I live in a large cement room...

Hi. I would be grateful for anyone out there with acoustical knowledge to offer ideas. Here's my system, room, and issues to address;
#1. OK, THE SYSTEM: Cary CD303, Cary sli80 (with a buffet of NOS tubes, so sexy they're almost pornographic), Meadowlark Hot Rod Shearwaters, 2 Coincident power cords, Harmonic Tech Pro silwayII interconnects, a Chang Lightspeed on the way, and biwired DH Labs T-14 (soon to be replaced with either Harm Tech Pro9 bi's or the Coincident wire). That will be all the upgrades for quite a while, I took some big steps this past year to put together a good system for what I listen to, which is primarily small ensemble acoustic instruments- jazz & classical.
#2. THE ROOM: length 24' width 17' height 8'. Hard tile floor, cement walls, and cement ceilings sprayed with stucco textured with kitty litter, wasn't my idea but it's a nice effect.
Currently I have my speakers 8' out from the short wall ( I live alone :-), and 4' out from one of the long side walls, and 7' from the other side wall, (it has to be this way due to foot traffic considerations), the speakers are about 7' apart from center of drivers.
ROOM TREATMENTS I'VE DONE ALREADY: the whole back wall is covered in two king size egg crate bed pads, then covered by two king size Martha Stewart (taupe colored) cotton blankets, a nice looking wall if I do say so with lots of double stick carpet tape underneath and duct tape on the perimeters. On the floor I've put two throw rugs- Kmart designer rugs, (~4'x7') from the exclusive Tangiers collection, which I throw out and replace whenever the dogs vomit on them. So there is a thin layer of carpet all around me between the speakers and my listening position. On the long wall to my right of the listening position (with the speaker 4' from the side wall) are two large sliding glass doors with panoramic views of the Caribbean, ( I'm in St Thomas, which is why the house is all poured cement). There is a sheet thin drape over the windows. Behind the speakers along the back wall are lots of cardboard boxes from all my equipmemt, and CD racks etc.
ISSUES TO ADDRESS: How can I improve my soundstage/imaging? Speakers are slightly toed in. I don't seem to be able to attatch anything to the ceiling due to the kitty litter, it just wont stick. I think better speaker cables will help. Frequency response seems nice, but I'd love to hear even better imaging. Sorry to be so long winded but I just finished a nice bottle of wine. Jay
Jay carlson: This has got to be the ultimate biggest bull shit story I have ever heard in the a/v world -no kidding. Think about it, you have those type of products and live in st.thomas but have a pure crap room like that, right! I am a builder and I am building a home theater room for a customer right now and will be done by the end of June. I would help you with your room but I am to tired right now swimming from St. John's trunk bay to St. Thomas. Sorry my arms are tooo tired from swimming that I can't type any more. Tiiired &&& Sleeeeeeepy. P.S. Buy some tickets & I will come over.

Thanks for the offer. It sounds like you've been here before, - next time you're down look me up, maybe you can help, I'll take you out to dinner. That's a long swim, especially since the water hasn't warmed yet up from the bitter cold winter temps, (I've been here a few years). Actually yes I guess my post was part B.S., I'm on the Northside, Magen's, so technically I'm lookin at the Atlantic. Maybe you'll have some helpful advice after a good night's sleep? thanks, J
Hi Jay
I have the same situation here on Guam. I,ve done some extensive work with my room. I took 2in. thick foam sheets and covered the ceiling and in the start of the second layer of 2in. sheets.This has made a great leap forward in soundstate and presentation of the musical event. My walls are similar to yours with carpet padding 2 sheets and beige carpet over that . Tile floors are covered with thick oriental carpet and the windows have been treated with 6x6 sheet of 1/4 plywood which has 1 inch thick insulation sheets and covered with dark brown cotton cloth stapled to the back side.
Back to the ceilings. I have the ceiling devided into 3 sections.The 2 inch thick foam sheets have been cut into 8 in,wide running the length of the ceiling, this canceled alot of the slap echo out, which increased soundstage.
Not to over deaden a room I put up first reflections and reflection directly behind the speakers 16in.wx10fth. the speakers dunlavys sc 4 a,s are 6ft. in to the room and 3.5 ft from side walls.The side walls have been treated like the rear wall.
My room is 13x10h x 39ftlen.Its taken over 1 year to get this far down the road the system is stating to be very very musical.
Christ jay, you describe a room like that and then write 'issues to address? how can i improve my soundstaging?'!!!!!

if i understand your room description correctly i think there's a good chance you're never going to get laid again! we've got some serious problems on our hands here and your worried about imaging??

this is going to be a tough one guys. this man needs some help.
Leave the rugs. Take the rest of that crap out of the room and replace it with a set of Argent Room Lenses. They work. I bought a set (of 3) here on AudiogoN for $850, and it was like I had spent the money upgrading a major component.

LOL! No problem in that dept. I have the opposite problem really. I've got to be careful, and strong. Jay carlson is a man of steel. There are a few very nice women on island who want me right now, but I'm trying to be good while my girlfreind is in the states for a couple weeks. How could I stray when she's bringing me back some of my favorite beer? (Geary's Pale Ale from Portland Maine).
Actually, I've found there is a little known and lesser discussed INVERSE W.A.F. in effect when you live alone. It's true. All those placement/room treatment issues you married guys get harped & bickered at about by your wifes are the same things that "visiting women" find so intrigueing. It's kind of like the "wedding ring = babe magnet" theory if you're familiar with that one.
Yes, the women that pass through my jungle love nest think it's pretty damn cool the way the living room is set up. And they can't wait to sit in "THE CHAIR" ;-) J
My dad lives in a small cement room. The feds provide it
free of charge. I dont think he's too worried about imaging though.
I wanna die and be re-incarnated Jay. Betcha the bastard hit it rich on the dot-com run up and bailed before NASDAQ fell apart. I'm sure he has every vinyl release know to man too. Following that thought a little further, the SOB is probably well endowed and can drink anyone under the table!
The biggest image I am receiving here is the one where I wish for a pair of wading boots.
Actually Jeff I live a very modest life. I don't own the house, just have an apt. in it. (house-sitting). The owner comes down a few times a year. I guess it's kind of like Magnum P.I. Remember that show? no vinyl here though, and no dot-com dough either, although there are a couple of dot com kids here this week, (the upstairs rents out weekly about half the year @~9K/wk). These two 20 something bright kids are down here getting married tomorrow, they flew down over 100 family & friends, putting them up at the Ritz Carlton....Man, must be nice, the bride to be founded getconnected.com, the groom started some other .com suppplying biotech co.s with stuff. I supose they'll be broke in a couple years, but for now there having fun.
The big problem I see in the above is easily rectified. Simply change the dogs' diet.

wedding ring theory: i get it. it also sounds like the wet-cat in the rain theory might be at play. they see it as a cry for help.

'the chair' huh? hm. that's a whole different thread :)
The room isn't that bad, at least you can actually run your simple little equations to predict the room's acoustic behaviour and they might work since cement is the closest thing to the constant ideal reflective substance the formulas assume. But get rid of the eggcrate foam; its not designed for absorbing sound and probably messes up the sound more than it helps it. Auralex measured it and it had an nrc of only .40 not to mention it isn't as linear in behaviour compared to an acoustic foam. The sliding window isn't great but workable. You mainly need good acoustic treatment, speaker placement, and measurement-and keep the dogs out so they don't vomit on stuff.
Ezmeralda is right on. Most foam is not NEARLY as absorbent or linear as most folks think that it is. As such, it can totally skew the frequency response of the room. I would HIGHLY suggest checking out Jon Risch's website. Sounds like his sound absorbing panels, bass traps, etc... would be right up your alley. They are also extremely cost effective. As a matter of fact, i think that he even has DIY versions of the room lenses mentioned above. You can probably build several sets for WELL under $100. Sean
Jay; nice to see someone with a thick skin AND a sense of humor. I've had success using various ASC products in a more conventional 14 X 22 wood room-- mostly 11" X 4 ft. tube traps and 15" X 5 ft. panel traps.

In your situation, I'd want to use 16" traps in the corners, and get some major carpeting on the floor. Also, I'd want several 11" tube traps and some panel traps judiciously placed around the room. The ceiling will be less of a problem with the walls and floor treated. I suppose getting bulky ASC products there could be expensive? Cheers. Craig
..... Got to www.tubetrap.com for ASC products. Craig
Sean & Craig,
Thanks for the helpful ideas. I'll look into them. Yes, shipping things here is quite expensive. I think a DIY approach would be the best.
Jay, you could cut out the shipping expenses very easily. Just provide air and a rental car, a place to stay and my wife and I will bring your order down for you. Lemme see, how many bass traps can you fit in that carry-on honey? Of course I won't mention how the last time I flew to St. Thomas on Leave Island Any Time airlines, the leaking fuel came in the rear door, driving all the passegers to the front so we could help the pilot land as quickley as possible. Some luggage had that sweet jet-fuel aroma for the next couple of years......
Anyhow, good luck, and call if you need a couple of mules.
Look at these sites echobuster.com, auralex.com, silentsource.com and xoom.com will get you jon risch's homepage that sean mentioned. There is also RPG at audioadvisor.com who has a webpage too. I've done the Jon Risch DIY treatment and the panels work well, I can't say the bass traps were that effective, at least that I could tell with my system. (I doubt I had any air spaces in the bass traps). If you have the money the ASC is good like garfish uses. Personnally, I wouldn't mind paying the money for them even though they are a bit overpriced IMHO; There's nothing that looks as nice as having something professionally done. However, my room won't facilitate them right now.
Jay: I have that humans make good bass traps when I throw parties, So..... invite all your lady friends over and that should quiet down the room and also test your Inverse WAF theory. Good luck, you might need it.

Brilliant! but I've tried that- while the bodies make for good absorption, there's a noise factor that I just can't control. Perhaps a combination of well placed ladies and duct tape would be the perfect solution. A well endowed woman in each corner, and a few others strategically placed throughout the room might just be the ticket.
Hi Jay
Since Iam the only one to deal with the same situation you are in...The biggest improvement I made was the ceiling.
Foam may not be the best according to other post..but I have expereince in this and they Do not..
Jay I cannot stress this enough.. do the ceiling. After 4 inches of foam on the ceiling It is without a doubt the biggest improvement you well make .
Room improvement is like ..Dunlavy on cable doesent matter. has long has it measures.B.S> Every situation is different,,foam may not measure but listen..
I envite anyone to come and listen to my concrete fortress before saying diff. Ezz and sean you two are most welcome before casting or stating diff.
Put up or shut up
Evo845, I never said foam wasn't good or its not the best. I said the eggcrate foam you buy at walmart/kmart/etc. isn't good, and for that matter not anywhere close to the best. Its designed to go on your bed, not the wall. Now I'm sure if you put so much on the wall that it absorbed all the sound (nrc of 1.00 across the spectrum because foam does measure) then the non-linear absorbtion characteristics of it wouldn't matter. Acoustic foam, on the other hand, can work well and I have no objections to it, I even recommended auralex.com which does foam only. A well designed 2" acoustic foam probably has roughly twice the absorbtion of typical eggcrate foam which means Jay won't have to buy as much for his ceiling/wall, not to mention the added benefit of better diffusion provided by the texture various acoustic foams offer. However, for absorbing bass, some of the other devices, ASC bass traps and possibly even hemholtz resonators, may be more ideal. Exactly where the foam, or whatever acoustic treatment is employed, goes is subject to the specific dimensions of the room.
While on the subject of room treatments, I'm reminded of a tweak that I read about in Stereophile's Fine Tunes. The suggestion was to place a pair of unused speakers into the corners of your sound room, not wired to anything, acting as passive devices similar to Hemeholtz resonators. The tuning can reportedly be varied by placing various resistances, or even a short, across the unused speakers' input terminals. Placement can also be varied of course. I have no spare set of spk's so have never tried this myself; just passing it on to anyone possibly interested.
I stand by my statements pertaining to the non-linearities of foam. This even applies to "professional grade acoustic foam". If you don't believe me, read what one of the foremost experts in the acoustic industry has to say: RPG.


If you follow the red line on the chart, this is equivalent to the 4" of foam that Evo mentioned. For a quick comparison, take a look at the other frequency response graphs. As you can see by RPG's own charts, the results of using professional grade foam can REALLY skew the tonal balance / frequency response of a room if your not careful with it. This is due to the fact that it does not absorb all frequencies in a linear fashion. Now if you take into account that "non-acoustic foam" will have different and uncharted ratios of absorption across the band, you can REALLY get into some hard to deal with and irregular responses. I'm NOT saying that foam won't work, just that you have to know what your working with and how to get the best results from it.

For a good reference on working with acoustics, you might want to pick up a book by F. Alton Everest entitled "the master handbook of acoustics, volume 4". Here are two different sources. Depending on what you might need or where you might order from first will depend on where it is actually cheaper / more convenient to get it from. Otherwise, it is the same basic price.




Hope this helps and clears things up a bit. Sean