Tracking room floors

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Michael Jones

Michael Jones

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Why is it that most of the tracking room floors I see are hardwood?
It just seems like one more reflective surface to attenuate.
Wouldn't some industrtial grade carpet, with no pad be better??
 
This is probably out in left field but I assumed it was because it is a "predictable" material (reflection, deflection, absorption and other words with the suffix tion). Of course it looks really good too :D

DD
 
My thought on this is that the carpet will only absorb the highest frequencies so your recordings would be deficient in the the high end since carpeting absorbs nothing else.

My question is though, what would be the difference in using a wood floor as opposed to vinyl flooring? Is it worth the cost?

Eric
 
Hi Michael, the only thing I can think of regarding the wood floors, is they sound GREAT. I've played music for 40 yrs, and every room I played in with wood floors sounded fantastic. I think beyond the reflection issue, that from my understanding, a tracking room, especially for acoustic instruments, need to sound GOOD. That means diffusion, as well as treating for reflection/diffusion. Mics pick up the room too! That is, unless you want an anechoec chamber, as knightfly put it. And then dsp it to satisfaction:p I would think that a wood floor is expensive, but if I could do it, I would. You can always put throw rugs/gobos where required. I read somewhere, that the use of throw rugs on a reflective floor, creates boundary zones? which makes for diffusion from the floor. I had a friend who had a vinyl floor, but installed a 2' wide carpet strip, along the wall/floor perimeter. Damn it sounded good. Don't know what it did exactly, but it sounded way better than just the vinyl floor by itself. Maybe it effects the modes at the floor/wall intersection? Who knows? Worked great though. One thing he did, was to curve the exposed edges of the carpet like a serpintine line. Don't know if that did anything acoustic wise, but it looked interesting. A bitch to install a carpet threshold though!!
I see you had diffusers along the tracking room perimeter. What type are these going to be? And BTW, did you ever work out your well width/depth issue on your control room RPG? I would be very interested in seeing those. I have always wondered what the parameters are for designing a RPG in relationship to room size. I mean, what do you use to determine the starting point of the design. I understand the frequency relationship to the wells themself and the quadratic/primitive root type sequence thing, but not relitive to the room. Are there some kind of room dimensions that determine anything in the RPG parameters? Sorry for all the questions, but I can't seem to get these type of questions responded to in the past. In fact, I still don't understand the underlying design decision hiarchy for absorbsion either. I mean, what determines the what and how of absorbsion use, and type, as I am sure it is not a matter of arbitrary quantity and placement. Any help would be greatly appreciated. And that brings up another question. What are your ceilings like? Parallel to the floor, or angled? Multilayer sheetrook? RC? etc. I've never seen anyone post a reflected ceiling plan, showing lighting, vents, structural etc. Did you have to provide one for permits? Just curious, as usually, the only people who would have to do this are the ones building from the ground up. The reason I am asking all this stuff, is I am planning my future studio right now, and there are a thousand things that I am curious about in relationship to acoustics, structural, etc. BTW, I think your plan is fantastic. Good luck with it!
fitz:D
 
Rick, thanks for the helpful insight. I'd love to be able to do wood floors too. Maybe if I can find an inexpensive flooring to use I'll do it, but Bruce Hardwoods run around $7/sq.ft.
The tracking room alone is over 600sq.ft. so thats $4200!
There goes my 6 pack of Brent Averill API mic pres for the drum kit :(

Now for your questions:
I see you had diffusers along the tracking room perimeter. What type are these going to be?
I plan on using a combination of the varible bass absorber/diffusor that John has detailed here:
http://www.locall.aunz.com/~johnsay/Studio/PDF Files/Variable_Bass_Absorbers-diffusors.pdf
and a series of RPG diffusers on the columns in the tracking room.
And BTW, did you ever work out your well width/depth issue on your control room RPG? I would be very interested in seeing those. I have always wondered what the parameters are for designing a RPG in relationship to room size. I mean, what do you use to determine the starting point of the design. I understand the frequency relationship to the wells themself and the quadratic/primitive root type sequence thing, but not relitive to the room. Are there some kind of room dimensions that determine anything in the RPG parameters?
From what I understand, RPG is just another type of diffusion. So, given that, you would begin by calculating your room modes.
Determine the problem frequencies.
And tune the RPG to eliminate or attenuate those problem frequencies.
Some one here on this board, I forget who it was, made this available:
http://studiotips.com/tools/
It is a series of spreadsheets that are helpful for this type of calculation.
The "Diffuser" spreadsheet has a calulator for the RPG duffusers.
And of course, there's a multitude ofHelmholtz calculators floating around too.
In fact, I still don't understand the underlying design decision hiarchy for absorbsion either. I mean, what determines the what and how of absorbsion use, and type, as I am sure it is not a matter of arbitrary quantity and placement.
Remember, Absorbtion is only one method of room treatment. Diffusion is another. The two are not the same.
Absorbtion techniques are employed to attenuate high frequency problems, and diffusion is used to attenuate low frequency problems. (someone flame me if I got that backwards!) It is my understanding that the best sounding rooms use a combination of both.
Again, running your room modes will determine your problem frequencies, then you have to decide, based on those modes which ones to use. As far as how much to use; well, I'm sure there's expensive acoustic design software that could tell you that answer. I'm going to utilize those techniques I've seen others use here with great degrees of success.
I believe once construction is complete, most of the room tuning is an emperical process. Thanks to this community, we have been given construction details for treatment, calculators to determine modes, and spreadsheets coupled with standard construction techniques to get our designs very close.
The rest is really up to your ears.

As far as construction
I plan on using a scissor truss for the roof and ceiling:
scissor_truss.gif


Sjoko, had me convinced on using a cathedral truss because of it's asymetery:
shape3.gif

But, well, economics dictate otherwise.

The room walls are 10' high, and the scissor truss provides another 4'-6" of height at the center. (based on my roof pitch and the coresponding internal ceiling pitch.).
I do have a reflected ceiling plan, and I'll try to post it soon.
 
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Just a thought here and sorry if its already been asked . Is it possible that wood floors sound better than other "reflective" surfaces because the wood floor vibrates sympathetically to the instruments? The more I think about it the more it seems feasible. concrete is reflective but does it vibrate? Same with linoleum. Or am I just way of the track here?

RF
 
why timber?? well as DD said it's neutral. If you carpet it you will deaden highs, but that's all. Also the reflections keep the instruments bright.

A floating timber floor is also a low frequency panel absorber.

cheers
john
 
Rick, if you go to the studiotips link Michael mentioned (I posted that some time ago, you're welcome) you'll also find a Sabin calculator. It's somewhat convoluted in operation, but basically here is the general procedure:

First, you do testing to find out the RT-60 of your room. There are software tools that can help you here, but damned if I can find the link at the moment. RT60 is the time it takes for the sound level in a room to decay 60 dB below maximum, after an impulse noise.

From the information the software pgm gives, you can find what the spectral makeup of the reverb is (bright, dark, only with specific frequencies)

Every material has its own absorption characteristics, which vary with frequency. Absorption is measured in units called Sabins. A Sabin is the amount of absorption (loss) that would occur thru a 1 foot square hole into free space (never to return)

There are Sabin charts available (I think the Studiotips site has one) that spell out what the absorption characteristics are for common building materials, carpet, foam, chairs, etc, AT EVERY OCTAVE - you can plug these values into their spreadsheet AFTER you calculate all the square footage of all the various materials on all the walls and floor and ceiling of the room in order to find what the absorption per frequency band is at present. 1.00 is perfect absorption - some manufacturers list higher numbers, but that is because they don't compensate for the edge diffraction of the sample under test. "0" is perfect REFLECTION, no absorption at all. Remember this is different for each octave band.

Once you find what the total absorption/octave is in the room, you can decide how much absorption at which frequencies you need to add in order to keep the room neutral, and still arrive at the RT60 you want for that particular application (longer for tracking room, dryer for control room, etc)

Did I mention this was kinda complex? Did I mention that I still don't know squat about it? Did I mention that I'm gonna forget building a studio and start a fix-it shop instead? (Yeah, right - fat chance there...)

Any-hoozitz, if you wanna be as corn-fuzed as I am, go to studiotips.com and subscribe to their emailed forum and read all the posts that show up in your inbox every day (about 5-20 per day) and file the ones you think are keepers so you can re-read them from time to time -

As far as your question on RPG, since you know that RPG stands for Reflection Phase Grating, it stands to reason that for a well to work at its design frequency the input has to be out of phase with the output, so the well has to be 1/4 wavelength of the pertinent frequency. Unfortunately, this means that lower frequencies would need a well depth of 3 or 4 feet which makes it not too good for low freq's - Sooo, RPG's are usually designed for mid to low-mids and bass traps are used for the lows. this allows manufacturers to standardize on the well depth to a degree, so the only decision is how much diffusion you want, where you need it, and how deep your wallet is (especially if you plan to BUY...)

There is a studio in Portland, OR that built QRD type goodies into the walls of one of their tracking rooms (piano, mainly) out of concrete building blocks - saw pix, but haven't actually fondled them - looked kinda cool in the pix though...

Brain drained, must recharge... Steve
 
Did I mention this was kinda complex? Did I mention that I still don't know squat about it? Did I mention that I'm gonna forget building

hahahahahahahahahahahahahahahahahaaaaaaaaaa!!!!! Shit, complex, thats a fucking understatement!!!! All I want to do is a little homerecording and damn, 10 yrs slipped by and I have yet to get this shit down. I read Everests book the first time 10 yrs ago, damn him. Been chasing my tail ever since:eek: Ha! I'm ready to do what you said too!! The more questions I have, the more questions are born. I'm sick of it I tell ya,. Sick of it.(love it really:D )

Hey Steve, how ya doin guy? Havn't seen you here much. You still on ot. Shit. The company I worked for just closed down for a while. But I just cleared up a legal thing here, and starting in Jan, its back to Oregon to look for a new place to live. Love it up there. Maybe I'll meet ya someday. Looking forward to it. And btw Steve, thanks for all the input you've given me. I am NOT an audio pro, just an old fart musician that manages to piss people off without meaning to.:D Your posts have been enlightening and my appreciation to you is due. Please don't let my little jabs piss ya,. Its all in fun.:D Actually, you've been more tolerant of me than most.(if you read what I said about pros in the "way it is" thread, please ignor it, as it pisses me off when a "pro" comes in here and bad mouths homerecording cause of the equipment level that "pros" use. I actually respect most, but dispise the ones that sit in ivory towers)

One question Steve, I understand RT-60, but how do you design for a certain RT-60 in the first place, and what are you aiming for in both the control room and studio? Does room size and geometry effect RT-60?
I'm trying to figure out, where is the fucking STARTING POINT?:rolleyes: ie, what are the things that you are aiming for in the first place, as it seems to me, that is what determines room size and construction, or am I barking at a cat in a tree? I have a hundred drawings of my studio, and they ALL stop at the point I always get to. LACK of understanding the underlying principles and design hiarchy. It just seems to me, that IF, given a chance for a 5 designers to design a studio from the ground up, they would all end up at the same point, IF there are a guiding set of design criteria. But what it comes down to so far, is simply a set of LIMITATIONS, that dictate the set of COMPROMISES and SOLUTIONS. ARGGGGGGRRRRRRRRRRR!!!!! Fuck it, I'm gonna go
play my geetar! Or try and get this damn wiring done for my second msr. Nice to talk to ya Steve. Keep postin!!
fitz:)
ps- heres what I mean-endless design changes and daydreams:
http://home.rcsis.com/beachchic/1studys.jpg>
http://home.rcsis.com/beachchic/2studies.jpg>
http://home.rcsis.com/beachchic/3studys.jpg>
http://home.rcsis.com/beachchic/4studys.jpg>
http://home.rcsis.com/beachchic/5studys.jpg>
http://home.rcsis.com/beachchic/6studys.jpg>
http://home.rcsis.com/beachchic/7studys.jpg>
There are many more, but as I said, only starts, never finished
 
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Hello Michael, say, thanks alot for the answers. I APPRECIATE it mucho. And btw, sorry for the rant on your thread. I was depressed today:D (envious is a better word! Envious of someone who actually makes decisions!:eek:
fitz:)
 
No sweat Rick.
The more questions asked, the more we all learn.
 
Room design seems to be a lot like instrument design. You pick the best materials, follow the basic principles and in the end just cross your fingers and hope for the best.

How come there are no reference room designs? Maybe there are and I just dont about them but it seems like there would be reference room designs with specific proportions and materials that could be used to yield a fairly predictable sound and be preferred for certain types of music.

How about a Strativarious room with a little extra diffusion suited for classical music. Or the Sun room with a little extra high end accents for blues and rock.

Has nobody gone through the effort of making a scientific catalog of room designs?
 
You pick the best materials, follow the basic principles and in the end just cross your fingers and hope for the best.

If you pick the best materials and follow the basic principles you don't need to cross your fingers and hope for the best.:):)
The other ingredient is intuition which some recently aptly described as thinking on your feet.

cheers
John
 
Hey Rick - Yeah, it has been a while - gave up for a while when the site was just a little slower than mole-asses in Michigan -

Anyway, (one of) your questions - "One question Steve, I understand RT-60, but how do you design for a certain RT-60 in the first place, and what are you aiming for in both the control room and studio? Does room size and geometry effect RT-60? "

First, what you're looking for as a result - in a tracking room, it kinda depends on the type of music you want to record. Generally, acoustic and classical wants a longer RT60, maybe around 2-4 seconds from what I've read (remember, I'm the bookworm that's only built one very mediochre space to date, then spent the last decade and a half studying so as not to make the same mistakes again...)

Anyway, for pop and rock usually a shorter RT60, say from somewhere just under 1 second to maybe 2.

The control room needs to be dryer than the recording space, so that you don't get fooled about ambience of the recording space, by the ambience of the listening space.

If you take ALL the surface area of ALL the walls, floor and ceiling, and separate them into total areas of each type of material, along with each material's absorption at each octave band, then calculate the total # of sabins of absorption at each octave band, you can get pretty close to what that room will respond like, and what its RT60 will be.

In a larger room, untreated, the RT60 will be quite a bit longer than you want (unless you're recording "arena rock" without any reverb processors) - Sooo, you then calculate how much MORE absorption you need at each octave band in order to arrive at the target RT60 for that room. (This is where the calculator spreadsheets at studiotips.com and other sites come into play.)

For a tracking room with good flexibility, Everest suggests hinged absorbers that, when closed, give more diffusion and less absorption, and vice versa - When designing such a tracking room, you would still need to keep the shortest RT60 you can achieve at a LONGER time than that of the control room, for the above reasons (ambience decisions)

Rather than rely on all this calculation as an exact science, I will, when the time comes, most likely start there and then MEASURE the REAL performance of the room(s) with a reference mic and software - At least, the formulas and spreadsheets should be good for getting in the ballpark, if not right in center field... Steve

(Oh, yeah, by the way, at what point did you decide you were man enough to piss me off? Hehehehehehehehe...)
 
(Oh, yeah, by the way, at what point did you decide you were man enough to piss me off? Hehehehehehehehe...)
:confused:
Thanks for the info Steve. I WILL check it out, and try these things. :) Hmmmm, I wonder what the best bang for the buck is for DSP:D
fitz
 
What is a good target RT60 for a tracking room and a control room?
 
Control room - .5sec - tracking room - .5 - 2sec.

cheers
John
 
Wooden floors are good ......... provided they have a good absorbsion layer underneath them.

Don't have to cost a lot if you look at materials like Pergo (which is basically a photoprint of wood but has the same characteristics).
Also, Pergo soundproofing underlay (the thin blue stuff) is very decent.

An alternative, cheaper floor is recycled rubber, which looks cool, feels really nice to walk on, is incredibly strong.
Rubber is my favorite, I prefer its acoustic properties over wood in a tracking room, especially in a medium to large room.
 
Yeah, I've been looking into alternatives to wood flooring.
With the underlayment, pergo-type flooring can be done for around $2.50/sq.ft.
That's a long way from the $3.00/sq.yd. for industrial/commericial carpet, but still a viable option.
It adds up fast!
 
John Sayers said:
Control room - .5sec - tracking room - .5 - 2sec.

cheers
John

So am I right to think that if you are making a dual purpose room for both tracking and mixing, aiming for .5 sec is about right? Is this the same for light folk (primarily acoustic) music?

Thanks,
-lee-
 
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