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Discussion Starter · #1 ·
Hi everyone,

I am in the process of building a listening environment in my basement, which in time (I hope) will evolve into being both a place where I can mix/master tracks, and perhaps also record with a decent quality.

I will probably need to do this in a two-step process though, as recording with reasonable quality would require me to build a "room-in-room" to do this in a professional manner.

So far I have completed the roof, with double "hanging plaster" soundproofing and also double plaster walls. (Not sure about the translations here, help me out if it's called something else in English.) :) The walls are concrete behind the plaster, but with insulation layers inside the concrete. So far so good.

Now for the real challenge. The room is "L" shaped. Not much I can do about this, I am afraid. The plan in the long run is to build the "room-in-room" in the short end of the "L", making a square recording booth in the end, and a mastering/listening space in the long shape. But for now, I am looking for advice in avoiding the effects of the unsymmetrical shape of the room for listening, as well as a good place for purchasing materials to put on the ceiling to "crush" the echoes/reflections.

I have been surfing for a couple of days, but it seems to me a lot of the foam types I could put on the roof are very expensive, I am not sure I need the sound dampening many materials offer, given I have the type of ceiling I have. I think the main thing is having a shape on the material that will "crush" the sound waves and minimize reflections. Any tips on where to buy materials like this, and what to choose from?

I have narrowed it down to two types of approaches (or both). 1. Pyramid shaped foam to make the ceiling reflect less. 2. Make sound absorbers from wood frames and Rockwool to try to stop the reflections from going into the "long end" and creating unwanted echoes.

I realize of course that the reflections will change a lot when I get the control desk and instruments/equipment into the room, but right now I have the possibility to do things before the construction of the room is finished, and since I am doing the painting/extra insulation right now, it seems as the right time in the process to start gathering advice. I can post drawings also if this is needed/wanted.

I have seen a lot of sellers on eBay which offer different foam types, but some are surprisingly cheap, which always makes me weary even if it's tempting.

Any takers? :)

My first post, BTW, hi all!

Best regards,
John Magnus.
 

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Hello John, I don't know how recent your post is but here goes...

Regarding the 'room-in-a-room' step - do you really need this? Is isolation from the outside world a problem or do you have sound leakage from your basement? I agree that this is the ideal for recording studios but it is expensive and takes up space. What are the actual dimensions of your room?

As far as acoustic treatment is concerned, we strongly recommend Jocavi/ATp (www.jocavi.net) and Scenic Textiles (www.scenic.cat) if you want ready-made materials - otherwise, you can go homegrown.

Best regards, Terry Nelson
 

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In my opinion, foam is a waste of time and money. Better performance can be had for the same or less money using a product with a fiberglass or mineral wool core of sufficient thickness.

The products referenced from what I can see basically ignore the mid and lower frequencies. Reference the graph on this page to see what I mean.

http://www.scenic.cat/panels_eng.html
 

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These are two manufacturers that make excellent products that we have used for screening rooms, Home Cinemas and recording studios - plus theatres. The Scenic panels are mainly for upper mids and highs - apart from the "Silent Panels" that have good midrange response.

It is obvious that any acoustical treatment has to address the full range situation - particularly for a professional environment - but economics and aesthetics also play an important role.

TN
 

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I don't doubt that they make excellent products for what they are. I just see no use in any sort of studio room for anything that rolls off completely by 800Hz.
 

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You mean you don't combine materials for a studio project? Well, each to his own. Swiss Television were very happy with their screening room that we did...also using other products for diffusion/absorption, etc. etc.
 

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Absolutely we do mix different absorbers, some partial absorber/scattering, and diffusion pending what the room needs. I just don't tend to use anything in terms of absorption that doesn't at least cover male voice on the bottom end.

There is a limit in terms of how much upper mid and high frequency absorption I want in the room and don't want to waste any of that on things that don't also address a lot more of the range. That's a good way to get a dead room where the bass is still out of control.

Bryan
 

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Discussion Starter · #8 ·
Hi guys,

Thank you for your quick responses! So far, since the room is not filled with equipment, I have not started to worry directly about the frequencies, but since the room has the shape it has, my first concerns are the reflections, which I reckon will have different values left/right since the "L"-room is not symmetrical. I have drafted a sketch over the room with internal measurements which should highlight the problem. I have used the room for rehearsals with our band as well as fired up the monitors, but since my control desk is not in place and the room is empty, my experiences will not be accurate. (Lots of flutter and peaks above mid-range, as well as low bass response from my bass guitar)

As you can see from the sketch, I have picked two possible placements for the desk/monitors, and each of them will most likely present their own problem areas. Placement "A" is the most practical in terms of setting up my equipment, but I have started to think about choosing placement "B" in stead, since it might give me less trouble getting the room to sound OK. This also seems to be the best listening position in the room when it is empty.

My calculations so far (which are amateur at best) shows I should at least worry about standing waves around multiples of 69-70 hz for position "A", but this might be a wider bandwidth problem should I choose placement "B".

I have mounted "Cable Gates" (again, not sure of the exact English word here, but it is the white kind of plastic rails used in office buildings and studios for power and Ethernet connections) from the wall which is left on the drawing and all around to and including the 1140 mm long wall, which now includes power, network and audio cables for easy hookup of equipment, and was planning to connect a lot of the equipment directly to the desk from there, but I can fix this by mounting another gate along part of the bottom wall.

The reason for this gate is that I have a separate room on the right side of the 1390 mm and 1140 mm wall which will act as a "technical room", for noisy equipment like computers, disks, etc.

The control desk is over 120 kilograms without any equipment though, so once I get it in position, it will be a real job moving it again, which is why I want to get it right the first time. If I choose placement "B" it will take up a lot more mid-room space, and I need the space I can get, since the room is rather small for a studio.

What worries me the most is if I choose placement "A", I might get strange reflections from the bottom right side of the room, and if I choose placement "B", the left/right reflections will be different, due to the asymmetrical "L" shape.

When it comes to absorbers and panels, I think I will build most of these myself, since I can wield a saw fairly well (still have my fingers, anyway), but was thinking about sticking some foam type squares in the roof, since it is a "bracket mounted hanging plaster" roof, it cannot support too much weight.

So, which would you recommend; A or B? And should I worry about the roof at all before mounting equipment?

Please, feel free to download and sketch ideas on the uploaded file. :) For me this is the time to make changes to the plan, since the room is in this phase, so any and all input is deeply appreciated! (Especially so I don't have to make stupid mistakes early on, or waste precious time) :)

Best regards,
John Magnus

PS. The reason for wanting to build a room-in-room in the top part of the "L" at a later time, is to be able to record in it, while monitoring outside of the room. Nothing more. The room itself bleeds very little sound both outwards and inwards at this time. Also, I have a ventilation system in the house which sends heated fresh air into the studio, and the sound of the air flowing into the room is making some noise which I want to avoid by doing this, so I don't have to shut down the ventilation system when we do vocal takes.

 

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A is more predictable but B gives your walls helping push reflections back toward the rear of the room and most likely actually more symmetry, at least in what woudl be the front 1/3 of the space. Really just a trade off so work with what's better for usability and ability to treat.

While it does take some time, it would be worth your while to experiment with both setups and see what you feel the better starting point is. Very tough to make this call purely from a picture without listening. I've seen both work well and both work badly.
 

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Hello John,

Give me an e-mail address and I will send you some photos of what we did for a DJ/musician (yes, they do exist!!) who had real problems with his half-basement studio and was in a similar type of situation as you are.

OK, the room was more or less just a rectangle with a 200 cm ceiling but he was only using about half of it for the control room/mix area. All hard surfaces, of course, and a very noticeable bass hump that made mixes very inaccurate.

As always, budget was a problem but he ended up a happy bunny :)

Coming back to some of your questions, I would tend to go with Solution A, having had to work with similar situations on the past. You are basically in a nearfield monitoring situation so getting the space around you to give a decent response is the most vital.

However, at the end of the day, it is what works best for you as a working environment. Compromises will be inevitable!

Not too sure of your reasoning behind a 'room-in-a-room' with regards to aircon (or air exchange): is too high an air velocity the problem? In this case, you will either have to reduce the flow rate or turn it off. However, you do not want the girl singer to pass out during vocal takes :)

The problem with airflow is that we do not hear it (or more correctly, the brain discards it) but the microphone does, and therein lies the problem.

If isolation is not an issue with your room, it seems to me over the top to go in this direction. However, a float floor is always useful. As a by-the-by, is the ceiling height the bare ceiling or with the suspended grid in place? There are ready-made acoustic elements that will drop into a ceiling frame and you could consider a mixture of absorption and diffusion.

The combined control room/studio is not a new approach but it can work well with good planning and thinking about what it is that you want to do. If George Massenburg can do it...

Cheers, TN
 
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