (mineral wool) is 100kg density. The superchunks are floor to ceiling, the 4' x 4' panels are 4" thick, and will be mounted 4" from the wall, assuming I can come up with a suitable mounting method. I also want to use an open frame for the edges to enhance edge absorption, so suggestions welcome. The 2' x 4' panels will be 4" thick as well, and 4" from the walls. The 4' x 4' x 4" panels will hang from the ceiling, with up to 6" behind them, depending on the slope of the ceiling. I will be hanging them level with the floor. The pictured configuration uses 15 packs of 6 boards each, which are 2' x 4' x 4", of 100kg density Rocksilk.

Any suggestions before I purchase materials appreciated.
Thanks

The completely free standing room I now have , is about 16' by 25' by 8'. The only thing in common, is the solid slab concrete floor, which is covered with a dense felt underlay, and high quality dense carpet. The walls are built of very high density concrete blocks 8" thick, and then covered with an 1" of plaster. The ceiling is made of three different thicknesses of plaster board, all cross laid, covered with a layer of plaster. Above the ceiling is 12" of fibreglass, made up of, three different densities of 4" slabs.

The door to the internal room is made up of two 1" thick pieces of marine plywood, for the door facings, built on a 2" by 4" frame, and the hollows are filled with sanitised sand, so the door is about 3" 7/8" thick, and weighs over 200 pounds. This is mounted to an acoustically sealed door frame.

As soon as you get a picture up we'll be able to help. See the READ THIS FIRST post which links to a free photo hosting site.

--Ethan

Sorry folks. I followed the FAQ, on this site, and posted the URL as instructed, and the link to the photo shows, and not the photo? If you copy and paste the link into your browser, the photo appears. What have I done wrong??
Thanks

Nothing - it's there..

Would it help if I were to put something like a sheet of Kraft paper, between the two sheets of Rockwool, or would it be better on the front or back of the bass traps?
Thanks

-corner ain't enought treated, some in wall to ceiling is important and wall to floor is good too.
-i would replace the big patch behind the "tv"(i guess), it won't be important if you have a big patch in front of it, on your backwall.
-i would replace the big patch on the ceiling, close to the back wall.
-The treatment of your ceiling would consist more in a good first reflection treatment and corner to wall treatment. If your carpet is dense, it will already kill a lot of the high frequency's. Of course you only have 8 foots high, but treating the ceiling with some treatment like that will not give a real benefit. Ceiling will still be apparent acoustically.
-at the exeption of first reflection point and corner, do not use 2 treatment in front of each others. Shift them so there is less total room surface untreated facing each others. You can leave a space of 6 to 12 inch between them.

-Treatment are usually sold in 2'X4' pannel, i would find more usefull 2 pannel of 2'X4' than 1 of 4'X4'.

Thank you for your reply Frank. I understand about the panels not facing each other. I can easily shift the wall panels, with the exception of the first reflection ones, to not face each other. I can put some panels across the wall to ceiling junctions.
As to using panels of 2' x 4', instead of 4' x 4', is no problem. I understand I will have more edge absorption that way. Should I face them with paper to increase bass performance and decrease high frequency absorption?
There is no TV in the room. This is an audio listening room only. The back wall, where the green 3' panel is, is a gap between the bookcases, holding all my cd's and records. The back wall has four bookcases across it.
There is nothing on the front wall, except whatever treatment I use.
The speakers are in the room about where the two red panels are on the side walls. They are 54" from the side walls, and 87" from the front wall.
Thanks again for your input.
You say the superchunks are not enough treatment for the 4 corners? I was under the impression they were more effective, than placing 4" thick panels across the corner junction. Are you suggesting that I do both?
I am happy to remove some of the ceiling paenls if not needed.

1-it is not that about the edge absorption but the dispatching of the treatment to uniformise the room.
2-the pannel in the back wall is good, specially for first reflection point behind your head.
3- the superchunks is better for sure! but at the junction of the wall and ceiling it is a corner too! you have at least 12 corner in a normal room
4- facing is really good in corner, it can be good in overall treatment, but never on first reflection treatment.

Thanks again Frank. As the superchunks are going from the floor to the ceiling, am I not effectively removing those corners? I will use all 2' x 4' panels, and face them all except the first reflection point ones,and the superchunks.

Modified drawing after Franck's suggestions.

Judging by how far way the listening point is from the speakers,I would expand your first reflection points to about four feet instead of two feet wide for the side panels.I think having the panels staggered for a listening room may not be the best approach.Staggering the panels in a recording room is standard practice,but I have never seen this done in a listening room,and I would most certainly not do it in a mixing room.That approach could mess with the stereo image,even when not at first reflection points.Ethan may want to weigh in on this one.

yes i think a bigger pannel for first reflection point is a good idea for that distance, didn't think about it

i don't understand how staggered treatment could mess the stereo image. Can you explain please?

How was the placement of the speakers arrived at please?
Have you heard them in this position?
7.25' from the front wall is a very long way - and can have a huge effect on them (you make no mention of what they are? Standmount, floorstanders, flat panel?).
If it's incorrect and you fix your first reflection point traps in position, what are you going to do?
I personally would be more interested in getiing them in the correct position first then work out where the panels go for first reflection.

by George Cardas
Very precise speaker placement can open up a whole new dimension in listening, so I will outline the system that is becoming the standard of the industry. This standardized listening room is a Golden Cuboid and is the model for the math used in this system. This method will work with any box speaker, in any reasonably sized rectangular room. You may find that you have already positioned your speakers this way by ear.
Active nodes are the main concern when placing speakers in a rectangular room. A node, or the frequency where speakers and parallel walls interact, is proportional to the speaker to the wall distance.
The three most importance nodes, in order of importance, are proportional to the distance between the speaker and:
1. The side wall nearest the speaker
2. The rear wall
3. The side wall across from the speaker
A secondary factor is the speaker-to-speaker time constant.
When you use this Golden Ratio method to set your room up, the speakers are placed so the three nodes progress or differ from one another in Golden Ratio. This eliminates any unison or near unison resonance in the nodes.
Panel or dipole speakers such as Apogees and Magnepans cancel their side waves, so a formula of .618 x the ceiling height can be used for determining placement from the rear wall. Most box speakers radiate low frequencies in all directions thus a formula that places the speaker to rear wall distance at 1.618 the side wall distance should be used.
Speaker placement, simply stated
The distance from the center of the woofer face to the side walls is:
Room Width times .276 (RW x .276)
The distance from the center of the woofer face to the wall behind the speaker is:
Room Width times .447 (RW x .447)
This is all you need to know to place speakers in a symmetrical, rectangular room!
________________________________________
Diagram A
Distance Percentage
Speaker to side wall: RW x .276
Speaker to rear wall: RW x .447
Speaker to opposite side wall: RW x .724
Speaker to speaker: RW x .447

This is how I set the speakers up, and I have been listening to them in this position for abiout 3 months. I am not worried about moving panels around, if that is needed after treating the room. If the speakers need to be moved, then moving a coupe of panels is no problem.

If you treat your room properly, you won't need that kind of placement...

Even though the later reflection effects will be more subtle.
If we ignor symetry in a small room,we get will get difference phase imformation from the left and right speakers. Due to the haas effect,even though we have taken care to keep symetry for the stronger early reflections(delayed only by a few ms),we will still be unable to percieve the difference between the direct sound and the reflective sound when it has an arrival time of less than 30ms.By rule of thumb,that equates to about 30 feet of wave length,and will be coming off just about every reflective surface in a room that size.The haas effect states the early sound will precendence over a delayed sound of the same amplitude by up to 10dBspl.This can make one speaker sound louder than the other at all frequencies.
That is not even taking into account the time,and phase differences that will occur due to reinforcing,and canceling different frequencies by phase.
en.wikipedia.org/wiki/Haas_effect

Oh - really... Good luck, I hope it works for you.

Those are not my words Steve! Those are George Cardas's words.

Well lets just say that if I followed that set of rules I would be sat over 5' outside the rear wall of my room to get the results I get - but hey - I'm not having a dig at anyone here - if it works for you - great!

okay i understand, it make sense. But im not sure if it would be noticeable since that delayed sound is not a first reflection and have a big chance to be extremely lowered by treatment before it is finally reflected to the ear.
At this point, it is really theorical
since im more in studio than listening room, having a stable room is really important. interresting, thx!
Frank