Design of control room for project/home studio asymmetry..

Hello everybody, This is my first post in this forum, but I know it for about 2 years and I have been here a lot and learned many things. It’s really a great online resource. I also read Rod Gervais Book, which was a big help, but still I´m not sure how to get the best out of my own project studio. So here is my post ^^… First about me: I live in Germany, I´m 25 years old. I´m a musician (I perform and teach classical guitar), but for several years I´ve been recording local bands and other music in my house. I have 3 rooms, that I transformed into a (Home)Recording Studio (Control Room, Studio, hang-out room). In the past I installed some DIY Absorbers to handle the acoustics, and just started recording. The room wasn´t great of course, so now I´m in the process of redoing the place to be “more professional”. I will start with the control room, because it will probably be the hardest part. I put down all that diy absorbers, and I got a measurement microphone and Acoustisoft R+D. My aim is to get as much as possible out of the room (acoustically and optically (professional looking, or at least not looking so “homemade”, if possible)) (I will upload some measurements from R+D, to show you where I´m starting from.) OK, I will give some more Information here, to clarify some of the typical questios. How loud will I be? I will be recording a lot of Rock Music, so a loud Drumset is in the game… But actually I didn´t have any problems with this in the past. The walls are thick here. Downstairs in the Living room you hear almost nothing from the drums, and the neighbors can´t hear it. Of course, it could be even better, but I think in the small room that I have, there is not a lot of things I can do to achieve better Isolation (at least not in a reasonable relation to loosing too much room space…) But, I worked that way for a few years, and didn´t have problems (I´m not recording at night) so I should go on the way I used to. (Maybe doing something about the windows, to stop sound from outside would be an option. (Until now, there hasn´t been an incident, where loud noise like trucks from outside messed up a recording. But that doesn´t mean it won´t happen in the future… If I record more classical music, problems may arise…)) My control room is pretty small, 3,96m x 3,38 m. Ceiling height is 2,48 m. I included a sketchup file and some pictures of the room. It includes the positioning of my workstation and the couch, for people to sit in the background and listen. The place is a mess at the moment, because I ripped it apart… The main problem, that makes it hard for me to figure out what to do with my room is the positioning of the door and window. They are right in the position where I would need treatment, to stop early reflections coming back to the listening position… Also, as you can see in the drawing/pictures, the ceiling is not straight, there is a pitched roof area ( I don’t know if this is the right English term, but I think you can see, what I mean). So, the first problem is the general positioning of the workstation inside the room. There would be 2 other choices: 1): Face the Workstation to the other side of the room (roof slope) Benefit: Window and Door position is less problematic, regarding absorption for reflections. Problem: a) I should probably install bass trapping in the corner next to the Door. Because of the door, this will be hard to do, there is not that much space… Without the Bass trapping in that place, or a smaller trap than on the other side of the room, wouldn´t room symmetry be a problem? b) Because of the lowered ceiling in this place, The Workstation with the monitors would have to back off from the wall. This would leave less space for me and the customer/musicians… 2): Face the workstation towards the Window. Benefit: The room would be “longer”, which normally is good. I would have more space, and could use it more efficiently. And no problem with doors, etc. , AND I could locate the speakers further away from the wall. (in the other 2 setups, they would have to be really close, because the space would be so small. That would be bad for my Lo frequency response… BUT Problem: Because of the roof slope, room symmetry will be a problem. (And again the Bass trap in the corner with the door… But I read in some other post today, that room symmetry is more important in the front side of the room. What about the window then? Would be behind the left speaker…) But I don´t know if this is really that much of a big problem. Maybe its possible, with the right amount of trapping in the right place, and some measuring, to solve this problem? Maybe this is the right way to go??? :?: I really don´t know… So, I have 3 different ways to set up the room. Each has Advantage and Disadvantage. What is the best way??? OK, that question should first be clarified, before I can come up with an actual desig :( As you can see in the measurement, the main problems in the bass response seem to be located at ca. 52 and 68 Hz. Most of the other dips and tips seem to be harmonics of these (like ca. 110, 136, 156, etc.) I took this measurement from the listening position. I also measured several other spots of the room. They main problems seem to stay at the frequencies listed above. Oh, and I took the pictures BEFORE I put the speakers on stands. The pictures don´t show the setup that I used for measuring :wink: Originally I planned to post some ideas about the bass trapping, but because of the asymmetry (ceiling, door), I will have to wait, until the first question is solved… Makes no sense now, to think where to put superchunck vs. slat resonator, etc…. But I hope you can help me to find my way. If you need any more information, please ask. I could also do more measurements, if required, just tell me what you need. Oh, and the Budget for this. I will build it myself, and I think the material is not thaaat expensive. I think I could make it for less than 2000€ (2600$) ?? Its just treatment for 1 room… Maybe if I build a lot of Slat Resonators, and use expensive/good looking wood, I would need more. But that’s OK, I don´t need to build everything at once. I´m sorry if this is a mess to read. I´m not a native english speaker... Wish you all the best Peter

few more pics

Hello Peter, I would definitely try and put the desk on the opposite wall! I would also suggest you put the monitors on stands beside the desk (whatever you do, they need to be raised, as they are currently being paritally blocked by your mixer) and perhaps mount the Video monitor on a wall mount (most of these mountings can be adjusted to come away from the wall and angled as required). Unfortunately you don't show which way the door opens (in or out) but I'm assuming in. Typically you want a wedge in the corner, but flat aborbers on each wall (one on the door in this case) meeting in the corner can also work. You mention drums but I assume these will be played in one of the other rooms - again we have no idea of the relationship between rooms - but you said you want to concentrate on the control room for now. I notice a piano in the room, this will need additional thought regarding acoustics if it is intended for recording, unless it's also an electric piano and you record DI.

Hi, thanks for the reply :) Actually I have stands for the monitors, I was just painting them when I took the pictures, so you cannot see them there. Maybe I forgot to mention it in the thread. I like the video monitor just behind the desk, if I rise it, my neck hurts, after long editing^^ the doors open to the inside, thats right And the drums will be played in another room (where the cables go to) Isolation between rooms is not perfect that way, but its possible to work, and room in room is not and option anyhow If i put the desk to the other side of the room, my main concern is, that I have even less space to the rear, and the speakers will be directly next to the angeled wall. If I put it in front of the window, I would have more space to the rear, and more space between wall and monitors. Would the added asymmetry from the angled wall make it impossible to work with? Anyhow, when I have time this evening, I will try to put my desk to the opposite side of the room, do some measuring, and check out how its working for me. best wishes peter

I noticed in a couple of your sketches the monitors on block stands. You really want to get them off the desk, plus the slightly wider field this would create might be beneficial to your imaging. My mention of the mounting for the screen was not to raise it but rather to also get this off the desk with the added possibilty of being able to pull it right out over the mixer if desired. I do this in my own project studio when I'm recording KBs, I use a remote DAW controller for tracking control and pull a video monitor right out over the desk, angling it toward me. It's not an important point anyway. just somwthing to consider. I think you'll find the acoustics with the speakers against the angled wall actually less problematic than the way it is now. Try doing some ray tracing from the speakers to the LP bouncing off your surfaces. I think you might find (and you should already be noticing this from actual listening) that currently, reflections from your rear wall (i.e. coming from behind) tend to dominate your audio image. Try the old test of listening at your LP and then cupping your hands just behind your ears - if you notice a major change then the rear reflections are making up a large part of what your hearing - not usually good for mxing. Also, with the current setup, that window (also the door) are at prime reflection points. Applying treatment to the bare walls will be easier and aesthetically more pleasing (due to having to plug up the window otherwise) if the desk were on the other (angled) side.

I understand the problems with window and door, and why the opposite side would be beneficial. You mean to put the monitors on stands at the left and right side of the desk? If I do that, they will be around 1,8m apart. So I would have to go back with my listening position, to have the right angle, right? But I would be sitting around the middle of the room that way, which also is not good. The room is just too small... :cry: So what if I actually face the desk towards the window??? The rearwall problem is there of course, and will anyhow have to be solved with a lot of treatment, right? thanks for your help, peter

I forgot to mention, the piano is electric, and can go to another room. It´s hardly used, and if I need to do some MIDI, I have a controller keyboard to handle that

derpeter wrote:

You mean to put the monitors on stands at the left and right side of the desk? If I do that, they will be around 1,8m apart. So I would have to go back with my listening position, to have the right angle, right? But I would be sitting around the middle of the room that way, which also is not good. The room is just too small... :cry: So what if I actually face the desk towards the window??? peter

Some people prefer a wider angle - the equilateral triangle is just a guideline - but actual listening tests and measurements will tell you if it will work in your case. Remember, the monitor stands can be built so that the monitors are still over the desk where you intended them to be, but the stand itself at the sides so you need not come further out from the wall with the desk as when the stands were to be placed behind. You could also consider a separate (not part of or resting on desk) bridge the video monitor may also be attached to this. Facing toward the window you room symmetry will be ... well ... not symmetrical, so I wouldn't do that.

BriHar wrote:

Facing toward the window your room symmetry will be ... well ... not symmetrical, so I wouldn't do that.

OK, I just wasn´t 100% sure if it was impossible to work around that I turned my desk today, ( to the opposite wall, like you suggested) and I will start doing some sketchup to plan my treatment. Wider angle seems to be a good solution I read, that John made some great sounding rooms with 90° instead of 60, so I will give it a try. Can anybode share some experience with this setup :?: Will any listening tests/measurements done before the room treatment be of any worth? Maybe it won´t work out well, before the treatment, but good after it? My speakers are Genelec 8040. Soffit mounting is not possible with them, I guess... I will look around the board for some speaker stands, I think I saw some good diy ones somewhere here They also have a filter to compensate for artifacts from putting them on the meter bridge. But I guess the stands will be better, right?

maybe position the speakers something like this? I just did 90° from the listening position at 38% of the room, and positioned the speakers on stands on this axis. The desk reflections will be better like this? Maybe the listening position can be a little bit more in the back, because of the angeled wall? And 38% is just a guideline of course ^^

Will any listening tests/measurements done before the room treatment be of any worth?

Absolutely, yes! That is a "must"! The measurements you take before treating are your baseline. They show the initial intrinsic acoustic problems that are inherent to the room, and that need treating. So you can then compare the new measurements that you take after each round of treatment against the baseline, to see how much of an effect the treatment had, and what still needs to be done.

My speakers are Genelec 8040. Soffit mounting is not possible with them, I guess...

Those are rear ported, yes, so soffit mounting could be a problem. - Stuart -

Soundman2020 wrote:

Absolutely, yes! That is a "must"! The measurements you take before treating are your baseline. They show the initial intrinsic acoustic problems that are inherent to the room, and that need treating. So you can then compare the new measurements that you take after each round of treatment against the baseline, to see how much of an effect the treatment had, and what still needs to be done.

Thanks stuart. Before I can do any testing, I will have to build some stands now -_- Is there any special design you would suggest? (I saw different approaches, like sand filled pvc or stands from brick)

Is there any special design you would suggest?

More massive = better! That's the basic rule. So make them as heavy as you can. Stacked concrete block is a cheap and easy way to do it. Wrap the concrete with cloth to make it look pretty. The only issue you might run into here is getting the speakers to the correct height: the acoustic axis of the speaker should end up 1.2m above the floor (about 47-1/4"). NOTE! That is the "acoustic axis", not the top or bottom of the cabinet.

Before I can do any testing, I will have to build some stands now -_-

For the testing, use REW. It is free! :) Download it from Home Theater Shack. One important point: Carefully measure the exact location where you have the mic as you do the initial measurement. You MUST put the mic back at at that exact same location for all subsequent tests, or you will not be able to compare the results. - Stuart -

Soundman2020 wrote:

The only issue you might run into here is getting the speakers to the correct height: the acoustic axis of the speaker should end up 1.2m

OK, so I will actually angle my speakers upwards, to face towards my ear height (1,3m)?? Like this: I have R+D by acoustisoft, wich rod suggested in his book, I think it will do it? He suggested doing a lot of measurements around the listening position, and make an average. When I did that, I found the response under 200 hz to be quite the same in all graphs. For lo freq information, this measurement method is OK? Why use only one position? Its more reliable for mid freq.?

And I have one more question. I´m dealing with a quite "noisy" Computer at the moment. My Idea would be, to just put it out of the room the following way: This is the corner on the right side to my Desk. I could drill a hole here. And I would come out in the hallway, right inside this cupboard: (This is the other side of the hallway. You see from right to left: control room door, studio door, bathroom door.) I could just put my computer inside there. venting wouldn´t be a problem. The only cables going through the wall would be digital audio from my motu pci express to the breakout/converter box, And 2 (video) monitor cables. Hole can be sealed later. Not a bad idea, I guess? But one problem. I don´t have an electricity outlet in the cupboard. Can I draw an electricity line through the hole, together with the other cables? The audio cables are digital, so I wouldn´t have to fear laying them parallel with the electric :?: I also have a 2HE powersupply for my D&R Desk. Its not that noisy, but it would be nice to get it out of my room. It is connected to the desk with a cable, using speakon connector Same thing as with the electric line. Any problem, if i put it parallel with the (digital) audio cable?

Hi, Sorry for posting so many things without giving chance to answer, but I don´t know how much time I will have in the next few days.

Soundman2020 wrote:

Stacked concrete block is a cheap and easy way to do it.

I still have these: 30x10 cm. I could build a stand out of them, and if I don´t get the correct height, add some wood plate to the bottom. Easiest way would be, to go 30 x 30 cm. But maybe I would overdo it that way? They would be really heavy, and quite hard to move around, i guess. Should I search for some smaller stones?

Soundman2020 wrote:

the acoustic axis of the speaker should end up 1.2m above the floor

The room is 2.44 m high, so this is very close to 50%. (1/2 room height) Is that OK to do?

I still have these:

They would work fine, yes, as log as you can figure out a way to keep them stable. Maybe just mortar between them?

The room is 2.44 m high, so this is very close to 50%. (1/2 room height) Is that OK to do?

Not ideal, but 1.2 m is the "standard" height for studios, since it is also average ear height for most people when seated. Measure the height of your own ears above the floor when you are seated at your console in your normal chair: that's the height you want your speaker acoustic axes. If you are concerned about this being at half the room height, then you have three basic options: 1) lower your chair and speakers a bit, 2) raise your speakers a bit and tilt them down, or 3) build a hard-backed ceiling cloud above your mix position. Any of those will work. - Stuart -

Does it make sense to fill the little holes in the stones?

Soundman2020 wrote:

3) build a hard-backed ceiling cloud above your mix position.

If I think about it, the ceiling over my speakers is allready angeled, and should bring this effect naturally, right? But I think I`m going to need a cloud in my room, anyhow :roll: I wrote some idea about putting my noisy computer into another room at the end of the first page of this topic, any idea on that??

Does it make sense to fill the little holes in the stones?

Not really, no.

If I think about it, the ceiling over my speakers is allready angeled, and should bring this effect naturally, right?

Right!

But I think I`m going to need a cloud in my room, anyhow

Yup! Since the ceiling is almost certainly a first reflection point, you do need lots of absorption on it.

I wrote some idea about putting my noisy computer into another room at the end of the first page of this topic, any idea on that??

If you can do that, then it's a great idea, but you'll need to extend all the cables, which means that you need to buy extenders for some of those. USB, for example, only goes to about 4.7m. After that, you need to use a pair of boxes to convert that, and some CAT5 cable to join them. - Stuart -

Thanks for your reply, Stuart

Soundman2020 wrote:

Yup! Since the ceiling is almost certainly a first reflection point, you do need lots of absorption on it.

Should I do soft back, or try hard back, and angle it, to send the refections to my rear wall to absorb them?

Soundman2020 wrote:

If you can do that, then it's a great idea, but you'll need to extend all the cables, which means that you need to buy extenders for some of those. USB, for example, only goes to about 4.7m. After that, you need to use a pair of boxes to convert that, and some CAT5 cable to join them.

4.7 m is within reach. Actually, I allready did the hole, and its working out fine. I just need longer VGA video cable to my computer monitor now. And now that I don´t hear that noisy computer anymore, I suddenly realize how noisy my MOTU 24io is ^^ :horse: But its ok, MUCH better than before! The other thing: I built my speaker stands (will send some pictures, when I have time ^^) So I´m ready to start measuring now, but I´m not 100% sure what to go for. Rod suggests not to use waterfall plots. And I guess, checking symmetry between the speakers doesn´t make sense without the treatment, its all about the lo freqency response of the room now, right? So I gues I should do Bode Response curve? I use Acoustisoft R+D - Which frequency Range should I check? From the bottom of my speakers (around 30 hz) to where? - what gate time should I use? - NO octave smoothing, right? - should I check left and right speakers? - Rod suggests in his book doing average measurements around the listening position, should I do that? (I also marked exactly one position at the listening spot, to check my future treatment with repeatable measurements) Any other things I should measure now?

I use Acoustisoft R+D

They haven't updated that software in years, and it is getting to be rather dated. I bought it too, years ago, but I have now abandoned it. I'm using REW now, which is free and much better, IMHO. You can download it from Home Theater Shack.

- Which frequency Range should I check? From the bottom of my speakers (around 30 hz) to where?

With REW, run the entire spectrum, from 20 Hz to 20 kHz. Then we'll just focus on the parts of the spectrum that need more detail, as needed.

So I gues I should do Bode Response curve? - what gate time should I use?

With REW, no need to worry about that. Just use the standard settings and you'll get valid readings, for the vast majority of situations.

- NO octave smoothing, right?

Correct. But that's a display function, not an analysis function, so it doesn't matter what you set it to: you can always change that later as needed, to see your data in different ways.

- should I check left and right speakers?

Yes. Do one compete analysis for the left speaker, and another for the right speaker, then a final one for both speakers. REW allows you to overlay the data from multiple tests, any way you want. That alone can be very revealing.

And I guess, checking symmetry between the speakers doesn´t make sense without the treatment, its all about the lo freqency response of the room now, right?

You'll be focusing on the low frequency end, for sure, but you still need to run the entire spectrum. The first test you do is your baseline, against which you will be checking all future tests, as you add treatment. This first one is a very important test. So it is important to have your speakers set up exactly in their final location, perfectly symmetrical, and to also have the measurement mic set up in the exact location of the listening position. In other words, set up up where your head will be when mixing. And take several very careful distance measurements from the tip of the mic to the walls, floor and ceiling: you MUST get the mic back to that exact location, very accurately, for all future tests. If not, you won't be able to compare your new readings against your baseline. The readings will still be valid, of course: just no longer comparable, so you will not know what effect the treatment is having.

I also marked exactly one position at the listening spot, to check my future treatment with repeatable measurements)

Great! Don't lose the paper where you noted down the location of the mic!

Rod suggests not to use waterfall plots.

I'm not sure why that would be. Maybe Rod was talking about the Acoustisoft software: I never did have much luck with waterfall plots in that. But with REW, the analysis tools for waterfalls are very useful, and can reveal where your modal issues are. If you don't use waterfall plots, then it's not so easy to visualize the time-domain issues in the room.

- Rod suggests in his book doing average measurements around the listening position, should I do that?

You can if you want! You can take measurements in as many locations as you feel like, and REW will keep track of them all. You can then view them in many different ways, as needed. But once again, you must keep track of the exact location of the mic in the room for each reading, so that you can compare future readings against your baseline. - Stuart -

Hi! This is where my ables go to my computer ^^ Was a good idea This is how i built my speaker stands: Didn´t want to use mortar, because my father didn´t want to make the stones unusable for future whatever :roll: I just put some wood through the holes, now they are heavy and solid, but it´s still possible to deassamble and move them ^^ I will have to cut the top plates, to make them fit, and then make some nice cloth or wood cover

I did some measurements today. See the last pic in the post above, for my setupt. Mic at listening position Speakers at 90° The speakers are around 15 cm. from the front wall. Should i put them more close, or more further away? I heard different opinions on that. They have a bass tilt, which can be switched to -2, -4 or -6 db. I have -4 engaged at the moment. I also used this setup for the measurements. I guess thats OK, because I will anyhow have to use it, when the speakers are close the wall?? These are my results from REW I made 3 tests: left speaker right speaker both speakers (stereo) This is the lo frequency response for the 3 graphs. The really big issues are 50 hz and 80 hz At 40 and 68 hz, there is a little difference between left and right speaker Here is the response 20 - 20.000 Hz, with 1/12 octave smoothing: Most frequencies seem to be within a 5 db range, but 500 - 1.000 hz need to be brought down 100 - 200 hz need to go down The big 50 Hz peak has to go down Here is the impulse response of the left speaker I´m not really sure how to interpret this... this is RT 60 reading: decay rate: And Waterfall for left, right and stereo: Easy to see the ringing of the modes at 50 and 100 hz... Please have a look and give me your opinion on this. Is there anything else I should measure, or maybe change the time/freq range in the waterfalls, etc? Peter

They have a bass tilt, which can be switched to -2, -4 or -6 db. I have -4 engaged at the moment.

I would set that to -6 dB and try again. Also, it seems that you are not doing the test at high enough volume: turn up the volume until you are getting at least 85 dBC, and 90 would be better: Measure that with a sound level meter, not with REW (unless you have already calibrated REW to a sound level meter).

Should i put them more close, or more further away? I heard different opinions on that.

If you are not soffit-mounting your speakers, then the best place is to have the speakers at least 2 meters away from the walls (both front wall and side walls), but in your room that is impossible. The next best thing is to have them right up against the front wall, with just thick absorption between the speaker and the wall. However, yours are rear ported, which complicates things a bit: I would leave about 10cm between the rear of the speaker and the absorption panel on the front wall. - Stuart -

Thanks for the fast reply Stuart, you are a great help!

Soundman2020 wrote:

Measure that with a sound level meter, not with REW (unless you have already calibrated REW to a sound level meter).

I did that, but only to 75 db, I think I read that number somewhere :oops: I will do a new measurement tomorrow.

Soundman2020 wrote:

I would leave about 10cm between the rear of the speaker and the absorption panel on the front wall.

OK, so lets say 10cm to give room to the rear port bass, and maybe 10 cm for additional absorption, so somewhat around 20 cm should be ok?