Acoustic Room Treatments 101

[silky smoove]

My preferred mastering guy, Henrik Jonsson, is apparently aware of this, too, and his work for me translates well on phones and buds.

This is critical for mastering engineers. Glad to hear you have someone who's aware of how music is being consumed these days. I've tried some different mastering engineers over the years and it's obvious that some of them do not pay attention to those sorts of trends.

 

[gmarcus]

Heavy room darkening curtains...the velvet kind, will make your window into a nice absorber. Same for the door and you can open and close the curtains to vary the acoustics. Book cases full of books make a pretty good diffuser.

 

[bassballs27]

Glass presents certain reflection characteristics that are a little different than wooden door, but they're not the worst thing in the world. Ultimately it's still just a flat, parallel hard surface to contend with. Curtains/drapes hanging in front of them will absorb a little high frequency and upper midrange energy but will leave low frequencies untouched. This may be beneficial if you have a problem in those frequencies or it may contribute to a boxy sound in the room by reducing reflections of mids and highs while leaving lows untouched and bouncing around the room. I suspect that once you get everything in the room and do some other treatments, especially corner trapping, the door won't be much of a problem.

Silly question, what if I leave one or two doors open? Effectively, does the next room then add length to my studio then? I guess there's a similar answer if I opened the window?

 

[bassballs27]

If you go the route of building DIY panels you should look into how RealTraps and/or GIK build theirs. Most DIY panel projects have flat, solid sides. Both RealTraps (high end product) and GIK (middle tier product) slot or perforate the sides of their panels to allow for more exposed surface area of absorptive material. Ethan Winer published a great paper on the topic with some included measurements for reference that you can dig up. It's a little added labor with a router during construction, but if done correctly can improve panel performance as well as adding an interesting aesthetic touch. You can further improve on most DIY panel designs by adding rubber stand-offs to the backsides of the panels to create an air gap between the panel and the wall.

Yeah, I see Primacoustics seem to bevel the edges of their panels. Makes sense to not include another "corner point" on the treatment itself.

 

[bassballs27]

Turning up while mixing will expose your rooms hot spots --that will make you do a lot of cutting of frequencies that are problems in your room, but not necessarily problematic in other rooms or in reality. I would not use a very small size monitor. If possible I would use one that represents a pretty broad range.

Yeah, I don't think I'm going to use the approach of going small with my monitor.
I've never liked the idea of using anything less than a 10" speaker with bass.....and even with my home stereo system, I have nothing less than a 6" in my centre channel. 8" speakers are great.

Heck, I play with a Bergantino NV610 for fun in this very room.....and on occasion my NV115.
I find speaker surface area to be a big advantage when producing bass.....but in the world of mixing, I guess it's the room that can fight you once you start producing some real bass and you're trying to find the source to eq when it fact it's your room that is causing the deception.

 

[bassballs27]

There was a recent publication, I'm blanking on which one unfortunately, that did a survey of listeners in the US. Home listening was among the lowest still in practice. By far the highest percentage was on earbuds and headphones with car stereos following not too far behind. It's definitely been a consideration for clients of mine lately.

Yeah, are there really a lot of audiophiles out there? There has to be and I think they just don't get in on these general surveys. I know LPs have made a huge resurgence (at least among younger from what I know). There's obviously some individuals buying ultra high end turntables and such.

It's sad to think that the general public is okay with how they hear music. Some of options do sound good, but many a good set of speakers or headphones certainly take it to the next level.

 

[bassballs27]

There is a lot of great advice in this thread!

One thing you should do for historical purposes is make some pre-treatment recordings, so you can compare the before and after.

There are many classic recording studios that have "live" rooms for when the need calls. Given that, the ideas to make easy to mount and remove panels may give you an advantage at times to wake up the room if needed. i.e. Sometimes singers no use to earphones do better in a live room.

Yeah, it's great to have it all in once place. I've been searching the internet over the past few weeks, watching YouTube videos and almost building an obsession over room acoustics, but it's simply astonishing how much misguidance and confusion there is out there. I totally get why people give up and just plug in their equipment and go for it. I've just had a ton of people tell me "treat your room"....and my question is "how do I do it?"
Well Rome wasn't built in a day....and neither should be any home studio...unless you have experience doing it before.

 

[bassballs27]

In my experience, a modest amount of room treatment can make a very big difference in the ability to really hear what's going on, and it sounds like the OP has a good realistic set of expectations!

A few things that I found pretty important/helpful in my treatment process:

- While a lot of discussion about treatments is about trying to tame various frequencies in the room in pursuit of a flat response, it's also critically important to create a situation where the sound coming directly from the monitors to your ears doesn't have to compete with sound that comes out of the monitors, bounces off a surface and then reaches your ears sometime after the direct sound. Here's a good piece from GIK that discusses the importance of the "reflection free zone": Early Reflection Points - GIK Acoustics

- You can take a big step towards achieving freedom from reflections with a bit of treatment on the walls on either side of your listening position, and on the ceiling above it, but don't neglect the nearly six-foot wide top of that desk! Sound bounces off it, too, which is why proper studios have the desktop at an angle - higher at the back where the monitors are, lower at the front where you're sitting. It looks like this is the case in the nice-looking setup @Kickass shared the photo of.

- While the formulas and rules of thumb are useful, be prepared to spend a fair amount of time experimenting witth adjustments to your monitor positions and listening position in all three dimensions. Even a few inches can make a significant difference. And when you do find the sweet spot, mark the locations of your monitors and your listening position on the floor so that you'll have them to refer to.

I know this stuff gets quite daunting; acoustics is a surprisingly complex and often counterintuitive field. But with patience and a methodical approach you can get the most out of your space, and once it's done you can forget about the mechanics and just enjoy the good listening environment!

Oh yes......this desk of mine is actually totally make shift. It's a plastic foldable desk temporarily being used for recording and I'm intend on replacing it something that is likely going to be narrower and likely going to place the monitors on independent stands. If I keep using the desk, I'm definitely going to place some isolation under the monitors or possibly some iso-acoustic stands at minimum. I've always known that the tweeters for any speaker in the listening position should be at ear level with the listener. For me, that's exactly a 48" height.
Table height is typically 29" high by standard....and I confirmed this table is that exactly...so I definitely need them raised. I totally get why many recording desks are multi-tiered, mainly to place the monitors up high!

I often thought of creating a specific listening area in front of the window and being separate from the desk and obviously computer, but that would likely be very counter productive. The computer is a laptop...and it probably wouldn't be much to have it in my lap and turn my body to face the window. I still feel though, it would be like having the oven and stove in two separate locations...but all the controls for both are in just one location. LOL!

 

[bassballs27]

Heavy room darkening curtains...the velvet kind, will make your window into a nice absorber. Same for the door and you can open and close the curtains to vary the acoustics. Book cases full of books make a pretty good diffuser.

My racks are either filled with basses or cases! LOL! But yeah, I can definitely understand that books in book cases are going to offer some multi-level absorption. Explains why a library with various aisles of book cases has this "silence" about them.

 

[littlebun]

Yeah, I don't think I'm going to use the approach of going small with my monitor.
I've never liked the idea of using anything less than a 10" speaker with bass.....and even with my home stereo system, I have nothing less than a 6" in my centre channel. 8" speakers are great.

Heck, I play with a Bergantino NV610 for fun in this very room.....and on occasion my NV115.
I find speaker surface area to be a big advantage when producing bass.....but in the world of mixing, I guess it's the room that can fight you once you start producing some real bass and you're trying to find the source to eq when it fact it's your room that is causing the deception.

As long as you mix at a moderate level and have a good set of phones to help you, you will be fine without treatment. When I first started mixing I chased a lot of anomalies that I created, and that made holes in my mixes when played on other systems. I just didn't know what I was doing but I eventually got the hang of it --you will too. Have fun.

 

[silky smoove]

Yeah, I see Primacoustics seem to bevel the edges of their panels. Makes sense to not include another "corner point" on the treatment itself.

I'm not taking about beveling the corner. Look at GIK's slotted DIY panels or the perforated sides on RealTraps panels.

 

[silky smoove]

Silly question, what if I leave one or two doors open? Effectively, does the next room then add length to my studio then? I guess there's a similar answer if I opened the window?

It moves the reflection to the next wall through the door. It may help, it may create a new problem. That's one you'll have to test.

 

[bassballs27]

I'm not taking about beveling the corner. Look at GIK's slotted DIY panels or the perforated sides on RealTraps panels.

Ah....you meant these?
Do It Yourself Bass Trap and Acoustic Panel Frames

 

[Standalone]

Ah....you meant these?
Do It Yourself Bass Trap and Acoustic Panel Frames

Those are very nice. I doubt the impact to the sound is detectible to the human ear.

One thing that can increase the surface area significantly is having a panel set up to be off the wall. This extends the effectiveness to a lower frequency as longer waves will be more impacted. I built some of my frames so that cross members stabilizing the wood functioned as stand-offs for the panel.

 

[Standalone]

Here are my panels the year I first installed them. The studio is much more filled in now! Less open space, but more functionality.

 

[bassballs27]

Those are very nice. I doubt the impact to the sound is detectible to the human ear.

One thing that can increase the surface area significantly is having a panel set up to be off the wall. This extends the effectiveness to a lower frequency as longer waves will be more impacted. I built some of my frames so that cross members stabilizing the wood functioned as stand-offs for the panel.

Great post. Yes, basically the similar concept of the bass trap with air behind it in the corner.
It makes me wonder if if it's better to build self standing acoustic treatments that I can move around the room as needed to find those sweet spots. I think with bass traps, they probably do need to meet the surface of the wall in some way in some way, but maybe not. It's kind of like the concept of room dividers or office cubicles to absorb sound.

 

[silky smoove]

Ah....you meant these?
Do It Yourself Bass Trap and Acoustic Panel Frames

Those as well as the other way that RealTraps does it.

Those are very nice. I doubt the impact to the sound is detectible to the human ear.

More exposure to the insulating material's surface area will only increase the absorption performance of a panel. For something, even on a DIY project, that requires very little extra effort or money there's no reason not to do it this way. There's a reason both GIK and the far higher performing RealTraps both do it this way.

 

[Frank Tuesday]

Yeah, a few days ago I sent out mix samples demonstrating a duet of classical guitar and double bass. As you can imagine, this was a sonic challenge due to the difference in instrument registers. One of the reviewers said, "I can't hear the bass on my phone!" Upon further follow up, I learned "phone" meant the phone's speakers. Duh! Sometimes you just can't give a **** about what a particular reviewer says.....

When they say they can't hear the bass, do they mean the frequencies? Or the instrument? If it's the former then they are talking rubbish. If it's the latter, then it is a valid critique. Whether you choose to modify your mix based on that critique is purely up to you, but it is at least worth considering.

 

[Standalone]

Those as well as the other way that RealTraps does it.

More exposure to the insulating material's surface area will only increase the absorption performance of a panel. For something, even on a DIY project, that requires very little extra effort or money there's no reason not to do it this way. There's a reason both GIK and the far higher performing RealTraps both do it this way.

Centimeter wide routs? My point is to
Consider the time spent doing that and buying router bits… just make one more panel instead with your time and money and get a hundred percent more absorption, and cheaper/sturdier panels to boot.

If you read the rest of my post, you'll see the point about standing the panels off the wall a bit, which in a certain way doubles the exposed area, especially to bass waves, which are the most difficult to tame.

No *need* to spend hours routing thin slots in cheap wood of DIY panels to chase undetectable improvements.

Panels routed like that are "nicer" for sure but if it adds cost or construction time, that's a trade off. Have you made such panels or are you talking theoretically?

I've posted a picture of my panels. Here's what the room sounds like when used for a full band studio recording. Check out the drums and vocals in particular. And excuse the harsh chorus on the opening guitar!

John Spignesi Band Halloween EP "Nameless"

 

[Standalone]

Great post. Yes, basically the similar concept of the bass trap with air behind it in the corner.
It makes me wonder if if it's better to build self standing acoustic treatments that I can move around the room as needed to find those sweet spots. I think with bass traps, they probably do need to meet the surface of the wall in some way in some way, but maybe not. It's kind of like the concept of room dividers or office cubicles to absorb sound.

Proximity to the wall is important for bass trapping. Consider a two inch panel. A bass wave goes through the panel, hits the wall and then travels back through the panel.

That is effectively four inches of condensed fiberglass. Pull the panel off the wall by an inch and you have sort of a six inch space interacting with the bass wave (yes some is air - two inches of fiberglass, one of air, wall bounce, one of air and then the fiberglass again) because of the wider space, you are impacting even lower frequencies than just having the panel in contact the wall.

Having the panel in the middle of the room etc. just means that bass waves encounter 2". So only use portable ones as gobos or spot treatments. Bass is really the difficult thing to tame so focus your efforts on that — the rest will follow.
Somi recommend hanging them on the wall where they will be out of the way and do their job.

Angled panels in the room corner have a variety of distances to the wall and do a great job impacting a wide range of bass frequencies right where bass treatment is most effective.

Here's John Spignesi in my home studio recording our Halloween EP. you can see two flat broadband panels and one 4" angled bass trap. OC703 equivalent with Muslin fabric staplegunned to simple frames.

We do our other album work in pro studios, but I've pulled good results out of my room. My son is doing sessions there now for a musical he wrote.