control room design, build, acoustics

[/color]Hallo, i just discovered this wonderful forum. :) My name is Kostas and i mail you from Greece. My English are not so good but i 'll try my best :lol: So, at first i came here for educational reasons as an opportunity was given to me to build a room from scratch. Promise i will respect your time and not bother you with a lot of questions as i am not looking for something perfect. Room propose: Mixing-Mastering/Production/Fun Expectations: Sound quality 60%, inspiring-beautiful 25%, experimental ideas-design(room size, layouts, dimensions) 15% NOT LOOKING FOR PROFESSIONAL SUPER QUALITY SOUND Dimensions: H2.40m W3.36m L4.56m ?? (cant be bigger) Maximum high is going to be 2.60m (from the outside) so i came up with the dimensions by following one of the most used ratios(as i read), having as standard height 2.40m (inside) 1:1.40:1.90. I really couldn't find a lot of information about different styles of room sizes, layouts, dimensions and i am open to all ideas including (if there are any) experimental stuff. Monitors: KRK Rokit 8 G2 I will try to flush mount them. Other info: I am not going to go with a room into a room. The wall is going to be, from outside to inside drywall->isolation->space-> and then drywall->plywood OR plywood->wood I am so excited about this, thanks in advance. :)

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1 Picture A1 Thinking about removing this red parts. How do i find out, how to design the whole red thing, i mean angles distances starting points(did this red thing out of my imagination just to show you the question) Also, should i do something like this or should i leave it rectangular? I dont know the effort it needs to be designed

Those are referred to as soffits and soffit wings. You can use the search feature on the forum to find a plethora of information regarding these. There are basic rules to follow but ultimately they exist to soffit mount your speakers and create an RFZ room. Greg

ok, i found a lot of information here http://johnlsayers.com/Recmanual/ thank you! i will follow this image but can i go 90degree instead of 60 and 45degree instead of 30? I couldn't find any information about the soffit wings. this image looks useful but i cant understand the angles of the rear and side walls :?: thank you for your time!

UPDATED POST INFO Dimensions H2.40m W3.36m L4.56 The dimensions are applying to this ratio 1:1.40:1.90 In both designs listening point has been calculated by 38% rule OPTIONS Option 1 Speakers - listening position=90 degree, flush mounting angle with front wall=45 degree Option 2 Speakers - listening position=60 degree, flush mounting angle with front wall=30 degree QUESTIONS 1 Do you see any problems in the info? 2 Does these designs make any sense? If yes which one do you prefer? Hope i made things more clear, hope i don't ask too much :)

You'll need to add soffit wings and also do a thorough ray tracing to ensure that you won't get any first reflections to your ears. After that, you're good to go! Greg

I really appreciate your help :!: :) So, after reading a chart with best room ratios for 50m3 rooms from Salford University that i will attach, i came up with similar new dimensions. I changed the height to 2.50m and new dimensions are 2.50m*3.55m*4.17m (I also attached the sketchup file.) New design: Questions 1 I somehow designed those wings 6 degrees from somewhere around the middle of the wall i think. How do they look? 2 I suppose will add absorption panels in those red circles right? (optional) 3 Question here is, will it make any good to cut the ceiling like this? Thank you!

1 I somehow designed those wings 6 degrees from somewhere around the middle of the wall i think. How do they look?

Getting there for sure! I can't see exact dimensions in your design, but how far back is your head from the front wall? It should be roughly 38% depth from the front of the room. 25 and 50% is bad. I would ray trace with wider angles as right now it looks like your wings might not be angled enough for less directional frequencies. After you get your baffles and wings sorted out, tackle the cloud next. You need to ray trace that as well. You may find yourself juggling all of this to make it work. Also, be sure to take the depth of your speakers (and future speaker upgrades) into consideration.

2 I suppose will add absorption panels in those red circles right?

Your wings are a very hard and heavy material. Their purpose is to reflect sound towards the back of the room. Your long room and between 6 and 24" (the thicker the better) of absorption across the ENTIRE back wall will create a great listening spot for you. You should be bass trapping as much as possible. That might mean that the entire cavity behind your soffit baffles and wings are full of insulation.

3 Question here is, will it make any good to cut the ceiling like this?

Sorry, I'm not understanding the question. Greg

Hallo greg, thank you again for your support :) 1

Getting there for sure! I can't see exact dimensions in your design, but how far back is your head from the front wall? It should be roughly 38% depth from the front of the room. 25 and 50% is bad. I would ray trace with wider angles as right now it looks like your wings might not be angled enough for less directional frequencies. After you get your baffles and wings sorted out, tackle the cloud next. You need to ray trace that as well. You may find yourself juggling all of this to make it work. Also, be sure to take the depth of your speakers (and future speaker upgrades) into consideration.

It is exactly at 38%, 1.70m from the front wall. (H2.50, W3.75, L4.50) Is ray tracing those lines i draw one the floor? (Doesn't look like any of those lines are hitting my listening spot.) The distance between the speaker and the side wall(wing) is now 37cm (0.37m). I tried to do the wings at 10 degrees, but then wings came to close to the speakers... SO -> IF {wings-angle 6 degrees}={speaker-distance-from-wall 37cm} | IF {wings-angle 10 degrees}={speaker-distance-from-wall 22cm}. What do you think about that? Placing a cloud might be too much for me right now, so i might do that in the future. Or maybe i can design the ceiling itself somehow, above the front side of the room, to help the sound. I found this picture, should i do something like this? -> 2

Your wings are a very hard and heavy material. Their purpose is to reflect sound towards the back of the room. Your long room and between 6 and 24" (the thicker the better) of absorption across the ENTIRE back wall will create a great listening spot for you. You should be bass trapping as much as possible. That might mean that the entire cavity behind your soffit baffles and wings are full of insulation.

I thought i am going to build the wings the same way with the other walls, i don't have specified information about wings. Should i build an extra plywood layer on them so they will be harder and heavier? Should i put absorption panels on them (on the left and right of the listening position) ? In general, i could put another layer of wood (plywood or mdf?) on some, or all of the walls. Do you think i should do something like that? 3

Sorry, I'm not understanding the question.

Is it going to be better for the sound to have a ceiling like this? ->

Is ray tracing those lines i draw one the floor? (Doesn't look like any of those lines are hitting my listening spot.) The distance between the speaker and the side wall(wing) is now 37cm (0.37m). I tried to do the wings at 10 degrees, but then wings came to close to the speakers... SO -> IF {wings-angle 6 degrees}={speaker-distance-from-wall 37cm} | IF {wings-angle 10 degrees}={speaker-distance-from-wall 22cm}. What do you think about that?

I can't say if that would work or not without seeing the ray tracing. Designing the soffit baffle (with speaker placement), soffit wings and ceiling cloud is a tricky process for sure. I've often spent hours tweaking to get an ideal placement.

Placing a cloud might be too much for me right now, so i might do that in the future. Or maybe i can design the ceiling itself somehow, above the front side of the room, to help the sound.

How come a cloud is too much? That's one of the easier parts of the build.

I thought i am going to build the wings the same way with the other walls, i don't have specified information about wings.

The wings are build similar to the soffit baffles. They are just frames holding wood sheathing, sitting inside of your inner leaf. Using the search feature on the forum, you can find a lot of examples.

Should i build an extra plywood layer on them so they will be harder and heavier? Should i put absorption panels on them (on the left and right of the listening position) ?

Your room shape (which I thought was just the treatment shape), along with your ray tracing, indicated to me that you want to build an RFZ style control room. That means hard surfaces on the front half of your room to direct sound towards your rear wall where there is a ton of absorption. That means no absorption panes on your wings. You can have absorption along the bottom portion of your soffit baffles and wings as you can see in lots of designs on the forum. Greg

Ok seems like things are getting a little bit harder for me to put together. Before we continue, is an rfz room the kind of room i should go for? Please let me explain how this project started in my mind, so maybe you can help me according to that. At first, the idea was to make my own music room. Only for my fun and not for work. So i thought why not do the best i could do also with the acoustics of the room. Note that i dont play any instruments. (Most of my music is computer (mpc-2000) based and it will be coming out of my monitors. I also loved the idea of mounting my speakers into the wall as it always looked wrong to me to place them in front of a wall. :blah: ) I am also mixing music and i am a little more seriously into it. (i dont know if my English makes sense :lol: ) (do you think i should pay someone to design it for me and then i will try to construct it? If yes do you know someone? thing is i dont want to put much money on the design as i look for something i would say simplier if possible) Sorry if i said too much :| Just want to make clear if RFZ room is the name of the room we will be designing.

Right now I feel that RFZ is the best mixing room design out there. If you want great acoustics in your mixing room then that's the best choice for you. With it comes a lot of design and build time. It also comes with a price as there are a lot more materials involved. So really, time and money are the determining factors here. You could also get away with building out a room similar to a lot of people do in bedrooms which is to just put a bunch of treatment up and then have your speakers on stands. This is a quick and easy way of getting a decent sounding room. Greg

hey greg! Okay then i am going for the rfz room. :D I changed a little bit the baffles, changed wing angle from 6 to 10 degree and did some ray tracing. I am not sure if this is ray tracing, and i cannot read it to understand if wings and whole design looks good. How does it look like?

Your ray tracing is done correctly but your angles aren't working correctly, yet. I've circled in red the one boundary in which you get a reflection that will hit your head. Try to make it so that you have a 2 foot diameter sphere around where your head will be in which you get no first reflections. This will allow you to move around a little bit without hearing a first reflection. I would suggest making your soffits less angled, shorten your wings and angle them more as well. This all might mean that your speakers are closer together, but that's fine. Your soffits could be at 25° to about 35° and that is a good starting point. Try placing your speakers somewhere between 28% to 34% the width of the room. You're doing great and you're close to getting it sorted! Greg

Greg i am deeply thankful ! Does it look good? :mrgreen: :mrgreen: (the circle on the listening point has diameter 60 cm)

I would suggest making your soffits less angled

So, i didnt make my soffit less angled because i wanted my speakers to be on 90 degrees. ( as i read good speaker placements are 60 and 90 degrees, and i cant make it work at 60) If you think its beeter at 60 i will try harder

shorten your wings and angle them more as well.

Thats exactly what i did :)

Your soffits could be at 25° to about 35°

They are 45°

Try placing your speakers somewhere between 28% to 34% the width of the room.

They are placed at 20% the with of the room I am amazed about how much you helped me. <3

ANOTHER QUESTION I saw this post from john, its a treatment recommendation about walls of small room. Do you think i should do the same? I was planning to cover the walls with gypsum board and behind put the insulation.

Does it look good?

ALMOST! I think I know how you can get it 100%. Here is a spot you haven't ray traced and I believe would be a problem: If I were you, I would angle my soffits less... make them more perpendicular to the front wall. which would fix that one reflection from hitting your head area. I would make the front center section deeper for more insulation. I would angle the wings more. They could be a bit shorter yet to help achieve a greater angle. Your speakers don't need to be centered on your soffit -- It's actually recommended by some to NOT have it centered, so don't worry if it is offset after these adjustments.

I am amazed about how much you helped me. <3

Trying to help people like you is how I continue to learn, so thanks for coming here and asking!

Do you think i should do the same? I was planning to cover the walls with gypsum board and behind put the insulation.

John Sayers invented what is referred to as "inside-out" construction. This is used when building a room in a room in which you build the inside room "inside-out". This leaves the studs exposed like in the picture you posted. It then allows us to fill the cavities between the studs with insulation and then put fabric over it. For a room in a room construction, it ends up saving a lot of material and space which is brilliant. This really shines for room in a room, inner room ceilings. For your build, which isn't a room in a room, you very well could still build a frame inside your room to hold insulation and other treatment devices. Without getting to technical, we can consider your rectangular drywall room the dimensions for your room modal distribution. The rest of the stuff you put in your room is just acoustic treatment. What are your concerns about tackling a ceiling cloud? Greg

Here is a spot you haven't ray traced and I believe would be a problem:

indeed, i ray traced it and it looks bad.

If I were you, I would angle my soffits less

Does they look wrong? Doesn't that mean that my speakers angle will also change? shouldn't they be at 60 or 90 degrees? here is a design with speakers at 60 degrees. Do you think i better place them this way?

I would make the front center section deeper for more insulation

Do you mean the space between the soffits? we can work on this later, lets finish designing soffits and wings first.

What are your concerns about tackling a ceiling cloud?

i am having a hard time designing the wings and soffits right now, ceiling and cloud can be the next step.

I would angle the wings more. They could be a bit shorter yet to help achieve a greater angle.

Ok, i made them shorter so now they are 5 degrees more angled. Does it look good now? Or would you prefer 60 degrees? Note that the circle on the listening spot has diameter 60 cm. (I also add the sketchup file in case you have some extra free time :) ) http://www.johnlsayers.com/phpBB2/download/file.php?mode=view&id=68005

After seeing you struggle for so long I decided to just try and sort this out for you. I'm not sure how deep your speakers are but I drew the width and height the same as the speakers you had drawn. Also, note, I changed the units to feet and inches since that's what I'm familiar with. Also, I kept your inner dimensions but just assumed you might use 2 layers of drywall and 2x4 framing for your inner leaf. With 30 degree soffits and short wings, you can eliminate any reflections back to the head sphere with ease. Your ceiling is pretty short though so it might not be as easy for the cloud. Also, in your drawing you didn't make any components or utilize the layers. Components and layers are SUPER important when drawing in SketchUp. Also, google or youtube inference or inferencing in SketchUp. It speeds things up a lot and prevents moving things off axis. The last tip I'll give here is that you can completely draw up one speaker soffit and wing, then turn off the other layers (like foundation, inner leaf framing, etc). After that, select everything you want to copy over to the other side of the room (when the move tool is selected, hold option/alt while click and dragging --> note, use the arrows to lock to your axis while moving directly across the room). Then, use the scale tool and push in the middle handle, then type in negative one like this -1. It will flip the entire selection, making a mirror image of it to place on the other side of the room :thu: I wasn't sure how deep your speakers are so I just took a wild guess when I drew up the speaker. Note, the distance the soffit baffle is from the front wall is very dependent upon the speaker depth because if it is too close, the back of the speaker will hit the inner leaf sheathing. The further you move the soffit baffle away from the front wall, the more you're going to have to angle the soffit so that the acoustic axis of the speaker aims at the tips of your ears. You don't have to be perfectly in line with the speaker as the speakers typically have a pretty wide horizontal dispersion. But be aware of it and adjust accordingly. With the short ceiling, you may find yourself needing to slide the entire soffit structure further into the room and this is when you might have to angle the speakers more. Anyway, I think you get the idea. Here is a picture and the SketchUp file. Oh, and speaking of the SketchUp file, you posted a 2020 version. We all use SketchUp Make on here as it is the free version and it stopped being made in 2017. A lot of people use older operating systems so they might have much older versions on their computer. When you go to save a version for the forum, first go to model info, statistics, then purge unused. This will typically make your file small enough to post on here. If it is still too big, upload it to dropbox or your google drive or something like that that will hopefully be there forever. Then, go file save as and for the file type, choose an older version. For the one I uploaded I selected a 2014 version. Greg

Greg you are so kind, thank you for all the help ! are you sure you want to keep designing the room with me? I don't want to be greedy by asking so many questions

I'll help when/where I can. It's tough to make the time but I understand the anxiety of feeling lost but wanting and needing to get a project done. Luckily the search feature is great on the forum and chances are damned near every question you have does have an answer waiting for you on the forum. Don't hesitate to ask though! Greg

Hallo Greg :) Just some questions about the walls so i can start constructing the frames. I would like to ask about the kg of the rock-wool. Because my room will be outside (next to) my house and temperatures here get really high in summer, i will also be using 4cm Styrofoam insulation. So, from outside to inside i am thinking to go something like this: two layers of drywall -> Styrofoam insulation -> rock wool -> two layers of drywall (except rear wall that i am going to be using cloth to make the whole wall absorptive) Does this order sound good to you? maybe you have an advice to make it better What kg/m3 of rock-wool should i be using? The heavier the better? Should i include a layer of empty space (air) inside the wall? If yes in what order should it be? Thanks in advance

Because my room will be outside (next to) my house and temperatures here get really high in summer, i will also be using 4cm Styrofoam insulation.

I wouldn't use the styrofoam if I were you. It is closed cell so it won't help acoustically at all. If you have thermal concerns, you could just use higher R value insulation.

What kg/m3 of rock-wool should i be using? The heavier the better?

In the wall cavity, use whatever really.

Should i include a layer of empty space (air) inside the wall? If yes in what order should it be?

Maybe check your local building codes, but acoustically speaking, don't leave any voids. Greg

In the wall cavity, use whatever really.

How is that? What about the rear wall that its going to be covered only with cloth ?

How is that? What about the rear wall that its going to be covered only with cloth ?

Acoustic treatment inside your room is different than the MSM cavity. For the inside of your room, if you can afford and find Owens Corning 703, that is the good stuff. Greg

For the inside of your room, if you can afford and find Owens Corning 703, that is the good stuff.

I assume when you say for the inside of the room you mean for the back wall, bass traps, panels and stuff like that right?