Bushido Audio Productions, version 2

Hey there guys! long time no see! Turns out I'm building my studio again, actually gonna move it on the next 2 years from where it's now to the new house I built with my wife. Here is the old thread with my first studio build: viewtopic.php?f=2&t=10403&hilit=bushido So, I'll have lots more space, aprox 10m x 4.5m (max space that I can use because of local building regulations), so my plan is to build a larger, taller LR to be able to record big sounding drums, since what I mostly record is rock and metal. The size of the CR is important to me also, so part of what I need advice on is what would be the best size for each room, acoustically speaking. So here we go.... First of all I must state that the location is a bit difficult, it's really close to a major highway so there's constant noise and the sudden air-break from big trucks so what I first did was to hire a guy who could measure the average noise of the place, so the first image here is the frequency chart of what happened during the 45min he was measuring the place. He recommended that I should use a wall construction that gave me at least STC60 so I read Rod's book and what I came up with was the MAM that's on the second image. The room within a room is the solution since the place is in such a critical situation. The first leaf being a 20cm filled concrete block, then insulation, air, insulation and 2x 16mm gybsum layers. Is that the best way to go? you guys are more experienced than I am so any advice, correction or spanking would be alright hehehe. oh I forgot...I'll be building the place from the ground up, so no structure in place at the moment, a clean, blank, nice chunk of grass hehehe. So the layout. there are a couple of things that I need from the place, first that people can get into the recording place (right door space) and out to the terrace (left door space) without interrupting me or the players who are recording , and since doors are the weakest isolation points in the design I decided to place them in the CR, behind my chair and place a glass door in between the speakers to go into the LR...is that the best way to do it to maximize the space? I really spent a loooot of time thinking about this but then again, you guys are more experienced so any advice will be more than welcome.....am I making sense? Acoustics. Well, I really have no idea what the best acoustic treatment would be for the space, I know though that I want a big live LR, one that maybe I can deaden up with gobos?. Would it be worth it to make a vocal booth on the inside of the LR?. I left the design with parallel walls (I know they don't work at all) but so that I can change them with your suggestions. Because of the space I was thinking about sofiting my nearfields (KRK rockit8s....yeah I know I should change those) but I'm not sure if they will work well as sofits. Many, many, many thanks in advance guys for all the help you can give me! Juan Pablo

Pura vida! Hola, y bienvenido nuevamente! :) Welcome back! Since this is your second studio, this time around you get the John Sayers Frequent Builder Discount, which means that all the free advice you get on the forum is now available at half of the price you paid for it last time... :) :shock: :!: Seriously, I remember your first studio, and it looked fantastic! How did it sound?

First of all I must state that the location is a bit difficult, it's really close to a major highway so there's constant noise and the sudden air-break from big trucks

:shock: Ouch! Not fun! Do you also get a lot of low-frequency rumble from heavy vehicles passing? Your analysis curve doesn't show it, but that might be a limitation of the equipment he was using: it might not have been sensitive down at very low frequencies. If you do have that problem, and you are planning on recording drums and other stuff that has a lot of lows in it, then you might be one of the few candidates for a real floating floor. Hopefully not, but being that close to a major highway makes me suspect that vibration and rumble from trucks might be an issue. This might be a bit harder to build than the first one!

He recommended that I should use a wall construction that gave me at least STC60

STC is not a good system for measuring isolation in studios. STC does not take into account low frequencies at all, and you have a LOT of low frequencies that you need to take care of. In order to get rated at STC-60 a wall does not even need to isolate AT ALL at 63Hz, for example... So don't look too much at STC. What you need is something that will give you the Transmission Loss (TL) that you need at each of the frequency ranges that are problematic. First, assuming that you set one of your design goals as NC-20, for example, then you will have to get your level at 63 Hz down to about 51 dB. It currently seems at be at 65 dB, so you need about 14 dB of transmission loss at 63 Hz. For 125 Hz you are peaking at 68 dB, but you need to be at 42 dB for NC-20, so you need 26 dB of transmission loss there. At 250 Hz you are peaking at 75 dB, but you need to be at 34, so you need 41 dB of transmission loss at 250 Hz. Etc. With that info in mind, you can then look for construction techniques that will give you the required amount of isolation for each band.

The room within a room is the solution since the place is in such a critical situation.

Yup! No doubt about that.

The first leaf being a 20cm filled concrete block, then insulation, air, insulation and 2x 16mm gybsum layers. Is that the best way to go?

Perhaps, but you'll never know until you do the math! :) In any event, I still have a hunch that your floor is going to be more of an issue than your walls. If you are just a few meters away from heavy traffic at high speed, then my bet is that you are going to get a lot of vibration coming in through the ground itself.

I'll be building the place from the ground up, so no structure in place at the moment, a clean, blank, nice chunk of grass

Perfect!!!! :yahoo: Lucky you! :)

and since doors are the weakest isolation points in the design I decided to place them in the CR, behind my chair and place a glass door in between the speakers to go into the LR...is that the best way to do it to maximize the space?

Sounds like a good plan to me. But I would forget about that door that faces the highway: That's asking for trouble! It will be really hard to get the level of isolation you need with that door. The overpressure from heavy vehicles whizzing by is not going to be kind to that door.

Because of the space I was thinking about sofiting my nearfields

Excellent idea! I'm a great believer in soffit mounting. One other question: Your design shows a wall going all the way across between CR and LR: that isn't the right way to do it, if you want good isolation. That wall should ONLY go across the front of the CR, without extending to the outer leaf (building shell) at each end. Ah, one more: This entire studio is going to be sitting on its own concrete slab, correct? No ties to the existing building? - Stuart -

Tuanis Stuart! My first studio sounded very nice...some acoustic problems in the CR but I got used to it. Made some very very nice records in there. It's very good to be moving to a nice place of my own...actually I've been living here for a year and got married last saturday hehehe. Thanks for your quick and kind advice! I understand what you mean about the measurments, any idea about how can I take the Transmission Loss (TL)? so I can do the math.

Quote: and since doors are the weakest isolation points in the design I decided to place them in the CR, behind my chair and place a glass door in between the speakers to go into the LR...is that the best way to do it to maximize the space? Sounds like a good plan to me. But I would forget about that door that faces the highway: That's asking for trouble! It will be really hard to get the level of isolation you need with that door. The overpressure from heavy vehicles whizzing by is not going to be kind to that door.

well, that's gonna be a problem since I want to separate my family from the clients...and the only place I sadly have for that is the side facing the highway....maybe if we desing a kind of "corridor" to go through behind the CR?

One other question: Your design shows a wall going all the way across between CR and LR: that isn't the right way to do it, if you want good isolation. That wall should ONLY go across the front of the CR, without extending to the outer leaf (building shell) at each end.

I know :( The problem is that the engineer that's helping me with that told me that if I'm gonna build a filled concrete wall that long it will have to have that wall in the middle to support it since it'll be too heavy...and with earthquakes and all... Now, if we figure out that I can use another building procedure than a heavy concrete wall, it might be posible to remove that wall in the middle.

Ah, one more: This entire studio is going to be sitting on its own concrete slab, correct? No ties to the existing building?

exactly, if it's a better idea :D thank you very much man!!!

Well, after what you told me bout the doors facing the highway I came up with this sketch, which is actually on scale. It shows a kind of corridor to go through from the entrance to the terrace on the back, giving me an extra entrance to the CR... I lose size on the CR and LR...but well... ¨sigh¨ hehe And well it is dependant on if we can build it in another material but concrete, because on this design we don´t have the central wall What ya think? cheers JP

much betterer!

much betterer!

Yup! I think so too. Your wall angles still seem to be a bit too much.

The problem is that the engineer that's helping me with that told me that if I'm gonna build a filled concrete wall that long it will have to have that wall in the middle to support it since it'll be too heavy

Why can't you use pillars at several points along the wall? That's the normal way of doing it. Just a square section, plenty of rebar, and pour concrete. You can have walls as long as you want, provided that you reinforce them correctly. Plenty of very long walls held up perfectly in the 8.8 earthquake that we had here in Chile last year, and I can assure you, that was a pretty good shaking. A common method of construction here is to have a reinforced concrete "cage" for the building, which is basically just pillars on the corners and every 5 meters or so along the full length of the walls, then fill in the gaps with brick. Works great! That's how my house is built, and it has survive two earthquakes above 8.0 so far, without even so much as a single crack. Some of the walls are over ten meters long, so that method should work for you too. - Stuart -

yeah...true true....so is the corridor a good solution for having those doors towards the backyard? And how can I measure the real attenuation that I need to figure out my walls? and my floor? :D For the slabs they can be separated from the outside walls and between them right? to work against rumble transmition? Thank you guys for your time and help!

bumpity bump hehehe

Measuring the existing structure is simple - get your self a decent sound level meter and use you largest speakers to play sine sweeps and drums/bass music and measure all around the building and areas where the sound can be problematic. To Stuarts point, placement of the proper supports is crucial for building integrity especially during seismic events high winds etc. Placing them to align with the corners of the rooms will make them much less intrusive as well as either sides of entry doors etc.

thank you for your answer Glenn! I was refering to what Stuart told me about what I need to know about the noise coming out of the highway on the frequencies below 125Hz that the STC analysis doesn't cover, so I can figure out the best way to build my walls and floor:

STC is not a good system for measuring isolation in studios. STC does not take into account low frequencies at all, and you have a LOT of low frequencies that you need to take care of. In order to get rated at STC-60 a wall does not even need to isolate AT ALL at 63Hz, for example... So don't look too much at STC. What you need is something that will give you the Transmission Loss (TL) that you need at each of the frequency ranges that are problematic. First, assuming that you set one of your design goals as NC-20, for example, then you will have to get your level at 63 Hz down to about 51 dB. It currently seems at be at 65 dB, so you need about 14 dB of transmission loss at 63 Hz. For 125 Hz you are peaking at 68 dB, but you need to be at 42 dB for NC-20, so you need 26 dB of transmission loss there. At 250 Hz you are peaking at 75 dB, but you need to be at 34, so you need 41 dB of transmission loss at 250 Hz. Etc. With that info in mind, you can then look for construction techniques that will give you the required amount of isolation for each band.

I wish to know how can I do the math hehehe, to figure out those aspects of my construction.....or maybe I didn't understand something? Thanks for your time!

Do you have a sound level meter with a direct mic output, or a spectrum analyzer, or even a good mic with flat response? There are many ways of measuring the ambient noise level around in specific frequency bands. It would be good to know exactly where on the spectrum your issues are, in order to design the isolation suitably. If you have a good mic with flat response then you can download REW and use that to get an idea of what you are dealing with. - Stuart -

Awesome!, will do and come back at you! Thanks for your help guys!

Ok, so the measurements showed like the graphic I placed on the first post: Max sound pressure Level for Low frequencies: 40db, at 16Hz 50db, at 31.5Hz 65db, at 63Hz 68, at 125Hz 75db, at 250Hz Equivalent sound pressure Level for Low frequencies: 20db, at 16Hz 32db, at 31.5Hz 50db, at 63Hz 52, at 125Hz 55db, at 250Hz equipment was: meter: Quest Technologies Soundpro SP DL-2-1/1. Número de serie: BHI080009 calibration: Quest Technologies QC-10. Número de serie: QII090032 Is this right for our purpose? do I need more info? Thanks guys!

Are those measurements A-weighting or C-weighting? And what was the response time set to? Those are important details: There can be pretty big differences in the low frequency end. - Stuart -

They are "A" measurements. You're form Chile right? cause the report is in spanish, maybe if I can mail you the whole .pdf? Thanks again!

cause the report is in spanish, maybe if I can mail you the whole .pdf?

Claro. No hay problema. Envíamelo vía PM. - Stuart -

Gracias!, ya te lo envié! un abrazo Juan Pablo

Hey hey Stu!, got time to check it out? Un abrazo Juan Pablo

hello there? :D

Hey Hey, thought I might upload the design I've benn playing with these days you we have something to discuss until Steve can check out my sound measurements :D. What do you think guys?

i think it's a good design. in the live room - consider shortening the right hand slats a bit and putting absorption across the corners - slats or super chunks.

Thanks Glen!, you mean like this?. Now that we have the general design in a good place let´s talk acoustics hehe. I want to tune my LR for drums, and since I record rock and metal I want big ass drums hehehe, so my idea is to leave the place sounding good but LIVE and then If I need to record something dryier I´ll use gobos or something to that effect. With that in mind is that treatment that I placed in the LR correct?. BTW I´ll make the room probably 4.5m tall

LOL I forgot to upload the image hehe

that works.

Thanks Glen! working on the 3D model right now.