Any way to reduce room echo w/o major mods?

[lbeck]

I just moved into a new home. Beautiful with high (flat) ceilings, hardwood floors, granite counter tops, and marble fireplace in the great room where most activity will occur - and where my home entertainment unit is. When we looked at the place I immediately noticed the echo, and the real estate agent said that would go away once we got furniture in the place. We've now been there a couple of months, have placed large rugs on the floor and have all of the furniture that we plan to get. The echo has been reduced in half but still terrible.

I have Googled room echo and of course the replies have addressed major modifications like putting up acoustic ceiling tile, hanging foam or burlap on the walls, and other gosh-awful ways that probably would work but are out of the question for us.

What I'm wondering is if there is any audio technology that will at least reduce the echo from audio components like TV and stereo. My receiver has several functions to ADD echo for a concert hall effect. Will any technology do this in reverse? Ideally something that can be tuned to our personal taste.

If we can at least get out electronics to be intelligible then we can have conversations in another room if needed. Of course, it will make my day if there is some way to remove the echo from all sound sources in the room without major modifications to the walls or ceilings, but I'm beginning to think that isn't possible

[mgh]

experiment with placement of speakers. probably moving them away from walls a little could help and definitely not in corners. if any two dimensions of your room match, would be very difficult to remove echoes. you can try room divider screens in that case.
that is about all you can do afaik without spending much.

[lbeck]

Thanks, MGH.

My objective is not trying to do something that doesn't cost much, but trying to learn what technically is possible. I think I know the answer (nothing) but want to explore all possibilities before I give up

Since this is a new house and newly decorated by my wife, hanging stuff on walls or placing dividers is not an option. I was (am) hoping that there may be some echo-cancelling technology. Maybe I can replace my receiver with one that has an echo-cancelling technology?

The speakers currently are behind doors that have acoustically transparent speaker cloth. I've taken them out of the enclosure (a home entertainment unit) and the echo seems to be worse with them out.

[Wombler]

I just moved into a new home. Beautiful with high (flat) ceilings, hardwood floors, granite counter tops, and marble fireplace in the great room where most activity will occur - and where my home entertainment unit is. When we looked at the place I immediately noticed the echo, and the real estate agent said that would go away once we got furniture in the place. We've now been there a couple of months, have placed large rugs on the floor and have all of the furniture that we plan to get. The echo has been reduced in half but still terrible.

I have Googled room echo and of course the replies have addressed major modifications like putting up acoustic ceiling tile, hanging foam or burlap on the walls, and other gosh-awful ways that probably would work but are out of the question for us.

What I'm wondering is if there is any audio technology that will at least reduce the echo from audio components like TV and stereo. My receiver has several functions to ADD echo for a concert hall effect. Will any technology do this in reverse? Ideally something that can be tuned to our personal taste.

If we can at least get out electronics to be intelligible then we can have conversations in another room if needed. Of course, it will make my day if there is some way to remove the echo from all sound sources in the room without major modifications to the walls or ceilings, but I'm beginning to think that isn't possible

Curtains and to a limited extent other soft furnishings have a noticeable dampening effect.

It's not clear from your original message whether or not you already have curtains installed though.

If it's compatible with your design scheme tapestries hung on the walls instead of paintings, as well as appearing to be there for aesthetic reasons, can also have a marked impact on unwanted reverberations.


Wombler

[mgh]

If you have a ten or twenty band equalizer, you could try cutting down on specific frequencies to reduce the echo, and yes, put the speakers back in their enclosures.
most probably the culprits are not the high frequencies.

[*.mp4 guy]

You can cancel echo in a similar manner to how noise cancelling headphones operate, but I don't know how effective or expensive this would be.

Echo cancellation (http://en.wikipedia.org/wiki/Echo_cancellation) (via dsp's) is mostly used for telephone networks, and recordings, so I'm not sure how you can make use of it, but its worth a shot.

[lbeck]

Thanks for your help. The answers here are pretty much what I expected. I just needed to hear it from experts before I give up. In general, I understand that I need to reduce the area of hard, flat surfaces as much as possible. We'll continue to do this to the extent that aesthetics will allow. I also am considering installing headphone jacks in the floor (easy job through crawl space below). I'll then use headphones for sound when the echo is unbearable. It seems to be worse with some audio than others. I have increased the higher frequencies and eliminated the lowest for things like speech from TV and that helps.

Anyway, now I know to stop thinking that there may be a miracle technology out there that I'm just not aware of.

Thanks again.

[CWR03]

It's an interesting thought, and something that seems feasible. I use noise-cancelling headphones at work, which do a fantastic job. I'm sure someone has come up with a method of cancelling an echo in the same manner, which I would think would consist of some microprocessor, a microphone and an input from the source so it would know what is echo and what is meant to be audio. Unfortunately, all my Google queries only came up with telecommunications solutions.

[lbeck]

It's an interesting thought, and something that seems feasible. I use noise-cancelling headphones at work, which do a fantastic job. I'm sure someone has come up with a method of cancelling an echo in the same manner, which I would think would consist of some microprocessor, a microphone and an input from the source so it would know what is echo and what is meant to be audio. Unfortunately, all my Google queries only came up with telecommunications solutions.

You must have used the same Google terms that I did. Cause I got the same results. Like you, I was thinking that my dilemma is probably not that unique and that technology is probably available to sense (with properly positioned michrophone(s)) echo and remove it. Thinking this through, though, it would be a difficult task to do in real time. Removing echo from a recording is conceptually more doable.

[Wombler]

You can cancel echo in a similar manner to how noise cancelling headphones operate, but I don't know how effective or expensive this would be.

Echo cancellation (http://en.wikipedia.org/wiki/Echo_cancellation) (via dsp's) is mostly used for telephone networks, and recordings, so I'm not sure how you can make use of it, but its worth a shot.

I'd imagine that would be impossible.

Removing an echo from a source is entirely different to removing unwanted soundwaves that are already travelling through the air in conjunction with desired sounds.

When you're removing an echo from a recording you're removing it before playback.

If you played that echo reduced recording in an echoic room it too would produce echoes. The echo isn't being generated by the recording it's being generated by the room.

The noise cancelling headphones remove all sound by generating an equal and opposing noise.

With today's electronics that's relatively easy to do and I remember seeing this demonstrated many years ago with just a pair of stereo speakers facing each other.

Removing only parts of the sound though is more difficult particularly when those unwanted reverberations have the same frequencies as the desired noise.

I don't think it's possible to do what the OP wants dynamically without substantially degrading the sound you do want to hear as any such process would not only cancel the unwanted reverberations but also the same frequencies in the desired sound.


Wombler

[*.mp4 guy]

Read the wikipedia article, their are algorithms for removing acoustic room echo, they are used for, ie auditorium systems, where you don't want the echo feading back into the microphone, I'm just not sure how feasable it would be for him to use something like that, or if something designed for concerts and and similar events could be configured to work in his situation.

[mgh]

The wikipedia article refers to combination of a mike and a sound system. The speaker sound gets back into the mike a little later and creates the echo. In other words, it is an echo created by a feedback into the mike. The problem he is facing is because of the acoustics of the room. The amount of echo will vary from place to place in the room unlike the mike speaker combination.

[*.mp4 guy]

yes, but as long as the mike is close to where you are going to be listening to the sound, you will still get significant echo cancellation.

[Wombler]

yes, but as long as the mike is close to where you are going to be listening to the sound, you will still get significant echo cancellation.

That's a method of removing feedback induced echo in recordings not stopping the actual echoes.

You'll cancel the effect of the echo on the recording but you'll still hear it in the room.

Don't forget the OP isn't using an electronic microphone he's using analogue ears. :)


Wombler

[mikeytown2]

Check out this article for more ideas
http://en.wikipedia.org/wiki/Acoustic_quieting

You could attempt redirect the sound to another room after it hit the couch, instead of letting it bounce around. Placement of your current furniture/speakers is key. You could even try pointing the speakers at the wall/floor/ceiling... try all options! Stuff like this is kinda a black art IMHO. avoiding 90 degree angles would be my first suggestion.

[2Bdecided]

Apart from the obvious (more damping, speakers closer to you than to the walls, you closer to the speakers than to the walls) you could try putting the speakers on the side walls, and sitting behind the line between the two speakers. It's a rare but sometimes useful speaker configuration - it works best with special speakers designed for it, but it might help here, depending on where you have rugs, curtains, hangings etc.

Cheers,
David.

[williamshood]

Every room I've ever used, if it's smaller and indoors, has had some echo. Changing locations isn't going to fix something that seems fairly universal, so I'm looking for ways to fix it using where ever we go. I'm looking to purchase light sound blankets that can be tacked up, but where to place them is an issue when you're shooting dialogue, especially back-and-forth OTS stuff that'll show half of the room. They'd have to be light enough to hang easily without tearing the walls up with mounts, as c-stands are expensive as hell. I'm also wondering what to do with corners, as I hear that's where a lot of the noise comes from. Blankets can go on the floor if there's no carpet, but where, specifically, is more of the question.

Here's an example of a film my friend just finished. It looks great and is edited very well, but the only criticism I have is the sound. A lot of echo and a constant hum under all the audio. Music covers it, but you can't use music over dialogue.

I WARN YOU, THIS IS NOT SAFE FOR WORK OR CHILDREN. THERE IS NUDITY. If this isn't OK to post here, I understand, but it's a perfect example of the problem I'm running into. Great video, great editing, poor sound, and it takes everything down a bit with it.

[hello_hello]

It sounds like maybe the sound is finding it's way up to the ceiling, which is high, bouncing around up there for a bit and then making it's way back down. If you already have the room furnished and have rugs on the floor the ceiling is the most likely culprit. If that's the case then deadening the ceiling is probably your only real option.

[hello_hello]

What about painting the ceiling using a textured paint instead of it being flat? I've seen ceilings in a couple of venues which seem to be painted with a paint containing some sort of rubber compound. The end result is a fairly textured finish and a pretty dead sounding room. Is there such a thing as acoustic paint... which is readily available?