Basic acoustic treatment... AND BEYOND!

[diamondj421]

With all of the quarantining and social distancing, there obviously hasn’t been a ton of studio work so I decided to take a deep dive into the world of acoustic treatment. I have a dedicated “room within a room” that I mainly use for mixing. It’s 11’ wide x 16’ deep and a whopping 6 1/2’ tall (I’m going to post some pictures below) I already had panels in the front corners and at my side first reflection points but I recently replaced my corner panels with superchunk absorbers, added another superchunk at the corner of my front wall and ceiling and then a 4’x4’ cloud above my mix position. Unfortunately, I’m still not 100% satisfied with the results that I’m getting so I bought 3 bags of Safe and Sound. Before I started slicing and dicing all of this insulation, I wanted to get some input from those of you with more experience than myself. Here are a few thoughts:

1. I've seen some studios with another pair (or more) of panels on the side walls and/or a ceiling cloud behind the mix position. I have also seen panels straddling the dihedral corners around the room (Wall/ceiling). I'm having a hard time finding information on optimal placement for all of these since they're somewhat beyond the realm of basic treatment. Any tips/tricks for starting points would be great.

2. A company had sent me a picture of their suggested treatment type/placement. It shows diffusion in the back half of the room but the few people I've spoken to about it have said that my room isn't long enough to benefit from diffusion. Thoughts?

3. I know that symmetry is important in placement when possible but I have a second door in the back corner of the room. It was necessary for my original layout but plans changed and while it's convenient, it's not necessary anymore. Would it be worth sacrificing the convenience and blocking the door with another corner absorber?

Thanks in advance for any advice. There's so much conflicting information out there that it's hard to know what really is the most effective placement.

PS The floors are concrete with an area rug under the mix position.

[SoWhat]

Greetings,

Would it be worth sacrificing the convenience and blocking the door with another corner absorber?

As many experienced voices have posted on this and other forums: "Always start with the corners." And it's corollary: "If you can't afford to treat anything else, treat the corners."

All the best,

Paul

[DanDan]

Best to post the .mdat but that response looks oddly scooped, and I'll bet sounds bright.
The SuperChunks originally tested were about 85cm wide. The home site studiotips.com includes a 60cm wide version, but I have found that to be very disappointing. I suspect simple corner straddling panels might be better due to damped resonance. I would always assume at least two or three side reflection absorbers, as thick as possible, perhaps including an airgap for the free lunch.
Low ceiling but area is just as important as depth.

[diamondj421]

Best to post the .mdat but that response looks oddly scooped, and I'll bet sounds bright.
The SuperChunks originally tested were about 85cm wide. The home site studiotips.com includes a 60cm wide version, but I have found that to be very disappointing. I suspect simple corner straddling panels might be better due to damped resonance. I would always assume at least two or three side reflection absorbers, as thick as possible, perhaps including an airgap for the free lunch.
Low ceiling but area is just as important as depth.

.mdat, you say? Ask and you shall receive!!! lol. Like you were saying, I’m not too impressed with the results of the superchunks at 60cm. I want to bring the width out but have a slight issue that I’m trying to find a workaround for. The two front corners are made with OC703 and honestly with work not being available (Not a good time to be a DJ) and the $150 worth of Safe and Sound I just bought being non-returnable at this point, shelling out for more OC would be a real kick to the groin. Here were two ideas that I had:

1) Fill in the corners with OC and Safe and Sound, alternating back and forth. I recall seeing research somewhere that said the use of materials with different densities can be beneficial.
2) Take all of the OC703 out of the corners, arrange the triangles back into squares/rectangles, join them somehow and then make them into panels. Then rebuild wider superchunks out of Safe and Sound.

If I'm being honest, at least 75% of the information gathered in REW is lost with me. I'm trying my best to learn more but I have a really hard time analyzing the graphs, finding issues and then figuring out a way to fix them. Your help is very appreciated.

[DanDan]

Well....... that .mdat looks pretty good to me. But there is not much low bass being generated so we don't know what might be happening down there.
What speakers are those? You would get more and lower bass if you move them to kissing the front wall.
We need single L and R measurements to see the early reflections in the ETC with the confusion of a second source.
Which SNS product have you got? Here nobody uses OC due to poor distribution and it is six times the cost of Isover etc.

[diamondj421]

Well....... that .mdat looks pretty good to me.

Yea? Obviously we all want to take measurements and see a perfectly flat line but that isn't realistic. The thing is, I'm not sure how much variance there can be before you'd consider things problematic. It doesn't help that I'm a perfectionist so when I see that the curve isn't straight as an arrow, I assume the world is ending.

What speakers are those?

I have a pair of A7Xs. They definitely lack weight in the bottom.

You would get more and lower bass if you move them to kissing the front wall.

Funny you should mention that. I tried moving everything 1' closer to the front wall last night but don't have the measurements. After reviewing them, it seemed like a step in the wrong direction so I trashed them. I still had another foot (30cm) behind them thoughThere was definitely a boost in the low-end though (I believe it was around 65Hz) so I could try again and play with the speaker placement if you think that might help.

We need single L and R measurements to see the early reflections in the ETC with the confusion of a second source.

Roger that! I'll attach them.

Which SNS product have you got? Here nobody uses OC due to poor distribution and it is six times the cost of Isover etc.

I have the 3" SNS. I honestly don't understand why OC is so highly recommended yet so hard to come by. If you look up OC 703 on Google it seems that the only thing it's used for is sound treatment so maybe the stores that carry OC products (Home Depot, Lowes, etc.) don't see it as something worth stocking. Whatever it is, the price definitely doesn't help.
Thanks so much for taking the time to help me out with this. I really appreciate it. Do you have PayPal?

[diamondj421]

I think I fudged something up on the last measurements that I posted so here's an update. While I was at it, I moved everything to the front wall again and took a few measurements so they're attached as well. Now, it could be that it's getting late and I'm really tired but I have a crazy idea that I'm going to throw out there. What if I shortened the length of my room by 2', making it about 14' deep instead of 16'? I know that room mode calculators, ratios and simulators are hypothetical but from what I can tell (which could be completely misinterpreted) it looks like it would have a flatter frequency response. Time to hit the hay! I'll check back in tomorrow.

[Waka]

Hi diamond. I would love to help you analyse your REW measurements, but for some reason they seem to be corrupted when I download them. Can you upload them to onedrive/dropbox and generate a share link for us to download them please?

Also if you can open them all in REW and then save it all together so there's only one file, that would be helpful.

I would definitely hold off on shortening your room at all. Your room isn't huge already.

Also DanDan was recommending placing your speakers so they're a couple of mm from the front wall, literally almost touching them. This will give you some bass extension.

I would usually recommend putting a 100mm thick absorption panel (rockwool etc.) between the front wall and each of your speakers, and then pushing the speakers up to just touch the absorption. This should reduce the first null.

Just in case you didn't realise, this would also mean moving the speakers off of your desk and on to stands. Your mix position shouldn't need to move forward along with the speakers. Just push them further apart and adjust the angles so they are pointing just behind your head at the optimised mix position.

Dan

[diamondj421]

Hey Dan.
Not sure what was/is going on with those files. I was having a problem posting all of the measurements at once. Even separating them into two sets wasn't working. I'm still learning my way around in REW so I'm not sure what would've made the measurement's file size so much larger. Anyway, I'm really glad you mentioned only moving the speakers. I was shifting everything forward and the measurements were looking pretty crazy. You'll see for yourself. I'm about to call it a night but now that I know that, I really want to head back to the room and try it. I hear sleep is good for you though so I guess I'll have to wait. Boooooo. I just wrapped up making my front corner absorbers wider and I'm too tired to even see if that helped anything. Here's a link to the measurements in one .mdat.

https://www.dropbox.com/s/zuz0g81pahpkd ... .mdat?dl=0

Let me know if there's still an issue and I'll run a few more tests tomorrow/today.

[diamondj421]

this would also mean moving the speakers off of your desk and on to stands.

I built the desk I’m using based off of the dimensions of the Sterling Modular Plan D. Only difference (aside from aesthetics) is that I flattened the top so I could place my monitors on it. I believe it’s 34 1/2” tall. Since COVID started I haven’t been able to work and had to sell a bunch of gear. I’m about to rebuild it with less rack spaces and flat top. That being said, I was going to need speaker stands anyway. I’m a DIYer so I was going to take on the task of building them today or tomorrow. A lot of the non-adjustable stands that I’ve seen seem to be sitting at around 36”. Is this a standard that I should stick to?

[SoWhat]

Greetings diamondj,

Have you considered cinder blocks for your speaker stands. Not only do they work well, but also cost next to nothing. They take paint just fine.

All the best,

Paul

[diamondj421]

Greetings diamondj,

Have you considered cinder blocks for your speaker stands?

Paul

I had not. I wonder if I could do that and then build a column around it. I know that aesthetics have nothing to do with how it will perform in the end but it’s still something I dwell over.

[SoWhat]

You could indeed. Just make sure the column is affixed tightly so there's no resonance.

Like I mentioned previously, they take paint well (make sure you use the proper kind), so you can dress them up however you want (and even change them!)

[diamondj421]

What about something like this?

Argosy Mon Stand.png

By using cinder blocks or filling the stand with sand are we just attempting to eliminate any resonance that the material would make? Basically, would something like this not be ideal because the wood would be resonating with the speakers?

[SoWhat]

Yes, eliminating resonance is part of it (why to keep your monitors off your desk). The other part is even more simple: HEAVY stands are sturdier, which in turn will support heavier monitors without jangling your nerves every time they are accidentally bumped.