Acoustic treatment for fireplace

[Truett]

See Focal center speaker in mantle. Fireplace is not used 99% of the time. So what acoustic features can be added that could be removed for a fire? Either something that stays behind and under the logs, or even something that comes further out if necessary.

By the way, we have metal and heat shield material under and behind the speaker, but it doesn't get hot there nearly what we thought. Like, not hot at all. Zero. And the speaker, which is two layers in, will not even know there is a fire, that one time a year.

 

[TLS Guy]

See Focal center speaker in mantle. Fireplace is not used 99% of the time. So what acoustic features can be added that could be removed for a fire? Either something that stays behind and under the logs, or even something that comes further out if necessary.

By the way, we have metal and heat shield material under and behind the speaker, but it doesn't get hot there nearly what we thought.

Just don't! That is one of of the daftest and most unsightly plans we have ever seen. Even small increases in temperatures are harmful to electronics, especially TVs. I expect you plan to put the TV above the fireplace which is another terrible idea. TVs really hate excess heat, and the screen is mounted way too high and very uncomfortable. You plan is a dead cert loser from start to finish.

 

[Truett]

Lol. You are hilarious. You must have your panties in a wad over losing the election.

 

[Trell]

Lol. You are hilarious. You must have your panties in a wad over losing the election.

WTF had his answer to do with Trump?

 

[Truett]

WTF had his answer to do with Trump?

Lol. You too? Well, it's either that or hemorrhoids.

 

[Trell]

Lol. You too? Well, it's either that or hemorrhoids.

Oh man, you’re daft.

 

[Truett]

It's a great morning, isn't it! Anyway, since we don't live in the Great White north, our fireplaces are for decorative purposes only, and compromises with my beautiful wife. You don't see it, but under the speaker is metal, and that metal is further lined outside with heat shield material. And when I say it doesn't get hot, I mean you can put your hand on top of the heat shield material. The heat just doesn't go to this spot. Like literally, none. But I digress, because the fireplace will never be used anyway. It's decorative here.

Even the mantle is purposely low so that the 150 in scope screen above can stay low.

Any unique acoustic ideas would be wonderfully appreciated!

What we are looking for here are suggestions and ideas to further improve the acoustics of this center speaker. Anything all the way up to a complete decorative insert to completely cover the hole, or something less to simply put up in the fireplace area.

 

[Eppie]

The stone hearth will have a greater impact than the fireplace cavity below. I would not bother with the fireplace but the floor could likely use a thick area rug to absorb first reflections from the floor.

 

[Trell]

The stone hearth will have a greater impact than the fireplace cavity below. I would not bother with the fireplace but the floor could likely use a thick area rug to absorb first reflections from the floor.

How about quite simply removing the fireplace, assuming it can be done without increasing the risk for mold.

 

[Truett]

The stone hearth will have a greater impact than the fireplace cavity below. I would not bother with the fireplace but the floor could likely use a thick area rug to absorb first reflections from the floor.

Yeah, good idea. The stone only goes 20 in, and then the rug starts. So we can add another rug to put on the stone. Thanks! You don't think the cavity messes things up too much to try to improve? This is not a dedicated theater, but a rather formal living room. But we certainly could consider putting some sort of insert in place, if it is even needed.

 

[Trell]

Yeah, good idea. The stone only goes 20 in, and then the rug starts. So we can add another rug to put on the stone. Thanks! You don't think the cavity messes things up too much to try to improve? This is not a dedicated theater, but a very formal living room. But we certainly could consider putting some sort of insert in place, if it is even needed.

What do you mean by a “very formal living room”?

In Scandinavia that would imply a room seldom used and usually for special occasions, and for sure there wouldn’t be any speaker hanging on any fireplace.

My grand parents had one and we children were not allowed in there, which, of course, made it tempting to enter.

 

[Truett]

What do you mean by a “very formal living room”?

In Scandinavia that would imply a room seldom used and usually for special occasions, and for sure there wouldn’t be any speaker hanging on any fireplace.

My grand parents had one and we children were not allowed in there, which, of course, made it tempting to enter.

How about I edit from "very" to "rather"? Will that work for you? I'll do that now. Did your grandparents have any good ideas on acoustics for a spot like this?

 

[Trell]

How about I edit from "very" to "rather"? Will that work for you? I'll do that now. Did your grandparents have any good ideas on acoustics for a spot like this?

I can assure you that my grand parents did not in any way care about acoustics in their home!

It’s not that they or their generation did not care about acoustics: Just visit an old church over here during a sermon or a concert. The composers and musicians knew this as well, of course.

So, I think that what you call formal is what we would call something else.

 

[Eppie]

Yeah, good idea. The stone only goes 20 in, and then the rug starts. So we can add another rug to put on the stone. Thanks! You don't think the cavity messes things up too much to try to improve? This is not a dedicated theater, but a rather formal living room. But we certainly could consider putting some sort of insert in place, if it is even needed.

There will be some mid and low frequency energy that wraps around the speaker and will reflect off of surfaces, but I think that the fireplace will have a small and likely imperceptible impact. If it's a real concern, the simplest solution is a custom acoustic panel the size of the opening. Add two short legs on the bottom so that it can stand up, and place it in the fireplace when needed. You can easily remove it when you have company. A 4" deep panel will likely stand on its own without feet but the panel needs to be at least 2" thick to be effective, more if you want to affect lower frequencies.

 

[Truett]

There will be some mid and low frequency energy that wraps around the speaker and will reflect off of surfaces, but I think that the fireplace will have a small and likely imperceptible impact. If it's a real concern, the simplest solution is a custom acoustic panel the size of the opening. Add two short legs on the bottom so that it can stand up, and place it in the fireplace when needed. You can easily remove it when you have company. A 4" deep panel will likely stand on its own without feet but the panel needs to be at least 2" thick to be effective, more if you want to affect lower frequencies.

That sounds like a great idea, and I can already picture some ways to do it. With the same wall fabric and it would match, too. What about something that would basically line the brick in the fireplace that could stay there all the time until the one time of year there may or may not be one short fire, lol? Maybe using the same wall fabric material and some foam I could line the surfaces of brick inside the fireplace and it would not be real noticeable. And when you do notice it would be acceptable in our situation, I think. But there would still be a cavity, with the logs serving as a diffusion, lol. But would lining the brick maybe help? I definitely see that the trump card would be the complete insert, and I can see now that we are definitely going to do that. But this may be something that could be left in place more often. Only if it would help.

 

[isolar8001]

How about I edit from "very" to "rather"? Will that work for you? I'll do that now. Did your grandparents have any good ideas on acoustics for a spot like this?

You are quite the snarky little motherfraker, aren't you ?
Those responding to your stupid fireplace thread were just being nice...

 

[Eppie]

Residential rooms are not perfect acoustic spaces. They have door ways, windows, furniture. First reflections will have the biggest impact on sound. I would get the rest of the system set up first and only worry about the fireplace if there are any issues with the center channel audio. My center is on a cradenza with open shelves below. I have never considered treating the space below the center. The impact is minimal.

 

[basscleaner]

It seems to me, that first of all it needs to arrange about terms. Are you really think, that first reflections are a negative factor for music listener? It depends of room kind and goals you whant to reach, don't you? Acoustics for recording studios is not the same for residental rooms. And any residental room may be "perfect acoustic space", if the volume, room shape, furniture, treatment and speakers are in harmony between them. And noise level, of course.

 

[Truett]

The most important thing for us for this center channel speaker is clear dialog. The room is large with 19' ceilings and we have hidden heavy absorption, 3 feet thick on most of the ceiling and large areas of front and back walls behind fabric. And heavy drapery at the first reflection side walls. This has really helped clarity. Just don't know how this fireplace cavity is affecting anything that we could further improve.

Whether we could put something that stays most all the time up in the cavity, lining the internal bricks, and only removed if we ever ever have a fire, all the way to putting an insert to cover the cavity opening.

The rug starts 20" from the speaker, and it has been suggested that we cover that 20" with a rug as well. We will definitely do that.

 

[Eppie]

First reflections are not a negative as many speaker manufacturers take those first reflections into account when designing speakers and crossovers. Those are typically side wall reflections though. Floor reflections are usually avoided but if the hearth is only 20" deep, then again, the impact is not going to be that great. If the ceilings are already treated and the side walls have heavy curtains, the room likely has enough treatment already. A simple clap test can show if the room decay is too long.

The problem is that room acoustics are complex. A professional would take measurements throughout the room and address specific issues. Making guesswork and adding random panels is like throwing darts at the problem. It's hard to tell whether things got better or worse without measurements. There can be expectation bias that will lead one to think that there are improvements when in fact there was no real difference.