Tiny All-In-One room

Hello to everyone, Finally after months of reading this forum-treasure and learning, is time to slowly start my own project! As the title describes I have the luck to be able to dedicate a room of my house to create a little home studio. Its dimensions are L: 3,74m W: 2,91m H:2,50m and is part of an old 50's house built of 70cm stone outside walls, 25cm solid brick inside walls, concrete tile floor, concrete ceiling and a solid wood 3cm door. The house is ground floor and there is another residence above. I already have done some work in Sketchup and put some ideas in you can play with, which you can find in the following link: https://mega.nz/file/F5kDELja#djt8Px0qH ... xU01IHJMNk Here is the empty room sketch: And here is a photo of how it actually is: I also have done the proper preliminary homework: https://amcoustics.com/tools/amroc?l=37 ... ing%20room and have also done some REW measurements, BUT with the room as seen in the picture (semi-empty that is..) so I don't really know if there is any point of posting them right now.. The heavy wall construction has already given good isolation from/to the outside world (nearest neighbour @ 4-5m.. ) with the weak link be the double-glazed window measuring 35-something db Loss just outside of it. I don't usually work with high SPLs, but there are dogs barking in the neighbourhood and airplanes frequently passing so I have to take care of this. I also have to take care of the inside door isolation, the room is IN the house me working is annoying to the others, as you can imagine.. The purpose of the room mainly is to be the best control room it can be according to its size, and also to have the ability to make a decent recording in it, mostly spoken voice. Things that I must do: 1) do something with HVAC. Since it is just a single room I think is will be relatively easy, but still I am searching and learning. 2) make a super-door to isolate from the rest of the house 3) decide how I must treat the room to have a good sonic result with the minimum space consumed. The biggest problem of all is the budget. I work as a sound engineer in the live industry and as you can imagine with the covid situation most works have stalled and I have no stable income, so the choices will be made with this in mind. Thanks for reading!

Wow, that is one difficult room. Massive walls and small size will lead to very strong modes, with low modal density. I would recommend:- A Cloud as big and thick as you can manage. Even a suspended ceiling over the whole room. Treat your Back Wall (behind you) as thickly as you can. You could do the same on the Front Wall, with the speakers sunk into the treatment perhaps. Side wall reflection absorbers of course. Thick fibre absorption is very effective and luckily it works best with low density cheap fibre. Another ray of sunshine, the acoustics needed for mixing are the same as for clear vocal recording.

Greetings, As you prepare your padded cell,

1) do something with HVAC.

. Given the amount of absorption you'll need (follow DanDan's suggestions!), your room will get stuffier, in both senses of the word. As a voice artist, you know how important breathing is, so you'll really need to sort this out sooner rather than later. If you are able to remove the window, you could frame in the space and use it for a mini split and ventilator. Your gear will also thank you for addressing this. All the best, Paul

Thanks both of you for your comments. I am currently converting the simple door to something more usable by adding a layer of 5mm mlv 10kg/m2 and an extra 30mm mdf layer. I am also searching about the ventilation and a question has came up: where I live we have mild winters (5-15 Celsius) and hot summers (30-35 Celsius). Is the Hrv an one-way solution or a simpler system would do? Thanks again..

Dio wrote:

And here is a photo of how it actually is:

Not preserved: IMG_1587.jpeg

sorry for offtopic: are those speakers diy/based on something etc?

anodivirta wrote:

sorry for offtopic: are those speakers diy/based on something etc?

Yes they are diy. The 8” woofers are Seas p21rex, the mids are Morel MDM-55 and the tweeters Seas 25tff. They are triamplified, the processor-crossover is a Void Acoustics Digidrive+ (rebranded Xilica DCP-3060), the amps are two Linn LK85’s (low and mids) and a Linn knekt roomamp (tweeters). The box is built with the assistance of the BassBox Pro software. The idea, the time of making, was to make a “poor man’s ATC” :D :cop: ,if possible..

Happy new Coronavirus quarantine everybody! I finally finished my door and while I am still perfecting the seals the results are within expectations. Here is pink noise playing in the room (blue) and the result just outside the door (purple). Note that I didn't make a super-heavy door because the house is quite old and I didn't want any surprises with cracked jambs etc... After done that, I am happy to post my baseline mdat which you can find here: https://mega.nz/file/RkMxSYJL#KDEZxVp4FuHYzZaPwtiOpUGHfGnwMwGmVYGovxWhF1I and some screenshots: Keep in mind that the room was not completely empty while measuring, there was a small drawer and cabinet in, things that will remain in place anyway. Below is what I have in mind doing for this room: 60cm of hanger at the back wall 20cm insulation on the door , 20cm insulation +10cm air gap in the "refection zone", 30cm absorptive ceiling, angled slats at the back half of the room (to keep some life where the recordings would happen) and flushed monitors with slot resonators in the lower and upper section of the speakerwall (an idea that came after seeng the results of this build viewtopic.php?f=10&t=21269&hilit=Door+seals&start=165), and maybe a limp mass absorber between the monitors for that 45hz mode.. spk file: https://mega.nz/file/toNDzYDR#dStoxAiAtXNLB-_ME4sJGkMB5SvTJIly3OucFlO0ee0 What is your opinion on this? And lastly the hvac part. A mini-split will take care of the air-conditioning and a small fan (I believe this https://www.solerpalau.com/en-en/in-line-duct-fans-td-160-100-n-silent-230v50hz-re/ will do) the ventilation. Since my walls are one leaf (and because of the lack of space) I will use one silencer for the fresh and one for the stale air. Calculations: Three people max 25x3=75m3 To obtain the 1,5m/s speed I need 13,3cm diameter register or almost 140cm2. I plan to use 10cm pipe and at the last meter 16cm (200cm2) with a 10x30 (300cm2) output (or whatever dimensions close to that). Will this work? For the silencers I triple the cross section area (from 100cm2 to over 340cm2) and add one more baffle to the Gregwor design. I will be happy to read your comments and suggestions!

Hello to all, One alternative layout I am thinking about is this: with soffit wings extended the more I could extend them, letting more room free with the cost of less absorption on the side walls. It has a quite good raytrace image too. What do you think?

Wandering around in the forum I found these topics: viewtopic.php?f=1&t=13996&hilit=.skp&start=15 viewtopic.php?f=1&t=14201 their rooms are almost identical in dimensions to mine, and also John Sayers himself has given some skp files, so I gave it a try: The first one seems nice and doesn't consume much space but its raytracing is not what one could expect. Since these "walls" are slot resonators is there any meaning in raytracing? Am I missing something here? The second maybe is more promising, are there any serious disadvantages is the "sawtooth" design? Thanks, dio

Happy new year to everyone, and a wish to try and make 2021 a better year. Small room-big update for the beginning of the new year: I finished the back wall hangers and I think regarding their size it was a success. I used Knauf Ultracoustic insulation (5kPas/m²) 100mm on walls/50mm on hangers and 200mm above the door. The hangers core is 4mm mdf, the choice of which was a result of the simplistic thinking that a 4mm thick 750kg/㎥ mdf surface would have closely the weight of a 12mm thick 440kg/㎥ Homasote same surface. Also I cannot find any Homasote where I live, mdf is everywhere. Measurements following: Waterfall, first with the hangers and then the empty room for reference Spectrogram, first with the hangers, then the empty room for reference Impulse response, hangers RT60, Hangers RT60 Hangers-empty room comparison Frequency response, hangers mdat: https://mega.nz/file/5stk1Z7I#OWIR4HuH8 ... 0aSscH-gzY To my -untrained- eye the installation seems successful. By looking the RT comparison alone we can see that the rt has reduced to half, even in the very low frequencies below 80hz. Spectrograms are another fun graphs to watch: all that spikes below 400hz are greatly damped, even that 45hz monster. One can notice that in the hangers version that mode has shifted to 42hz, because travelling in insulation the speed of sound is reduced and it takes more time to make that 60cm to the wall, so it "thinks" is a bigger room. The rest of the spectrum is nicely ironed as well. Same applies to the waterfalls: all those long modal "legs" in time are beautifully shortened with that 89hz almost disappeared, something visible in the frequency response also. Would using homasote or fibreboard produce better results? Who knows ? What are your comments? Next step, door treatment and HVAC! Dio

looks great! yeah, you might see some difference with a lower density panel but the results are promising.

Thanks Glenn! Hangers definitively are effective. For comparison see a triple graph below: baseline-wall insulation without the hangers-final construction. It is clear that the hangers do their job below 150hz By seeing the effect the deep speakerwall slot resonators had in this built http://johnlsayers.com/phpBB2/viewtopic ... &start=150 I am convinced to take the same route: to tame this 42hz monster. Acoustic modelling gives this prediction (from-to) for my tight soffit dimensions: Since I won’t have a large desk (the one showing is temporary), back reflections from it will not be a problem I believe.. Dio

Happy New Year y'all. Watching Dio, keep up the great work.

Thanks DanDan! It's nice to hear encouraging words! Dio

Looking great! Any updates? What width are each of the rear hangars? and what depth is the total rear frame?

Thanks Mattsal, Things have slow down a little construction wise, the truth is... the hangers core varies from 210x15 to 210x62 (in centimetres) the on-hanger insulation is 4,5cm but is a bit fluffy and in reality is 5-6cm per side.The on-wall insulation is said to be 9cm but is over 11, respectively. The total depth of the frame is 60cm. dio

Minor Sunday update: finished the absorptive door with 20cm of Knauf Ultracoustic insulation (≥5000 kPa.s/m²) and now (keeping in mind that the door does not isolate perfectly) the back wall is considered as an acoustic "black hole" . mdat: https://mega.nz/file/Rk1UXJqT#9vP9Q4Vwy ... mQIZ0utRSY Screenshots: As expected there are only minor changes, mostly visible in the reflections diagram (ir). Here is the comparison between the previous situation (hangers only) and the added door insulation. Some strange behaviour in the mids I believe is from the various stuff that is still in the room and should be ignored: Not big differences but certainly listenable. Music is more "focused" and clean now, details have appeared even in very low volumes, and high volumes are now tolerable.. And now two questions: 1) Planning the final layout many different configurations have passed though my sketchup and I ended up that the safest one for my limited space is with absorbent reflection points (30cm insulation) and full absorbent ceiling (30cm insulation), see previous post. I keep reading that insulation alone will not suppress the early reflections enough end the proper way is to redirect them, something that I am unsure if I can accomplish in this room. Will I gain anything noticeable if I embed hard reflective surfaces inside the insulation on the reflection points? 2) Seeking a way to tame the 42hz standing wave I am planning on using slot resonators in the above and below soffit sections. An also ideal place for a low tuned resonator seems to be the outer part of the soffit: will the resonator be effective being so close to the side wall insulation? How big the gap has to be? Are there other options? Thanks, Dio

it's LF (42hz) so the proximity of the side wall to the resonator shouldn't be a problem.

Thanks Glenn, actually the gap I was wondering about is this: If the insulation being so close to the resonator makes it less effective. dio

i don't think it will be a problem :)

Time has passed and things have moved forward a bit. The man with the drill came and made three really beautifull holes on the wall, where the hvac ducts, cabling etc passed through. Then, I made the "on-wall" silencer and connected the fan. Being aware of the Murphy's laws I made the silencer internals visitable. Playing loud music (~95dbC) inside the room corresponds to about 56-57dbC at 1m from the silencer. I wouldn't call it bad performance for a start. After done with that it was time to begin the soffit construction. Being tight in space and incorporating bass traps the soffits have a little strange shape but being bolted on the stonewall are rigid enough .. And finally time to fit the speakers in! It is allready a really tight fit, but I am thinking of additionally screwing them in the frame to turn it into one mass. Testing with loud tones didn't reveal any rattling or resonances from the (still unfinished) construction, which is good, of course. Coming up next: side soffit slot aborbers! Thanks for viewing, Dio

nice work Dio!

It's Sunday and it's time for another update! The part the fun begins! Having finished the soffit frame and put the speakers in,I removed the office desk and took a measurement: Mdat: https://mega.nz/file/I4tgSDLB#aiWCNF-eg ... wikcX7_efs It seems that this office desk was a big problem for this small room, good I got rid of it... but what are these peaks? Something resonating? Been in a hurry to continue working I decided to investigate later. So I proceeded with stuffing the soffits and took another measurement. Mdat: https://mega.nz/file/cp0wFbhK#ruX93jDiw ... NVHtJ_nCPE Now things are slowly becoming nicer, but these 100 and 200hz things still exist... let's move on and build the side slot resonators and we will find out later. Mdat: https://mega.nz/file/okkwyZbI#X9H2R8rOT ... 9Bb-TPlpmE Now, these resonators are tuned to 80-110hz, so they are doing their job on damping that 97hz resonance but that 200+ thing is still standing there proud... so with the old and tried method of playing the resonating tone and with the help of our friend "the mute button" the culprit revealed: it is the heater radiator! To verify I took another measurement. The results on the following post. Dio

So, the next two screenshots are with me in the room holding (and damping) that radiator, the images are self-explanatory, the 200hz resonance is gone! After finished with this it's time for the lower soffit slot resonators, the ones I had big expectations with. Mdat: https://mega.nz/file/BgdyUBDI#cCm2pWXh4 ... qTw6bTP8sM To be honest in the beginning I was expecting a little more from them in the 42hz issue since the calculator gives o 0,7 coefficient in this region. Then I realised that only two out of ten slots have the cavity depth to absorb this frequency so I sat back and admired the rest of the performance. First and most impressive is the total disappearance of the 200hz radiator resonance!! Unbelievable. Then the rest of the spectrum <300hz has also been tamed very well at around 200ms, not bad. That bump in the 600-900 hz in the RT I don't know where it came from, could be something from the stuff the still exist in the room. Anyway, now it's time to finish the soffits with a 30mm thick MDF baffle. Mdat: https://mega.nz/file/0kNCSDDb#NA9u9S4yL ... fsWQDJFafI We see the lows have gained a few decibels from the baffle, we also see that the 42hz mode has shifted to 43hz since the room is now a little smaller. The rt60 is a little smoother also, but the cancelations in the 100-130hz region have been increased. Next move is to built the upper soffit slot resonators, and I haven't yet decide if I should make a copy of the lower ones or if I should try to tune them as low in frequency as I can to hunt the lowest mode. What would you do? The nicer of all is that the listening experience in the room has dramatically changed. Every tiny detail is revealed and the technical aspects in recordings are easily observed.I defenetely feel that I am moving to the right direction, Thanks, Dio

you can easily EQ the 43hz - it's nulls you cannot EQ :-) looking good!