Time for treatment

#1

I am coming here from the recording studio construction posting on this forum. You can see my photos and my journey there under New Studio Build Underway. I have a few things left to do for construction, but now I am turning my attention towards treatment.

My space is 24ft long x16ft wide x 9ft-3inches high. 3,552cubic feet. It's function is a rehearsal/recording space. It is a one-room space. All mastering would occur elsewhere. So a tracking room. Lots of drums and percussion will be played in here but also electric guitar, bass, keyboards, and vocals at times. It has an inside out ceiling and one layer of 5/8 drywall over 3/4 OSB on walls with green glue in-between. The floor is laminate.

I have read different views regarding the necessity or lack there of for REW or similar software for analysis for tracking rooms. What do you think?

Right now my room is very live. Too live for my high end percussion where wooden percussion is sounding metallic with lots of echo and reverb.

To start I plan on building floor to ceiling bass traps in all four corners of my room. To control the high end I read that acoustical tiles work well. Any advice on the number, type, and placement of tiles would be much appreciated.

I have focused my research mainly on the studio construction and planning and not much on treatments. Any help will be great.

Thank you!!!!!

#2

: Here is the room as of today looking east

: Looking west

#3

Wow! It's looking pretty good in there, Howie!

OK, about REW and live rooms / rehearsal rooms / tracking rooms. Yes and no.

Yes, it is worth doing REW tests! No, you can't do it the same way as you do a control room, and no, there's no "correct" response for such a room. Unlike a control room, there isn't even a "correct" place to set up your speakers and mic for doing REW tests in there! In whatever spot you set them up, you'll get different results from other places.

So why would you do it then? And what will it tell you?

First, you do it because it it will reveal a lot of useful information about the empty room, that will help in deciding roughly how to treat it. For example, it will show you what the overall decay times are like, and you can compare that to suggest decay times for the type of instruments you will be recording / playing, then that will give you a clue on how much treatment you need, as well as the characteristics of the treatment (coefficient of absorption, thickness, panel size, percent coverage, etc.). However, this isn't a control room! So it's not just a matter of plugging a few numbers into a calculator then putting specific things in specific places. Live room treatment is different. It's about your ears too, not just graphs and equations.

Second, you do it because it is more accurate than your ears.... and I'm saying that right after I tell you to trust your ears! :roll:

What I mean is that your ears will tell you there is something wrong with the bass response (for example), but your ears won't tell you what frequency range is causing that... but REW will tell you. Or your ears might tell you that you have flutter echo issue, but you can't quite figure out what is causing it: REW can help you figure it out. Etc. So it's a combination of ears and REW that will help you treat your place.

So, do some REW tests (I'll get to that later...), then do some listening tests (with a good speaker playing typical instruments in typical locations), then use those two to make a rough plan of the treatment.

BUT FIRST! Before you do that, decide on WHAT you want the room to sound like! You mentioned several instruments and purposes for the room, so based on that you should come up with a description of how you want the room to sound: Do you want it bright, airy, subdued, warm, dull, dead, zingy, neutral (probably not...), dry, heavy, bold, clean, boomy, etc... That's your decision, as the studio owner: Nobody can tel you what is "right" for your place... you have to decide on that yourself. What is it that would keep musicians coming back to your place, because they love how it sounds? There are some general guidelines for that, but it's also a personal thing. I'm not sure if you have seen the new series that I'm writing right now, but there might be some useful advice for you in there: INTRODUCTION TO DESIGNING YOUR OWN STUDIO

Having said all that, and considering that you want to play and track a broad range of instruments and genres, I would suggest that the best approach for your pace would be to make it variable. If you have a room that sounds great for percussion and drums, it will be pretty lousy for vocals and acoustic guitar... and the reverse i also true: if you make it sound great for vocals, then it will not be so good for electric guitar or drums. Etc.

There are two approaches for making your room variable: you can do what I call "zoning" it, or you can treat it with variable devices. Or both!

"Zoning" just means that you have two (or maybe more) different acoustics regions in the room: make one end of the room very bright and airy, the other more subdued and dry, and maybe a warmer, more diffuse area in the middle. That way, you can set up each instrument and the mics for it, in the locations around the room that are most suited to that instrument. Thus, when you are tracking vocals you might put the artist very deep into a "dead" zone in the room, with them facing a "warmer" zone, but the mic facing the deadest part. While for drums, you might set those up in the "warm" zone, facing the "bright" zone, and have a couple of distant mics in different spots to pick up the room sound, in addition to having mics on the drum kit itself. Zoning can work well for tracking individual instruments, or maybe even small bands with 2 or 3 instruments, but it gets complicated when you have half a dozen musicians with their gear and instruments... you normally find that you want to put several of them in the same spot! Or you can't find a good spot for the ambient mics, because you can't get them far enough away from all the gear.

The other option (the one that I prefer), is to just some of your treatment "variable", so you can change the acoustic response for any point in the room (or for the entire room), as needed. Here's an example of how to do that: What is variable acoustics? How do I do that?

Regarding REW testing in live rooms, I do mention that in the follow-up comments on the article about how to test your control room with REW: How to calibrate and use REW to test and tune your room acoustics

I would suggest NOT using so-called "acoustic ceiling tiles" in your room. They are fine for offices and shops, but they don't really do what you need in a professional tracking / rehearsal room, like yours. Recording drums under acoustic tiles, for example, will make them sound like c**p! Rather, I would first figure out what you want for your room, then treat the parts of the ceiling accordingly. And yes, you can also have variable devices on your ceiling! I have a design for that...

- Stuart -

#4

Greetings Howiedrum,

I read through your build thread. My reaction, like many others, was a mix of pure joy mixed with a dose of horror. You apparently have the patience of a saint...

While I am no expert, I am a fellow drummer, so I'll add my two cents based on the photos above. Please periodically check the track light mounts, but particularly before recording. Since drums and percussion can offer plenty of vibration, the lights may become loose in the track. After all of the aggravation you endured, the last thing you need is annoying rattles/buzzes on your recordings, which might be picked up by your overheads.

Congratulations thus far!!!

All the best,

Paul

#5

Hi Stuart. Thanks for your advice!

So it's a combination of ears and REW that will help you treat your place.

Thank you and that makes sense. I ordered this mic

I have an XLR to USB adapter so I can plug the Dayton mic into my computer. Can I use my headphone output on my computer for the test signals? Also for speakers I have some old Fostex studio monitor speakers and a full PA system. What should I use?

BUT FIRST! Before you do that, decide on WHAT you want the room to sound like!

I read your new series and the variable acoustics write up. I am definitely intrigued by the variable option but I am worried about how much space it would take. I have a lot of percussion instruments and the space will fill up quickly. After thinking about it I like the zoning plan best. Three zones, dead - warm - bright. Do you have a plan for that?

I am so excited to be at this stage! Paul I hear you about rattles caused by drums. They drive me crazy. Thanks for reminding me to check my track lights. Will do!

#6

howiedrum wrote:Source of the post Hi Stuart. Thanks for your advice!
... I ordered this mic Screen Shot 2020-07-02 at 6.40.39 PM.pngI have an XLR to USB adapter so I can plug the Dayton mic into my computer. Can I use my headphone output on my computer for the test signals?

You sure can! That will work fine. Just make sure that there are no plugin EQ's of effects in the software chain: sometimes laptops come with pre-installed stuff to make things "sound better", or even to add "surround sound" (!) effects to the headphone output. So check for that. The REW calibration test should reveal if you have a problem there, but check your software setup in any case.

Also for speakers I have some old Fostex studio monitor speakers and a full PA system. What should I use?

Whatever has the fattest response, and the greatest frequency range. You want a speaker that can put out a decent SPL level (around 90-100 dBC) when playing typical music that you intend to play in your room. Here, too, make sure that there is no EQ or effects applied in the signal chain: set the speakers for flat response if they have rear-panel controls, and ditto for whatever amp, console, etc. you happen to have.

BUT FIRST! Before you do that, decide on WHAT you want the room to sound like!

I read your new series and the variable acoustics write up. I am definitely intrigued by the variable option but I am worried about how much space it would take. I have a lot of percussion instruments and the space will fill up quickly. After thinking about it I like the zoning plan best. Three zones, dead - warm - bright. Do you have a plan for that?

We can probably figure out something! But actually, the variable panels don't take up any more space than ordinary acoustic panels! The thickness is about the same (perhaps 6" thick: similar to normal wall treatment panels). That's the same when they are in the "open" or "closed" position, at the two extremes. Sure, when you change them from one position to another, you need a bit of space to swing them, but when they are at the extremes, they are just as thick as any other panel.[/quote]

But that's just for the ones in that specific example: it is also possible to design variable acoustic panels that need NO extra space! They can be adjusted "in situ", without needing any additional room at all....

Lots of options!

- Stuart -

#7

Also for speakers I have some old Fostex studio monitor speakers and a full PA system. What should I use?
Whatever has the fattest response, and the greatest frequency range. You want a speaker that can put out a decent SPL level (around 90-100 dBC) when playing typical music that you intend to play in your room.

My QSC K12 Powered Monitor speakers for my PA have a frequency range of 48Hz - 20KHz and a SPL level up to 131dB. Is that sufficient?

I appreciate the flexibility of your variable acoustic panels especially those that need no extra space. Could they be integrated in a zoning-like set up? Could we split into three equal zones (Dry, Warm, Bright) but each zone would have a variable panel. So the dry zone could be made warm, and the warm zone could be made drier or brighter, and the bright zone could be made warmer. This may be too complicated but what do you think?

For now, I will focus on getting the REW done. My microphone should arrive by the end of next week.

Thanks!

Howie

#8

QSC K12

Those will be fine! Great speakers, by the way. I have used that QSC line of speakers (K8 / K10 / K12) in a few installed-sound systems, with great success. I love them! Small, but powerful, and very clean, smooth sound. And I do like the wide dispersion in vertical and horizontal. Reasonable prices, too.

Just make sure you set the rear panel switches for flat response!

I appreciate the flexibility of your variable acoustic panels especially those that need no extra space. Could they be integrated in a zoning-like set up?

Yup! They sure could!

Could they be integrated in a zoning-like set up? Could we split into three equal zones (Dry, Warm, Bright) but each zone would have a variable panel. So the dry zone could be made warm, and the warm zone could be made drier or brighter, and the bright zone could be made warmer. This may be too complicated but what do you think?

That is definitely possible, yes.

- Stuart -

#9

Thanks Stuart!

I sent you a PM.

For the REW use on tracking room, your article mentioned option 1:

set up one single speaker in a location where there would typically be an instrument, then put the mic at a location where a room mic would typically be located, for picking up the room ambience of that instrument when it would be being tracked

Would the speaker be on the floor or raised a bit?

For second option:

have the speaker down on the floor in one corner of the room, and the mic high up near the ceiling in the diagonally opposite corner of the room: that test is a good way to reveal all of the low frequency modal stuff at its worst.

Which do you prefer? Should I do both?

Also does the REW generate all the sounds itself or do I have to play audio files on my computer?

Thank you!

H.

#10

howiedrum wrote:Source of the post Would the speaker be on the floor or raised a bit?

That depends on which instrument you are trying to simulate. For example, if you wanted to see how a drum kit might sound, then set the speaker on a low stool, similar to a drummer's "throne", since that's roughly where the acoustic center of a drum kit would be. If you wanted to simulate for a vocalist, then set the speaker on a speaker stand roughly at standing head height. For an acoustic guitar, at chest height. For an electric guitar, down on the floor where the cab would typically be. etc.

Try to imagine how you would have the instruments laid out in the room for a rehearsal session, then set the speaker in each of those locations, and the mic in a couple of typical "listener" locations for each instrument. Yes, this will produce a lot of REW data, and it will take you a while to work your way through it, understand it all, analyze it, and figure out your treatment options. Also, do take note (and photos) of exactly where you had the mic and speaker for each test! Write that down, so you can come back to those positions in the future, after you have the treatment in place, to see the difference.

Which do you prefer? Should I do both?

Definitely do both! The "corner trick" setup will reveal the overall modal response of the room, which is useful for figuring out your bass-trapping strategy, while the tests at individual potential instrument positions are more location-specific, to give you an idea of how the room is performing for each of those positions (they will be different!).

Also does the REW generate all the sounds itself or do I have to play audio files on my computer?

REW will generate all the sounds by itself. It does a "logarithmic sine sweep" across the entire spectrum that you set, for each test... and that could be LOUD! Which is why I suggest wearing hearing protection while you do the tests. Better still is to leave the room while the test runs... hence the "delay" option in REW: it allows you to set a delay from the time you hit the "start" button until it actually starts the test: enough time for you to get out the door, close it, ´plus another few seconds so your own "exit sound"s die away in the room.

In addition to letting REW do its own thing, you could also play sounds through the speaker at each location so you can use your own ears to see what that setup might sound like. For this part, you could simulate the right instrument at each location: for example, when you have the setup that you think would be appropriate for drums, after you do the REW test at that spot, then also play a track that has ONLY close-mic'd drums on it, with no other instruments, and no effects: just very dry, close drums and listen as you walk around the room.. Then when you do the setup for vocals, after REW does its thing at that spot you can play some acapella vocal tracks, also close mic'd, with no effects, and once again listen as you walk around the room. This will help you to get a "feeling" for the natural empty room response, and maybe even motivate you to try several different locations for each instrument, before starting on the treatment design. It is quite possible that you'll find a location that you really like for the drums, and another that you really hate, so it would be good to consider that the room should be treated around the "good" location for drums. Etc.

I'd suggest spending quite a bit of time on this, just walking around the room with various speaker locations and various dry instrument tracks, to help you decide on a rough layout for where you will likely have the instruments for a typical session. Mark those on your plans, and then based on that layout, start planning the treatment. That way, you'll b working with the room, not fighting against it, with your treatment.

Of course, having said all that, it IS still an empty room, sounding very resonant, harsh, bright, boomy, and ugly, so you might not find ANY locations that you really like, for anything! In that case, just choose the "least bad" locations.

- Stuart -

#11

Got it! thanks!

#12

Pleas do some of that REW testing when you can, Howie! It would be cool to see how your room is performing, and to help you plan the treatment.

- Stuart -

#13

I will be doing the REW test this weekend. I planned on doing it sooner but I had my suitcase with all my mics (3), cables (3 each), mic stands (2), plus my XLR to USB adaptor stolen last Sunday. I will give a summarized version of the story on the studio construction thread. Big wake up call, but it could have been way worse. All of my expensive drums, PA, monitors, etc. were in my main house. But what they took prevented me from conducting the test. I am waiting on a tall K&M mic boom stand to arrive this morning and then I am good to go.

#14

Hi Stuart and all,

I did my calibrations and made my first test. I am just uploading one file to see if I did everything ok before doing more tests. Since this is a tracking room, I only used one speaker. I positioned the speaker where I envision my drum set going, so there is not a L baseline, R baseline, L+R baseline. Just left baseline.

Howie

howiedrum REW 1.mdat: (3.19 MiB) Downloaded 1294 times

howiedrum REW 1.mdat: (3.19 MiB) Downloaded 1294 times

#15

I just downloaded the MDAT, and I'm looking at it, but it seems there's an issue with your setup. Here's what your soundcard calibration shows:

That curve should be almost completely flat, but it shows a large 5 dB roll off on the lows, and a large 5dB boost on the highs. So you have some type of EQ applied in your signal chain. And since you did that with just the loop-back connector across your soundcard output and input, this has nothing at all to do with your mic or speaker: it is within your system, or your soundcard itself. Modern soundcards have very flat response, with maybe just a small roll off at the very high end and low end (fraction of a dB). I would suspect that you have some type of filter applied within your computer settings. Either that, or in your soundcard itself.

Also, do you have a speaker that goes lower in frequency? Or maybe you have some type of cutoff filter set somewhere? It rolls of real fast below about 130 Hz, and there's nothing at all below about 60 Hz. Your K12's should do much better than that! Are you sure you have them set to flat response? The K12's are supposed to START rolling off at 48 Hz (-3dB), but in your data the actual level at 48 Hz is more like -30 dB!

So, please track down these problems, and do the calibration again.

Apart from that, the data looks fine! And it's good to see that you have plenty going on in that room that bodes well for it being a good live room. Your decay times are approaching 2 seconds in places, and above 1 second for most of the spectrum (+/100 Hz to +/- 4 kHz).

I'm assuming it climbs even higher in the bottom end (below 100 Hz), but there's not enough level to see anything down there. In the high end you still have good long decays, even right up near the limit: around 600 ms at 10 kHz.

The reason this is good (but sounds terrible right now!) is because you have a lot to play with! Treatment can be targeted to make the room dead, or keep it live, as you wish, which is good! So you'll have t be careful with your absorption, to not overdo it. A common mistake is to use all the same type and depth in several places around the room... which usually leaves a "hole" in the spectrum, often around 250 Hz.

So, even though it sounds really awful in there right now, that's a good thing. You have lots of "bad stuff that you can use to your advantage, and turn it into "good" stuff...

(Sounds strange, I know...)

Anyway, please see if you can figure out why your soundcard calibration is off, and also why there is no low end coming out the speakers. In both cases, I suspect some for of EQ is being applied...

- Stuart -

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