Hi everybody. What a great place.
I have tried to search the web and this forum to find some advise. I do not hope that i have missed a topic. If so I'm very sorry for posting again. My first question is about the ceiling. And the only thing i could find about ceiling was for soundproofing this is not an issue in my room. Soundproofing doesn't matter at all. What matters is the flattest possible frequency response specially from 300hz and down
I bought a Behringer ECM8000 three months ago downloaded REW EQ and thought i would make a nice bedroom with a flat frequency response :oops: My wife and I quickly decided that it would be better if i found another place to build a studio :yahoo:
I have some questions that i hope some of you can help me with. This is a totally new world for me.
I moved in to my new room two months ago. The room is actually in 2 plans. But the upstairs will be used as a lounge/office/soldering-nerdy-lab-ish thing. We mostly do Producing/mixing and mastering for electronic music but occasionally we will be recording in the room as well. Therefore there will be instruments in the room, drums, guitar/bas amps, a upright piano and some synthesizers. This means that i can't sit in the 38% spot of the room. I have to sit closer to the front wall, but after moving my speakers around this seems to be a better spot anyway. (I could be terribly wrong here ) :oops:
I have done all the wrong things. Moved in taking measurements with a lot of stuff in the room. Put up bass traps measured again, moved speakers around after implementing traps and absorption etc etc. But i has been okay for learning how to measure. But kind of useless. now i wanna do it probably. Unfortunately i don't have a mdat file from where the room is totally empty with out any traps. I know this is really bad :oops:
In the room i have made superchunks in all four corners. These are made of isover (I'm Based in Europe it's the insulation mostly used here) - From floor to ceiling.
My room:
Length 21.8 feet
Width 15.1 feet
Height 8.7 (actually 7.9, but i will explain later )
The walls are all made of pinewood. On the side walls there are beams supporting the upstairs plan. These are 4X4 inches which means the side walls isn't plain. The beams are sticking out from the walls with 4 inches. (drawing attached)
I have three questions to start with. There might come more down the road bare with me.
The first one is about the ceiling. At the moment the ceiling is just spear's with 1 inch plywood on top. The height now is 8,7 feet. But after closing the ceiling the height will be 7,9. The Plywood functions as the upstairs plan floor. I have attached a picture. This is not from my room but it's the same kind of spear's in my room though they are a bit more far apart. My plan is to fill up the gaps with rock wool/isover then put laminated water vapour retardant climate membrane on the rock wool/isover and then some kind of fabric and some slim wooden panels.
The reason I wanna do this instead of drywall is because of the height in the room which already is on the short side of what is preferable. In this way I hope to be able to not having a cloud but make the whole ceiling function as one big cloud. Is this good thinking ? or am I missing out on something crucial ?
I have attached waterfall graph and spl measurement from Room EQ wizard. I have a null at 64hz and 108 hz. unfortunately this is an older reading with some bass traps installed. But it might help anyway. I can't figure out what these peaks and nulls come from. But when i play 64hz/108hz with a sine generator. It is clear that i have a lot of resonant going on in the ceiling between the spears (of course) :oops:
Second question. Would it be preferable to build the front wall with 8inch air to the pinewood then 8inch rock wool/ isover and some fabric. to try and reduce the bouncing of the front wall now that I have my speakers placed close to the wall? This will of course take some of the length in the room.
And the third. Because of these 4 inches beams on the side wall. I get small corners vertical all the way down both side walls every time there is a beam. Would I gain anything by filling up the wall with rock wool and add on drywall or fabric ?
Remember soundproofing is not important. It is only for the acoustics in the room.
to summarize:
Ceiling:
Should i use fabric or drywall?
Should i fill up the whole cap in height or would it be better to go with 9 inches of rockwool 9 inches of air? or anything better.
Front wall-
what to do ? Fill up the whole wall with rockwool ? rockwool - air pinewood? leave the pinewood.
Side walls
Do i gain anything by putting 4 or 8 inches on the whole wall to get it plain and nice. If so. What would be better drywall or fabric. (there are also some aesthetics involved here, would love to do something to the walls they are not nice at all).
And last. I was thinking about doing these things side walls/ front wall / Ceiling filled with rockwool. For low end absorption.
Then adding some skyline diffusers in ceiling and behind the listening spot. My thoughts are to give back some liveliness to the room so it's not totally dead when we need to record instruments. But isn't my room to small for ceiling diffusers? I would build them into the ceiling so they would end at ceiling height (7,9 feet) (this of course depends on the design/ which frequency to target.
Any advice is highly appreciated. I wanna nail this ones and for all and get my life back :( My plan is to do the ceiling and the walls. then start measuring and decide if more bass trapping is needed. Am I on the right track here ?
And i should add that my main speakers are genelec 8040A with a 6 inch woofer. If you need any kind of information or if I haven't made my self clear. Let me know and will provide you with what ever you need. Here is a link to the mdat file froom Room EQ https://www.dropbox.com/sh/g9bj6jxzivdn ... PhEXa?dl=0
All The Best
Jakob
Ceiling in mixing room and then some..
Originally posted at johnlsayers.com, topic 20654.
I Had hoped for some thoughts on my questions. Don't hope they are to common/not well enough reflected. If so i apologies.
But now we can wait anymore I will start building today. The first thing i will work on is the ceiling. I have decided to fill up the gaps with 8 Inches of rockwool. Then there will be a short gap of 2 inches of air before 1 inches of plywood. The plywood is the floor of the upstairs room. At the end i will put some thin plastic on the rockwool and then fabric. Hope this is a good solution. I have a hard wood floor in the room.
I am deeply in doubt about how to make the front wall and the rear wall. Can't figure out if i should A) keep the front wall untreated (pinewood) and then add 8inches of rockwool to the whole of the rear wall then fabric. Or if i should B) fill up the front wall with 8inches of rockwool, fabric and then only use 4inches of rockwool on the rear wall. My speakers will be placed close up at the frontwall whether i choose to go with A or B.
But first i will build the ceiling and then do some measuring.
Jakob
Hi there Jakob, and welcome! :)
Sorry about the delay: It seems I'm the only moderator on the forum at present, but I'm really busy with several projects at once, so sometimes it takes me a long time to answer a post. Sorry about that!
. That is mostly a function of room dimensions, and room treatment. Your ceiling will be beneficial to that.Soundproofing doesn't matter at all. What matters is the flattest possible frequency response specially from 300hz and down
:) :!: :roll: 8) It happens! But if that's the case, then I'm wondering why you don't also need isolation? If your wife does not like your music, then I would have thought that you'd want to isolate the room a bit as well. If not, then the sounds will get into the building structure and HVAC system, and she will hear them all over the house...My wife and I quickly decided that it would be better if i found another place to build a studio
Maybe I misunderstood: This new room, is it in the same physical building as where your wife will be? Or is it in a different building?I moved in to my new room two months ago.
:shock: How much closer?This means that i can't sit in the 38% spot of the room. I have to sit closer to the front wall,
Perhaps because the way you had your speakers, mix position, and treatment set up in the other location was terrible, and this is merely "better"? If you do a test with REW with your current setup, we'll be able to see just how good that position is...but after moving my speakers around this seems to be a better spot anyway.
Yep! Because now we don't know what the major issues were BEFORE you put in your treatment, so we don't know if any of that treatment is working at all! Or working partially... or working wonderfully! We just don't know that...Unfortunately i don't have a mdat file from where the room is totally empty with out any traps. I know this is really bad
The dimensions are reasonable. Rather long for the height, but not too bad.Length 21.8 feet Width 15.1 feet Height 8.7
:shock: :?: :?: Why do you want to close up the ceiling??? You said that you don't need isolation, so there is NO need at all to close it up. Just leave it like it is. That's a great ceiling, acoustically. Closing it up will be really bad for your acoustics.The height now is 8,7 feet. But after closing the ceiling the height will be 7,9.
Yes! Correct.My plan is to fill up the gaps with rock wool/isover
Why? Does it rain inside your room? :) More seriously, why do you want to do that? For what reason?then put laminated water vapour retardant climate membrane on the rock wool/isove
:thu: Yes! Correct.then some kind of fabric
:shock: :?: Why?and some slim wooden panels.
You do not need drywall up there, and you do not need wood up there: All you need is absorption. Fill the gaps with mineral wool, hold it in place somehow (string, wire, plastic strips, etc.) and put fabric over it. If you are concerned about fibers falling out of the mineral wool all over you and your gear, then use very, very thin plastic, such as painter's dropcloth, but not sealed air-tight, and not over the entire surface. And also use two layers of close-weave fabric.The reason I wanna do this instead of drywall
You have enough space for a small cloud, and will probably need one anyway. It can be made in several sections at different angles, if needed.In this way I hope to be able to not having a cloud
You seem to be confusing cloud and bass trap. Clouds are not meant to be bass traps.I hope to be able to not having a cloud but make the whole ceiling function as one big cloud.
Where??? I don't see your graphs in your post....I have attached waterfall graph and spl measurement from Room EQ wizard.
Those are both probably modal. 64 Hz is spot on for your 0.0.1 mode, and 108 is really close to your 4.0.0 mode.I have a null at 64hz and 108 hz.
The name in English is "joists", not spears. They are not the cause of the problem: It is almost certainly due to room modes, or SBIR, not resonance between the joists.t is clear that i have a lot of resonant going on in the ceiling between the spears (of course)
Why do you want a front wall? You said that you don't need isolation, only treatment, so why do you want to have walls in there?Second question. Would it be preferable to build the front wall
Probably not, but you would first have to explain the positions of the speakers and mix position, in relation to the walls, floor and ceiling.Second question. Would it be preferable to build the front wall with 8inch air to the pinewood then 8inch rock wool/ isover and some fabric. to try and reduce the bouncing of the front wall now that I have my speakers placed close to the wall? This will of course take some of the length in the room.
That's actually not bad! It provides some very decent diffusion... but the problem is that it is all at the same frequency, so it might not be wonderful, either.And the third. Because of these 4 inches beams on the side wall. I get small corners vertical all the way down both side walls every time there is a beam.
You could do that to some of them, but with fabric, not drywall, and make others into "slot walls".Would I gain anything by filling up the wall with rock wool and add on drywall or fabric ?
Fabric.Should i use fabric or drywall?
All insulation.Should i fill up the whole cap in height or would it be better to go with 9 inches of rockwool 9 inches of air? or anything better.
Not enough information. I would need to see photos of the actual room, and an accurate description or diagram of where the speakers and mix position are, with regard to the walls, floor and ceiling, and also how the speakers are mounted.Front wall- what to do ? Fill up the whole wall with rockwool ? rockwool - air pinewood? leave the pinewood.
Probably not. As long as you can have at least 10 feet (3m) of distance between the diffusers and your head at the mix position, then you would be able to use diffusion, probably.Then adding some skyline diffusers in ceiling and behind the listening spot. My thoughts are to give back some liveliness to the room so it's not totally dead when we need to record instruments. But isn't my room to small for ceiling diffusers?
That would not be much use! Diffusers need to be out in the open, on a flat panel,such as the rear wall. That's where I would put them. On the rear wall, or the side walls at the rear of the room, but not in the bays between joists... They would not be very effective there.I would build them into the ceiling so they would end at ceiling height (7,9 feet) (this of course depends on the design/ which frequency to target.
I downloaded that and tried to look at it, but it is really messed up! You did not calibrate REW: Please calibrate REW correctly, using a hand-held sound level meter, repeat the tests, and post again. To start with, according to that file, you did your tests at a level of MINUS 200 dB! :shock: That's impossible, of course: it is millions of times quieter than the quietest place on the planet.... Impossible to measure, even with the most sensitive instruments. So I can't draw any conclusions from your MDAT file, as the data itself is suspect. Re-calibrate, re-test, and post the new file. It is possible that the file was corrupted in the upload/ download, but I don't think so: I downloaded it twice.... If the data is valid, just measured 200 dB too low, then you have some major issues in that room, mostly in the mid range and high end, but not so much in the low end. the low end is reasonable, but the rest is terrible! - Stuart -Here is a link to the mdat file froom Room EQ
Hi Stuart. Thanks for the reply :) The room is in a new building!
I think i have calibrated REW wrong. But i have played the the test at around 85db. I have attached a new file (which is as low as the other one so there is definitely some calibrating gone wrong I apologies for that) I have also attached some pictures of the room. everything is here https://www.dropbox.com/sh/ffujhx2ayz73 ... wPTya?dl=0
I don't hope I have spend a lot of time and money on nothing. Lets see :shock:
I think it might be easier if i tell you what i have done since I posted my first post a month ago. Then you can tell me how terribly wrong I did :D
I thought that the main reason for my peaks and nulls in the low frequencies (I have up until now only focused on even out the frequency response from 300 hz and down) was due to SBIR. And my understanding (please correct me if I'm wrong) of that is that when a sound wave hits a wall and bounce back then dependent of the phase relation between the 2 waves there will be peaks and nulls. (very basic. As my understanding so far)
Therefore i decided to make the walls/ceiling absorbing as much low energy as possible. For reducing the bouncing between walls. I know that the wavelength of a sound wave is= The speed of sound divided by the frequency. And therefore for absorbing low frequency energy I need a lot of mass because the wavelengths are very long.
Therefore I Decided to fill up the whole front wall with 20cm of rockwool. I'm placed in Denmark and have used rockwool flexi Batt A which I'm pretty sure has the best absorption coefficient at least here. It is the material that the forum experts here (in Denmark) recommend for building DIY bass Traps.
I then filled up the gaps between the ceiling joists (thanks! tried to look up the word in my dictionary, had a felling spears was wrong :D ) with 20cm/8inches of rockwool as well. Now the reason I asked for the vapour membrane was because i thought fabric wouldn't be enough to cover the rockwool in terms of health/dust etc. And I had this idea about maybe giving some live back to the room if it ended up being really dead. That was also why I talked about thin plastic. But i haven't done anything yet.
And it strikes me now. The reason for the -200db issue is probably because i have typed in a - in front of the number when i have typed in the measured spl in REW :oops: could this be the problem? In that case is the measuring valid? just showing up to low in the dB scale? I apologies for that I'm totally noob :oops:
The measuring attached now is after making the ceiling and front wall. In the mean time if have filled up the whole back wall with 4inches of rockwool and half of the side walls as well. I don't have any measurements of that yet. will post it very soon. (correct calibrated of course!!!!!)
My plan is to make 2 skyline diffusers to put on the rear end of the sidewalls and a QRD diffuser in front of the stair (see picture attached) behind the listening position 3m away. There are a bit of flutter echo between the bare walls in the back I want the skyline diffusers to deal with this instead of putting anymore rockwool on the walls. Does this make sense?? I have been playing around with QRdude, but I might gonna need some help determining which frequencies to attack. It's a bit to much for a noob like me :D
I also thought about some wall ceiling bass traps on the front wall and maybe on the sides. And some on first reflecting points? I just wanna get as flat a response as possible in the low frequencies.
I must say that after listening some time I find the bass extremely well defined and focused. And the new measuring seems to have flatten out quite a bit in the low frequencies. I still have a null at around 108hz but it is not as steep anymore.
(The speakers are placed 15cm from the front wall on stands height is 114cm. They are 137 cm from the side walls and I'm listening 110cm from the front wall) They are Genelec 8040A.
Stuart I'm very happy that you have taken the time to reply. Let me know if you need more information. Of course it would have been nice to consult someone before doing all this but i hope that it is not a totally waste of time and money. Please let me know if I'm on the right track? (it sounds like it) Or if I have totally missed out on the core concepts. Hope it's okay that I tell you what I HAVE done and how it looks now instead of answering all your questions. I think this make more sense. If not let me know.
All the best Jakob
Edit: I should add that the ceiling height now is 242cm
Hey there Jakob, I hope this is still some use for you! I was just checking back over old threads, and found that I never answered yours! :oops: Sorry about that! Hopefully the comments are still useful.
You seem to have calibrated it correctly... but for -85 dB, not 85 dB! Somehow you put a "minus" sign in front of your calibration number, it seems. I had to add 150 dB to your data to get it to make any sense... The good news about it is that your room is looking very nice. The acoustic response in there is very good, as you have to right now. IT can be improved a bit, for sure, and it's a bit on the dead side, but the overall response is very smooth, in bot frequency, time and phase. Nice!I think i have calibrated REW wrong. But i have played the the test at around 85db.
Correct. Which is why you see the SBIR dips and peaks at different points in the room for each frequency.due to SBIR. And my understanding (please correct me if I'm wrong) of that is that when a sound wave hits a wall and bounce back then dependent of the phase relation between the 2 waves there will be peaks and nulls.
You don't need a lot of mass! You need a lot of depthIn other words, you need to make the absorption thick: many cm, not just a few.I know that the wavelength of a sound wave is= The speed of sound divided by the frequency. And therefore for absorbing low frequency energy I need a lot of mass because the wavelengths are very long.
Covering your insulation on the ceiling with plastic is a good idea, but in your case you will need to make it thin plastic, and you'll also need to take care to not cover 100%: Leave some slits, holes and gaps in the plastic in many places, so air can still move through, and you won't be trapping moisture in there. You might need some thicker plastic in places, but try with the very thin stuff first.the reason I asked for the vapour membrane was because i thought fabric wouldn't be enough to cover the rockwool in terms of health/dust etc. And I had this idea about maybe giving some live back to the room if it ended up being really dead. That was also why I talked about thin plastic. But i haven't done anything yet.
Yep! definitely!And it strikes me now. The reason for the -200db issue is probably because i have typed in a - in front of the number when i have typed in the measured spl in REW could this be the problem?
Please do ! I'd like to see that.The measuring attached now is after making the ceiling and front wall. In the mean time if have filled up the whole back wall with 4inches of rockwool and half of the side walls as well. I don't have any measurements of that yet. will post it very soon. (correct calibrated of course!!!!!)
It would be better to have them all on the rear wall. I would suggest doing un-tuned wood slats over thin insulation on those parts of the side walls. The room is a bit on the dead side (too dry), and doing that would help to return some of the missing energy. You can do it with different sizes of slats, and test the room as you go, to see how each one is affecting the response, until you get it perfect.My plan is to make 2 skyline diffusers to put on the rear end of the sidewalls
As above: Thin, light-weight insulation with thin plastic, then fabric, then widely spaced large wood slats.There are a bit of flutter echo between the bare walls in the back I want the skyline diffusers to deal with this instead of putting anymore rockwool on the walls. Does this make sense??
Don't put too much extra absorption in there! You are already doing rather well. Cover your bass traps with thicker plastic too. You are nearly at the point where digital tuning can be beneficial. PM me about that.I also thought about some wall ceiling bass traps on the front wall and maybe on the sides. And some on first reflecting points? I just wanna get as flat a response as possible in the low frequencies.
Exactly. It's looking good in there, and that null is probably SBIR, or floor bounce. To help determine which do one REW test with the floor bare, and one with thick insulation on the floor between the speakers and the mic.I must say that after listening some time I find the bass extremely well defined and focused. And the new measuring seems to have flatten out quite a bit in the low frequencies. I still have a null at around 108hz but it is not as steep anymore.
Definitely you are on the right track, but I also think you might be about to over-do the treatment. It's very good the way you have it, and only needs a bit of extra tweaking, then digital tuning.... - Stuart -Stuart I'm very happy that you have taken the time to reply. Let me know if you need more information. Of course it would have been nice to consult someone before doing all this but i hope that it is not a totally waste of time and money. Please let me know if I'm on the right track?
Hey Stuart. Your comments are very useful. No worry I'm happy that you are still with me. For a moment I feared that you had abandoned me because I had misunderstood some of the core concepts :D I'm verry happy to see that I'm on the right track :yahoo:
Quiet a lot has happened since my last post. We have closed all the walls and ceiling with fabric and made all the electrical installations plus ceiling lights. Unfortunately (maybe) the room has gotten a bit more dead. But I'm not sure if it's a problem I still have a hard time interpreting the waterfall graphs. I can say that i like the sound of the room so far actually i like it a lot just need to find the perfect listening position and speaker placement.
I have calibrated REW corretcly now. Only with a mobile app haven got an dedicated spl meter yet. But it looks more right than the last measuring. Here is a link with pictures of the room. the old measurement from the last post and a new one taken a couple of days ago. https://www.dropbox.com/sh/htnwb1hkcx9y ... bLhVa?dl=0
We did put some very thin plastic on the ceiling behind the fabric and the thinnest I could find where indeed the stuff painters use. But not over a good square of where the listening position will be. Here we just used two layers of fabric instead.
To deal with the flutter echo I decided to but insulation behind the fabric like we had did in the rest of the room. Looking back this was might overdoing it as you just warned me about :oops:
At the moment we are making an multi-band fractal diffuser. This diffuser will then be mounted on the stair (in front ) behind the listening position. Depending on where the listening position will be I will have at least over 3 meters from where I'm sitting to the diffuser but probably 4 meters. I hope this will bring back some of the energy in the room.
The picture studio 2 shows the stair in front of the backwall. In the right corner of the back wall picture studio 3. The plan is to use this space for recording vocals. Therefore i would like not to put any diffusers in there on the backwall. This is why I have decided to put it in front of the stair. also because this is behind the listening position and i do not know if the stair is doing any harm but I could imagine.
In the latest measurement there are some dips from 2k to 8 k. I hope that the diffuser will help on this. I also have a upright standing piano in the room that I will need to move around and find the best spot for. I have a feeling that this is reflecting some. It's placed different here than in the old measurement. My new desk is probably also reflecting some. This is only a dummy. Our final desk will have a les steep slope on the 19" racks on the side. But first I will be moving speakers around and finding the best spot with the best overall response. I just have to hand in my bachelor in musicology first. Then i have time to find the best positioning.
And last. I have not decided 100 % on where to sit yet. I have spend 4-5 hours the other day moving my speakers and listening position around. How can I determine whether the nulls is because of room modes or SBIR ? There is a big difference in frequency response when moving around.
If it is because of room modes. Is it correct understood that I can't do much about the dips in frequencies then. But what I'll then do is to try to control the decay time of the modes so that they are ringing the least?
Some weeks ago I picked up a pair of Tannoy fsm-U dual concentric monitors. Well.. I know... these monitors are a bit big for my room. But i got them for 1400$ and i couldn't resist. I'm very impressed. They sound really good. Of course they should have been flush mounted. But this will not be the case for this time :D The walls and ceiling are done I can't take down the fabric. I have to live with it as it is for now (which i hope is still pretty good) Looking back I could have done things different. But this is my first room design ever and the learning curve is rather steep for designing studios :D But this forum and your posts has been a big help.
At the moment my tannoys are at service. When I get them back I will be spending some days moving around and find the best spot for my Tannoys the genelec 8040's and myself. At that time I have installed the diffuser as well. I will then do some more measurements and post them here. Both current measurements are made on the genelecs without the tannoys in the room.
I'm looking forward to reading your thoughts I hope that i haven't over-done the treatment yet.
All the best
Jakob
Not at all! I just lost track of your thread when I switched over to a new computer, after my old one died... In the future, if you don't get a response with a week or so, feel free to "bump" your thread, or even PM me.For a moment I feared that you had abandoned me
Yes it has... too dead! It went from this: To this: Your decay time went down from about 200 ms to about 120 ms! That's way too dead for that room. It should be around 230 to 300 ms for that size space. I would go for around 250, to be honest, but your less than half that. It will be uncomfortable and tiring to work in there for long periods.Unfortunately (maybe) the room has gotten a bit more dead.
It is! :)But I'm not sure if it's a problem
Waterfall plots wont tell you much about decay times. They only tell you about modes, SBIR, and reflections, mainly. For decay times, you need to look at the RT60 graphs, and the filtered impulse response.I still have a hard time interpreting the waterfall graphs.
Well that's easy! :) There's math for that... combined with a bit of experience... :) Your room is almost long enough to give you two options: Either have your speakers away from the walls, or have them tight up against the front wall. For both of those options, there's math that will get you to the right point, but then you need to change the treatment. Let's do the most likely one first (especially considering that you will be making the room shorter in the future, when you do the vocal booth). Set up your speakers on stands, vertically, such that the acoustic axis of each speaker is 123cm above the floor (51"). NOTE!!! ACOUSTIC AXIS!!!! Not the top or bottom of the cabinet, and not the tweeter: you need to find out where the acoustic center of your speaker is, and set that at the right height. All of the measurements I'm going to give you are for that point. The stands must be very massive (heavy). For speakers, get rid of those huge monsters. (Are those Geithains? they sort of look like it. Or Tannoys, maybe?). Those are way too big for that room, and you'd never be able to position them well. Stick with the Genelec's. So set them up on stands 123cm above the floor, and 10cm from the front wall. That's the distance between the rear corner of the speaker, and surface of the wall. Each speaker needs to be 129 cm from the side wall (acoustic axis). That means that they will be 202 cm apart. Now set up your chair on the room center-line such that your head (ears) will be 245cm from the front wall, and set up a vertical pole of some type (mic stand for example) at a point on the room center-line 280 cm from the front wall (in other words, 35 cm behind your head). Use a laser pointer temporarily taped on top of each speaker, directly above the acoustic axis and lined up perfectly with the acoustic axis, the rotate the speaker until the laser is aimed directly at that vertical pole. If you have two laser pointers, put one on each speaker and get both laser dots lined up perfectly at the exact same spot on the pole. After you do that, check that both speakers are still 10cm from the front wall and 129 cm from the side walls. Adjust as necessary, until everything is perfect. That's the theoretical best position. Do not put the desk in yet! Move the desk right to the back of the room, and also all the other objects in the room (organ, other speakers, equipment, etc). Everything must go to to the back. Just have your chair alone at the front, nothing else. Now sit down, and listen to some music like that. Critical listening. Keep the EQ flat on everything, and listen very carefully to music that you know well. Listen for clarity in the highs, smoothness in the mid range, and tightness in the bass. Listen for stereo image and sound stage: close your eyes and see how well you can determine where each instrument seems to be in front of you, arranged across the imaginary "stage". Listen for detail, and evenness- Listen to several songs of different genres, that you know very well. I'm betting you will hear details that you never noticed before. Now do a REW test like that, with the mic set up exactly where your head will be, above the chair, aiming forward but tilted upwards towards the ceiling about 60°. You must leave the room for this test, so use the "start delay" feature in REW to give you enough time to do that, plus 5 seconds. Your body can affect the tests, so you cannot be in the room for this. Do three measurements like that: one with just the left speaker turned on, one with just the right speaker turned on, and one with both speakers. Do not adjust any levels at all in between tests! Just do all three in a row, one right after the other, and label each one inside REW. Leave the room for each test. Now for the part that you will not like: :) : without changing anything at all, put the desk in place where you would be able to operate the equipment comfortably while seated in the chair. Don't move the chair! Move the desk to get the position right. THe chair must remain in exactly the same spot. Now repeat those same three REW tests, and label them carefully. Also listen to the same music again, and notice the difference. Notice how the mid-range suddenly got "gritty" and unclear? And the bottom end lost it's tightness a bit? And the high end got a bit more harsh? That's the effect that the desk is having. It is too big for that room.. Too tall, the rack modules extend up too high, and the angles are too flat, and too parallel to other room surfaces. It LOOKS very nice, but it's not a practical desk for that room. Those changes you heard in the response will convince you that it's just not what you need. I said you wouldn't like that part, but it's the truth. Post that MDAT file with all six tests in it, and also photos of the room the way you had it for each set: without the desk, and with the desk.just need to find the perfect listening position and speaker placement.
Yep! :)To deal with the flutter echo I decided to but insulation behind the fabric like we had did in the rest of the room. Looking back this was might overdoing it as you just warned me about
I'm familiar with the leanfuser, yes. It's a great concept, and I'm using it in a mastering studio that I'm working on right now.At the moment we are making an optimized step diffuser from a design made by Tim Perry.
I have a design for doing that, if you are interested... :) I like to use the other side of the device as well, for doing other treatment.... :)The plan is to make it in 5 modules an then put them together in profiled modulation
It must be centered in the room, from left to right. It cannot be more to one side than the other.This diffuser will then be mounted on the stair (in front ) behind the listening position.
IT is doing something, certainly, but I don't think it is doing much harm. I would not worry about it.i do not know if the stair is doing any harm but I could imagine.
Looks like typical comb filtering. Probably from your desk...In the latest measurement there is some dips from 2k to 8 k
It won't do much for that. I'm fairly sure it is artifacts from your desk, or from something else in the room. Diffusers cannot fix problems created by other objects in the room.I hope that the diffuser will help on this.
It will have to go towards the back of the room, well behind the mix position.I also have a upright standing piano in the room that I will need to move around and find the best spot for.
Yep! More than just "some". It is also doing other things, in addition to reflecting. ..I have a feeling that this is reflecting some.
Very much so!My new desk is probably also reflecting some.
Actually, the slope needs to be even MORE steep, not less. The top and rear surface of those rack modules also need to be angled. Take a look at the desks that Sterling makes, to get an idea of the high angles that you need.This is only a dummy. Our final desk will have a les steep slope on the 19" racks on the side.
See procedure above ! :) 8)And last. I have not decided 100 % on where to sit yet
That's what the math and theory is for! To predict the optimum locations for everything... Plus a it of experience, since reality does not always match prediction perfectly...How can I determine whether the nulls is because of room modes or SBIR ? There is a big difference in frequency response when moving around.
Nope! Not correct. It actually is possible to improve on that, electronically, and your modes are pretty well damped already in any case.If it is because of room modes. Is it correct understood that I can't do much about the dips in frequencies then.
You already did that. It might be possible to improve that some more, but the problem is the staircase: It is located right where you need to put the treatment.But what I'll then do is to try to control the decay time of the modes so that they are ringing the least?
:shot: :shock: :cen: :cop: :blah: That's for sure!!!these monitors are a bit big for my room.
.... and that's the problem! They are not supposed to sound like anything. They are supposed to sound perfectly neutral, like your Genelecs.They sound really good.
There's no need to move around. Just position things where they are suppose to be, and you'll be fine. Then tune the room around that.When I get them back I will be spending some days moving around and find the best spot for my Tannoys the genelec 8040's and myself.
I think you did.... :) - Stuart -I hope that i haven't over-done the treatment yet.
Thanks for clarifying the speaker placement procedure. I will be looking forward to doing this and posting the results.
Yes it has... too dead!Unfortunately (maybe) the room has gotten a bit more dead.
[/quote] well great :D I've been having a feeling about this the whole time. Can i deal with this in a way so I don't have to take the fabric of the walls. Will adding diffusers give me a better deacy time? Or do i have to remove insulation behind the fabric ?It is! :)But I'm not sure if it's a problem
Yep that is Tannoys dual concentric. I'm definitely sticking with the genelecs they will never leave :DFor speakers, get rid of those huge monsters. (Are those Geithains? they sort of look like it. Or Tannoys, maybe?). Those are way too big for that room, and you'd never be able to position them well. Stick with the Genelec's.
I'm familiar with the leanfuser, yes. It's a great concept, and I'm using it in a mastering studio that I'm working on right now.At the moment we are making an optimized step diffuser from a design made by Tim Perry.
I am very interested thank you :DI have a design for doing that, if you are interested... :) I like to use the other side of the device as well, for doing other treatment.... :)The plan is to make it in 5 modules an then put them together in profiled modulation
Of course the diffuser will be dead center. In front of the stair. But dead center in the middle of the room.It must be centered in the room, from left to right. It cannot be more to one side than the other.This diffuser will then be mounted on the stair (in front ) behind the listening position.
There will be no vocal booth.. We will keep the corner open. Then maybe have a moveable panel to place if needed. Tracking will be with headphones for both engineer and singer. Someday we make a live room upstairs.Let's do the most likely one first (especially considering that you will be making the room shorter in the future, when you do the vocal booth).
Very much so!My new desk is probably also reflecting some.
[/quote] Will do that!!Actually, the slope needs to be even MORE steep, not less. The top and rear surface of those rack modules also need to be angled. Take a look at the desks that Sterling makes, to get an idea of the high angles that you need.This is only a dummy. Our final desk will have a les steep slope on the 19" racks on the side.
Got it!There's no need to move around. Just position things where they are suppose to be, and you'll be fine. Then tune the room around that.
Yes! :)Can i deal with this in a way so I don't have to take the fabric of the walls.
It will help, yes, but one fractal diffuser on the rear wall is not going to be enough.Will adding diffusers give me a better deacy time?
You could if you want, but I think non-tuned slats might be enough. Here's something you can try: When you have the speaker setup that I mentioned before, do some extra REW tests with some large panels of thick building materials leaning up against the walls in a few places, but NOT at the first reflection points. You'll need something like large pieces of plywood, MDF, OSB, drywall, fiber-cement board, or something like that Get several large pieces (each one at least a meter long by about 20cm wide, and hopefully much bigger), and stack them up OUTSIDE the room. Then bring one in, lean it against the wall, do a REW test, take a picture of the room with that piece in, then bring another one as well, do another REW test, another picture, bring in another piece in addition to those two, another REW test, another pic... Keep on bringing in pieces and leaning them up against the wall at various locations, until you run out of pieces of wood. Hopefully you'll end up with enough pieces to cover about 30% or so of the total wall surface. Then post the MDAT file with all of those tests in it, along with the pictures, and I'll take a look to see if it is working as expected. That's not a very scientific way of testing, but it works! It well help reveal hoe much slat area you will need, and what areas are good potential candidates for doing that in such a way that it does not mess with the overall acoustics too much. - Stuart -Or do i have to remove insulation behind the fabric ?
Hey Stuart.
I think that there is something wrong with the dimensions that you recommended for speaker placement in my room. And I think this is because the room dimensions have changed a bit since my first post. If I place the speakers 129cm from the side walls there will not be 202cm between the speakers.
My room is 443cm wide and 630cm long. Can you send me in a direction so I can read up on the math about speaker placement so I can calculate the right placement. Would love to know how to calculate this.
All the best Jakob
Edit:
But the real room boundaries is the actual walls right? So just because I have 10 cm of insulation and fabric on both side walls. This doesn't mean that the room dimension has change right? In that case I cannot place the speakers 10 cm from the actual front wall. because the whole front wall has 20 cm insulation and then fabric :D But then your dimensions are spot on. ( of course) :oops:
Right! :) It's the hard, solid, massive surfaces of the room that matter. If you have insulation in front of that, then ignore it for this arrangement. If the insulation on the front wall is so thick that you can't get the speakers that close to the actual wall, then just get it as close as you can, with the rear corner of the speaker almost touching the insulation.But the real room boundaries is the actual walls right?
Right! Weeeellllll... sort of... There's two concepts here: For low frequencies, modal response, decay times, SBIR, and suchlike, what you are interested in is the actual solid walls of the room itself. But for some acoustic calculations, it's the face of the treatment device that matters, and often that is also in relation to the wall as well! So it can get complex... :)So just because I have 10 cm of insulation and fabric on both side walls. This doesn't mean that the room dimension has change right?
Then place the speaker with the rear corner almost touching the fabric. The extra thickness of insulation is good, but the extra depth from the wall, not so much. At 20cm you are getting close to the limit of how far the speakers should be away from the actual wall. You are still OK, but don't move them further away than that. The greater the distance between the speaker and the wall, the lower is the first cancellation frequency. If it is too low, then the absorption won't do much too it, because the wavelength is too long, so it's a "double whammy". The greater distance forces the frequency lower, and lower frequencies are more problematic and more noticeable, but lower frequencies are harder to treat because of the longer wavelength, and less effectiveness of porous absorption.... At 20cm you are still OK: the first dip is at about 430 Hz, but at 40 cm it would be 215 Hz, which is getting to be problematic, and beyond 80cm it gets down under 100 Hz, which is a big problem... 10cm of insulation can have a good effect on 430 Hz, but it won't have a good effect on 100 Hz...In that case I cannot place the speakers 10 cm from the actual front wall. because the whole front wall has 20 cm insulation and then fabric
:thu: :D - Stuart -But then your dimensions are spot on. ( of course)
Thanks for clearing this out so fast. Will do all the measurements right away :D
Okay.
First of all. You where right about the desk :lol: Hugh difference. I have removed the racks from the desk and we will make another design. You where spot on with the difference in the bottom, mids and highs. I'm actually very impressed about how spot on you where :thu:
Here is pictures and all the new measurements https://www.dropbox.com/sh/r96wjfni8nld ... 2QLwa?dl=0
You pointed out that my room was almost long enough to also be placing the speakers away from the wall. I would might try this aswell. The reason we have those big tannoys is because that while the genelecs are very nice to mix on and do all the critical stuff with. We also need a bigger pair of speakers for when we are preparing our live performances or simply just jamming ideas.. For this we need to play loud. The gennelec's can't go that loud. I didn't wanted some ugly PA system in the room so we got the tannoys. And someday when I get a bigger room they will definitely go inside the wall :lol:
Unfortunately I can't dedicate the room for only a mix and mastering room. I also do all production, composition and rehearsing in here so it's a bit of a puzzle. So I'm thinking (hypothetical). If I Keep the genelecs as they are positioned at the moment. Then put the tannoys in right next to them. Then I'm ruining everything right? The Tannoys will act as a boundary to the genelecs right? But If I positioned the genlecs further away from the front wall could it might be possible to still keep the tannoys with out ruining everything. I know I can't place the tannoys for getting the same sweet spot as the genelecs. But would it might be possible to place them in a way so that you get a sweet spot back in the room somewhere in front of the stair maybe?
In this way we could still use them for when we are preparing our live sets ( which is electronic music aimed at clubs and festivals) and maybe have a critical listening spot in the back. I hope this can work out in some way cause we need them. Alternatively we could place them in the back of the room but would really prefer to have them in the front. But lets take this later.. Just a thought I needed to put out there. Cause if it could work It would be worth the try. And I need to think this in when I position the genelecs.
The room is definitely to dead. I could hear a big difference just by adding different materials to the walls. I'm looking forward to hear some ideas :lol:
All the best
Jakob
I hope that the measurements are sufficient to give an idea about where to put the slats. I have used materials that I had laying around. Let me know if they need to be bigger or cover more of the walls :D
Jakob
Yup. The way sound behaves in a small room is fairly predictable, and the effect that large objects have on that is also fairly predictable. I'd love to tell you that I have a magic crystal ball that I rubbed and stared into intently, to see what your room would sound like! But it's nothing that exotic. Just some basic acoustic equations and "rules of thumb".First of all. You where right about the desk Hugh difference. I have removed the racks from the desk and we will make another design. You where spot on with the difference in the bottom, mids and highs. I'm actually very impressed about how spot on you wher
Key word: "almost"... :) We can try it if you want, but I wouldn't hold my breath about getting good results like that....You pointed out that my room was almost long enough to also be placing the speakers away from the wall. I would might try this as well.
For the same reason as above (acoustic equations, rules of thumb, crystal balls...) I would strongly urge you to NOT put those things in your room. They are just too big, and will mess with your acoustics. Those were pretty good speakers when they were made.... thirty years ago! :)The reason we have those big tannoys is because that while the genelecs are very nice to mix on and do all the critical stuff with. We also need a bigger pair of speakers for when we are preparing our live performances or simply just jamming ideas
Yup.If I Keep the genelecs as they are positioned at the moment. Then put the tannoys in right next to them. Then I'm ruining everything right?
Doubtful. Big boxes affect big waves, and edge diffraction / baffle step response / power imbalance guarantee that the big waves from your Genelecs will be going backwards, behind the speaker, and hitting the "big boxes"...The Tannoys will act as a boundary to the genelecs right? But If I positioned the genlecs further away from the front wall could it might be possible to still keep the tannoys with out ruining everything.
:shock: :?: How loud do you need to go??? According to Genelec, the 8040A can produce 105 dB- If you need more than that, it's probably the low end you are missing (those 8040s only go down to about 50 Hz.) So adding a good sub solve both problems: Fill in the bottom end, and increase total SPL level. Adding a decent sub could probably get you up around 110 dB. If you need more than that to hear clearly, then you should be talking about visiting an audiologist, not an acoustician! :) For reference, normal listening level in a control room is around 75 to 85 dBC, and perhaps pushing it to 95 or 100 dBC to "check the mix". In fact, looking at the specs for the Tannoys, they actually don't do much better than the Genelec's, believe it or not! I wonder how much of your feeling that you are getting more "bang" from those big boxes, is "placebo effect"...For this we need to play loud. The gennelec's can't go that loud.
Implying "big heavy thumpy bass".... The Tannoys wont do that. The only go a few Hz, lower than the Genelecs (40 Hz vs. 48 Hz. - basically, just two notes, going from G1 to E1). Do yourself a favor, and ditch BOTH sets of speakers on ebay, then use the money to buy a single set of speakers that will do the job you want, and work well in that room. Consider mid-sized offerings from Genelec, Eve Audio, Adam, Dynaudio, Focal, etc. that have fairly narrow dispersion angles both horizontally and vertically, and that can be soffit-mounted.In this way we could still use them for when we are preparing our live sets ( which is electronic music aimed at clubs and festivals)
That would be possible, with some deep bass treatment on the rear wall and a couch set up a few feet in front of that.and maybe have a critical listening spot in the back.
"Need" them? Or just "want" them because they look cool? :)I hope this can work out in some way cause we need them.
:shock: :ahh: :cop: :blah:Alternatively we could place them in the back of the room
:?: I already showed you where to put them for optimum performance. You already tried it. You already said it was fantastic. So I'm wondering why you would want to "position" them elsewhere???I need to think this in when I position the genelecs.
Of all the measurements in your MDAT file, the last one (#17) is the best, but it's still far short of where you need to be. Surprisingly, that's the one where you said that you removed the panels on the first reflection points. You also said that they were the "black panels from picture #1" that you removed, but I don't see any "picture #1", and I don't see any "black panels" in the few pictures that you did provide. Are the some pictures missing? Your MDAT file mentions a lot of "pictures", but there are none in the zip file. What other treatment did you have in place when you did that last measurement? Anyway, clearly what you did there was improving things, but not enough. I would leave out the "black panels at the first reflection points" for sure, and also add thick plastic in broad horizontal strips behind the fabric in the front-most bays on the both side walls (between the edge of the suprchunks and the next vertical trim). Use 4 mil plastic or 6 mil plastic for that (the type of polyethylene plastic that you can buy from large rolls, in hardware stores), in strips around 20 to 30cm wide, separated by gaps of about 10 to 20 cm. Do the same for the second bay on the side walls, but only at the top and bottom of the wall, not in the center section at ear height. In other words, leave the insulation without plastic from 90cm above the floor up to 180cm above the floor. Do the same for the first two bays on each side of the front wall. Do another set of three REW test like that (L, R, and LR), but this time using the Genelecs set up in the locations I gave you, and without the Tannoys or the desk in the room, and without the "black first reflection point panels". Actually, do two sets of tests: One just like that, and one with all of your diffusers set up against the rear wall, right in front of the fabric. (And send photos this time! :) ) - Stuart -The room is definitely to dead. I could hear a big difference just by adding different materials to the walls. I'm looking forward to hear some idea
Hmm.. Thats odd. when I use the link provided I can see all the pictures.. In the folder called pictures. There are 17. has made a new link only for the pictures.. https://www.dropbox.com/sh/01gcqgdmm6ss ... C4pAa?dl=0
Strange... I had only see the MDAT file in the link you sent before. https://www.dropbox.com/sh/r96wjfni8nld ... 2QLwa?dl=0
But anyway, those new pics are very helpful! I'll go over the REW file again, with the pictures there at the same time, and let you know if there's anything new I need to add...
- Stuart -
Thanks for taking the time to reply.
I don't need to play louder than 85db when mixing. For this the genelecs are more than fine. But when I need to play synths/organs/ while a drummer is playing and a guitarist is playing on a amp. I don't want to use the genelecs for this purpose. Here we are talking a band rehearsing situation. The drums alone plays 100db :shot: . Add a guitar amp and a bass amp. :jammin: Now if I use the genelecs for playing synths/organ over that, and maybe driving a vocalist as well. :inn: Then I would have to crank them to the max. I don't want my main monitors to be used for this purpose. I don't want them to be playing on the edge of where they distort for long periods. I only wanna use them for critical listening. Therefor I need another set of speakers in the room. Now it so happens that I have these Tannoys. And they have more than enough power for this purpose. And yes it is a pair of thirty years old speakers, that happens to sound pretty well. So if I could use them for this purpose and also be able to enjoying listening to music on them, from the back of the room. Then it's a win win. But if it can't be done. Then it can be done. As stated right from the start. These speakers are way to big for mixing in this room. I'm just asking a hypothetical question. Would this mess up the frequency response of the genelecs. It would. Fine. I'm not putting anything in here just for the looks, if it's messing with the acoustics. Though I think the aesthetics of my working environment have an important impact on the creative process. And thats why I am asking an acoustician! So there is no need for an audiologist yet :lol::shock: :?: How loud do you need to go??? According to Genelec, the 8040A can produce 105 dB- If you need more than that, it's probably the low end you are missing (those 8040s only go down to about 50 Hz.) So adding a good sub solve both problems: Fill in the bottom end, and increase total SPL level. Adding a decent sub could probably get you up around 110 dB. If you need more than that to hear clearly, then you should be talking about visiting an audiologist, not an acoustician! :) For reference, normal listening level in a control room is around 75 to 85 dBC, and perhaps pushing it to 95 or 100 dBC to "check the mix".For this we need to play loud. The gennelec's can't go that loud.
For the purpose of rehearsing just described. It dosen't matter if they are placed in the back or the front of the room. But it would take up some space that it wouldn't in the front. But I'm not compromising the sound of the room over the looks.:shock: :ahh: :cop: :blah:Alternatively we could place them in the back of the room
No need for big heavy thumpy bass for this. 40 hz is enough. We roll everything pretty sharp off below 32hz. For preparing live sets I don't need critical listening. I just need a set of speakers that can, if needed play louder than the genelecs and of course sounds good. Even though I have been thinking about adding a sub to the genelecs. I have one. Not a good one but a decent one. with a 10" woofer. It's from prodipe. Will try to set it up and see how it sounds.Implying "big heavy thumpy bass".... The Tannoys wont do that. The only go a few Hz, lower than the Genelecs (40 Hz vs. 48 Hz. - basically, just two notes, going from G1 to E1).In this way we could still use them for when we are preparing our live sets ( which is electronic music aimed at clubs and festivals)
So this CAN be done? But will ruining the sound from the genelecs in their sweetspot. So it CAN'T be done :D But anyway at the moment the biggest problem in the room is the deacy time. So that is what I'm gonna focus on for now.That would be possible, with some deep bass treatment on the rear wall and a couch set up a few feet in front of that.and maybe have a critical listening spot in the back.
See the pictures.What other treatment did you have in place when you did that last measurement?
:shock: Do you mean 4-6 mm. Or do you actually mean 0.04-0.06 mm. Couldn't find anything that was 4-6 mm on rolls in my hardware store. Where did we go from. Wanting to do something without removing the fabric. To removing the fabric and adding plastic :) In that case. IF removing the fabric. Why not remove some of the insulation as well?? But I had hoped for a solution without removing the fabric. Cause it's gonna be a pain. After looking at the last posted test, and doing some more last night. It is clear that I'm way behind of reaching 250ms decay time. I need to add at least 100ms more. The worst spot is from around 300 to 1K. I guess this is because I have 10cm of insulation on the sidewalls and the rear wall. you mentioned earlier thatUse 4 mil plastic or 6 mil plastic for that (the type of polyethylene plastic that you can buy from large rolls, in hardware stores), in strips around 20 to 30cm wide, separated by gaps of about 10 to 20 cm. Do the same for the second bay on the side walls, but only at the top and bottom of the wall, not in the center section at ear height. In other words, leave the insulation without plastic from 90cm above the floor up to 180cm above the floor. Do the same for the first two bays on each side of the front wall.
I guess there is a clear connection here ? I'm such an idiot. After reading and reading. I decided that you can't have to many bass traps in a small room. That is the lingo around the internet. Weeeelll.. As you stated 10cm does nothing below 100 hz. So what I have done here has nothing to do with bass trapping. Instead I have been decay trapping :horse: :lol: :oops: But the good thing is I'm learning. Which beside a good sounding room is the purpose of this project! I did some tests last night. First I emptied the room. Then I added some plastic that was 2mm thick. I wanted to do some testing without removing the fabric for seeing how it worked. I placed it in the bottom and top of the sidewalls in stripes as you had recommended. Then I tried to hang some wood over it to see how it reacted. I'm thinking about maybe adding wood slats all the way in top and bottom on the sidewalls (see left side wall drawing 1). But not in ear height. Do you think this could work acoustically for bringing back some decay time? Or is wood slats in front of the room no go!!? Then I could add some more slats in the back rear side behind listening position if needed (see Left wall drawing 2). These slats I would make opposite on the right wall. So no slats are directly opposite each other in ear height. So when there is a slat on the left wall there will be fabric in the right side at same height for preventing flutter. Then adding some slats, skylines and a leanfuser in front of the stair (see rear wall drawing). This was just an idea not sure if it would work. But I'm thinking that plastic alone isn't enough for raising decay time as much as needed. https://www.dropbox.com/sh/tchkt90rq4xw ... -1xMa?dl=0 Thanks for the help. Jakob10cm of insulation can have a good effect on 430 Hz, but it won't have a good effect on 100 Hz...