Topic: Acoustic treatments for “Mastering Room”?

[down2earthlandscaper]

So I have an extra private office that’s not being used. I thought it might make a good “mastering room”.
I was looking into sound deadening methods to keep the sound in the room, and acoustic treatments for the walls to reduce reflections, etc.
I found this product (and many others like it) on amazon.
https://smile.amazon.com/JBER-Acoustic-Soundproofing-Resistant-Treatment/dp/B08R3J6XZG
Is something like this necessary? I imagine it’s more for a recording studio/isolation booth, but can anyone see any benefit to having a room such as this for mastering recordings (or any other reason to do this other than Covid Boredom??)

[voltronic]

It is hard to say if something like this is "necessary" without being in your physical space.  Do you have a set of high-quality monitor speakers, correctly positioned? If not, then doing this is not worth it.

Acoustic treatments for mixing / mastering rooms can do a number of things, depending on how sophisticated you want to get. One of the simplest things is dampening early reflections in the treble bouncing off nearly surfaces, and reducing standing waves in the bass.

You might want to go through a test tone program and listen carefully for anything that is excessively tubby in the bass, or extremely harsh in the treble (this is assuming those problems aren't coming from deficiencies in your monitors). When you find a problem area, take note of that frequency for something that needs addressing.

I wouldn't buy those panels from Amazon. I do have direct experience with the Markerfoam acoustic treatments, and recommend them. They may not be the prettiest, but they work very well and are priced far below the big name brands. Keep in mind that the thinnest panels will only absorb high treble frequencies. Go thicker if you need to absorb lower in frequency.

I like the Blade Tiles and the corner Bass Traps especially. The big 54x54 panels are very effective also, but might be more than what you need. Some blade tiles arranged in a checkerboard pattern usually do a decent job of taming enough reflections.

https://www.markertek.com/brand/markerfoam-noise-control

[Gutbucket]

Volt posted above while I was typing with much of the same recommendations, so apologies for any redundancies below..

Keeping the music in the room and external sound out is "isolation", which is different and more difficult than "treatment" of the room intended to improve listening acoustics within it.

Isolation-
Close it up tight as you can which helps at low mid through higher frequencies, as any air gaps represent a path defeating isolation.  Not much you can do to isolate (or treat) low frequencies.

Treatment-
Try multiple options to find the best arrangement of speakers and listening position and then work from that as starting point.  Arrange everything else around that.  Just like recording, position is number one. The most effective "treatment" is reducing the influence of the room as much as possible by using an arrangement with the speakers placed well away from the walls and a relatively close "near-field" listening position to them.

A clean stark room with nothing in it looks nice but is unlikely to behave well acoustically.  Lots of cushy furniture, storage shelving, and other stuff of life in the room is all good.  Don't worry about clutter, that's good diffusion. Keep as much furniture and bookshelves and stuff in there as you can.

Some stereo test signals are useful.  Send mono pink noise sent to both speakers and arrange things to achieve a tight cohesive mono image between the speakers.

[edit- all the stuff above is fundamental and costs nothing.  It will improve the performance of whatever playback gear you are using.  The limit beyond this is likely to be defined by the quality of your monitors]

Before you go out and buy foam or anything else, play around with thick couch cushions, mattresses, thick layered blankets, thick rugs stuff like that if you wish to experiment with reducing reflections.  Anything you put on the walls to absorb reflections really needs to be sufficiently thick to work effectively.  The one inch thick foam stuff is only effective at high frequencies, it needs to be more like 3" or 4" thick.  Anything absorbent will be more effective if you mount or hang it off the wall with an air gap behind it.  If the room needs to be normal looking, you might hang a few carpets, or put 2"-3" foam on the backside of large paintings or wall hangings and mount them off the wall with an air gap behind them.

If you are serious about it, make room response measurements along the way and use that to guide you.  That's an entire discussion in itself.

[edit- Use good monitors that you can trust, such that your recordings translate well to other systems outside your own room.  This is probably where any money is best spent.]

[Justy Gyee]

any recommendations for a surface mount ceiling tile options for noise isolation treatments?
have a full basement that id like to keep the sounds inside of.
did some quick research online, but wondering about first hand experiences.

[Gutbucket]

As mentioned previously, isolation is more challenging than acoustic treatment.

If the goal is reducing the nuisance level of level of sound escaping the room the two key factors are the air-tightness and mass of the boundary (the ceiling in this case).  If its an unfinished basement ceiling with exposed joists, sheet-rocking the ceiling is likely to be a somewhat effective option.  But if making that effort make sure there is not an easy path around that massy, air-tight boundary, like the walls or door at the top of the staircase or whatever.

I was involved in building demo rooms for a regional stereo retail chain many years ago.  It was cost driven and the primary concern was increased isolation, not treatment.  Those rooms featured a double layer of sheet rock on all walls and ceiling to increase the mass of the boundaries, and a heavy double pane glass door with a tight seal.  There was no specific acoustic treatment installed in those rooms other than furniture, carpet with thicker padding, and the equipment racks and lots of speakers. I think they later installed some diffuser panels on the walls, probably because that imparted a "serious audio" vibe as much as improving things acoustically, although it likely provided a bit of both.

[Gutbucket]

We also made some effort to seal up wall fixtures such as power outlets and cable accesses so they did not provide an "air leak" path for sound leakage through the walls.

[Gutbucket]

Another isolation thing and the easiest one to do- support the speakers on some sort of compliant base rather than rigidly coupling them to the floor.  This reduces direct-path transmission through the floor to other parts of the building, which can be significant with wooden floors.  May not make much difference if any on a concrete floor.

[rocksuitcase]

We also made some effort to seal up wall fixtures such as power outlets and cable accesses so they did not provide an "air leak" path for sound leakage through the walls.

When designing studios (or from my job, installing them), one thing great architects did was offset outlets from each side of the walls. IOW, typical residential construction will place an outlet on opposite sides of wall in the same orientation from side walls, corners or the floor. This is for ease of electricians running the wiring. In studios, they would never do this, making sure if walls were shared, the outlet holes were at least 2 feet apart.

[kindms]

any recommendations for a surface mount ceiling tile options for noise isolation treatments?
have a full basement that id like to keep the sounds inside of.
did some quick research online, but wondering about first hand experiences.

Ive done some renovations around the house. I really like the rockwol insulation. I dramatically cuts noise, its got a great fire and R rating.

So if you happen to be going in to or opening walls might be a good choice to consider. Its not prohibitively expensive and easy to install. You cut it with a bread knife

[live2496]

I can give you some general advice which will improve most untreated rooms.
I am not an acoustician but I have tried a few of these things to improve my own room for mastering.
The idea is to get as much direct sound from the speakers as you can and little to no first reflections from the walls and ceiling.
Near field monitoring is helpful.
One of the better things for this is Owens Corning dense insulation available in 2 ft x 4 ft panels OC702, OC703 and OC705.
Placing them right on the wall at first reflection points is effective but also they are more effective if you leave an air gap between the panel and the wall.
You could also place a panel overhead to catch first reflections off of the ceiling.
You can also make bass traps of the same type of material and place them in corners. This really helps absorb excess energy.
I opted to use rolls of fiberglass insulation and they seem to smooth the room out a lot.
In recent years someone has developed a recycled blue jean product to absorb sound. This is worth looking into.

[voltronic]

I can give you some general advice which will improve most untreated rooms.
I am not an acoustician but I have tried a few of these things to improve my own room for mastering.
The idea is to get as much direct sound from the speakers as you can and little to no first reflections from the walls and ceiling.
Near field monitoring is helpful.
One of the better things for this is Owens Corning dense insulation available in 2 ft x 4 ft panels OC702, OC703 and OC705.
Placing them right on the wall at first reflection points is effective but also they are more effective if you leave an air gap between the panel and the wall.
You could also place a panel overhead to catch first reflections off of the ceiling.
You can also make bass traps of the same type of material and place them in corners. This really helps absorb excess energy.
I opted to use rolls of fiberglass insulation and they seem to smooth the room out a lot.
In recent years someone has developed a recycled blue jean product to absorb sound. This is worth looking into.

I wouldn't have thought to use those Owens Corning panels for bass traps. Looking up the data on them, they don't seem to do much below 250 Hz compared to purpose-built bass traps unless you get the 4 inch versions, but you can't beat the price.
700 Series Data Sheet (PDF)

https://www.acoustimac.com/catalogsearch/result/?q=owens+corning

[Gutbucket]

4" is the sweet spot for more balanced absorption, especially with some airspace behind.  That thickness also work well for free standing gobo absorbers which can be moved into position in use and out of the way afterward.  They can be placed between the speakers and reflection points, angled away from the listening position.

Easy route to bass trapping if appearance doesn't matter is to stack rolls of fiberglass insulation in the corners.  Just leave them in the packaging and stack them up from floor to ceiling.  Can wrap in burlap directly over the plastic packaging so as to not look like an insulation warehouse.

[live2496]

I have seen bass traps made of the Owens Corning panels cut into a triangular shape, stacked and then placed in corners. With some type of frame to hold it all together.

Gordon

[rocksuitcase]

From this thread: https://www.gearslutz.com/board/studio-building-acoustics/1141401-diy-bass-traps-work.html
I found this material which I would say is great as does the designer Glen:
https://www.gikacoustics.com/product/knauf-rigid-fiberglass-3-lb/

[ero3030]

Setting up your speakers properly for imaging is the most important step IMO( and easy )  Unless u live in a empty box, too much reflection shouldn't b a huge problem for most.   I'm a 2 channel stereo guy, but from most of the reading I've done over the years on here I feel the younger guys/gals r only headphone users??? Anyway, reflection and adsorption is pretty easy to do for most listening rooms.  Ed

[wforwumbo]

Certified PhD in architectural acoustics here, and I’ve been a mix engineer for half of my life.

I’m gonna echo everything Gutbucket says. You gotta seal up the space and add as much mass as you possibly can. Box-in-box construction is standard for many high end studios, and box-spring-box systems offer the best isolation IMO, though it’s obviously gratuitously expensive.

Owens Corning 703 is a standard. It ain’t cheap but it is effective when placed correctly. Personally since my grad school days I have taken medium to heavy weight blankets and cover them with boho shawls for building acoustical absorbers - much cheaper and aesthetically more in tune with my hippie sensibilities, and gets you most of the way there. Building the frame to be rigid and sturdy will be the biggest challenge. Air gaps can help, but only to an extent - they serve to “trap” waves with a 1/4 wavelength shorter than the distance between the wall and absorber, and keep in mind it’s still possible for sound to diffract around materials if you’re not careful in your construction.

My usual advice to people is, focus on making a good room better rather than trying to fix a bad room. The same philosophy carries over to mixing and mastering but that’s another conversation for another day. I get convenience is a thing, but trust me your basement will become a time, energy, and money pit if you try and wrangle it in to do what you want when that’s not what it wants to do. Reflections are not always the enemy, so don’t focus on making your room a sealed dead box if that’s not what it wants to do. Listen to the space telling you what it wants to do, and if it’s at a baseline “acceptable” sound then work to bring out the best in it; if it isn’t, I suggest you spend your efforts finding a good room to mix and master in.

[voltronic]

Certified PhD in architectural acoustics here, and I’ve been a mix engineer for half of my life.

I’m gonna echo everything Gutbucket says. You gotta seal up the space and add as much mass as you possibly can. Box-in-box construction is standard for many high end studios, and box-spring-box systems offer the best isolation IMO, though it’s obviously gratuitously expensive.

Owens Corning 703 is a standard. It ain’t cheap but it is effective when placed correctly. Personally since my grad school days I have taken medium to heavy weight blankets and cover them with boho shawls for building acoustical absorbers - much cheaper and aesthetically more in tune with my hippie sensibilities, and gets you most of the way there. Building the frame to be rigid and sturdy will be the biggest challenge. Air gaps can help, but only to an extent - they serve to “trap” waves with a 1/4 wavelength shorter than the distance between the wall and absorber, and keep in mind it’s still possible for sound to diffract around materials if you’re not careful in your construction.

My usual advice to people is, focus on making a good room better rather than trying to fix a bad room. The same philosophy carries over to mixing and mastering but that’s another conversation for another day. I get convenience is a thing, but trust me your basement will become a time, energy, and money pit if you try and wrangle it in to do what you want when that’s not what it wants to do. Reflections are not always the enemy, so don’t focus on making your room a sealed dead box if that’s not what it wants to do. Listen to the space telling you what it wants to do, and if it’s at a baseline “acceptable” sound then work to bring out the best in it; if it isn’t, I suggest you spend your efforts finding a good room to mix and master in.

Thanks for adding your professional experience here.

I was considering making some DIY absorbers for my finished basement "studio" area where I sometimes record vocal tracks. It is an area about 11'x11', carpeted, drywall with an 8' ceiling and totally open towards the rear. I've never had problems monitoring there, but the past year or so I have found myself recording vocal tracks and I am definitely hearing some early reflection issues. It's almost certainly the ceiling as the main culprit, since my preferred vocal recording technique is in front of and above the singer / speaker with the mic angled down aimed at the bridge of the nose, about 2' away. That has my mic only about 1-1.5' ft from the ceiling.

DIY 703 panels look like a great way to go, but I was poking around my back storage room and found I have a few pieces of this stuff which I used years ago to quiet down my upright piano when living in an apartment building. There are no specs on it, but it is quite absorptive and mid and high frequencies. What would you recommend as far as making these into presentable-looking clouds, and mounting them to drywall without using spray adhesive? I have 2 pieces about 1x3, and two more about 2x2; none in the original shape.

[Gutbucket]

Box-in-box construction is standard for many high end studios, and box-spring-box systems offer the best isolation IMO, though it’s obviously gratuitously expensive.

When the founder/engineer/bassist Gabe (I'm spacing on his last name) buit the Daptone studio into a row house in Brooklyn on a the cheap something like 15-20 years ago, he used old car tires as spring elements supporting the interior box. Always thought that clever, and metaphorically appropriate for the Motown inspired enterprise. I recall a Youtube vid where they talk about hacking the studio together and getting going.

[2manyrocks]

Voltronic, I have no comment on the acoustics of mounting the panels to your ceiling, but my suggestion would be to attach them to a 1/4 plywood or similar panel and then screw it to the ceiling.   If the acoustical foam is spray mounted to the drywall, that could be a real headache to remove from the ceiling later. 

[voltronic]

Voltronic, I have no comment on the acoustics of mounting the panels to your ceiling, but my suggestion would be to attach them to a 1/4 plywood or similar panel and then screw it to the ceiling.   If the acoustical foam is spray mounted to the drywall, that could be a real headache to remove from the ceiling later.

Yes, that's the whole reason I don't want to use the spray adhesive that all the companies seem to recommend with foam panels.

I was also thinking of building some cheap frames for them and covering with fabric matched to the paint in the room. Something like this looks nice:
https://www.gikacoustics.com/product/diy-bass-trap-acoustic-panel-frames/

[2manyrocks]

I don't think I'd want to suspend any wood frames overhead unless you were very, very careful to make sure they were well attached to the ceiling.  For the work involved, I wonder if it would be that much better than suspending an acoustical blanket with a net.   Fire safety would be an important consideration. 

I've built frames like the ones you linked and routed out the sides.  It was a lot of work to rout the cutouts in the sides. 

The easier and cheaper method is to use  6' cedar fence boards to build a simple frame around 2x4 sections of minwool insulation---but again, not something I'd suspend overhead.  I'd suggest predrilling the cedar to keep it from splitting when you screw it together if you decided to build some simple frames for your space.  Or just run an open studwall from floor to ceiling and fill the openings with minwool insulation.