komencanto, post: 443625, member: 50097 wrote: Since I'm recording voice only, I'm thinking I might get away with using only 2-inch thick panels (2'x4' OC703 fiberglass)?

I'm far from being an acoustician.. but 2'' thick will get rid of flutter echo and reduce natural reverb of the room but will also change the frequency curve of the room and suck out the highend..
It may not be what you want.

The first thing I would do is to record in the room while intact. Post samples if you want and let's find out what defects we are dealing with.
Second, what is the level of quality you are aiming ? Is it for radio, movies, audio books, or just for fun ?

Start with this

https://www.amazon.ca/dp/B01182HM9K/?tag=r06fa-20

pcrecord, post: 443626, member: 46460 wrote: I'm far from being an acoustician.. but 2'' thick will get rid of flutter echo and reduce natural reverb of the room but will also change the frequency curve of the room and suck out the highend..
It may not be what you want.

The first thing I would do is to record in the room while intact. Post samples if you want and let's find out what defects we are dealing with.
Second, what is the level of quality you are aiming ? Is it for radio, movies, audio books, or just for fun ?

I will get some samples.

It will be for a serial audio drama podcast, which for the most part is just for fun; but a not-insignificant amount of the satisfaction will come from having pretty high-quality audio. I have heard some audio dramas that stand up surprisingly well with sub-par audio quality but I'm not sure that mine would be among them.

You said "23'x23".

This is your biggest concern at the moment. Any room will have at least 1 pair of parellell walls that create flutter echo. With a square room such as yours, you have 2 pair that will produce flutter echo at the same frequency compounding your room sickness acoustically speaking.

I suspect the easiest out , since you did as about treatment, would be to hang a heavy drape or blanket about 8 feet from any wall that wouldn't confine you.

Ideally you would construct a new wall to eliminate the multiple pairs but only as an option if you really wanted a better defined acoustic environment.

I use this room for other purposes when not recording, so a permanent wall (that divides or drastically skews the room) is not an option.

I may be able to purchase some used acoustic panels, if I can talk the seller down a bit. He has:

12 4'x8' 2" AlphaSorb Wall Panels (rigid fiberglass)

20 4'x6' 2" AlphaSorb hanging baffles (flexible 2# per cubic foot fiberglass)

The panels were bought in 2012 from AcousticalSolutions.com .

Would it help either to hang the baffles from the ceiling, or to arrange the rigid 4'x8' panels on stands, at non-parallel angles while recording? I could take them down / push them up against a wall when not in use...

More generally, how might I treat the room with these? How many of each would I need and how might I use/arrange them?

First, be very carefull about using a bunch of 2 inches thick pannel without other formats. 2 inches material will affect only the higher range of the frequency Spectrum. Which may create more problems.

Without creating a new wall (which is a great Idea) you could fill a wall with a bookshelf with various items in it. It will give you some place to put stuff (who don't need to put stuff away) and will create a pseudo natural diffuser. if you place this bookshelf behind your mixing position, it will resolve a many problems.

Then I would test the room to hear how it sounds. if you still have flutter echo or other defects, use a combinaison of 2'' and bass trap panels.. You could build your own for not much money, there is many video on youtube.. I made mine to be removable from the wall with a hard back and I can put them on feets to use like gobos..
Treat the first reflections first, don't put your mixing place to a corner but with equal distance of the side walls..

General speaking . ..if you do not make an attempt to remove the multiple pairs of trouble making hard boundaries then you need to eliminate as much of the boundary as possible.

At this point you are not as much treating as you are trying to get ahead of the problem that does exist in your current configuration.

How many people will be participating in your "serial audio drama podcast" at any given time?

Usually, one - parts will be recorded separately and mixed. At most, two.

That's a big enough room to an old-time golden age of radio drama, with 10 voice-actors and live foley / sfx artists. (like this cheesy old gem)

If that's in your plans, it would make sense to me to buy a bunch of acoustical treatments and try to make this room sound more like a soundstage. If this is for 1-2 people doing spoken-word I'm not sure it's practical, but it's your party. Is there no smaller room you could use? There's a reason voiceover artists and radio DJs are in cozy booths. If this is the only room available, personally I'd try to make one small dry area 1/10th that size, even if it's just by limiting the room reflections with gobos - unless I'm missing the point ( which is always a strong possibility ) and you absolutely need 529 sq.ft. of performance space.

dvdhawk, post: 444302, member: 36047 wrote: Is there no smaller room you could use?

Ironically, my original plan was to build a 5'x8' room in one corner of this room to record in - but I was advised to treat the entire room instead. :)

I do have a ~ 10'x10' spare bedroom, but the 23'x23' room is more accessible/public.

Which would be the better room to start with, assuming it will:

- always be used to record 1 (maybe 2) people, voice acting;

- never be used to record music;

- never be used for listening on monitors, or for mixing (this will usually be handled by my friend/partner in another state, who is a professional music/audio editor and composer, and has better hearing than I do).

About the gobos - would it be possible to get good-to-excellent results if they were used in the larger room?

Here are the room acoustics audio samples pcrecord requested.

The first half contains recordings in the large room (which I inquired about originally), and the second half contains recordings made in the small spare room I mentioned after dvdhawk asked if I had a smaller space available.

These are made with a Rode NT1-A into a Zoom H4n. I recorded voice and some percussive sounds at recording levels 90%, 70%, 50%, 30%, and 10% in each of the rooms. I tried to keep the meter peaking at about -12.

Where to go from here? Is there a clear choice between the large room and small room as a starting point?

(PS - as someone new to this, let me just say that hearing your own mouth sounds at 90% is horrifying.)

[MEDIA=audio]http://recording.or…

Attached files room-acoustics-samples.mp3 (3.4 MB) 

"Where to go from here? Is there a clear choice between the large room and small room as a starting point?"

Yes...I think dvdhawk suggested the smaller room.

Thank you @Brien Holcombe and dvdhawk - I will set to work on the smaller room.

I just listened to your test recording. Honestly, neither room sounds all that bad at 70% or 50%. At the 90% settings not only do we hear the dreaded "mouth sounds", but with that much gain I hear way too much of the room, and something running in the background. The sensitivity of the condenser mic probably isn't doing you any favors here either. If you have one, try a basic dynamic vocal mic (Shure SM58, or similar) for the sake of experiment and see how it sounds.

Something else that I don't think got addressed from your original post, yes, you might need to worry about a big reflective table in either room. Something as simple as a towel, blanket, or whatever you have will soften up that surface from sound reflections and help to quiet any sound of papers rustling.

So, I built this 7-foot bi-fold gobo and placed it in the large room as shown in the attached photo (with the bookcase behind me to act as a diffuser, as recommended by pcrecord).

I did another set of sound test recordings and created three before/after MP3 files (also attached).

Even though my hearing is going, I'm pretty sure the recordings are noticeably better/cleaner with the gobo. I'm wondering if this might make it possible to record in the larger room... maybe I need to add some panels to the walls too?

I still have about 1/3 of a bundle of Roxul left - I might build a panel to hang on the short stretch of wall directly to the right of the seating position as show in the image...

I might build another set of these gobos too - it was actually kind of fun. I used dark grey felt for the fabric - the panels remind me of the Monolith from the opening scene of 2001: A Space Odyssey :)

[MEDIA=audio]http://recording.or…

[MEDIA=audio]http://recording.or…

[MEDIA=audio]http://recording.or…

Attached files 50pct-a-b.mp3 (573.5 KB)  70pct-a-b.mp3 (589.8 KB)  90pct-a-b.mp3 (327.5 KB) 

It sounds very good.
Were you at equal distance from the mic ? there is a lot more high end on the second recording.

pcrecord, each audio file contains a before and after - the "before" first, the "after" second. They're recorded at 90%, 70%, and 50% of maximum input gain (according to the Zoom recording level control). I was trying to keep the meter at about -12dB for each recording, so the tone of voice and sound characteristics vary between files.

It seems in the 90% recording especially that some of the lower end "boominess" has been eliminated; and in the other recordings, the reverb from percussive sounds (snapping fingers and clapping) is considerably less in the second halves.

In addition, I just arranged to pick up six used 2-inch acoustic panels, 4' x 8', this weekend. I will trim them down to 6' and put them between the windows (I guess?).

It sounds very good already..
Be carefull not to thame the room too much, or give yourself the possibility to move them around or cancel them with hardboard.

This thread should be kept as reference because it shows that threating a room even just a little makes a lot of difference on the end result.
That's why I love RO so much. When the recommendations become results ! ;)

What would help would be pictures of what it is you are doing. I know what a square room will do, large or small, so I would like to see what it is that is happening when you are doing these recordings. My gut says you are isolating the mic from the room. But I would have to see it to know it.

@Brien Holcombe - this shows the microphone and gobo position for the "afters":

http://recording.org/attachments/bifold-in-activity-room-png.16333/

The microphone is unseen in the "vee" of the gobo, in front of the chair.

Or did you mean actual photographs?

Tomorrow morning I'm picking up the 2" panels to put on the walls between the windows. It seems even if I block off the microphone (and most of the sound source) with the gobo, those walls will still reflect whatever sound does get to them.

The panels are 4'x8', and finished with fabric and mounting hardware. But I can cut them down to 4'x6' and re-glue the fabric, and then have six 4'x2' left-over sections of OC703 to do something else with...

Real stuff...not that...whatever that is...lol

If you isolate the microphone, like you are doing, from the room it is going to help and the room will interfere very little.

OK, this is my latest (and possibly final) configuration, and a... sound test? recorded for my friend and project partner in NJ, who has concerns about the more "dynamic" scenes - NSFW.

[MEDIA=audio]http://recording.or…

Attached files acoustic-treatment-test.mp3 (4.8 MB) 

The first voice sounds very nice. Round and clear.
The second and loud voice have a weird resonating room frequencies.. Was the speaker far from the mic ?
With a cut of 5db around 330hz and a 4db cut at 1k it sounds better (at least on my monitors) ;)

Brien Holcombe, post: 445626, member: 48996 wrote: If you isolate the microphone, like you are doing, from the room it is going to help and the room will interfere very little.

As I'm reading through all this, and seeing he only wants to do podcast type stuff, I think treating the whole room is a little overboard....just make some sort of large reflection filters (which is basically what he did).

To accomplish the same thing by treating the whole room and using no reflection filter, would be pretty extensive. Plus he has 9' high ceilings, popcorn at that. I think treating the room is overkill for what you are trying to accomplish.

I'm not educated in this field like some others here, but just from my experience, I would fabricate some sort of reflection filter setup for your mic/s. The room is huge, the ceilings are high, the mic is going to be right in front of you. You can either fix the room so that you can use the mics freely in the space, which is a much bigger project than the alternative, which is to effectively eliminate the room (which is what I would do if I was in your shoes). Unless the aesthetics are super important to you.

But I thought your first example was not far off from where you want to be.

What he asked first was "Suggestions for treating this room"

After much teeth pulling we can all agree he just needs to isolate the mics...because the only way that square room can be treated is 100% to completely eliminate it.

pcrecord : about 3 feet from the mic. I would get distortion otherwise. It's a Rode NT1-A - I don't think it's intended to be used for, basically, screaming. Would another mic handle that kind of input better? I would need that very infrequently, but wouldn't mind investing in a better-suited mic to have on hand when the need arose. Is the problem here that the original sound source is falling off relative to the reflected sound because of the distance?

@Brother Junk : The consensus seems to be that the bi-fold reflection filter / gobo is what I need to get things done in the short term. The aesthetics are not (too) important. I think I will start with this, and consider altering the room some time down the line and treating it with the panels. BTW, ceilings are 8' if it matters.

@Brien Holcombe : hypothetically, if I were to do something as radical as changing the room layout (by introducing or altering walls?) - what's the most conservative thing I might do? Skew a couple of the walls so there are no parallels?

I imagine I will have to pick up a book at some point if I keep asking questions.

komencanto, post: 445708, member: 50097 wrote: I imagine I will have to pick up a book at some point if I keep asking questions.

That book that was mentioned in this thread is often suggested to people.

komencanto, post: 445708, member: 50097 wrote: pcrecord : about 3 feet from the mic. I would get distortion otherwise. It's a Rode NT1-A - I don't think it's intended to be used for, basically, screaming. Would another mic handle that kind of input better? I would need that very infrequently, but wouldn't mind investing in a better-suited mic to have on hand when the need arose. Is the problem here that the original sound source is falling off relative to the reflected sound because of the distance?

Ok I get why I heard more of the room. The NT1-A is usually able to sustain high SPL so you could have just lowered the gain of the preamp. Of course with very wide dynamic contents, you could end up with very quiet passages that will end with a bit of noise once leveled. Another thing to do is to use a compressor on the way in but the internal one of the zoom H4N isn't the more natural sounding. A dynamic mic like a SM57 or an SM7 are great choice for screamers but need a lot of gain at the preamp to record lite passages.
Most of voiceover facility use external preamp and compressor or a channel strip including both. It helps getting better overall levels.
Something like the ISA 430, Millennia ST1 or others.. I don't care much for the avalon 737 that many have, I think it sounds too steril. (personnal taste here)

pcrecord : OK, I'm considering a Shure SM57, which, hopefully, will be OK going into the Zoom H4n for the (very) few occasions we'll need it.

Brother Junk, post: 445713, member: 49944 wrote: That book that was mentioned in this thread is often suggested to people.

I bought it (the older edition). It's fascinating reading, although I will stick with the isolation panels for now - they seem to do the job.

But if I reach the point that I need to record regularly during business hours, I will have to do something about the SAW MILL across the street...

BTW, it seems I live about ten miles from Rod Gervais.

Attached files

pcrecord, post: 445715, member: 46460 wrote: It helps getting better overall levels.

I read this really quickly and thought it said, "It helps getting better overalls."

Then I thought, "Hey, I'm not the only person in the world who still wears overalls!"

Now I realize, I still might be lol.

komencanto, post: 446412, member: 50097 wrote: BTW, it seems I live about ten miles from Rod Gervais.

What are you doing talking to us then man?

Bring that guy a pie and some coffee, or cigarettes and liquor, or prostitutes and heroin (whatever he's into, no judgement)....get to networking!!!

The book that I read waaaayyyy back when, all I can really remember was the writer's first name was Henry lol. I don't remember what the book looks like, the title, his last name, or even anything that I learned from the book. By that I mean, I probably learned a lot, but just don't remember that I learned it their first. It was about speakers design, not room acoustics though.

My point is, if he lived a bike ride away from me, I would be mowing his lawn for audio knowledge lol.

komencanto, post: 445724, member: 50097 wrote: OK, I'm considering a Shure SM57, which, hopefully, will be OK going into the Zoom H4n for the (very) few occasions we'll need it.

The SM57 is just a great all around mic. I got rid of mine, and I'm going to have to get another one to replace it. I didn't realize how good it was till it was gone.

To record today (meaning Sunday), I am literally having someone bring one over, bc my mics, a Bluebird and a Behringer Condenser don't cut it.