I'm back seeking design ideas for basement studio #2

[Soundman2020]

my poor wife will only tolerate my studio gear filling up the dining room for so long!

Ooohhhh you have an AMAZING wife! I'd be dead long ago, if our dining room had my gear staked in it like that.... I could sneak that one by for maybe ten minutes or so, .... then WWIII would start

(Naah, just kidding: My wife is not really that bad, but still, she would not be too happy at all with that!)


- Stuart -

[andy_eade]

My wife truly is amazing. She puts up with all of my artistic idiosyncrasies. Luckily (miraculously) for me she married me knowing what she was getting in to. I had already built studio #1 by the time we met, and so when our family started expanding and we needed more space she was really supportive knowing how tough it was for me to leave the old studio behind and go through the designing / building process all over again.

With that said, she really isn't happy about it (neither am I quite honestly) and if the dining room isn't back to being a dining room soon... Btw - this pic is just studio gear. The salvaged doors and other building supplies are in the garage and storage room

[andy_eade]

Ok Stuart. Hoping you can help me here. So I finally got an RFZ design to work with the wall splay starting a bit further in as you suggested, and with an angle of 22.5 degrees. There are no reflections going through my 1ft circle, and only a few, further off-axis (50 - 54 degree) reflections making it into the 2ft radius circle. Here's the thing though - I had created my two circles' origin, as well as the third point of my speaker triangle at the 38% point in the room, however I recall reading in Newell's Recording Studio Design book that it is standard practice to positions speakers such that the focus should be 60 to 80cm behind the principal listening position. I don't see how I am able to do that given the limited width of the room. I can't bring the speakers any further forward to gain some width since then the soffits would be right on top of my desk.

What do you think?

Many thanks,

Andy

[Soundman2020]

I recall reading in Newell's Recording Studio Design book that it is standard practice to positions speakers such that the focus should be 60 to 80cm behind the principal listening position.

In an ideal, perfect world, yes. But most home studios don't fit that! I'm more inclined to go for about 30 - 40 cm, realistically.

I don't see how I am able to do that given the limited width of the room. I can't bring the speakers any further forward to gain some width since then the soffits would be right on top of my desk.

There are two other options open to you:

1) Angle the speakers (and soffit) slightly less: Instead of 30°, try 28° for example.

2) Slide the speakers outwards along the soffit panels, so they are not centered on the panel.... closer to the outside edge than the inside edge. They should not be centered anyway...

Where are your axes meeting right now? In the middle of your head? That would be fine, if your ears are located in front of your eyeballs.... But if your ears are located on the side of your head, then that's where the axis should be pointing... Actually, it should be a bit further out that that: The idea is that the axes should graze past your ears, an inch or two away, and therefore meet at that point behind your ears.

There's another option too: Don't be so dead-set on the 38% thing! Slide your chair forwards a couple of inches. In the real world, it turns out that most engineers prefer a position like that, just a bit in front of the "perfect" location.

Or maybe a combination of the two... slight angle change + slight "soffit slide" + slight chair move...


- Stuart -

[andy_eade]

Thanks Stuart I will go through these and find a way to make this work. I also noticed last night while playing with Bob Golds calculator that I can increase the room width and length a small fraction without adversely affecting the room behavior. Adding this with your suggestions and I think I should be able to do this The only significant change I notice is an increase of 17 sabins to achieve RT60. It looks like I actually benefit from losing one of the Tangetials. Critical distance shifts back about 10 inches. I did just want to sanity check with you though that this looks acceptable - make sure I'm not missing something:

Room Dimensions: Length=17.07 ft, Width=12.75 ft, Height=7.5 ft
Room Ratio: 1 : 1.7 : 2.27
R. Walker BBC 1996:
- 1.1w / h < l / h < ((4.5w / h) - 4): Pass
- l < 3h & w < 3h: Pass
- no integer multiple within 5%: Pass
Nearest Known Ratio:
- "4) L. W. Sepmeyer: 1965" 1 : 1.6 : 2.33
RT60 (IEC/AEC N 12-A standard): 243 ms
- ±50ms from 200Hz to 3.5kHz = 193 to 293ms
- ±100ms above 3.5kHz = 143 to 343ms
- <+300ms at 63hz = 543ms
- 300<RT60<600ms
RT60 (ITU/EBU Control Room Recommended): 193 ms
- ±50ms from 200Hz to 4kHz = 143 to 243ms
- <+300ms at 63hz = 493ms
- 200<RT60<400ms
Absorbtion to achieve ITU RT60: 413 sabins
Volume: 1633 ft^3
Surface Area Total: 880 ft^2
Surface Area Floor: 217 ft^2
Surface Area Ceiling+Floor: 434 ft^2
Surface Area Front Wall: 95 ft^2
Surface Area Front and Rear Wall: 190 ft^2
Surface Area Left Wall: 128 ft^2
Surface Area Left and Right Wall: 256 ft^2
Surface Area 4 Walls: 446 ft^2
Surface Area 4 Walls + floor: 663 ft^2
(sabins - front wall - carpet) / Left+Right+Rear wall: 28 %
(sabins - front wall) / Left+Right+Rear wall: 90 %
Schroeder Fc: 122hz
Frequency Regions:
- No modal boost: 1hz to 33hz
- Room Modes dominate: 33hz to 122hz
- Diffraction and Diffusion dominate: 122hz to 488hz
- Specular reflections and ray accoustics prevail: 488hz to 20000hz
Count (33-217hz) : Axials=12, Tangentials=44, Obliques=48
Count (33-100hz) : Axials=6, Tangentials=5, Obliques=1
Critical Distance (direct = reverberant field): 12.90ft

And here is a pic of the Bonello 1/3 octave:

Bonello171-129-90.jpg

Many thanks as always and wishing you a fab Friday!

Andy

[Soundman2020]

It's all looking pretty good to me, Andy! It seems you have been tweaking very nicely.

I also noticed last night while playing with Bob Golds calculator that I can increase the room width and length a small fraction without adversely affecting the room behavior

Are you also using the "room simulator" mode of REW, to take a look at the predicted low-frequency behavior? Sometimes it can reveal things in more detail ...

- Stuart -

[andy_eade]

Are you also using the "room simulator" mode of REW, to take a look at the predicted low-frequency behavior? Sometimes it can reveal things in more detail ...

Yeah I did download it this morning and plugged in my proposed dimensions. Very cool new feature that they added although I wonder how much it translates to non-rectangular rooms. I'm not exactly sure how to interpret the results yet, and the REW help functionality does not appear to yet include the Room Mode Simulator.

I'm going to have a poke around in the HTS Forum and see what I can learn. Of course any nuggets of wisdom are always appreciated

[andy_eade]

If you slide the entrance door a bit further back, and put in a window to that "hallway", it would make a great emergency vocal booth...

However, you do still need inner-leaf walls for that hallway/booth: right now, it is in the air cavity of your MSM system. That will make it narrower, of course, and will create an issue with the door to the drum booth, but if you splay your CR walls a bit more (aiming for a true RFZ design... ), then the door should still fit in just fine.

So the door fits just fine now, the widening of the room helped me get RFZ without deviating from a 30 degree speaker angle but my question de jour is - how does one finish the inner leaf walls for the hallway / booth with just the one door without mechanically coupling to the drum booth? I would have separately framed walls for the CR, Drum booth, and Hallway / emergency booth. The door out of the CR goes into the Hallway / emergency booth (kinda like a very large sound lock) and then there's a door from there into the drum booth. How do I put a single door in a double wall frame assembly without mechanically coupling the two room's together?

Many thanks and wishing you a great weekend!

Andy

[Soundman2020]

How do I put a single door in a double wall frame assembly without mechanically coupling the two room's together?

Ummm... you don't! You put doors in, back-to-back, one in each leaf. That goes for all doors. If hinged doors won't work like that, then do glass sliders...

- Stuart -

[andy_eade]

Sorry Stuart, I should have been more specific. What I had in mind for this hallway / booth / soundlock area was to use Rod's SuperDoor approach. I'm just concerned as to whether the mechanical coupling of the Drum Room to the Control Room by way of the door frame is going to cause issues. I re-read the section on doors in his book twice today and while he stresses that it's not a big deal I can't help but have some lingering concern. Here is what he says in the book on page 93:

"tests have proven that a through jamb does not effectively lessen the total isolation value of a wall assembly to any great degree. So don't worry about any miniscule amount of isolation you may lose. Just build the frame straight through the cavity"

[sandledfoot]

andy,

i'm not seeing where your door to the drum room is connected to the control room? what am I missing... can you post your "final" plan and point it out?

k

[andy_eade]

Hey Kevin,

I'm still working on adding the final framing, electrical, and mechanical details and will post the .skp file then (unless it is not clear from the attached picture below and then I will upload it in it's current state). Hopefully this helps answer your question. As you can see the Hallway wall is connected to both the drum room and the Control Room by way of using a common door Jamb - using Rod's Superdoor approach.

DoorJambQuestion.jpg

Thoughts?

Andy

[sandledfoot]

ok, to clarify yet further, the wall between the CR and hall is just a single stud wall, drywall both sides with a common top and bottom plate? and then this wall carriers over to and adjoins the drum room wall... but this is where I get lost... the hallway wall where it meets the drum wall should be adjacent to, but not touching the other wall, it should be 1/4" seem, filled with acoustical sealant... then that doorway is only in the single stud wall... correct? or otherwise you'll need a double wall where the door is, with two doors... or am i missing it?

[andy_eade]

Actually no not quite. All walls are double stud walls with a one inch gap between, with the exception of the wall at the top of the CR and bottom of the drum booth - the air gap is significantly larger here due to a) maintaining a favorable ratio / predicted CR behavior, and b) the location of the structural support pillar (in red). The two doors in the picture are then using Rod's superdoor design where there is one door with one common jamb straddling both stud walls.

In Rod's book he also recommends using a common Jamb even with double door assemblies. This is not something I did in my last studio. To be honest I missed that detail in his book.

Hope that clarifies, but do let me know if you have any other questions or would like me to post the .skp file.

Many thanks,

Andy

[andy_eade]

Hi Stuart, Kevin, and all,

Well after quite an eventful year I am finally back and able to dedicate time to this project - my apologies for the radio silence. There has been some progress since I last posted and I will post some pictures of the demo'd space later. All of the sheetrock is removed, as is the electrical - the only thing that still needs to come out is the framing and insulation (which I hope to reuse for the new framing as much as possible.)

As I'm putting thought into my final plans and construction details I wanted to ask you all a question, as I could not seem to find an existing answer here on the forum. It's with regards to the structural pole that I had mentioned that sits between the live room and control room. In the new floor plan it will be sitting in the MAM gap between the two walls. As far as I can tell this pole goes up through the floor and continues through a wall in between the Family Room and Kitchen. I suspect it is supporting the weight of the bump out on the back of the house detailed in the picture below:

IMG_7066a.JPG

IMG_7165a.JPG

So my question is this. By placing it between the two rooms in the MAM cavity in my design - it should help minimize the noise transfer from the studio below, however I suspect there will still be significant resonance of the pole occurring - especially LF caused by Bass or Kick drums for example. What steps should I be taking to minimize this? The previous owner had framed around it and added drywall. What would be the best way to damp this? Remove the existing framing and add damping and then extra mass? I know from knocking on one of the other poles in the basement that is exposed - they have a pretty good ring to them, so I'm assuming they are hollow.

Any guidance you can offer would be gratefully appreciated as always.

Many thanks and hope you are all well,

Andy