Room treatment and how to measure first?

[John Vere]

I am completely redoing my studio room and a huge part of this will be applying proper room treatment to the best of my ability.
My daughter had to re do all her flooring and I ended up with a lot of the original material. The face side is hard and mostly looked like hell but when I flipped it over the back is in perfect shape and it is soft cork. So I have used this.

My room is in the basement and was unfinished. The ceiling was floor joists and I had stuffed 3.5" of rockwool in the cavities. So I have now covered that with the cork flooring as well as my face wall and part of the side walls. ( see photo ) So the room will now need to be analyzed before I start adding treatment.

I started looking into "How to measure a rooms acoustic properties" and so far I'm told to purchase $1,000 worth of mikes and software! not going to happen.

My wife is keeping a sharp eye on the budget for this! ( as example she saw the purchase for Studio One!) I'm expected to do this on the cheap.

There is a free Room Measurement software called REW- https://www.roomeqwizard.com/
But then they also talk about purchasing a mike that comes with a profile that you have to first feed into REW.

So here is the big question. Can a person get "close enough" room measurements just using a good flat response condenser mike and a few plug ins?
I was thinking I could simply send a pink/ white? noise out of my NS 10 M's and move a condenser mike around the room. I have a Shure condenser that has a very close to flat response down to 100hz.
That could feed into something like Span or Melda M analyzer.
I don't want a dead room. Right now it has a typical small empty room echo. My goal is a nice live room for acoustic guitar and vocals. the room is 11x14 with a 7'2" ceiling.

 

[reginaldStjohn]

I use the free Room EQ Wizard (REW) and a behringer measurement mic that has been calibrated. Then I take the measurements and using the curves that the REW shows I can see before and after. I also use my mixer (Behringer X32) to correct for some of the issues measured at the location I normally sit.

 

[OutrageProductions]

John: as someone with an MS in Acoustics I'll clue you in on a couple of things; as @reginaldStjohn mentioned, I've used the Behringer [cheap] and White [$$$$] mics to analyze rooms and systems for decades, and either will work well. They are specifically small diaphragm (<1.5cm) omnidirectional. If a calibration chart comes with it you can enter that into the application to null the response. And the only important location to measure is from the mix position.
While steady-state pink noise will get you an EQ curve, only a sine/square wave sweep will tell you the time response anomalies, and that can usually only be achieved with dedicated software that can compensate for the AD latency. And then you have to shuffle absorbent materials around to locate where they are an issue. Not to mention all of the permutations involved in a LEDE room design.
Good luck.

 

[John Vere]

Thanks for the replies. Seems a lot of familiar user names found here, no surprise.

Is the Behringer EMC 8000 the one you are talking about? I hope so because I just ordered it. I will now download the REW software and start learning how it works, a new challenge in the wonderful world of audio!
I guess the mic for $65 Can. and free software is a pretty good deal when you compare that with Sonarworks which looks like it's over $300 for me. !

I also ordered my flooring which will be this rubber workout room stuff. Only $75 to do the room
https://www.amazon.ca/ProSource-Exe...-Equipment/dp/B00K2TWXD6?ref_=ast_sto_dp&th=1

My son put it in his basement in his music room.
So I should get the room mic and then the flooring next week. I make my first measurement before I lay down the floor.

 

[gabo]

Thanks for the replies. Seems a lot of familiar user names found here, no surprise.

Is the Behringer EMC 8000 the one you are talking about? I hope so because I just ordered it. I will now download the REW software and start learning how it works, a new challenge in the wonderful world of audio!
I guess the mic for $65 Can. and free software is a pretty good deal when you compare that with Sonarworks which looks like it's over $300 for me. !

I also ordered my flooring which will be this rubber workout room stuff. Only $75 to do the room
https://www.amazon.ca/ProSource-Exe...-Equipment/dp/B00K2TWXD6?ref_=ast_sto_dp&th=1

My son put it in his basement in his music room.
So I should get the room mic and then the flooring next week. I make my first measurement before I lay down the floor.

That's awesome, good luck. REW is an awesome tool and now rivals anything you can find in the world of acoustics. There are a number of good resources for how to best go about measuring your room. The AvNirvana forums, which is where you download REW from has a lot of good information.

Just like any good DAW, it does take some time to learn and get used to the interface.

Also, It might be more important to get the decay times in order than it is to actually get a completely flat frequency response. But sure to learn about the Impulse, RT60, Waterfall, and Spectrogram charts in REW. If you get those things looking right, the frequency response will take care of itself.

 

[John Vere]

Thanks. I was away for a week and just got back. I now have the Behringer mic. I will start watching tutorials. So far the ones I watched were using a laptop computer and the on board sound card so used a USB Mike. I need to get set up with ASIO and my Motu M4 and the NS10M’s.
I also got one box of the rubber floor tiles. They screwed up the order so the rest come next week. Hopefully I will have first run of measurements by then.

 

[BillS]

My studio is as acoustically treated as it possibly can be with panels on all the walls, bass traps, panels on the ceiling etc. I was put off by the price of Sonarworks and instead used IK Multimedia’s ARC software and measuring mic. It’s super easy to use, was less than half the price of Sonarworks and it made huge difference in an already decent room. I mean, a really a big and obvious step up, especially for lower frequencies which are now well defined. I’m making better mixes now, and essentially ones that I can trust. Just my experience, good luck.

 

[John Vere]

Have now successfully completed a measurement with the bare room as well as one with the rubber mat flooring. I compiled a video documenting how I’ve progressed.

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[TDF1981]

Have now successfully completed a measurement with the bare room as well as one with the rubber mat flooring. I compiled a video documenting how I’ve progressed.

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Years ago I got a great advice from another professional: do not measure the empty room, instead put all your equipment there and set it up how you prefer to work.
Then, when all is in there, measure and treat the room.
It was the best advice for small studios I had heard in a while.

 

[gabo]

Have now successfully completed a measurement with the bare room as well as one with the rubber mat flooring. I compiled a video documenting how I’ve progressed.

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Good plan of attack. Once you get your wiring all set, for the ceiling I would recommend just adding another layer of rockwool (looks like you have the space) and then going back with something like the landscape cloth you had. Having that ceiling good and dead is actually a good thing. If you want something that looks better, any type of open weave cloth works well. There are art things you can buy and even large cloth "album covers" can be purchased off ebay if that's your thing.

Then I would suggest putting traps in the corners. There are many ways to do them, building a frame across the corners and stuffing them with rockwool is pretty easy and as cheap as you can get. The cover those with cloth.

For the walls, you'll probably need some panels. Something like 4" panels that you can make and wrap with cloth works well. This is there it will require a bit of trial and error. You want to get your times on the REW RT60 graph page (which does a variety of things RT60, RT30, ETC, and more) even. When I say "even," I'm talking about from the schroeder frequency of your room upwards. What you don't want to do is kill all the reflections on the high end. So if you have graphs that trend downward, then you need some reflection in there, but it probably needs to be more "slat" type of reflection and not full wall. You can research how wide the slats need to be based on how the graph goes down. What you're trying to do is get those reflections to be even from the schroeder frequency upwards. No trending up or down.

In a room that small, you'll likely never get the very low frequency reflections completely controlled. Unless you get sophisticated with things like tuned membrane traps. It's not worth it in my opinion.

And you can have some limited success with tools like sonarworks or other "EQ" tools, but it's never as good as fixing the room. You can never "fix" a null with EQ. A null is a cancellation of sound due to reflections, if you "turn those frequencies up" you just get stronger reflections and thus they still cancel. You can do some limited fixes of peaks, but that also is only good for one position in the room and actually unbalances other places in the room. You can also never fix comb filtering with EQ, and good treatment will totally fix that. And EQ will do nothing for reverb either, and that's very important.

Good luck.

 

[John Vere]

Years ago I got a great advice from another professional: do not measure the empty room, instead put all your equipment there and set it up how you prefer to work.
Then, when all is in there, measure and treat the room.
It was the best advice for small studios I had heard in a while.

Thanks. This is something that I’ve thought about and these first couple of measurements are strictly for understanding what happens as I progressed.
Actually the room will only have the 2 desks and my guitars. Im going clutter free this time. So what is in the video is not that far removed from the complete studio.

 

[John Vere]

Good plan of attack. Once you get your wiring all set, for the ceiling I would recommend just adding another layer of rockwool (looks like you have the space) and then going back with something like the landscape cloth you had. Having that ceiling good and dead is actually a good thing. If you want something that looks better, any type of open weave cloth works well. There are art things you can buy and even large cloth "album covers" can be purchased off ebay if that's your thing.

Then I would suggest putting traps in the corners. There are many ways to do them, building a frame across the corners and stuffing them with rockwool is pretty easy and as cheap as you can get. The cover those with cloth.

For the walls, you'll probably need some panels. Something like 4" panels that you can make and wrap with cloth works well. This is there it will require a bit of trial and error. You want to get your times on the REW RT60 graph page (which does a variety of things


Good luck.

Thanks all good stuff.
The ceiling is only 7’. So no room for clouds. Then what Im doing now is cutting out holes in the cork ceiling. I will cut out 24” long sections and up to the floor joists so that is 14.5”. I will make 6 more to go with the 2 I already made. I will then make fabric covers for these. They will be only 1.5” deep. So instead of clouds these are reassessed traps that will be 10” deep. There will be 5.5” of rock wool with a 4.5 “ air space above it.

I will make 12” traps for 3 of the corners. One corner is a closet which will be treated with carpet so when door is open it will serve as a trap.
Then rear wall gets a Quadratic diffuser.

Side walls I will start with a 3’x3’ x 3.5 “ absorbent panels placed at the spot using the mirror trick. I will add more if needed after testing.!

 

[gabo]

Thanks all good stuff.
The ceiling is only 7’. So no room for clouds. Then what Im doing now is cutting out holes in the cork ceiling. I will cut out 24” long sections and up to the floor joists so that is 14.5”. I will make 6 more to go with the 2 I already made. I will then make fabric covers for these. They will be only 1.5” deep. So instead of clouds these are reassessed traps that will be 10” deep. There will be 5.5” of rock wool with a 4.5 “ air space above it.

I will make 12” traps for 3 of the corners. One corner is a closet which will be treated with carpet so when door is open it will serve as a trap.
Then rear wall gets a Quadratic diffuser.

Side walls I will start with a 3’x3’ x 3.5 “ absorbent panels placed at the spot using the mirror trick. I will add more if needed after testing.!

Oh geez, sorry last time I didn't have much time and only watched the first part of your video. You actually would have been better off to NOT put the cork on the ceiling, and added more rockwool and left the cloth covering. That would negate the necessity for ceiling clouds as it would effectively made the entire ceiling a cloud. But all it not lost, as you said, you can cut holes. I would suggest instead of holes, you cut long slots the length of the room and cover them with cloth. Something like 4 to 6 inch wide slots, then leave 4 to 6 inches of your cork, and cut out another row, all the way across the entire ceiling. That will help control low frequencies as they won't even see the cork slots, low frequencies would see that as an open ceiling. You can calculate the reflected frequencies off the cork slots as it will be whatever the wavelength width of what you leave is and up.

Not sure where you heard that cork is a good acoustic treatment... It's ok at very high frequencies, and yes better than sheetrock, but that's generally not the problem area. It's virtually useless at lower frequencies.

Cut those slats, put in the corner traps like I suggested above, and then shoot your room again. Oh, and no the rubber floor tiles do very little for sound, but they are nice to walk on.

Low frequencies have to have depth, it takes almost 17 inches to trap 200hz! 6ft to trap 47hz! But you do get some partial trapping at lesser depths. For wall hangers you need at least 4 inch panels, if you have the space go deeper or build them into the walls. This is why professional studios have membrane traps or tuned helmholtz traps, all of which require very detailed analysis and design. Not something you want to do in your room.

What you want to do is as I suggested. Build corner traps first, come out two ft from the corner on each wall and build a frame across that and stuff it will insulation and cover it with cloth. That's the biggest bang for your buck in getting some lower frequency control. Cutting the slots in your ceiling will get you some more reasonably low trapping as the depth of that stuff in the ceiling could be as much as 10-12 inches.

And I know you're wanting to design it by listening to it, and that's good. But it's really next to impossible to get where you want to go by ear. Everything below the schroeder frequency of your room will be standing waves, which present as hot spots or nulls in the bass response of your room. Everything above schroeder will present as comb filtering and reverb. Although it's not an exact cut off, more like a gradual transition from schroeder up through 4 times schroeder. REW will tell you a lot more about what you need to do than you can determine by ear.

 

[John Vere]

The thing is I don’t have a low frequency problem. The REW readings so far showed nothing happening below about 150hz. Yamaha NS10 M do not go that low. The echo is happening at around 600hz and up.

I got rid of the fabric cloth because it made the room depressing to be in. I like wood. I like being in warm places not black. I love the cork. It was free!

If 8 traps that are 16”x24” x 10” deep don’t get me the correct results I will simply add a more as well as I can place carpet behind me.
This is why I need to measure as I go and try and understand the results after each new component is added.
Many videos about room treatment advise not to overdo it. I don’t want a dead room and I’m using my ears along with the science. I like a new challenge!

but thanks for your input and thoughts these are definitely helpful.

 

[John Vere]

Here's a screen-shot of measurements I'm saving so I can compare as I make the changes. So far seems there's very little changing. But then I'm only guessing at what I'm looking at so far. I don't think it's that bad and now I did the ceiling traps I really hear a big difference in the reflections. The room is not as dead as it originally was when the ceiling was open to the rockwool. To me that's a good thing.
At some point I will hook up my Sub Woofer to test the low end.