DIY acoustic panels

[Stokely]

Hey there, 

I have a small "hobby studio"--meaning, for non-client and non-money making music mixing and recording!--and it's in the front office of my house.  Kind of an odd space: rectangular with two angled walls (doors and the front window area) and a very tall ceiling (14 feet).   Not a terrible space but it does have some slap echo and a weird ring going on when I walk around doing some hard clapping   Not all that scientific I guess.

Anyway, I mostly use good headphones to mix and create on (Senn hd600s) but I have my old 90s era Crown amp and KRK speakers that still work fine from what I can tell!  As the saying goes, upgrade your space before worrying about the speakers, within reason.  Or at least I've heard that sentiment a lot on forums.

I found this vid to be quite inspirational and I'm considering making these.  I'm about as handy as a foot but even I might be able to pull this off.   Thing is, I haven't priced materials (prices have gone up).   I've found some decently-reviewed panels that for a 4x2x2" panel would be about 70 bucks, 10 more if I chose the "eco" material as the vid below is using (and I probably would for peace of mind, plus my cat noses around so any small bits that shed he'd be exposed to).   I like that the construction shown is lightweight and not using heavy frames as some other videos show.

If I made these, after watching some other vids I'd probably try to build in a space at least as wide as the insulation, for lower frequency trapping.  The main wall I want these on is very bare and tall and there's no issue having them stick out as far as I want.

Just wondering if any of you have made anything like these?
 

 

[KuruPrionz]

Please keep us posted as you move forward with this project. 

It's something I need to do as well, I'd love to have a treated room. 

I do use headphones for some aspects of mixing but I really prefer to do the final mix down on speakers. 

Headphones are great for pre-mix booger-fixing. 

[Anderton]

I'm no John Storyk, but I'd recommend starting with corner bass traps instead of panels. You'll need them both eventually, but the biggest problem I've seen in smaller studios is below 150 Hz. Bass traps can help keep the low end under control. 

[Greg Mein]

I had a nice basement space with big plans for treating the room. My research lead me to buy some boxes of the Owens Corning 703 rigid fiberglass panels I was going to use to make isolation panels and I stuffed the ceiling with batt 30. Sadly though I moved away before I could finish that whole project.

[Stokely]

This is probably a good thing, but it's a 6 sided room counting that angled double door and one window wall, with only two actual 90 degree corners.  The others are more open angles, maybe 120 degrees at a guess.  I've currently got the speakers pointing diagonally across the room into one of those corners so that's certainly a candidate for a bass trap I'd think.  Any thoughts on size/shape of a bass trap?  I've seen round columnar ones, the typical tall cube etc.  I've seen a vid or two that argues to worry more about the whole wall vs the corner as well but that's another discussion where i'd be over my head  

I was thinking maybe to grab some measurements beyond what I did with clapping with a free app (clap IR) and listening.   That's stuff I don't know much about so I'm leery of overthinking things and misusing advanced tools   I think it was John Storyk who I watched recently in an interview, where he said stop endlessly messing around--put something up and get started with the music!    Of course when he would put something up it would be in the right place. 

It wouldn't hurt to try and see what shape my amp and speakers are truly in, being around 30 years old.  I don't really trust my ears so much to know in a vacuum.  I can play reference material through them but the only comparison I can make would be with my phones.

[KuruPrionz]

35 minutes ago, Stokely said:

This is probably a good thing, but it's a 6 sided room counting that angled double door and one window wall, with only two actual 90 degree corners.  The others are more open angles, maybe 120 degrees at a guess.  I've currently got the speakers pointing diagonally across the room into one of those corners so that's certainly a candidate for a bass trap I'd think.  Any thoughts on size/shape of a corner bass trap?  I've seen round columnar ones, the typical tall cube etc.

I was thinking maybe to grab some measurements beyond what I did with clapping with a free app (clap IR) and listening.   That's stuff I don't know much about so I'm leery of overthinking things and misusing advanced tools   I think it was John Storyk who I watched recently in an interview, where he said stop endlessly messing around--put something up and get started with the music!    Of course when he would put something up it would be in the right place. 

It wouldn't hurt to try and see what shape my amp and speakers are truly in, being around 30 years old.  I don't really trust my ears so much to know in a vacuum.  I can play reference material through them but the only comparison I can make would be with my phones.

The fact that you are getting slapback echoes from a clapping sound indicates that you have some high frequency problems. 

I fully agree with Craig regarding bass traps, you should research those and start there. The next thing I'd try after that is diffusion instead of absorption. 

Many recordists have had good results with tall bookcases filled with random sized books and leaving some spaces. The clap sound hits that inconsistent surface and does not bounce back in a congruent way, it's been diffused. 

 

Well worth your time to look into that! Doesn't have to be expensive, thrift store furniture goes cheap and you can get boxes of books at garage sales for nearly nothing, especially if you go late and they just want to get rid of stuffs. 

[Anderton]

Also, remember that speaker placement is huge. I have mine quite a distance from the nearest wall behind them, which is loaded with acoustic foam. It's basically the deadest part of the room.

[Stokely]

Good stuff.  I agree that there is definitely a high end problem with the clap echo and the ringing.   Low end, I don't know yet.  While my speakers still work and sound decent to me--I played a couple of my high quality wav reference tracks to see last night--they aren't particularly low-endy. My HD600 phones are way more low-end heavy with the same material.  These are 7" speakers so I kind of wonder if something isn't up.  I'm just not used to speakers anymore to have a good frame of reference.

I have the speakers probably way too close to one of the angled wall(with a window) behind them.  Unfortunately it's not a big enough room to bring them out much more.  I also don't have acoustic foam or panel behind them as you mentioned.

I messed with a few things.  I played some files that Genelec has on their site, including an 85hz tone and a pink noise tone.  There were some resonances with the lower tone, really strong in one corner but not one of the 90 degree ones  It was by the door so perhaps a good spot for a bass trap.   With an RTA app on my phone, I measured the pink noise.  I have a graph, but not all that sure what to make of it   

I do have one really tall bookcase so that's good!  Diffusion is somewhat covered due to all the cases and whatnot stacked on two walls along with the books.   The back wall (speakers facing, at a bit of an angle) is pretty bare and that's where I was thinking the panels/bass traps could go as a start.

As far as DIY, I'm a bit disappointed that the "eco friendly" insulation as shown in the vid I posted is very hard to come by.  One 2" slab from the few places I found it is basically almost the cost of buying a panel depending on the store.  There's a company not far from me in Tampa called Acoustimac that has reasonable prices and some good recommendations on the web (and while they don't offer pickup, shipping isn't bad as I'm not very far.)  Unless I can save at least half on DIY, maybe more, I'm leaning toward throwing some gig money (aka, "folding money" to take a term from O Brother Where Art Thou!) at a pre-built bass trap.  

As far as bass traps, I have a credenza on that back wall and a 2' wide panel (not built for a corner) will sit perfectly across the corner with space behind it.  Or I could get something  angled for a corner.

[Stokely]

BTW, I'm not necessarily against rockwool or Owens corning...I'm a skeptic and like scientific data before proclaiming something "safe" or "dangerous"   Eco for the sake of eco, no.  But I do have a cat that likes to come in by me, and it's in a family home, not to mention I work at home.  I've heard that panels or traps work best with air gaps and not with a sealed backing, but I don't want fiberglass or rockwool fibers coming out (or cotton ones for that matter).

Speaking of my cat, he's rapidly heading for a studio ban.  He keeps jumping on keyboards, which are covered but I've resorted to laying tinfoil to try to train him off them...I fear something like a bass trap or panel would quickly become a scratching post if he can reach it.  He likes to hang with me while I work (looking out the window from a bench, which is great) but not if he's going to wreck gear.

[Nowarezman]

You can spray the fiberglass with an adhesive that will keep fibers from escaping.  

 

My take on all the great discussion so far:

 

1.  gotta get rid of that ringing and echo.  Small room ringing and echo makes for a terribly fatiguing listening environment, aside from the blatant inaccuracies.

 

2.  The smaller the room, the more you need bass traps.  I made bass traps from the recipe off of Ethan Winer's website.  A dozen 4' x 2' Owens-Corning panels costs about $100 nowadays.  I made mine with two panels each and they took care of (most of) the bass issues and also the ringing.  Here's a link:

 

Build a Better Bass Trap

 

3.  Small rooms will have some problems no matter what you do.  So the job here is to minimize the most gross problems.  Shoot for making things sound good at the listening/mixing sweet spot and don't worry about how things sound at other positions in the room.  

 

4. Try EQing the room after you've done a reasonable job with physical traps and panels.  EQing is ok as a tweak, but the more you EQ, the more your system is lying to your ears.

 

Best o'luck!

nat

 

[Nowarezman]

One other thing - try to find an outfit that sells insulation to contractors.  Or a contractor with a few odd batts left over after a job.  If you buy the Owens Corning 703 or 705 from any outfit that sells acoustic treatment DIY stuff, you will likely get an ungodly markup.   There's a place in Austin called Specialty Products & Insulation that will sell bundles of insulation off a palette to whoever walks in.  E. St. Elmo if you're ever in town.  Google will get you there. Looks like a dump - nice guys, 'tho.  My kind of place!

 

I don't know current prices and we all know about inflation....about four years ago I bought 12 panels for $80 give or take.

[Stokely]

Awesome!  That is a LOT cheaper than the recycled denim type of insulation.    Lowes has some that wasn't too expensive but it's out of stock, and further searches suggest they don't make it anymore.

It's true that when I looked for O.C. 703 I mostly got acoustic treatment stores and yeah the prices weren't great.  I'll check around my area, and hit up our "AC guy"  My wife is a property manager so she knows a fair number of handypersons and contractors.  They might know where to go.

I've also got a retired woodworker on my street, he said if you have anything you want, let him know.  Not even looking for payment, though I would pay.  He specializes in fine furniture--way, way beyond something like this, but I honestly couldn't think of anything I needed built when he offered  He could probably make some killer looking corner traps whereas anything I make is going to look like an elementary school project (and that's being kind to myself)
 

[jerrythek]

On 1/10/2023 at 12:04 PM, Anderton said:

I'm no John Storyk, but I'd recommend starting with corner bass traps instead of panels. You'll need them both eventually, but the biggest problem I've seen in smaller studios is below 150 Hz. Bass traps can help keep the low end under control. 

I'm researching this issue for my upstairs music space - bass traps are the first step for treating the room, as told to me by countless friends who are more expert than I am. The best advice I got was:

• start with bass traps
• listen to some source material you know well, in your normal working spot and judge the sound from there. I.E. fix what you hear, instead of just doing things based on theory, or whole room kit approaches
• a few good friends agreed that diffusion for the side walls is a better approach than absorption. To judge the side wall reflection issues read here.

It's a good start - you can always do more, but fix the problems you actually hear that bother you.

 

Good luck!

 

Jerry

 

[Stokely]

The sides should be reasonably covered if diffusion is good, though I could do a bit more. 

If I DIY (or not), I'll try a 4x2 4" panel straddling the back corner first I think.  It would fit very nicely on the furniture that is there, starting at about 2 foot up.  If that credenza needs to go I can make that happen    My office up to now has been the place where furniture goes to die!   I do use the storage to be sure.   The speakers are basically pointing across the length of the room diagonally toward that corner.  For now at least.  I could shift around so they are pointing at the wall but I'm hoping this is better.  
 

[Stokely]

Unfortunately, materials are hard to come by apparently.   After checking into safety studies and lots of discussion (on things ranging from fibers in the air to formaldehyde) I'm kind of feeling easier about using Rockwool or Fiberglass despite the talk in that video I first posted.   There's kind of two safety components:  when you work with it, and after it's installed.  I'm more concerned with the latter, I'll wear mask and gloves or whatever while doing the work.

Rockwool comfortboard 80 seems to be highly regarded, and Lowes has a great price on it (less than 60 bucks for 6 panels) but it's out of stock and they don't know when it will be back.  Likewise for another store.  I'm not in a huge hurry in any case.

[Stokely]

Hah, bringing this back up as I am considering a couple options.

First, this place has rockboard pieces useful for broadband panels and possibly bass traps:
https://www.buyinsulationproductstore.com/4-thick-4-mineral-wool-acoustical-board/
That's the 4" pack that comes with 3 pieces.  More pieces for the thinner boards.

Then I'm also considering the less-rigid and less-dense Rockwool Safe-and-sound batts for bass traps (though the numbers on the 4" boards above look good, 1.06 score at 125 hz.)   SnS is quite a bit cheaper and available just up the road at Lowe's.

I would definitely save money even with the shipping costs for that rockboard vs buying finished panels, but my fear is that my DIY skills may be lacking   For that reason I might try making SnS bass traps first to make sure I can make something halfway presentable.   My thought is to go with 4x2 ft 4" thick panels that can straddle a couple corners across from my speakers.  4 inch wood board at Lowes is less than 4 bucks for 8 feet long, that would be the outer frame.  The rockboard I'd probably go with 2" which would be cheaper and maybe easier to make but less effective with bass.  Those I'd hang around the room as needed.