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dmlandrum

Help with room acoustics
« on: November 25, 2016, 09:44:52 PM »
If this isn't the correct forum for this, please feel free to move it.

I just bought a house, a 1930 vintage two-story with an unfinished basement. My studio only needs to be one room, just enough to be able to mix in, and record vocals and occasional samples (everything else is either hardware synths or plugins). Finishing the basement is out due to expense, so that's going to become a wood/metalworking shop.

My original plan was to use one of the bedrooms. It's a decent size, but there's an issue: it's square. 10'4" by 10'5" (by 8' tall), to be more precise. Now, bass-trapping the crap out of it is an option, and rockwool is readily available where I live.

The remaining option is to use the first floor, and basically kit out the dining and living rooms (which kinda merge together). However, it also merges with the kitchen (the three rooms together are all kinda one L-shaped space), where I can't exactly hang traps.

Honestly, I'd like to use the bedroom, as it's a quieter space and I can seal it up even more. So my question to all of you is: is there anything I can  do to whip this room into shape? Searching around the web has been getting me a range of answers all the way from "don't bother" to "just bass-trap the hell out of it."

I can provide more details and pictures/video of the options if necessary. Thank you!
Darren Landrum

Be comforted that in the face of all aridity and disillusionment
And despite the changing fortunes of time,
There is always a big future in computer maintenance.


fazer

Re: Help with room acoustics
« Reply #1 on: November 26, 2016, 12:30:09 PM »
Its going to be very modal in dimensions.   Also size is small so not a lot of room for treatment.   Alton Everest has info on panel traps  that can be very narrow compared to a full quarter length bass trap. This might be more of a headphone room.   It will  still have resonance for vocal and acoustic instruments.  If you do electronic loop/midi stuff it may not matter much.  You can record in one of your bigger rooms with a iPad for a controller with a long microphone cable.   

JohnRoberts

Re: Help with room acoustics
« Reply #2 on: November 26, 2016, 01:09:20 PM »
Ethan Winer (a different Ethan) has written a lot about acoustic room treatments and sells bass traps (I think). The info is free...

http://ethanwiner.com/basstrap.html

JR

John Roberts
http://circularscience.com
Tune it, or don't play it...

john12ax7

Re: Help with room acoustics
« Reply #3 on: November 26, 2016, 06:15:15 PM »
I would first try speakers in there at various poisons and measure to see where you are at. Another option is to sweep some sine waves and listen, you will get an idea of how bad the peaks and valleys are.

It will have issues but it doesn't mean it's unusable. I had a room that was 11x12x8 that worked ok. You will need to do a decent amount of treatment though.

Another useful tool is room eq wizard. Both for testing and simulation. The simulator will give you a decent idea of where you are at and what you need to do.

Things will also depend on the music you do. It will be hard to get accurate bass, but for singer songwriter type stuff is less of an issue.

gato

Re: Help with room acoustics
« Reply #4 on: November 26, 2016, 08:17:23 PM »
What are the walls made of?

dmlandrum

Re: Help with room acoustics
« Reply #5 on: November 26, 2016, 10:43:47 PM »
The walls are all lath and plaster. Like I said, old house.  :)

I'm not going to be recording any drum sets, just vocals and the occasional samples, which honestly I can do elsewhere with the portable setup. Everything else is all in the wire.

The issue is getting the room to not affect mixing, or at least not too much. The other issue is, I have to decide in the next day or so what I'm going to do.

Thank you all for the help!
Darren Landrum

Be comforted that in the face of all aridity and disillusionment
And despite the changing fortunes of time,
There is always a big future in computer maintenance.

abbey road d enfer

Re: Help with room acoustics
« Reply #6 on: November 27, 2016, 08:58:34 AM »
If this isn't the correct forum for this, please feel free to move it.

I just bought a house, a 1930 vintage two-story with an unfinished basement. My studio only needs to be one room, just enough to be able to mix in, and record vocals and occasional samples (everything else is either hardware synths or plugins). Finishing the basement is out due to expense, so that's going to become a wood/metalworking shop.

My original plan was to use one of the bedrooms. It's a decent size, but there's an issue: it's square. 10'4" by 10'5" (by 8' tall), to be more precise. Now, bass-trapping the crap out of it is an option, and rockwool is readily available where I live.

The remaining option is to use the first floor, and basically kit out the dining and living rooms (which kinda merge together). However, it also merges with the kitchen (the three rooms together are all kinda one L-shaped space), where I can't exactly hang traps.

Honestly, I'd like to use the bedroom, as it's a quieter space and I can seal it up even more. So my question to all of you is: is there anything I can  do to whip this room into shape? Searching around the web has been getting me a range of answers all the way from "don't bother" to "just bass-trap the hell out of it."

I can provide more details and pictures/video of the options if necessary. Thank you!
You would probably get more benefits by making the two lateral walls not parallel than by trapping the hell out of it. You would need some traps, and probably some EQ; I know it's not fashionable with purists, but do you care?
Who's right or wrong is irrelevant. What matters is what's right or wrong.
"The important thing is not to convince, but to give pause for thought." (B. Werber)
Star ground is for electricians.

DerEber

Re: Help with room acoustics
« Reply #7 on: November 27, 2016, 11:13:05 AM »
One of the nicest rooms I used to work is square.
But it's treated all over.

joaquins

Re: Help with room acoustics
« Reply #8 on: November 28, 2016, 08:22:05 PM »
  Small rooms are harder to work with, but also cheaper as you can fit just so many treatment inside.

  Would be hard to get a good "natural" sound out of it, so you probably will need some EQ. Mainly to attenuate the LF SBIR (speaker boundary interference response, google it if you haven't!). For this kind of rooms (and almost any) you will be looking for the smallest DIPs you can get from your speaker placement, and then attenuate electronically the peaks. It's important to make the difference between SBIR peaks and room resonance, as room resonance can't be EQ'ed out, but in a transfer response would look similar. Waterfall plots are your friend, room eq wizard could be a useful tool. For HF add diffusion and absorption as desired.

  Choose a room orientation so it's as symmetrical as it can be between the speakers and the engineer, the door in the back side for instance, see what you can do with the window, etc.

  As you already have the room at disposal  I'd skip initial simulations, my steps here would be measure the room in 2 ways, one just to find the room response, one speaker in the corner, mic in the potential listener position or something like that. That would show the main resonance problems to be treated, gives you an idea of the traps you'll need, as well as HF properties, RT10, RT60 could give an idea of how much diffusion and absorption you'll need, for each frequency band. That's all about the room it self and gives an idea of what you are working with, save it as a reference, general idea of the starting point.

  Then find the best position for the monitors as I said with the smallest dips (some soft tool is useful here), eq the peaks out, run a waterfall again and look for the long lasting regions. Start trapping them out, once you are getting to it with the LF time response, add the general treatment (abs and diff). Keep measuring each stage so you know what each thing does, tune the traps as needed at the end. Fake walls and traps are part of the same thing, tuned membrane for instance could be doing both tasks at the same time. If you are building fake walls use that missed volume for traps, in some way or another. Don't build a wall and then start treating the smaller room from scratch as you will be loosing ton's of volume you don't have to spare.

JS
If I don't know how it works, I prefer don't turn it on.

ln76d

Re: Help with room acoustics
« Reply #9 on: November 29, 2016, 06:56:54 AM »
My drum room is only 20m2.
Rectangular 4x5.
Also old building, acoustic pretty not bad in an empty room.
I used regips and rockwool to reshape room.  There's no parallel walls as also one corner  is filled and remodeled (green on the pic).
It don't have to be huge angle.
For now it works pretty good, there's improvement (regips as also wool have their own great properties) it's of course unfinished. Drums sounds great.
I will make measurements after finishing whole studio.
Really great material is wood wool :D
I'll be using  it in whole studio, especially in control room.
http://www.knaufinsulation.com/en/heraklith
I have few other ideas for absorption, distraction etc.
After using it i'll e able to say something more.

Btw.  rockwool need to be high density, am using 50kg/m3, but i have few layers of it.
If there would be need to use for example only one layer of 10cm thick, then i would go for 80kg/m3.
« Last Edit: November 29, 2016, 07:36:54 AM by ln76d »


gato

Re: Help with room acoustics
« Reply #10 on: November 29, 2016, 07:17:32 AM »
I would like to add that wood wool is very helpful. I think most of the lowest lows will go through the walls of your existing construction, and C-40 mounted wood wool (with fiberglass/rockwool behind) will help with the rest.

abbey road d enfer

Re: Help with room acoustics
« Reply #11 on: November 29, 2016, 07:40:34 AM »
My drum room is only 20m2.
Rectangular 4x5.
Also old building, acoustic pretty not bad in an empty room.
I used regips and rockwool to reshape room.  There's no parallel walls as also one corner  is filled and remodeled (green on the pic).
It don't have to be huge angle.
For now it works pretty good, there's improvement (regips as also wool have their own great properties) it's of course unfinished. Drums sounds great.
I will make measurements after finishing whole studio.
Really great material is wood wool :D
I'll be using  it in whole studio, especially in control room.
http://www.knaufinsulation.com/en/heraklith
I have few other ideas for absorption, distraction etc.
After using it i'll e able to say something more.

Btw.  rockwool need to be high density, am using 50kg/m3, but i have few layers of it.
If there would be need to use for example only one layer of 10cm thick, then i would go for 80kg/m3.
When you think of the volume taken by rockwool (in order to be effective, you need at least 20cm (8"), for a total volume of about 3 cubic meters, you may see a strong case for using less rockwool and using some a the volume for building Helmoltz resonators. That's what I've done in my control room, where the absorbent is 70mm polyurethane foam on the walls and 50mm Basotect foam on the walls. From the measurements, I think this takes care of most of the issues above 500 Hz.
I've built 3 Helmoltz resonators that take a total volume of 1 cubic meter. They are tuned to the primary measured eigenmodes. I found I had to apply very little EQ to sort out the remaining issues (using the Room Mode Correction that comes with the JBL 4326). Helmholtz resonators can be built in the form of a desk, on which one can put tape recorders, effects, keyboards... or a bench where you can put your girlfriend or a client,  ;Dso they would not be too obtrusive.
Since it's a small room (4x3x2.5m), the "sweet spot" is quite small, though.
Who's right or wrong is irrelevant. What matters is what's right or wrong.
"The important thing is not to convince, but to give pause for thought." (B. Werber)
Star ground is for electricians.

ln76d

Re: Help with room acoustics
« Reply #12 on: November 29, 2016, 10:33:49 AM »
When you think of the volume taken by rockwool (in order to be effective, you need at least 20cm (8"), for a total volume of about 3 cubic meters, you may see a strong case for using less rockwool and using some a the volume for building Helmoltz resonators. That's what I've done in my control room, where the absorbent is 70mm polyurethane foam on the walls and 50mm Basotect foam on the walls. From the measurements, I think this takes care of most of the issues above 500 Hz.
I've built 3 Helmoltz resonators that take a total volume of 1 cubic meter. They are tuned to the primary measured eigenmodes. I found I had to apply very little EQ to sort out the remaining issues (using the Room Mode Correction that comes with the JBL 4326). Helmholtz resonators can be built in the form of a desk, on which one can put tape recorders, effects, keyboards... or a bench where you can put your girlfriend or a client,  ;Dso they would not be too obtrusive.
Since it's a small room (4x3x2.5m), the "sweet spot" is quite small, though.

Biggest wall, marked red, is filled from 20cm (from the floor) to 40cm.
Blue goes in different angle, is filled from 7cm to 50cm. Corner from 20cm to 50cm.
Yes, helmholtz resonators are another option ;)

emrr

Re: Help with room acoustics
« Reply #13 on: November 29, 2016, 10:44:33 AM »
You've probably already looked here, but if not:

http://www.johnlsayers.com/phpBB2/index.php

Best,

Doug Williams
Electromagnetic Radiation Recorders

"I think this can be better. Some kind of control that's intuitive, not complicated like a single knob" - Crusty

"Back when everything sounded g

Whoops

Re: Help with room acoustics
« Reply #14 on: January 08, 2017, 12:34:16 PM »
I highly recommend you read this book also:

Philip Newell - Project Studios: A more professional approach
https://www.amazon.com/Project-Studios-more-professional-approach/dp/0240515730