Heavy curtains as acoustic room treatment?

[decryption]

Do floor to ceiling curtains do anything to treat a room's audio? I don't need them to control light (room is already pitch black) but is there any benefit to getting really thick curtains around the entire room as a form of deadening the room and reducing audio reflections?

Or is it a waste of time and I should use rockwool filled boxes hung on the wall or similar sound treatment foam blocks etc? (not my room, just some pics off the net to explain what I'm talking about).

 

[kemmler3D]

They do work, but tend to cut high and very high frequencies while not affecting mids or lows much/any. Unless your only acoustic problem is excess treble, too many curtains will make the room sound muffled / too dead / boomy, same as any other thin absorptive treatment.

Think of absorptive treatment like EQ - you don't want to cut frequencies more than it takes to get to a flat response. You ideally cut everything equally unless there's an excess of energy in a given frequency range. So ultimately a room fully covered with thick curtains probably won't sound balanced.

 

[EERecordist]

It looks like you have a fine room to work with. I would subjectively make your own notes in different listening positions with different content. I would measure the room with a microphone and software designed for that in your listening positions. Calibrated USB measurement microphones are about $100US. Then you can design your sound treatment. You could try to get one listening position flat with the microphone, software, and parametric/fraction octave filters. After that is an adventure if you want to get all listening locations flat. You could even update this thread on your progress.

 

[decryption]

They do work, but tend to cut high and very high frequencies while not affecting mids or lows much/any. Unless your only acoustic problem is excess treble, too many curtains will make the room sound muffled / too dead / boomy, same as any other thin absorptive treatment.

Ahhh, gotcha. Thanks for the info.

It looks like you have a fine room to work with.

The pics aren't my room! They're just examples - but yes, I've ordered a calibration mic (UMIK-1) and look forward to doing some testing to see what's going on in this room!

 

[kemmler3D]

Ahhh, gotcha. Thanks for the info.


The pics aren't my room! They're just examples - but yes, I've ordered a calibration mic (UMIK-1) and look forward to doing some testing to see what's going on in this room!

As a rule of thumb, covering more than 20-25% of the room's surface area (including ceiling) with treatments that don't affect bass can make the room "too dead". So in that case you might only use curtains on one or two walls, depending on the shape of the room.

The UMIK is a great investment, it saves you from having to rely on rules of thumb.

The main thing you want to look at is the overall frequency response in-room (I'd suggest MMM around the whole seating area) as well as the waterfall. The idea is to get an even (and short-ish, like 250ms) RT60 decay time across the whole frequency spectrum. Certainly easier said than done, but doing measurements is the best place to start.

 

[Chazz6]

Just a double-layer curtain of light fabric (having a weave loose enough to let plenty of light through) across a window behind the listening spot yielded (subjectively as I hear it) more even frequency response.

 

[Somafunk]

Curtains with pockets and stuffed/lined with 2” rockwool sheets, there’s an idea you can have for free.

 

[decryption]

The main thing you want to look at is the overall frequency response in-room (I'd suggest MMM around the whole seating area) as well as the waterfall. The idea is to get an even (and short-ish, like 250ms) RT60 decay time across the whole frequency spectrum. Certainly easier said than done, but doing measurements is the best place to start.

Is there a good beginners guide out there? I'm familiar with REW and getting measurements, but more info on how to interpret the measurements, etc?

 

[Holmz]

Is there a good beginners guide out there? I'm familiar with REW and getting measurements, but more info on how to interpret the measurements, etc?

I would suggest that you try to do the low notes first.

If the curtains are relying on the sound passing through them, then they are relying on velocity.
If they are not really permeable, then they are more of a pressure system (e.q. a tympanic membrane)…
If they are on the wall, then they cannot be a velocity based absorber at low frequencies, as there is not enough room behind them to get them at 1/4 wavelength.
So…
More of a plasticy shower curtain, might work for bass if the mass/area is high enough.

it probably makes some sense to try a blanket, a shower curtain, and something like a shower curtain with some heavy plastic/rubber glued onto it… if there is something like a St Vinnies around to get some daggy piece to test with.
That would at least get some ideas and results in order to determine if you are doing anything helpful.

Where in Au are you bruss?

I cannot really see the ceiling.
How much room do you have above you?
The boxes with the wool might be easier to float above you.

 

[amirm]

Pleated heavy curtain a bit away from the wall acts like a pretty good absorber down to fairly low frequency. Given the carpet there, the two combined likely make for rather dead room.

 

[decryption]

@Holmz I am in VIC! A blanket on the stands

@amirm Good to know - I would be using a very thick pleated curtain, it's basically a blanket, not a thin sheet.

Some pics of the actual room might help people instead of the examples I posted earlier that are *not* my room (just pics to show the curtains).

Rear wall:

Front wall:

Right wall (window)

Left wall (door)

Room dimensions:

I am looking to add thick, blanket like, pleated curtains from floor to ceiling on the left & right walls, possibly some sort of panel on the rear wall. Not sure about the front wall, probably nothing.

 

[Bjorn]

Doesn't work well because it's so band limited and it's not preferable to treat so large surfaces either.

Use more broadband treatment surgically placed to deal with specular reflections. And ideally quality diffusion for late arrival reflections. Only absorption generally leads to a dry, dead and non spacious sound and which isn't something we prefer.

 

[jaakkopetteri]

Everyone seems to talk about spread/closed curtains although OP doesn't need the light control. Having them open/bunched seems like a great tool if you have any consideration for looks. I remember seeing heavily pleated curtains influence down to 100Hz or so, and bunching them leaves plenty of reflective surfaces too

 

[Justdafactsmaam]

Do floor to ceiling curtains do anything to treat a room's audio? I don't need them to control light (room is already pitch black) but is there any benefit to getting really thick curtains around the entire room as a form of deadening the room and reducing audio reflections?

Or is it a waste of time and I should use rockwool filled boxes hung on the wall or similar sound treatment foam blocks etc? (not my room, just some pics off the net to explain what I'm talking about).

View attachment 374084

Yes they can, best to get curtains specifically designed for that

 

[Pareto Pragmatic]

Pleated heavy curtain a bit away from the wall acts like a pretty good absorber down to fairly low frequency.

Away from the wall is the trick, for sure, for lower frequencies. It also helps with my couch on a side wall; pulling it out just a couple inches kills some bass from a problematic corner. Not a lot, but enough to help for sure (and a slight angle helps a bit more). Many people never think about the back of things.

In this case, the curtain would allow for additional treatment behind if desired. Curtains look good in a theater setting. They are easy to "tune" by bunching/flattening the fabric, or even opening up slightly. So if you go too far, and things sound off, you can push the pleats to the ends of the curtain rods, leave the center flat fabric. If that's too far, you can open them up a bit, or a bit more. You can open them up at different places along the wall. Very "tunable" solution.

There needs to be enough length to keep those pleats full length, so keep that in mind when buying.

It's also easy to start with the back wall and evaluate the effects. Which is nice before going all in, budget wise

I would 100% try curtains first. Then go with additional treatment behind the curtains if needed.

BTW, consider ceiling treatment for this room. A couch width "cloud" midway between the front speakers and the seating area seems like something you want to do, if you are going to the extent of covering all the walls. Given in ceiling speakers, I think you want to control ceiling reflections at least somewhat to improve that vertical imaging (but I only run 5.1, so no direct experience on my end on this aspect).

Good luck!

 

[Holmz]

My hunch is that doing the sides, and something on the ceiling would be ”the go.”

It seems like mounting curtain rails on the sides and back could at least allow for measurements to be made.
(And you would need at least a single curtain to start with.)

Doesn't work well because it's so band limited and it's not preferable to treat so large surfaces either.

Use more broadband treatment surgically placed to deal with specular reflections. And ideally quality diffusion for late arrival reflections. Only absorption generally leads to a dry, dead and non spacious sound and which isn't something we prefer.

I have no idea on a HT whether adding diffusion on the back would be good, but “I get it” for 2 channel.
That sort of drives one towards a couple of curtains.

And it is sort of “standard” for HT to have lower RT60 than for 2 channel.

Do floor to ceiling curtains do anything to treat a room's audio? I don't need them to control light (room is already pitch black) but is there any benefit to getting really thick curtains around the entire room as a form of deadening the room and reducing audio reflections?

…

What is the problem you are trying to correct?
Is it specific bass problems, or higher freqs?
Or more like a theoretical “what to do”?

(We are out West.)

 

[Newman]

... The idea is to get an even (and short-ish, like 250ms) RT60 decay time across the whole frequency spectrum. Certainly easier said than done, but doing measurements is the best place to start.

ooh, so maybe I should be happy with mine:-

But I have posted before about the limited value of RT60 numbers in small rooms. Now I regret it! I can't really brag like I want to!

cheers

 

[Newman]

As a rule of thumb, covering more than 20-25% of the room's surface area (including ceiling) with treatments that don't affect bass can make the room "too dead". So in that case you might only use curtains on one or two walls, depending on the shape of the room.

@decryption
When Toole attempted to provide some guidance on room treatment, he seemed to be suggesting about 25-35% of wall coverage with good quality absorption. He also seems to be saying that more socially friendly rooms can get by with much less treatment, intelligently applied, and still sound very enjoyable to the audiophile. He added a lot more devil-in-the-detail, too, but….read the book(s)!
cheers

 

[Keith_W]

Cool, a gathering of Aussies

 

[decryption]

What is the problem you are trying to correct?
Is it specific bass problems, or higher freqs?
Or more like a theoretical “what to do”?

Before I get my measurement mic and find any specific problems to solve, it's just a simple question - do curtains do anything? So far the answer is yes, maybe, it depends