Acoustical Treatments Master Thread - Page 224

The air won't change if you are only sucking air out of the room.

I agree. And that was my point. His ambient temperature is the best he can expect. People / equipment will certainly elevate the temperature in the space over time. The solution with the rack ventilation was essentially to have the equipment just over ambient temperature, assuming that the basement would never reach crazy hot temperatures - although uncomfortable. Cheers.

I don't understand why "the air won't change if I'm only sucking".

Assuming I've got an appropriate inlet air channel??

I understand that the theater room air will be no cooler than the inlet air. Under some conditions, say only a few people in the room, I'm pretty sure the elevation will be tolerable. At some point this breaks down. I'm not an HVAC guy so I don't know when But that's where the AC comes in if necessary.

You need to understand that I don't have HVAC and that its impractical to install one beyond the mini split.

llj

Well then, you're not just sucking. You're getting blown, too.

There is a "supply" even if it is passive. "Supply" and "return" are both necessary. One without the other and there is no air flow.

I am in the process of converting a finished basement into a theater and will be using inwall speakes and AT screen.

Since I have existing wood trim that I don't want the acoustic panels to stick out too far past, would it be of any benefit to only use 1/2" linacoustic on the screen wall instead of 1"?

Not much. Many use 2".

Jeff

Pepar is right, and this is the lengthy HVAC discussion I was avoiding in my very first post to your question. You must have supply and return. If you have a passive supply, such as a window, door, hole in the wall, etc. then your air flow will be directly from your passive source to your active source - in this case the proposed Panasonic fan through your rack. But this won't accomplish what you are ultimately looking for - pulling heat out of a multi-bodied theater.

For example, let's say your rack alcove is near your theater door entrance. The pressure balancing I was talking about will create a flow of air between the door straight down to your alcove and NOT ventilate your room like you would like. Granted, there will be some thermal exchange between warm and cool air, but ultimately it will have little to no impact. And even if your passive supply (i.e. a "hole in the wall") is allowing air into a tightly sealed room with the only escape being the ducting attached to your equipment rack, this will NOT allow for thorough mixing of the air in the room to cool it down to the same ambient temperature as the rest of your house (the area just outside your theater). There will be some minor air mixing, but nothing of any consequence whatsoever.

So, to address your original question / concern . . . exhausting the heat from your equipment into the theater through a single whisper quiet fan panel with multiple variable speed fans is not going to have that great of an effect on the overall temperature in your theater room. Any heat impact will be minor in such a large theater space. So as long as your equipment is ventilated, putting the "heated" air from your equipment inside or outside the theater is not going to really matter. So I would close up your equipment alcove and use the thermostatically controlled fan panels.

Now, for the greater problem of cooling / ventilating your room. A picture of your room would help greatly, but even if you used one Panasonic fan to supply your room and then used another of the EXACT same Panasonic fan to remove heat from your room would be your least expensive pure forced ventilation option. The supply fan would be installed in a separate room of your house and then ducted into your theater. In other words, the "exhaust" of this fan would be coming into the theater room, preferably near your seating position. The other fan would be located on the ceiling or as high on the wall as you can at the OPPOSITE side of your supply fan to allow for proper mixing of the room's air. Keeping the fan high will obviously capture the warm air that has risen to the top of the room.

Your only other option is to add the dreaded air conditioning unit. Let me know if you have any other questions.

In fact, one might argue that the shallow depth might do more harm than good (shallow depth = only working on a small range of frequencies at the high end of the audible range which can suck the air out of the high end of the sound because it only deadens sound at those high frequencies instead of a broader wider more even impact across more of the audible range -- which is what a thicker panels does). A few thicker panels with nice wood trim around them that is compatible with the look of your room might serve the sound better.

Whould putting a light behind an acoustic panne and having off the wall 4" instead of flush affect its affectiveness?

-Alan

The air gap typically helps improve effectiveness.

Hi Alan,
The answer is "it depends" on what kind of panel it is.

If it's a resistive-type filled with fiberous material (i.e. fiberglass) then an air space behind the panel is your friend and will allow the panel to absorb to deeper frequencies; placing the absorption out from the wall equal to 25% of a wavelength maximizes the absorption abilities of a resistive-type panel. A 4" air gap is equivalent to 25% of 847Hz. Try and pull it out further to say 6.8" or more to get absorption down to 500Hz which is at the top end of most domestic room's transition frequency zones. Absorbing a broad range of frequencies is best so as not to throw off the spectral balance of the reflections and reflections of those reflections.

If the panel is a diaphragmatic-type which is best hung right against the wall for max effectiveness then moving it out 4" will diminish its effectiveness.

Hope this helps somewhat.

Hi - plse let me know if this should be a new thread, but it seemed to go here.

I'm building a mancave from scratch... the current design is shown below. This is a golden trapagon, with ideal average dimensions. Speakers as shown are placed per Vandersteen method.

I'm thinking that I should start with 'superchunk' type traps in the 4 corners, and first reflection broadband (4", w/ about 1 1/2" air space behind) built into the walls as shown on the front and side walls and the ceiling. Does this seem reasonable? I'd like to incorporate all I can into the construction. I'll probably need diffusion on the rear wall as well?? I don't want a dead room.

Appreciate any advice. Thanks!

Attachment 192102

Guys,

Need some guidance on treatments.

I have a dedicated room 26 x 16 x 8 in a basement. Split level home. I have dual 18" sealed subs and needless to say, I hit high SPLs etc.

I have panels against all my main reflection points in the room and am working bass traps.

However my main issue right now is that I want to contain sound within the room so that it's not as loud in the upstairs part of the living room. What are my options here to seal the room off in terms of sound from the rest of the house.

Re-drywalling is not an option. I believe it's single drywall, older house.

It's rather late in the game to be looking at sound isolation. And, since you have no interest in adding a layer of drywall, you're pretty much SOL. I would image you have holes in the drywall for HVAC vents and recessed lights as well.

Electrostat ... looks like you have some great bass traps already ... they are called "windows". With a two channel room, your early reflection points should be diffusors or absorbers.

Thanks Dennis.

I know it's a tad late. Because it's not new construction, I was limited with existing structure when we moved in. I was afraid you were going to say that. I guess I need to look into how much work it would be. Yes, note the huge vents in HVAC in pics.

I already freshly painted and textured not long ago, so the thought of adding a layer of drywall to ceiling doesn't thrill me much.

Here is the room as it stands now.



GRRR. Shoulda, Coulda, Woulda

Dennis, yes...although they can't be open all the time!
Any other thoughts on what I can build into the construction that would help, or am I doing what I should now, and need to deal with any other issues when I can get into the room and listen or measure. Do you have any thoughts on the helpfullness of software like REW to tune a room?

Say a little more about what sounds are bothersome outside the theater. Thumping bass? Or are the full range of sounds audible and problematic?

For bass, additional construction is needed and it can be substantial. For higher frequency sounds some strategic surgery on the ducting, outlets, doors might help a bit.

The other alternative, unrelated to work on the room, is to consider using high quality headphones instead of the speakers at the times of day when the loudness might bother other household members. I lived in one place where my method was simple: spouse is watching the movie=use speakers, spouse is sleeping=use headphones.

Nathan -

Right now it's more of the full range that is audible from the upstairs living room. I mentioned it's a split level, 1979 house. living room/kitchen being directly above the HT. HT sits on concrete.

I've identified a couple of problem areas that I would like to address

1) Vents. These are super old vents that were there when we purchased the house. 3 of them in the room. What can be done here? Obviously the room needs to have heat.

2) Door. While the house is old, new doors were put on by previous owner. Home Depot specials, as you can see from picture. One door goes to laundry room, and the other adjacet door goes to stairwell. Lightweight, hollow cheap wood with pretty wide gaps. What are better options for doors?

3) I notice that some people put padded fabric material along their walls. (filled with fiberglass?). Would this help in my situation at all?

...even when closed.

This is beyond my area of knowledge, but I think if you do some searches for "vents" in the construction threads, you may see what people have done. I believe this is the most invasive of these three ideas, but may make a big difference. It would mean tearing into the walls/ceiling at those locations, etc.


This is relatively easy and effective: Use solid core, exterior grade doors with weather stripping. If you are really lucky, the spaces would accommodate a pre-hung home depot exterior door -- making it less arduous to install.


Not so helpful for preventing sound from escaping, but used in the right places (first reflection points) and of the right thickness (2 to 4 inches) it can greatly improve how the room sounds when you are in it (but don't overdo it). Bass traps, again, which are just bigger batches of insulation, typically in the "corners", will also improve the sound in the room, but not really help with your sound leakage.

-------------

Anyway, these items above won't solve the problem, especially in the bass range, which really is a structural thing, but may improve the situation for you.

OK I have tried the search function but can not find any guidance. I want to make a corner super chunk bass trap. All I was able to purchase locally in Certainteed 300 with the FSK backing. I have found that the FSK is OK to leave on if using a full panel with the air gap behind.

My question is do I need to remove the FSK backing if I am going to stack the triangles?

Thanks.

Yes, though you could / should add similar type paper to the new front surface that faces the room.

--Ethan

Thanks Ethan.

I have spent time reading the articles on your website. Thanks for helping us DIY guys.

Seating area of theater is directly beneath main house hallway.

The good news is the hallway floor/theater ceiling has 1.5 inches of gypcrete in it making it relatively massive. However, footfall noise is quite evident with unfinished theater ceiling.

The theater has a soffit around the perimeter. Initial idea is to drywall the room without the soffit and then apply the soffit on top of the drywall.

Considering clips and channel to isolate the ceiling. However, this means applying the soffit to the isolated ceiling drywall. Two no-nos... Hanging something other than drywall from the clips, and coupling the isolated ceiling to the walls via the soffit.

One potential solution is build the soffit region "normally" without isolation. Isolate only the field region inside the soffit. Don't know impact of not isolating the soffit region.

Comments? Other solutions?

Hi guys,
I have had my HT for about a year now and plan on adding some accoustical treatments hopefully early next year. I will probably start with bass traps in the corners and early reflections on the walls and ceiling. I have read most of this thread from beginning to end and it's full of information on how to treat a room, but not much talk on how the rooms sound after treating them. I would like to hear from some people that have treated their rooms and what they think it sounds like before and after. Was it worth the time and money spent, and how much better does it sound now? Is it a huge difference or just a minor improvement? I know every room is different and some people put more treatments than others, but if you do the minimum like I plan on doing, will it help enough to notice a difference. When I do plan on treating my room I will post some pictures of my room and hopefully get some advice on what I should do and where. Thanks

Hi Jay,

I think that most here will agree that there is a incredible improvement with their rooms are treated. Mine is small and it made a HUGE difference in every respect: cleaner more detailed bass, non-smearing of the midrange and highs (dialog is much more clear and cymbals are extremely crisp with no ringing), and just much nicer sound over all. I found it to be one of the best improvements to our system - money and time well spent. There is a lot of info on this thread (awesome resource!) and many knowledgeable folks that can guide you through you plans. Have fun with it!

Well, that's the kind of testimonial I was looking for. What size room do you have? Mine is 16.5ftW, 25ftD, 8ftH. I guess that's considered small. My room seems to echo quite a bit it seems like when I listen to music, but I can't hear it as much when watching movies. I just wan't to make sure I'm doing it correctly when I install the treatments, and not putting things where they don't belong.

Hi,

Quick question on Rockwool - 23kg vs 60 kg sq m?

I'm building false wall at both ends to reduce sound transmission to my neighbours. (It's an old terraced house in built 1850 in Dublin, Ireland)

Front of room:

Back of room:


Essentially I plan to:
1. throw up some batons on x2 walls touching my neighbours wall (mid terraced house)
2. install Rockwool in the cavities*
3. add resilient bars
4. apply some plaster board
5. and then use Green glue to apply a 2nd layer of plaster board.

* Rockwoll: I have choice of using:

a) Standard 6 inch thick 23kg per sq m
b) RW3 4 inch thick 60Kg per Sq m
* Option B is roughly 2.5 times the cost of A.

Question) is the higher density Rockwool worth the extra expense it or is it overkill when using in conjunction with decoupling & Green glue combination?

How does foam corner bass traps compare to other material bass traps?