Acoustic treatment for my little studio. Some advice please.

Hi, I have build a little studio. you can see the plans here attached. I had no other chance to build this into my concrete building. So please help me designing the acoustic. Some infos: 1. The Control & recording room window is angeled. 2. The hole Studio is build with Gypsumboard. (Knauf diamant System) 3. Its a "room in a room" System. 4. the celling is also gypsunboard. Its attached to the concrete Cellinging via some "hangers". (These little things with rubber in the middle) 5. The floor is a "dry screed" also from Knauf on a concrete floor. This "dry screed" is a isolation layer with a fiber board on top. 6. The hole System is build with gypsum-Insulation-air-insulation-gypsum (concrete) 7. The box on the left side of the control room is a support. It was covered the same way like the walls. (gypsum-Insulation-air-insulation-support). Thats the reason because its now soooo big. Now, how can I optimize the acoustic? In both. The recording room and the control room. I think i have to make the recording room as dry as possible because i have no chance to "design" the acoustic. Now my questions: 1. How can I calculate the modes in these rooms. They are not Rectangle and all online calculator need Rectangle dimensions to calculate the modes. 2. When i listen to the controlroom I hear some resonances at 65 Hz, 108 Hz, 472 Hz etc. Is this correct, or do I hear it wrong. My plan is to build some Panel bass absorber for the rsonances in all edges, some "mid/High Absorber" with (18cm) mineral wool for the rest of the walls and the celling over the listening position For the Controlroom I will also put a little Diffusor on the rear to make the room not to dry. You see, I am a newbe to all this stuff, but it would be very nice, if someone can help me out. My big question is: What should I do?...:-) Many thanks in advance. Best Hendrik P.S. sorry for my bad english. I hope you can understand me....

And here the "Cross section of my studio. Best Hendrik

1. How can I calculate the modes in these rooms. They are not Rectangle and all online calculator need Rectangle dimensions to calculate the modes. You will find it nearly impossible to calculate that shape room; measurement is about the only practical way. I have a program, CARA, made in Germany - it's very complex, and I think it might be able to do what you want - but I've yet to find enough time to dig into it deep enough to be sure. It's only about $70 euro for the whole package including tutorials, and there's an optional RS232 controller that their tech people told me will work with a USB adapter cable (the controller adds about $250 to the price) A faster, more practical way is to use a program like ETF and MEASURE your room - that way you can measure, make a change, and measure again to see the exact result. 2. When i listen to the controlroom I hear some resonances at 65 Hz, 108 Hz, 472 Hz etc. Is this correct, or do I hear it wrong. Probably not; but is your ear precise enough to measure frequencies like that, or are you generating those frequencies and listening for changes in volume? My plan is to build some Panel bass absorber for the rsonances in all edges, some "mid/High Absorber" with (18cm) mineral wool for the rest of the walls and the celling over the listening position. A better approach for nearly all rooms is first to do broadband treatments wherever possible (corners, including wall-to-ceiling corners, rear of room, "clouds" over the mix position - this will "even out" the response and may eliminate the need for "tuned" treatments, which are much more difficult to place correctly. For the Controlroom I will also put a little Diffusor on the rear to make the room not to dry. Your room isn't deep enough for diffusion in most cases; you need typically 10-12 feet behind your head before it's a good idea. In addition, if you're actually planning on 5.1 sound you'll want the room less live anyway; see this for more - http://www.grammy.com/pe_wing/5_1_Rec.pdf HTH... Steve (Your English beats the crap out of my German - no need for apology... :wink: )

Hi Steve,

knightfly wrote:

You will find it nearly impossible to calculate that shape room; measurement is about the only practical way. I have a program, CARA, made in Germany - it's very complex, and I think it might be able to do what you want - but I've yet to find enough time to dig into it deep enough to be sure. It's only about $70 euro for the whole package including tutorials, and there's an optional RS232 controller that their tech people told me will work with a USB adapter cable (the controller adds about $250 to the price)

Ok, but than it´s better and easier to measure my room.

knightfly wrote:

A faster, more practical way is to use a program like ETF and MEASURE your room - that way you can measure, make a change, and measure again to see the exact result.

Ok, I will do so....

knightfly wrote:

2. When i listen to the controlroom I hear some resonances at 65 Hz, 108 Hz, 472 Hz etc. Is this correct, or do I hear it wrong. Probably not; but is your ear precise enough to measure frequencies like that, or are you generating those frequencies and listening for changes in volume?

Of course! My ears are the best ears in the world. Believe me, I heard this 65 Hz!....:lol: No, no I used a sinus generator and a normal omni condensator Mic with real time analyzer (Waves Paz). Not perfect, but I heard a volume change and saw it on the analyzer too....

knightfly wrote:

A better approach for nearly all rooms is first to do broadband treatments wherever possible (corners, including wall-to-ceiling corners, rear of room, "clouds" over the mix position - this will "even out" the response and may eliminate the need for "tuned" treatments, which are much more difficult to place correctly.

Thanks. I will try that first....

knightfly wrote:

For the Controlroom I will also put a little Diffusor on the rear to make the room not to dry. Your room isn't deep enough for diffusion in most cases; you need typically 10-12 feet behind your head before it's a good idea.

Yes I saw it in a post, where you wrote that the reflection are to early than. Right?

knightfly wrote:

In addition, if you're actually planning on 5.1 sound you'll want the room less live anyway; see this for more -

Yes. I also need a absorbing Front, because of the rear speakers. So you´re right. I will try the broadband absorbers first...

knightfly wrote:

(Your English beats the crap out of my German - no need for apology... :wink: )

I don´t now, how well you speak german, but if your sentence is right it must be dreadful..... :lol: Thank you very much for your help!!! Regards Hendrik

My "Deutsch" is really dreadful... and I took 3 years of it in high school (20 years ago)! I can barely speak a complete sentence anymore! :oops: Not only do you not need to apologize for your English, Hendrik, but your English is [i]sehr gut[i] -- better than most of us native speakers in my opinion! 8)

Hi All, now I have a plan for my Absorber. They will be 2 Meters high (Basstraps will be higher direct to the celling) and 60 cm wide and all 18cm thick filled with 10 cm 703. The distance between the moduls will be around 20 cm. The red lines will be molleton curtain for the windows... The celling cloud is not right in the plan. They will be nearly all over the celling... 2 questions: 1. Is it a problem, if I have in the right rear corner a big basstrap and in the rear left not? I cant put it there, because the door is to near to the wall. 2.Do you see any other problems? Thanks in advance for your help! Best Hendrik

Bottom line - IF YOU STILL WANT MY INPUT ON ANYTHING, PLEASE 'BUMP' YOUR THREAD; THAT WILL PUT YOU ABOVE THIS POST SO I'LL KNOW.

Bump :wink: Best Hendrik

1. Is it a problem, if I have in the right rear corner a big basstrap and in the rear left not? I cant put it there, because the door is to near to the wall.

IMO, symmetry in low end treatment is not important. It should be fine to do things as you have outlined. Danmed doors should stay out of the way! :lol:

I agree; although (for higher freq reflections) if you have any reflective surfaces there I'd use the "mirror trick" and at least put some kind of absorbent in those spots... Steve

Hi Steve and David. Thanks for your help. One more question.... :oops: Would it be better to put some hangers behind the front speakers or should i fill it with 703? My room ist very small and i dont have much space. So i dont know if hangers will bring me an improvement.... Thanks in advance Best Hendrik

Your earlier sketch of the room looks like the speakers are free-standing; hangers normally go inside a trap wall. Can you explain further what you mean? Your later sketch doesn't link to anything for me, so I'm not sure if the room has changed... Steve

knightfly wrote:

Your earlier sketch of the room looks like the speakers are free-standing; hangers normally go inside a trap wall. Can you explain further what you mean? Your later sketch doesn't link to anything for me, so I'm not sure if the room has changed... Steve

Yes, they are free standing. But in the back of the front speakers I want to put broadband (bass) corner traps. My idea was to put some hangers instead of making the whole trap with 703. Bad idea? Is it better to fill the whole area with 703? Best Hendrik

Hendrik wrote:

knightfly wrote:

Your earlier sketch of the room looks like the speakers are free-standing; hangers normally go inside a trap wall. Can you explain further what you mean? Your later sketch doesn't link to anything for me, so I'm not sure if the room has changed... Steve

Yes, they are free standing. But in the back of the front speakers I want to put broadband (bass) corner traps. My idea was to put some hangers instead of making the whole trap with 703. Bad idea? Is it better to fill the whole area with 703? Best Hendrik

Hi Hendrik From where do you get 703 in Hamburg? by the way ...are you the Hendrik from Logicuser.de ?