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Help with control room acoustic design, room built already

Posted: Tue Dec 17, 2013 7:19 am
by sosranch
Hello experienced designers on this forum. I am building a recording studio. I have been in a number of pro studios over the years (I was with Paul Anka in the mid 70s and have recorded with Merle Haggard and others). I currently have a studio below the office of my day job and it has functioned for many years for me. However, as I age and slow down my day job I am spending more time out at my property, a 60 acre ranch, and am currently building a new studio on the property. Being in great studios is not necessarily a lesson in how to build one, thus the inquiry on this forum.

The studio in question is in the construction process and the sheetrock is being finished as I write this. My question is regarding the acoustic treatment of the interior of the control room. Caveat: I realize that an ideal room would possibly be longer than wide, and I also realize that control rooms can be made to function well being wider than long.

The dimensions of the room in question is 20 ft wide, 16 feet long, with 10 foot ceiling on a cement slab that will be covered with hardwood flooring. the front wall construction is stud/genie clips/rc channel/sheetrock (all is 5/8)/green glue/sheetrock/MLV/sheetrock. All other walls and ceiling are clips & rc channel/SR/green glue/SR. The 3'6" door is offset from center of the right wall (as seen from mix position) and there is a 4/0 window in the same position on the left wall. The control room-live room window is 4 ft tall and 8 ft wide.

So, without my influencing the query with my thoughts, what are yours?

Re: Help with control room acoustic design, room built alrea

Posted: Tue Dec 17, 2013 3:15 pm
by Soundman2020
Hi "sosranch", and welcome to the forum! :)
Being in great studios is not necessarily a lesson in how to build one,
How very true! I wish more people would realize that, before trying to build studios...
The studio in question is in the construction process and the sheetrock is being finished as I write this.
Ooops. It probably would have been much better if you would have found the forum before you got that far! There are many very important things that can be done to the actual dimensions, size and shape of the studio to avoid problems with the acoustics later, but that has to be in place BEFORE the framing goes up. For example...
The dimensions of the room in question is 20 ft wide, 16 feet long, with 10 foot ceiling
There's your first problem, and it's a biggie. Your width is exactly twice your height, and a quarter wave of the length fits five times into the width. This means that you will have major modal resonance issues at fixed frequency intervals. In other words, the natural resonance due to the length of the room will line up perfectly with the natural resonance due the height of the room, and there is also a non-musical relationship between both of them and the length of the room. This is not good.

There's an on-line "Room Mode Calculator" that you can use to help you figure out these types of issues, right here: http://www.bobgolds.com/Mode/RoomModes.htm Just plug in your room dimensions, then look at the results. Your room fails one of the three critical tests for a control room, and if you scroll all the way to the bottom you'll see part of the issue in the Bonello diagram for your room. Not very heartening.

The only way to fix that is by adjusting one or more of the room dimensions, which implies taking down one or more of the walls that you just completed, and re-building it (them) a few inches away from where they are right now. There is nothing at all that you can do in terms of acoustic treatment within the room to fix this problem. Since modes are directly related to the distance between the solid boundary surfaces of the room, the only way to fix modal distribution problems is by changing the position of those surfaces.

This is not what you wanted to hear, I'm sure, but it is why you came here: to find out what you can do to make you room the best it can be. Right now, it can't be the best. It can't even be particularly good.
on a cement slab that will be covered with hardwood flooring.
Excellent! No problems there at all.
the front wall construction is stud/genie clips/rc channel/sheetrock (all is 5/8)/green glue/sheetrock/MLV/sheetrock.
Wow! Why all the mass? What are your isolation goals, in terms of decibels? You seem to have some pretty major goals there. Three layers of 5/8" sheetrock plus GG and also MLV! :shock:

Here's something else you don't want to hear: You wasted a lot of money unnecessarily on the MLV. It is mass, yes, but very expensive mass. Sound waves really don't care how much you pay for the mass in your walls: they can't read the price tags, and all they do is respond to the total amount of mass. MLV has no magical properties when used as a layer of mass in a sandwich like that (despite what some unscrupulous sellers of MLV try to tell you!). Mass is mass. The equation for calculating how many decibels of isolation a wall gives you is this:

TL = 14.5 log Ms + 23 dB (where: Ms = Surface Mass in lb/ft2 )

That's it. There's nothing in that equation about HOW you make up the mass in the wall, and in reality it really doesn't matter. The only thing that DOES matter, is the amount of mass, period.

Now, don't get me wrong: MLV does work. That's not an issue. It is mass, so it works as mass. The issue is that it is darn expensive mass! An extra sheet of drywall would have given you even more mass, and would have been much cheaper. You already have it in there, so there's no need to take it out, but that wall cost you an awful lot more than it should have.

I also noted that you said you used both Genie clips AND resilient channel: That's a problem. You cannot do that. Resilient channel is designed to be attached directly to the studs, with no clips. If you use clips, then you need hat channel, not resilient channel. Hat channel is for use with clips. There's a big difference between the two, even though they look similar. And resilient channel cannot be used on clips. It isn't safe. So unfortunately, you do have to take your walls down, to fix that, and I'm rather surprised that they even passed inspection!
All other walls and ceiling are clips & rc channel/SR/green glue/SR.
OK, there's another issue here: Why did you put over twice as much mass on the front wall as on the other walls? The isolation shell of a studio must be kept consistent all around, with the same surface density everywhere, on all five sides of the room. If you have one really massive wall and five less massive ones, then you wasted money on the really massive one, since the sound waves will simply ignore it, and take the simplest path out of the room: through the less massive walls.
there is a 4/0 window in the same position on the left wall.
I'm not sure what you means by " 4/0 ". Can you elaborate on that?
The control room-live room window is 4 ft tall and 8 ft wide.
How thick is each pane of glass in that window, what type of glass is it, and how big is the gap between the two panes?
So, without my influencing the query with my thoughts, what are yours?
It would REALLY help to have photos and an accurate diagram of the room, plus more details of the design goals and the construction materials and techniques used beyond the part you told us about.

Also, please read the forum rules for posting (click here). You seem to be missing a couple of things! :)


- Stuart -

Re: Help with control room acoustic design, room built alrea

Posted: Wed Dec 18, 2013 7:53 am
by sosranch
Thanks for the reply. I posted my profile, thanks for the kick, Stuart!

Here is another good saying: Being highly educated in one field does not make one smart in another! Ha.. Yes I should have queried y'all prior to construction. Oh crap. Width twice the height. Is it possible to build, inside the room, walls on each side (the 20' width) to bring them in to change this relationship? (The flooring will change the height by 3/4 of an inch.. probably moot but I mention it anyway) Such as a 2x4 inner wall on each side, reducing the width by say, 6" per side making the width 19' rather than 20? I have not put the MLV and third layer of drywall on yet and that can be nixed immediately. The wall between the live room and the control room, on the live room side (2x6 construction throughout) is, from the stud, OSB, G glue, SR, G glue, SR all taped and sealed. My reference to "rc channel" is wrong. I am not a contractor and I got the terms mixed up.. it is hat channel for sure. I used the wrong term given all the terms that have been around in this process.. Oops again! Again, terminology.. I used 4/0 for the window meaning 4'x4'. And I have not constructed the control room window yet. Was planning > than 4" width between glass at the bottom and 9-10" separation at the top, 1/4" thick glass on one side, 3/8" on the other, both laminated glass.

I can post photos but I don't have them for this post. Building sits alone, outside noise and bother of neighbors is not much of an issue (neighbors are more than 3/4 of a mile away and I live in the mountains. As stated, all on a thick slab, nearest road is 1/2 mile away (other than driveway that is private), 2x6 construction, live room is 20' wide, 18' deep (facing control room), and has an open vaulted ceiling with a 10/1 pitch (I would have to ask the contractor to be precise here) with exposed trusses (two in the middle of the room), ceiling starts at 10 feet off floor. This makes the dimension of the control room to live room (which goes east (CR) to west (LR)) 34 ft x 20 ft, with a foyer north of the CR that is 8' x 20' x 10 ft ceiling. One enters the foyer and either keeps going, slightly left, to enter the CR or turns right and then left into the LR. Perhaps, without photos, this will give an overall configuration of the building. This building started as an agricultural building for my cattle and then, after slab and general construction, I decided to turn it into a music studio and move my present gear from the studio below my office into this space and that is one reason I did not consult y'all prior to beginning.

So, the question is then, Stuart, perhaps I could build inner walls in the CR to reduce the width? Thanks! Michael

Re: Help with control room acoustic design, room built alrea

Posted: Thu Dec 19, 2013 3:45 am
by sosranch
I measured the exact dimensions of the control room: W= 223.75 inches H= 117.5 inches D= 175.5 inches

223.75 divided by 117.5= 1.945

Several interesting points to consider? 1) I paid for a consultation with a studio builder in the Los Angeles area when the framing was done and as soon as I decided to do a studio rather than an ag. building; I gave him all dimensions and he never pointed out the dimension problem... I will contact him and ask him why. This was after the thing was framed (recall, it was first going to be an agriculture building) and changes could have been made easily. 2) This will be a space for me my friends only, not a commercial space in any way. Of course I want it to be good sounding and I look forward to more discussion if anyone is interested (thanks Stuart!). 90% of the time in the control room is spent in the phones working on ideas (piano/guitar) and writing songs, and/or playing with keys, 2 guitars, and bass.. all plugged in. I also close mic acoustic guitar and vocal in this setting. 3) I am not a fan of bass heavy or loud music, no pounding of sounds. 4) When I mix something, I do it at levels that one can carry on a normal volume conversation with several people in the vicinity; I do not mix loud. 5) It would be easy for me to add an interior wall to each side reducing the width by whatever is needed, such as a 2x4 framed wall with SR/GG/Sr, lowering the width of the room by those dimensions thus eliminating the nearly "height 1/2 the width". Suggestions would be appreciated.

I will post some photos soon. Thanks to anyone that wants to jump in here. Michael

Re: Help with control room acoustic design, room built alrea

Posted: Thu Dec 19, 2013 4:45 am
by Soundman2020
I posted my profile, thanks for the kick, Stuart!
:thu:
I paid for a consultation with a studio builder in the Los Angeles area when the framing was done and as soon as I decided to do a studio rather than an ag. building; I gave him all dimensions and he never pointed out the dimension problem... I will contact him and ask him why.
Not everyone takes the "room ratio" and modal response of rooms into account when designing a room, but pretty much all of the best studio designers do. It's a key indicator of how well the room will perform, and if the dimensions can be changed, then that's best opportunity for fixing potential issues: before you even get to them! Just don't let them even happen.

It works like this: Any time you have two parallel walls, certain musical tones will fit in perfectly between those two walls, bouncing back and forth and actually "amplifying" themselves, because the wavelength of that tone fits in perfectly between the walls: on each bounce, the wave ends up in phase with itself, so it adds to itself, and gets louder. So there will be a set of frequencies associated with that distance, where notes will sound louder, whereas all other notes will sound normal. Even worse, the energy is sort of stored in that mode (which is technically also a "standing wave"), so even after the instrument stops playing that note, the room carries on playing it for a short time, until it dies out. This is called "reverberation" and is also a type of resonance, as you probably already know. So for every pair of walls in your room, there is a set of frequencies associated with the distance between them, and notes at those specific frequencies will sound louder and reverberate longer than other notes for which the room does not have "modal support".

But this doesn't just happen between pairs of parallel walls. There are other ways that a room can reverberate and resonate that involve waves bouncing around between four walls, or even between all six (counting the floor and ceiling as "walls"). So there are many different "modes" in a room, and they all depend on nothing more than the distance between walls, and the relationships of those distances to each other. In fact, the walls don't even have to be parallel for this to work: Even in rooms with non-parallel walls, there are still modes, and they are even more complex than in a simple rectangular room.

The worst situation occurs when two or more modes "overlap", and occur at the same frequency. So for that particular frequency, you get a double-boost, since the room vibrates in two different manners at the same time, amplifying that note even more, and making it "ring" for an even longer time after the speaker stops playing it.

Obviously, this is not good: the room is doing things to the sound coming out of the speakers, changing it, making it different, adding it's own "ringing" to some notes and not others, while also making some notes sound louder while others are softer. So what you hear when you are trying to mix, is a combination of the direct clean sound from the speakers, plus what the room itself adds and takes away. Even worse, since this is all happening with "standing waves", there are specific places in the room where each mode is at the maximum peak value, and other specific places in the room where the note is at its minimum value, which can even be zero in extreme cases. So you have "peaks" and "nulls" occurring at precise locations in the room, due to these modes. Therefore, what you hear depends on where you are standing. If you move a few inches to a different location, you can hear something totally different, since you will be in a different set of peaks and nulls at the new position.

So the room is "coloring" the sound, and you are not hearing the sound cleanly. In practical terms, you are adjusting things in the mix that actually don't need adjusting, and you are not adjusting other things that do need adjusting. Your mixes will not "translate" well, since they will ONLY sound good in YOUR room, with the compensation you have built in. If you play your mixes in other places, they will sound lousy since that built in compensation is not needed in any other room, except yours.

That's why serious studio designers take modal response into account. You cannot get rid of modes (since they are a simple direct consequence of having walls around your studio), but you can do several things to minimize their effects. One easy thing to do, is to make sure that your modes are spread around the spectrum evenly and smoothly, instead of being clumped up at some frequencies with nothing at others. After all, if you could have one mode for each and every note on the scale, then your room would add the exact same amount of "modal response" to each note, and they would all sound the same again! That's the ideal goal, but is not actually attainable in small rooms. The room has to be very large before you can do that. But you still can choose dimensions that spread your modes around evenly, and that's what room mode calculators are for.

I'm not sure if you tried it, but please do go to the link I gave you in my first response, plug in your numbers into it, then look at the results for your room.

http://www.bobgolds.com/Mode/RoomModes.htm

Red, purple and yellow brackets under the "group weighting" column indicate problems. So do comments about starting and ending "iso" sections, which are isolated modes that are far apart from other modes. In the "percentage" column (second from left), anything over 4% is a potential issue, and anything over 5% is a problem. That tells you how much of a gap there is between modes, as a percentage of the modal frequency. Ideally, you want ALL your modes to be less than 4% away from its neighbors.

Scroll down to the section with the heading "Computed Information". First it lists your room dimensions and ration, then there's a heading about "R.Walker" from the BBC. There are three items under that, with pass/fail comments. Those are the three critical tests that the BBC uses for accepting or rejecting a room for critical listening (ie, control rooms). A fail in any one of those tests means there are problems with the room.

Finally, scroll right down to the bottom, and look at your Bonello chart. That tells you how evenly the room modes are distributed around the musical spectrum. The curve should rise smoothly from left to right. Any dips or straight sections are a problem.

I'm not sure why your architect didn't consider all these points: only he can explain that. Perhaps he's just not aware of modal response, or doesn't think it is important, but you won't find many professional studio designers who never consider modal response.
2) This will be a space for me my friends only, not a commercial space in any way. Of course I want it to be good sounding and I look forward to more discussion if anyone is interested (thanks Stuart!).
Note my signature, at the bottom of each post: :) Do you want to impress your friends, and have them think your studio is amazing? :) :shot:
I also close mic acoustic guitar and vocal in this setting.
Even more reason to have your modal response under control! Close mic'ing brings out all the detail in voices and instruments, which will then be lost in the mush of modal response, if the room is lousy...
3) I am not a fan of bass heavy or loud music, no pounding of sounds. 4) When I mix something, I do it at levels that one can carry on a normal volume conversation with several people in the vicinity; I do not mix loud.
Excellent! Very smart.
5) It would be easy for me to add an interior wall to each side reducing the width by whatever is needed, such as a 2x4 framed wall with SR/GG/Sr, lowering the width of the room by those dimensions thus eliminating the nearly "height 1/2 the width". Suggestions would be appreciated.
That is an option, but building another wall next to an existing wall introduces yet another acoustic issue that most people aren't even aware of. It is called the "three-leaf" problem. Basically, a wall made up from three "leaves" will have WORSE isolation than the equivalent wall made of only two leaves, all other factors being equal: This is non-intuitive at all, but is a big problem in some cases. A "leaf" in acoustic terms is just a bunch of layers on a stud frame. So your "two layers of drywall with Green Glue between" constitutes one leaf. If you had a brick wall behind that, that would be another leaf. Those two together will do a good job of isolating ("soundproofing") your room. But if you then build another frame in front of that one and put another layer of drywall on that frame, you now have three leaves, and the isolation goes down, not up, for low frequencies.

So your best bet is to actually take the drywall off one of your walls, then build a new frame (or move the existing frame), and put the drywall back on again.

Once again, probably not what you wanted to hear...

However, if isolation is NOT important to you (you don't care if anyone is bothered by your sound getting out, and you also don't care if outside sounds get in, such as thunder, hail, rain, wind, cars, aircraft flying over, the dishwasher running, phones ringing, people walking / talking, doors opening and closing, etc.), then you could just build that third leaf anyway, and live with the reduced isolation.
Perhaps, without photos, this will give an overall configuration of the building.
Yep! Plus a diagram of the rooms, preferably done in SketchUp, which is sort of the standard around here....

So, the question is then, Stuart, perhaps I could build inner walls in the CR to reduce the width?
Possibly (but see the caveat above), and you do need to spend some time playing around with lengths and widths to get the best possible ratio you can.

You could also consider building one ore more of your walls "inside out" (search the forum for what that means... :) ), as that has some benefits too, bit in space savings and in acoustics.
I will post some photos soon. Thanks to anyone that wants to jump in here. Michael
:thu:


- Stuart -

Re: Help with control room acoustic design, room built alrea

Posted: Thu Dec 19, 2013 11:28 am
by sosranch
Aaah yes, I should have thought of that. The same reason one does not want triple pane windows, one wants double pane for isolation. I will consider this as I check out the calcs on the site you mentioned. I am not intently focused on outside sound interferences as these are very minimal. One of the biggest sounds I might here is a Highland cow fart. THAT would be a big problem unless it is timed with the kick drum. :yahoo:

(That is the FIRST time I have ever used one of those little face thingamajigs!!)

Re: Help with control room acoustic design, room built alrea

Posted: Thu Jan 09, 2014 11:29 am
by sosranch
UPDATE AFTER HOLIDAYS:

I would like to thank you for the time spent to give opinions and advice, which has been very helpful. I have acquired the assistance of several professional studio builders with the help of my friends in the music business. We are taking it from here. Again, your advice was very helpful and if something else comes up I will attempt to reconnect with the forum.

In leaving I will say something that I have found after many years of being in recording studios: 1) I have never seen two alike. 2) I have seen many rooms that do not fit the often recommended shapes that have produced magical music that sounds excellent wherever played. 3) Ultimately it is about a) the music and b) the experience of the players and the listeners (which is really about the music). 4) I have been in or part of many recordings done in all kinds of rooms including home bedrooms, basements, and bathrooms (yep), with A list players that sound astounding. Of course, having said that, which is probably of no surprise to you great room people, an excellent sounding room for both engineering and recording sure makes it easier and more fun. So, I will do my best with the advice of my friends and associates to create a great environment for both of these endeavors.

Thank you for your help. Perhaps I will present the final product in photos although I am a very busy fellow and more interested in my and my musician friends personal journey in our musical lives. Above all, play music. That is the bottom line! :D

Re: Help with control room acoustic design, room built alrea

Posted: Tue Jun 17, 2014 12:16 pm
by sosranch
Well, hello, Stuart and others! A bunch of months have passed since I posted my query on this site and received a response from Stuart. First of all, I would like to thank Stuart for his timely and excellent response, which essentially was to tear down some walls and start over. Naturally, I was reticent to do that for a number of reasons. But here we are later on and the studio is finished.

The live room is one of my design and features a vaulted ceiling that is 1x4 pine with gaps with 1x4 pine over the gaps and with a 1x1 pine strip over the top 1x4 pine. This makes strips that are not the same width that acts as a diffusor to whatever degree the math (and I am sure Stuart could figure this out!). Anyway, I will not describe the treatments I put on the walls for this post is not about that, but I will say that the room sounds wonderful and I am very happy with how it turned out and the look and feel of inspiration that is there. After all, as a songwriter and instrumentalist, inspiration is what it is all about. Everyone that has been in the space is blown away and this includes some world class musicians.

The control room is really the subject of this post, however. I have no doubt that what Stuart told me was correct albeit some things were missing. It would have been nice to contact you great folks prior but alas, as I mentioned in the earlier posts, this building was supposed to be an agriculture building on my ranch initially.

Here is the kicker: Since I am now finished with the building, I contacted a fellow that is world renowned for tuning rooms. He has done over 1000 rooms around the world including rooms for Sony, and Abby Road Studios in London. I sent him photos and dimensions of the control room and along with that I asked him "Take a look at my dimensions and let me know if there is anything wrong here." You know what he said? "Well, in regards to your dimensions, they are pretty close to the "golden dimensions" of a control room. Well, as you might imagine, that made me feel better but I do not doubt the math and concerns that Stuart had so graciously communicated to me so I set that aside, put it in perspective, and waited until he got up here to do the work. He arrived last Wednesday and we spent 7 hours non stop analyzing, moving things around, and doing his job of tuning the room.

Incidentally, I asked him if he had ever found a room that was so wrong it needed to be torn down. He said that he had run into about 3 or 4 over the last 25 years that were too far gone. Anyway, after the 7 hours of tweaking, the sound was absolutely astoundingly good. I was very fearful during the process as he frowned and tried this and that but in the end the sound was wonderful. I have been in many studios over the years, full blown professional ones since that is what I used to do. I never saw rooms that were alike and some were better than others.

Frankly, I was blown away at the result he was able to get in a room that I was advised to partially tear down and start over. Honestly, I was prepared to accept less than stellar results given Stuarts advice. But that was not the case. Of course, Bob was probably using the Placebo effect on my by telling me the following, but this is what he said in the end. "Michael, I have been in million dollar rooms that don't sound as good as yours."

By the way, there are no SuperChunks in the room. There are no traps in the corners (we tried that and did not get any positive response). There is a cloud in the correct position and verified. There is diffusion on the back wall and verified that it is working. There is a large furniture piece, my mothers Queen Ann dresser in the back left corner and two large Acoustic Surfaces traps in the opposite corner (interestingly, ASI recommended these be placed on the front wall one to each side of the CR window but we found by actually analyzing the room that they were not doing anything constructive there and found, after moving all this around in the room, that they worked best in the back right corner). Absorption is on the walls where it worked the best, and certainly in the desired non reflective areas. And the front wall? Not much there at all. A small absorber above the window and one on each side placed high. That is it for the front wall.

In the end, all of the treatments that are proposed based on mathematics, the treatments that are proposed by "pros" that have product to sell, and others may not be the best treatment for your room. The only way to really optimize is to take the step of having the room analyzed by someone with lots of experience and a track record that supports his/her recommendations. I used Bob Hodas, whom I have heard of for many years and he and I both swear that we have met in the past whether it be in some sessions or wherever, but we have met in the past. Look him up if you doubt his credentials.

I will tell you, that the imaging that I can see/hear using broken in Focal SM9s is astounding. I am completely blown away by the quality of sound and imaging. I have mixed several sessions already and they translate beautifully out of the room. People that have come by are completely blown away, not only by how it sounds but also how it turned out looking.

I have no doubt that checking in with you all and particularly Stuart might have been the best idea but I will tell all who want to listen to my rant here, that I am completely stoked and excited about my rooms as all are that have visited and some of the folks that have been in the studio are well known and in the rarified air of world class professionals. So, the studio is a resounding success in looks, location, and sound in both rooms. Inspirational as I stated at the beginning.

I am one happy guy with one hell of a toy.

So, while all the ideas and recommendations that are given on this site are stellar and no doubt correct in many ways, do't get too caught up in the forrest to miss the trees. No matter how good you build your room it will never be optimized unless you also get someone respected to "Shoot the room" as they say. Also, the obtuse is also true and that is if your room is not perfectly built and dimensioned, shooting the room and tuning it with analyzation can make it sound better than a great room that is not analyzed.

Building a studio and not going the extra step to have it analyzed and corrected according the results is like recording a great record and not having it mastered by an experienced mastering engineer with great ears.

All that said, Thank you, Stuart for your great advice. Regardless, however, I am completely stoked and so it seems is everyone else that has entered my studio so far.

M.

Re: Help with control room acoustic design, room built alrea

Posted: Sun Jun 22, 2014 6:26 am
by Soundman2020
Welcome back, and thanks very much for the update on your studio! It's always good when members come back after their rooms are done, to share their experience.
his timely and excellent response, which essentially was to tear down some walls and start over
Not all of them! Just doing one would have been enough... :) But that's water under the bridge, now, and your room turned out well anyway.
The control room is really the subject of this post, however. I have no doubt that what Stuart told me was correct albeit some things were missing. It would have been nice to contact you great folks prior but alas, as I mentioned in the earlier posts, this building was supposed to be an agriculture building on my ranch initially.
As long as it all turns out fine, and you end up with a room that works well for you, that's what really matters. And it certainly seems that you got that!
Honestly, I was prepared to accept less than stellar results given Stuarts advice. ... I used Bob Hodas, whom I have heard of for many years
Well, you hired one of the best in the business, so I'm not surprised that it turned out well, without you needing to modify the room! My original advice was given thinking that you'd be doing the acoustic design, treatment and tuning yourself, which is what most forum members do. If I would have know back then that you'd be hiring someone like Bob to do the final tuning, then my advise on modifying the room might have been different! I reckon Bob could probably make a concrete pipe sound good :shock: :!: :)

For example, you'll often see me (and others) recommend never to put the listening position in the middle of the room: But John has done that with a few of his designs... You'll also see me recommend never raising the speakers more than a few inches above ear height, and never tilting them down more than 5 degrees or so... but John has done some rooms with the speakers much higher than that, and tilted much more. Ditto with square rooms, and rooms with lousy dimensions: John sometimes DOES designs rooms like that, with seemingly bad sizes, shapes and angles. So what's up with that? Am I wrong to recommend that forum members should NOT do things that John does all the time? Or is John wrong for doing things that should not be done? Neither! The things is that John knows what he is doing, and knows how to design and build rooms that "break the rules", because he knows how to compensate for those things. He has the knowledge and experience to do that. It is perfectly fine to do that... provided that you know what you are doing! Most home studio builders will never get to the point where they know enough to be able to do that, and to be honest, they never should get to that point! It's just a waste of time for most people, since their career is not to be a studio designer. But not for those of us who design studios for a living: we do need to go the extra distance to learn how to deal with those things. However, that does not make it right for typical home studio builders to put their chair in the middle of the room, have their speakers 7 feet above the floor, tilt them down at 15 degrees, or have a room where the dimensions are mathematically related. It's fine for us to do that, because we have learned how to deal with the issues. But it's not fine for the causal builders, just as it is fine and safe for a professional rally driver to burn down country roads at ridiculous speeds, slide around corners in perfect four-wheel drifts, and get their cars airborned every now and then, while it is NOT fine for the rest of us to do any of that: they know how to do that, we don't, and should never, ever even try.

I guess my point here is that it is possible to break the studio design rules for people who have the training and experience to do so, but not for most people. That's one reason why Bob was able to tune your room so well: because he knows how to do it! :)
There is a large furniture piece, my mothers Queen Ann dresser in the back left corner and two large Acoustic Surfaces traps in the opposite corner (interestingly, ASI recommended these be placed on the front wall one to each side of the CR window but we found by actually analyzing the room that they were not doing anything constructive there and found, after moving all this around in the room, that they worked best in the back right corner). Absorption is on the walls where it worked the best, and certainly in the desired non reflective areas. And the front wall? Not much there at all. A small absorber above the window and one on each side placed high. That is it for the front wall.
Perhaps you could post some photos of how the room ended up, after everything was done? It would be refreshing and very useful to see that different approaches can also lead to excellent results. There are other ways of doing things, beyond superchunks and skylines. Photos of your room would be a good opportunity to show that unconventional approaches can also work, in the hands of an expert.
In the end, all of the treatments that are proposed based on mathematics, the treatments that are proposed by "pros" that have product to sell, and others may not be the best treatment for your room.
Yes!!! :thu: Very, very true. Acoustics is a science, and there are equations for figuring all this stuff out. Also, there are no "magical" materials that defy the laws of physics, that some of those companies you mention want to sell you. Simple devices, properly sized and correctly placed, can achieve really good results. No snake-oil needed. Yet another reason why I'm hoping you'll share some photos of the room with us.
The only way to really optimize is to take the step of having the room analyzed by someone with lots of experience and a track record that supports his/her recommendations
Another big "Yess!!!!" to that. I couldn't agree more. If you want a world-class room, then there are basically two options here: the "cookie cutter" approach, where you start out with a stock "standard" room, with the correct dimensions and materials all worked out already, all the way through to the treatment, using a proven design that has already been built and works. Or the "custom" approach, where you bring in an expert to do it for you. That's not to say that most people can't get a good room by learning themselves, designing themselves, and building themselves: many, many forum members have proved that you absolutely can get such a room. But if you really want a world-class place, then the two options above are the best ways of getting there.
I am completely blown away by the quality of sound and imaging. I have mixed several sessions already and they translate beautifully out of the room. People that have come by are completely blown away, not only by how it sounds but also how it turned out looking.
Photos! Photos! :)
I have no doubt that checking in with you all and particularly Stuart might have been the best idea,
Not necessarily! You followed a path that worked, and got the results you needed, so that's great! It would have been nice for the forum if you would have documented the build here, and we might even have been able to help you along the path a bit, but all that really matters at the end of the day, is that you have a great studio.
I am one happy guy with one hell of a toy.
So go play with your toy already!!! :yahoo: and then send us some photos of you playing with it.... :)
So, while all the ideas and recommendations that are given on this site are stellar and no doubt correct in many ways, do't get too caught up in the forrest to miss the trees. No matter how good you build your room it will never be optimized unless you also get someone respected to "Shoot the room" as they say.
Once again, very true. And while some people can learn how to do that themselves, most folks just do not have the time or the inclination to do that. It takes a lot of time, dedication, and practice to be able to do it well. After all, the goal of most home studio builders is not to become acoustic experts! It is to have a studio that that can track and mix in. So why bother learning a skill that you'll only use once or twice in your life, when the REAL goal is to use the skills you already have to make music! If you don't plan to become a studio designer/tuner, then there really is no need to do that. spend your time doing what you do best: making music, and hire some else to do what THEY do best: designing and tuning rooms.
Also, the obtuse is also true and that is if your room is not perfectly built and dimensioned, shooting the room and tuning it with analyzation can make it sound better than a great room that is not analyzed.
Yes, yes, yes! Even a bad room can be improved with good analysis and good treatment, and a good room can be made great.
Building a studio and not going the extra step to have it analyzed and corrected according the results is like recording a great record and not having it mastered by an experienced mastering engineer with great ears
I think we should hire you as the advertising agent for the forum! :) Just kidding. But what you say is so very true. I wish more people would realize this, and act on it. Designing and building the place is only half of the job. It doesn't matter how well it was designed, it will ALWAYS benefit from being analyzed and tuned properly. Reality doesn't always mach prediction, since the actual construction cannot be perfect: theory assumes perfectly reflective, perfectly rigid surfaces, but no such material exists on planet Earth. Theory assumes that all dimensions will be matched perfectly in the actual build, that all materials are perfectly straight, plumb and flat: in reality, they are not. So real life does not match theory, even in the best of rooms. You ALWAYS need to test the room, and analyze it, and treat accordingly.

I seem to be repeating that phrase all the time, so it's great to have you say it too, coming from someone who "went the extra mile", and actually did it right by hiring an expert to do it right. And as you say, the room was sounding pretty reasonable before Bob came, but the tweaks he did took it from being merely "OK" to being "fantastic". I'd say that was money well spent. A far better investment than a new set of speakers, or some greatly hyped piece of equipment...
Thank you, Stuart for your great advice.
You are more than welcome, even though you didn't need it in the end.

But I'd be really grateful if you could post some photos of the room, and also one other thing: do a quick test of the room using the REW acoustic analysis software, and post the results here so others can see just how good a room can get, when tuned properly. REW is free (download it from the Home Theater Shack web site), and it will only take you a few minutes to do a test. Then just upload the resulting MDAT file to a file sharing service, such as Dropbox, and post the link here on the forum. (MDAT files are too big for the forum to be able to handle).

We'd really appreciate it if you could do that, to show just what a good idea it is to have an expert tune your room.

- Stuart -

Re: Help with control room acoustic design, room built alrea

Posted: Wed Jul 16, 2014 12:08 pm
by sosranch
Hi Stuart! I have not looked at this for a while and I missed your post. I will take photos and post them with a dialog about what I did and what Bob Hodas and I did (7 hrs of hard work for me while he told me what to do, what to hang, what to remove and what to put where and I was TIRED at the end of the day..). I can also post the SIM file he sent to me regarding the room but it is latin to me. I am not quite finished.. I have 3 thick curtains coming in the next week to hang on the 3 4x4 windows (one in the control room, two in the tracking room) to control the windows, and I have yet to find what I want to hang on the door in the control room. This will be mounted between two bars separated from the door by an inch or so… Bob suggested a nice rug and I will probably do that but I have some Scottish Highland cow hides that are real hairy and maybe I will hang one of those.. Have not decided yet. But when I get the last 3 curtains hung I will put together a posting that has the photos and the analysis of the room that Bob sent.

And yes, I have been playing up a storm and recording what I by myself and with my friends do and really enjoying having it so close to the house. More records to come for sure. Not that it is a big deal to anyone else, but alas, it is what I want to do for the rest of my life after already doing it for over 50 years. It has been quite a journey over the last year to build this sucker and I don't want to ever do it again! They will bury me in the control room with a smile on my face.

I WILL post the stuff mentioned above. Thanks for your post and you DID help me more than you think!