Room treatment poll

[Colin]

Probably wont get read in this forum or this weekend, but here goes: what room treatments have you tweaking audiophiles tried and why; what works and what doesnt? Did you try an EQ first? Do you still use the EQ after adding room treatments? What size was the room you treated? How much did you end up spending? What proportion is the room treatment expense to your investment in your home movie and music reproduction system? How does your room treatment investment compare to your other tweaks or improvements: cables, tube rolling, vibration isolation platforms, etc. in quality of sound improvement and value for the investment?

Thanks in advance for all your responses.

[picky]

Man-Oh-Man:

Huge questions here! FYI: My theater is currenlty in construction.

EQ: Yes, I did try EQ first as it is built-into my Pioneer Elite VSX-49TXi Receiver and it is is automated (MCACC System): http://www.pioneerelectronics.com/pna/article/0,,2076_4151_20157532,00.html

Room Treatments: Because the theater is being built in a basement and there are cinderblock walls and a concrete floor, I went with a partially suspended ceiling that utilizes specialized acoustical foam tile from Illbruck Industries (Sonex) that absorbs 90% of the sound that hits it to help eliminate some of the reflections. They're called Harmoni Acoustical ceiling tiles: http://www.illbruck-archprod.com/ceilingwall/ceilingwall_harmoni.html They are made of Melamine foam that will not burn and has a Class 1 commercial fire rating per ASTM E84. 14-2'x2' ceiling tiles were about $600.

I am also using a thick, rubber membrane to cover all of the walls and the ceiling prior to drywall and/or ceiling tile application. This membrane blocks sounds transmitted from the upper floor and helps to stop any reflection that might occur from the cinderblock walls. Several companies sell this acoustic membrane at some rather high prices (more than $200 for a 48" x 60-foot roll). But, I found a roofing product at Home Depot for about $35 per 48" x 50-foot roll that seems to work just as effectively. Some roofers refer to it as "Ice Sheild". It is applied to the studs and the joists using short button-head nails. The "buttons" are plastic and act as washers and are also available at Home Depot or Lowe's.

After the room is completed, if I need to address any standing wave problems with the bass, I plan to install Sonex foam corner bass traps that are shaped like a triangle: http://www.sonex-online.com/Specialties.htm I do not believe these are very expensive. They may be used in corners and in other room boundaries such as where the walls meet the ceiling.

If early reflections from the side walls becomes a problem, I will install a couple of Illbruck Fabritec Wall Panels: http://www.illbruck-sonex.com/products/products_FABRITEC.html I do not have pricing. Sorry. I do know that they work great.

Just in case you were beginning to wonder: No, I do not work for Illbruck nor do I receieve any kickbacks. I have simply done a lot of research and I have a resource near my home that carries these items.

I also plan to cover the cement floor with floor tile and an area rug just in front of the main viewing area. I hope this information helps you! Best of luck!

-Picky

[artto]

The first room treatment one really needs to consider first is the itself. Its proportions. Its size. If this is not first taken into consideration, no amount of acoustical treatment or moving speakers around is going to make up for it, especially in the lower frequencies (consider that bass is nearly half of the musical range).

Next on my list is isolation. A quiet room is a good room. Look at how much money & effort goes into real auditoriums. Theres a reason you can hear a pin drop on stage at the back of the hall. Its not just about the acoustics. These places are built to be isolated & quiet. A truly good listening room or HT needs the same thing.

What works is BROADBAND treatment for both DIFFUSION & ABSORPTION. You need to consider both & do so across the full bandwidth of audio frequencies (as much as possible).

Room EQing is BS in my opinion. Whats there to EQ? The size of most domestic listening rooms is far to small for an equalizer to be much more than anything but a sophisticated tone control. Furthermore, its usefulness is basically limited to EQing the listening position only, not the room. The room size & proportions will have much greater affect.

I did not try & electronically EQ the room first. IMO there are more important issues, all of which ultimately affect the rooms EQ anyway. I did take measurements after making acoustical adjustments by ear for things such as flutter & slap echo, hot & dead spots, etc., not only in the listening position, but all around the room, and then confirmed the results with a calibrated mic & real-time audio frequency analyzer.

Convex polycylindrical surfaces are most efficient at diffusion. Inexpensive fiberboard such a Masonite can be easily curved to achieve this. Non-parallel room boundaries can accomplish the same thing, to a certain extent.

Its good to have a variety of treatment applications, using both absorption and diffusion. Ive had better results with more absorption in the rear of the room, wall & rear side walls. Absorption is often most effective in room corners so this is where the heaviest (thickest) absorption should first be applied to control the low frequencies. Consider, that the longest distances in the room are from corner(s) to corner(s). So naturally this is where the longest wavelengths (lowest frequencies) tend to collect, creating standing waves or pressure zones. These same pressure build-up's in the corners often causes the opposite effect in the middle of the room (cancellation).

For absorption I use a combination of Celotex (or Homosote) rigid insulation board, and combinations of 2, 3 & 4 Sonex anechoic style open-cell foam and Auralex 2 open-cell foam tiles, sometimes stacked 3 deep. I use Auralex LENRD (Low End Node Reduction Device) and MegaLENRD bass traps in the rear vertical & horizontal corners. Many folks think this stuff is expensive. And yes it is, relatively speaking, compared to products Celotex & Masonite which costs a few bucks per sheet. But it works.

How does your room treatment investment compare to your other tweaks or improvements? As far as Im concerned, you have not ever heard what your basic components or recordings sound like until youve heard them in a proper, acoustically tuned room. When you do, youll realize how worthless most so-called tweeks are. And the ones that do make a difference, will be more audible than ever.

And Colin.....I'm sure you've been there already, but in case you haven't, I discuss what I did in more detail in my post in the Architectural Topic Area (artto's klipschorn room). I'll will be posting some more pics & info in the near future.

[m00n]

All my tweeks and what not have come at the helping had of artto in my thread "artto, here is my results with a jpg of a basic room layout.". With the help of the DIY Rigid fiberglass I created in this thread. Too much information to try and dup all that there.

I have not been doing much... Well actually nothing in my theater for a while. Lost my motivation, but I am feeling a spark of it once again.

[picky]

Colin:

With all due respect to artto, whom I must admit, probably knows more about the subject of acoustics than I would ever hope to know: for my own personal room needs, the equalization-route (which he dislikes), coupled with the other things I'd mentioned, works fine for us. We did not have the luxury of developing a room of optimal size relative to all of the wavelengths, etc. So, we are working with what we have. Basements are not very forgiving size-wise. We are not about to take our room to the level that artto has taken his, nor would I begin to compare the two rooms. If I had to classify the two approaches, artto's would probably be the ultimate, while mine would merely be adequate. But, we like it just the same. Different strokes, I guess.

-Picky

[artto]

Picky..you had me so excited. I thought maybe you had found the source (OEM manufacturer) of Auralex Sheetblok ($$$) when you mentioned the ice shield material. One has to be careful of using a product made for one application, and thinking it is useful in another (like egg cartons or cork for instance. Bad for acoustical applications). Alas, such is the case with ice shield. Ice shield or WinterGuard is indeed a roofing material product. Its a rubberized asphalt fiberglass reinforced membrane used in lieu of conventional asphalt roofing felt or to protect vulnerable areas under shingles. However, I doubt very seriously that it has much acoustical or sound transmission blocking value, at least when compared to the pricey limp-mass vinyl sound barrier products from companies like Illbruck or Auralex. Its no where near as heavy/massive. Auralex SheetBlok is many times heavier (120 sq. ft. roll shipping weight was 190LBS) even though its just slightly thicker (1/8). SheetBlok is 6dB more effective at blocking sound than solid lead. It (like many sound transmission blocking materials) is most effective when used as part of a multi-layered construction system. I also have to disagree that it will be effective to stop any reflection that might occur from the cinderblock walls. Neither the ice shield or SheetBlok products would have much effectiveness in this application. And indeed, that is not what the products were engineered to do. Although the ice shield products may have some value in blocking sound transmission (as in providing some isolation between surfaces), it is definitely not in the same performance class with SheetBlok which has an STC rating of 27. (also, just a minor correction, ice shield is 36 wide (not 48) just like many other roofing products).

Some clarification on the EQ thang. IMO the only useful equalizers are those that have parametric capability for both bandwidth and center frequency. But even here, you are still introducing an additional component into the signal path. More distortion and noise (the noise is almost always apparent with speakers like Klipsch). And as Ive said before, the EQ will be valid for only one location (even Pioneer with their MCACC admits this between-the-lines). Outside of that particular location, it will have made things worse. Its the nature of the beast. You cant control things like reverberation time, slap, flutter echo or standing waves with EQ. If you get those things right in the first place, you wont need any EQ anyway. Youll have a larger acceptable listening area. And it will sound better.

And now that youve gotten me to read the Pioneer Elite propaganda regarding their MCACC, I must throw in my 2 cents on this product as well. Professional Acoustic Calibration set-up takes into consideration the reverberant qualities of your media room, and uses this information to adjust the frequency response more accurately for human ears. All-Channel EQ: equalizes all speakers to neutralize ambient reflections. Is there a big Yellow Button on the receiver or remote? You CANNOT neutralize ambient (room) reflections by equalizing you speakers! The two have nothing to do with each other. This is marketing department B*******. The other thing is these A/V receivers also introduce or achieve A longer reverb that is more like that of the original soundtrack. Excuse me? Do you really want to add reverb to the original recording or enhance it? No Thanks. Sounds more like an effects unit to me. But, as Ive always said, to each his own.

One final note: Picky, the tile you used in the washroom, looks like the same stuff (NovaBellei from Italy, got it at Home Expo) Im installing in my kitchen next week. Although Im making the pattern a little more random to break-up the continuous seams.

And just for the record, while my room is quite generous in its size, its size & proportions are by no means optimum. Its as close as I could get(same problem most other folks have)at the time.

[picky]

artto (et all):

On the Ice Shield rubber membrane and wall construction:

The roll of ice shield I was able to get at Home Depot measures 48" wide. The most problematic area of noise I must contend with in my theater is an adjacent utility (furnace/laundry) room. To eliminate this problem, I have built the following:

A double-studded wall consisting of a 2"x6" top plate and sole plate with 2"x4" studs that are staggered along each edge of the top and sole plates and not touching one-another. Between these staggered studs I have run one thickness of the rolled, ice sheild rubber membrane material. I have also added standard fiberglass insulation to each side of the ice sheild simply to fill the void. On the furnace side of the studs I have applied 1/2" sheet of B-C Plywood and a sheet of 5/8" Drywall. To the theater side of the studs I have added a 1/2" of Homasote sound deadening board and a 1/2" sheet of drywall. As with all walls in the theater, all studs were coated on each side with elastomeric chalk, prior to screwing the wall coverings to them.

The 32" door that goes from the theater into the utility room is an oak verniered, solid wood-composite door with aluminum strip-mounted, extruded rubber bead weather-stripping along the sides and top of the door and a 1-1/2" x 32" Flex-Guard Brush Seal sound barrier brush from Memtech along the door's bottom. http://www.flex-guard.com/brushield.htm

The results? From the theater, I no longer hear the roar of the furnace when it is operating, nor can I hear the washing machine during spin-cycle. My conculsion is that the wall and isolation materials are working successfully in concert with one-another as expected, although admitedly, the ice shield is not as dense (nor nearly as expensive) as the other vinyl barrier materials that are available.

I am very happy with the results I got for the money.

The bottom line for me was to follow the basic rule of thumb to isolate one room from another: In order to form a sound barrier, it is imporant to literally form a seal between the rooms. The ice shield and door weather stripping helped me do that, and for the least amount of money.

About EQ:

No arguement here. I realize I am introducing additional componentry into the signal path. However, when I do an A/B test between my saved EQ setting and the Dry signal path, I like the saved EQ settings best in this room. After all, we invested in this setup to make US happy. I'm sure you are happy with yours.

About the ceramic tile in the bathroom:

You were close....We got ours at Lowe's: Portobello 12" x 12" & 6" x 6" Ibiza Ceramic Tile, Item #: 121141 Model: 78288. We have been to both Home Expo (run by Home Depot) and to The Great Indoors (run by Sears) and they both have a huge selection of ceramic tile. This was my first-ever attempt at installing ceramic. It was easier than I had imagined, but it was still a lot of work.

-Picky

[artto]

Thats great Picky. Thats the way I built my rear wall (one third of my rear wall is adjacent to the utility room too). At the time (1982) things like SheetBlok werent available & the acoustalead product(s) was no longer made due to its now obvious environmental hazzards. So, as I have the opportunity to make some room improvements this winter in concert with some other home improvementsthat will affect it anyway, I may add a layer of SheetBlok and another layer of drywall to the utility room, especially if the furnace has to be replaced and things are easy to get to.

I realize youre satisfied with the result, but the ironic part for me is, that as I have recently made some substantial improvements, especially in terms of making the room more acoustically quiet, other noise problems are exposing themselves. The dryer which was not audible is now audible. Water pipes that are foam wrapped with aluminum facing & isolated from the building structure can be heard now. Even the new much quieter rubber suspension garbage disposal is coming through from upstairs.

So I guess I what Im saying is that while the ice shield membrane may be contributing something to the sound blocking equation, it probably isnt significant. Its not even close to the material that was engineered for this application. And that there really isnt such a thing as too much sound isolation or broadband absorption/diffusion. As you make improvements to the room in the future, as Im sure you will, saving a few bucks here & there now, may eventually expose itself. Sometimes you can do something about it. Sometimes you can't.

The tile sounds & looks like its the same thing. Im using 12x12, 6x12 & 6x6 sizes, fitting them to form a random rectangular pattern, like you often see used with slate (we have slate in other areas but the wife poo pooed it for the kitchen & she wouldnt stand for white tile either). This stuff fit the bill perfectly with its 5 tone color range & mottled darker details so it doesnt look dirty 10 minutes after its been cleaned. My kitchen floor needed quite a bit of leveling. The cabinets & countertop too. And like you said, it was easier than I thought. But what a pain in the a$$ ($pun intended). Much of it a logistical problem with moving the appliances back & forth over the work. I must have put over 1000 screws in that floor to get the underlayment & subfloor to stop squeaking before the leveling even started! Sheetblok installed as the last layer of leveling underneath the cement backerboard. Now I usually cant hear anyone walking in the kitchen above, but the aforementioned noise problems are now more audible. And so it goes.

[picky]

artto:

You pointed out a VERY profound discovery that we in the automotive interior engineering field have become painfully aware of over the last decade or so: Elimination of the majority of interior noise, always uncovers other annoyances not priviously realized! Such as the way that rear suspension struts are able to "telegraph" noise from the road right into the steel body structure along the strut towers of the truck area and back window region, thereby giving the rear seat occupants a free, live "concert"! Or, the elimination of engine noise reveals wind noise, etc. Thus, the same goes for home and business interiors: the elimination of know annoyances within a room will always reveals things (both good and bad) that we weren't aware of because their sounds were being masked by louder, more prominent sounds. {SIGH!} It never seems to end...........

BTW..the 2' x 2' x 2"-thick Illbruck (Sonex Harmoni) melamine foam ceiling tiles I am using in our suspended ceiling are also available (at an extra charge) with the sound blocking membrane already bonded to the unexposed side of each tile, which saves you some time in applying isolation materials between floors.

Everyone: If you do celebrate Thanksgiving Day, please have a wonderful one!

-Picky