Home Theater Set up.

[Pockytofu]

I really didnt know where to post this, but I am wondering if anyone knows a good resource book for building a home theater.

I am not talking about selecting componets but how to actually build a room with correct sound proofing methods and sound set ups.
I tried searching online but I have only gotten general information.

Any info would be GREATLY appreciated!!!

[Grayson]

I might be of some assitance. I have built small theaters and mixing control rooms.

AFAIK there aren't many books on building home theater rooms. There are a few on building small control rooms and the priciples do cross over. Look for Alton Everest and Crraig Anderton (not sure of the spelling.)

To get you started you need to look at a lot of questions.

1. Is this tio be a single use room? Video only, Music, Living room
2. What is the budget?
3. How noisy is the area and how much noise will you be allowed to put out to the rest of the house and the neibors
4. What are you allowed do to the structure of the building?
5. What is the maximum wheight load for the floor
6. How much space do you have.
7. The Big One: What will your significant other require of the room?
8. Can you do the work yourself or do you need to find a contractor? Friends and or Family help"

I will be glad to let you pick my brain.

Grayson

[iroc409]

there are a few books and home-theater related magazines out there to check out. if you have a reasonably decent audio/home theater retailer in your area, check them out, they usually have that kinda stuff (at least as far as periodicals go).

books are probably best to google, but they aren't as easy to find.

[Grayson]

Most of the information Pockytofu will find will be on the electrical and electronic aspects of the project. He seems to be looking for help on the acustical end of it.

That my friends is an entirely different can of worms. And snakes too.

He will have to control the transmition of noise into and out of the room. He will have to control the production of noise in the ventilation of the room. And worst of all he seems to be looking to control the reverbaration in the room. All of these problems have sometimes led those who are not experienced in the field to call it a black art rather than a science.

I spent 15 years as a stagehand specialising in sound and lighting then I spent 15 years at NBC-TV New York doing the same thing. In that time I worked in nearly every Broadway Theater and all of the NBC studios at 30 Rock and in Broocklign. I became intematly familiar with a number of recording studios in NY from Electric Lady (Jimi Hendrix's personal room) to the old Columbia 30th Street room (an old church that was Frank Sanatra's favorite in NY).

At NBC we put together 2 editing suites, 2 radio studios and an audio sweeting room. I also was the mixer on the experiments to decide how to do basebal in stereo and the Sarnof (spelling?) Labs HDTV presentations for NAB. I was one of the team that first put Friday Night Videos on the air and did 8 years of preproduction mixing for SNL. My first two years while I was a field tech I did all of the audio patching for the Miss Ammerica Paggent. I think I might have a little information that is of use in doing a home theatre room.

Please feel free to ask any questions you want I will do my best to give or find the answers.

The prodject will be complicated and I suspect thart most of your friends will not notice the difference and not just because of a lack of knowledge. The human ear/brain combintion is very good at ignoring the things it does'nt want to hear. Your reward will be in a sence of increased clarity in the sounds you hear and in a decrease in the fatauge you will feel from listening to the programs you watch. That and the sattivaction of a job well done.

Grayson

[iroc409]

lol, i'm not questioning your abilities in the least grayson. i'm sure that you're more than capable, and would be an excellent resource for pocky. i just thought it would be good to have some more hands-on reference.

and yes, most of those are more electronics-oriented, but you can find a few things, and see others' layouts with pics in a lot of those pubs, for some visual reference, which may be helpful.

now if he'd just come back and lay things out a bit, i'm sure you can help him considerably

[Pockytofu]

Hehe,
Thanks for the replies. I didn't think anyone would...

Yeah, I am just starting this project and I have no definite plans.
Thats why I am trying to do some research and get some references.
For now I think I will be focusing on sound proofing design and then acoustics.

I will be moving to a new house in the next few months and when I saw the basement I thought, "I am so gonna build a home theater here!"
As for the room layout, I am still unsure about size. I plan on using this room mainly for watching movies and tv. Maybe hook up my computer with wireless av device.

Right now my budget is undecided because I still need furniture, but it will be easier to build the room now and then worry about components later. Good ol' inflation, technological advancement and falling prices will help me out in that department.

The most I got out of google was double drywalling is ok, but building a separate staggered frame is better. I was possibly thinking of concrete walls, but I know that will be pricey as well as more complicated.
Having a raised floor should improve boom from a sub.
But all this information is just from a couple of sites and I really don't want to spend a lot of money and time building redundant things.

So that's the gist of what I am trying to do. I could pay someone to do it but where's the fun or pride in that (as well as I really dont have the money to anyways)?

Any more info or ideas would be greatly appreciated.
Thanks!

[Pockytofu]

Ok, I was kinda typing about a whole lotta stuff but to answer the list:

1.Video Only.
2.Unknown guessing $1000.
3.In a cul de sac, noise is minimal. Inside house, no problems...maybe.
4.Anything.
5.This is in the basement on concrete flooring.
6.Basement is unfinished but biggest I would want to go is 16*12.
7.Hmmmmm...as long as the sound proofing works, its all good. Everyone likes movies!
8.I can do it as well as get family/friends to help.

I am still in the research/planning stages of this project.

[BaconGrease]

I've been batting around similar thoughts about my basement. Though I'm unwilling to give up much space (raised floor/redundant wall frames). I was hoping that spending a bit more in the insulation would make up for the difference.

[Grayson]

I have some bad news and some good news

First the bad news: You may find the budget some what tight to do a good job and the basement usualy meens a low cieling height.

Now for the good news: The location of your house and being in the basement will go a long way to reduces the need for extreme sound isolation measures. The walls of the basement are probably concrete or cinder block with earth on the outside. This should serve to control sound leaking out of or into the house relative to your neibourhs. You should be able to get away with filling the spaces between the floor joist with fiber glass bats, adding some 2X4 blocks between them and doing a tight sheet rock cieling to seal the top. That would leave you with only one or two walls that need to have a low transmition figure and anything else you do will just to control reverb.

The Ideal room would have a mildly trapasoidal cross section in all three planes with the back wall having a very gentle convex curve to it. The smaller of the two parallel sides of each trapasoid would be the front wall. This would leave you with no parrallel serffices. It is also desireable to not have any two major dimentions share a mathamatical factor. (The next time I go to the library I will dig up the peffered ratios for you) All this serves to smooth out the reverbarant field and diminish the effect of standing waves in the room. Doing it with the shape and size of the room makes the fine tuning a lot eazier and less costly. It would also serve to focus vision twards the front and the screen

If you are tying into the house HAVC system you need to decouple the ducting for the room from the rest of the house. The ducts need to be lined with fiber galss to absorb sound and should make at least two right angle bends between the room and the rest of the house. They should also be resiliently mounted to decouple them from the structure. On the house end of the ducts you want to use a short fabric duct to ferther decouple. Double the cross section and slow the airflow to reduce niose production at the regiters.

Try to think of a way to have the equipment rack in a pass through the wall with a heavy, stiff door on the front to remove any noise from the room. Use as much remote control as you can. Try to use lighting that is very efficient and also quiet -- less noise and heat to contend with. You are not trying to do quality control so you don't have to be to strick with color temparature in your lighting but you do want some light around the screen and I would go for some controled lighting for any tables and walk ways.

I am going to stick my neck out a recomend againts using even the best computer speaker systems even though they do come with an included amplifier. These systems are designed for what is called "near field" use, from one to three feet away from your ears not eight to ten feet to the front row in a home screening room. I saw some decent sets from Warfdale, Infinity and JBL at CompUSA today. I sugest that you make those a starting piont in your chioce of speakers. You don't need to buy those particular ones but get a good matched set, all of the same manufacturer and all using the same drivers for high and mid range. This will go a long way to nail down the localization of sounds in the sound field. If you don't go for exotic speaker cables get some really heavey wire 14 gage at the smallest and #12 for the subwoffer. It's not the current that the amp is sending to the speaker but the back EMF from the voice coil that matters. In this day and age do as much as you can in the digital domain, use optical cables to connect the system. A to D convertions are murder on Audio.

If you can raise the floor for the second row and all the way back to the back wall about 6", it will improve both sight llines and the sound for those in the back rows.

I hope this helps.

Grayson

[Grayson]

Read this: http://www.dansdata.com/gz029.htm

Grayson

[Pockytofu]

Thx, for the reply!

Hmmm, this give me alot to think about. I could actually make a somewhat curved wall in the back of the room fairly easy with drywall and plaster.
And I figured that the hvac and the door would probably be the biggest problems of sound coming in or escaping.
Yeah, the biggest problem comes down to quality, practicality and budget.

Also I was reading about tiled ceilings and acoustical panels, but are those just for sound reflection? With a low ceiling I'm guessing that it might cause sound too much revertabration?

By the way, was not planning to use computer speakers at all for this project.
Or are you saying that I should use that matched speaker set as the first step to determine audio placement and quality then buy speakers later?

Anyways, thx again for the help!!!

[Grayson]

I meen that you need to have a matched set no matter what you buy. You want all the front left, front right, front center speakers to be very close in performance with the center speaker perhaps having a little more power handling cappacity. The two rear speakers can have a little less low end responce than the fronts but all of the speakers need to have the same frequency and dispersion patterns. There was a trend a few years ago to use "rear" cabinets that had a figure 8 patern. They were placed on the side walls just behind the main listening position but not on the back wall. They seemed to spread the sound field more but lost some of the localization in the rear channels, they worked really well with sound field generator circuts to simulate listening in a variety of envirements like a concert hall or jazz club. The important thing is that all the speakers, other than the subwoffer of course, sound identical but you can allow for a little less base in the rears

Allong with the dimention ratios I will also dig up some suppliers of wall treatment products to help control the reverb field. I think one of them might have a computer program that taken the dimentions of your final room design, funiture placement and equipment layout could recomend what specific modules to use and where to place them. I saw this in one of the home recording mags.

Grayson

[superart]

What would be a better layout for an audience area that is pretty wide, like a long rectangular couch?

Would Layout A localize the soundstage too much towards the center of the couch? Would Layout B be better or worse?

Thanks.
I appreciate any insight you might offer?

[Grayson]

Here is the information I found so far.

Everest recomneds the following ratios: Ceiling HT:Length:Width
1: 1.14: 1.39
1: 1.28: 1.54
1: 1.60: 2.333
1: 1:90: 1.40
1: 1.90: 1.30
1: 1.50: 2.10

These ratios are for the performing room of a recording studio and produce a fairly even distribution of the resulting room modes that would tend to reenforce specific frequencies in the reverbarent field.

As for the trapizoidal shape, taking the last example and using a Ceiling Height of 10' would give you a room 10' X 21' X 15'. This gives some coincidence of room modes so a litlle splaying would reduce the strength of the standing waves and spead the peaks of the modes. What I'm talking about is about 6" difference in length along the paralell sides of the trapazoid and 3" to 6" bulge for the curved back wall. Just enough to make a building ispector or carpenter cringe.

The two books I have found in our local library system are How to Build a Small Budget Recording Studio From Scratch...with 12 Tested Designs, Second Edition by F. Alto Everest and Mike Shea, ISBN 0-8306-2966-1, and The Mater Hand book of Acoustic, 3rd Editon by F. Alton Everest, ISBN 0-07-019897-7

The first book has a screening room as one of the tested design projects

The second book apears to still be in print and is avaiable from the publisher at http://books.mcgraw-hill.com/cgi-bin...071360972.html

The vendor who has the program to select and place their reverb control panels is Acoustic Science Corporation at http://acousticsciences.com. I checked their site and the have a section on Home Theater.

For ideas for the rack closet take a look at http://www.silencecases.com.

If you can find a copy of Mix magazine they have a prety good cross section of adds from acoustic suppliers. Another mag to check out is HomeRecoding.

I hope this is of help

Grayson

[Boli]

On a side note... the noise from the actually HTPC could be a problem (a low grade PC for example)... even our good friend bladerunner has noticed a "buzz" factor on his motherboard... this could be a second option to may have to incorporate into your building work.

If you are going the "full hog" with room proportions you might as well find a way to get rid of the ambiant sound... LED lights that don't buzz as another factor etc. etc.

Sorry to be a nag, I only mention it because I spent the last day carpeting the inside of my computer to get a better night's sleep.

~ Boli

[Grayson]

Agred Boli, that is why I sugested puting all the electronics other than the screen and or projector in a closset with a heavy stiff door with a thick plexi window for visablily.

What you sugest would be a great idea for marker lights at any steps or obsticals in the room.

Grayson

[Pockytofu]

Wow, thats a lot of info.
Thx, I'll try to find those books or similar ones at my library to check them out.
At first, I didn't really think building a home theater would be this complicated, but I really want to do a good job so I gotta research, research, research!

That reminds me that I should probably look up city ordinaces for permits and all that fun stuff too, heh...

I did not even think of separating the components, but now I think it will be a great idea not only for sound isolation but then you won't have to notice all the leds on when watching in a dark room.

All right, thnks for all your help!!!
When I start to get actual room plans, I will post them up (not anytime soon though...).

[Pockytofu]

I just checked out a couple of books on amazon and I think i'll be picking up, The Master Handbook of Acoustics if I dont find it at my library.
It seems that i'll be a really good reference for room acoustics and after I figure out the inital size and design of the room, I'll figure some thing out for sound proofing once I get a better understanding of acoustic properties.

[Grayson]

You think this is complicated? When we did eidt rooms and TV studios in the 80's - 90's we had to keep all the signal runs the same lenght to maintian timings. Then we figired out that we could trim the runs from the sync generatot insted and if we were willing to spring for a little more money and put a sync generator at each device, slave it to the master gernerator and us delay lines to set the timing. We hated to use delay lines in the signal path as that would degrade the signal. And boy did we have to watch out for ground loops or it was hum city even humbars in the video.

One funny story about video sync timings: At one time NBCTV and the other major networks were using rabidum ocilators for master sync sources. Well they would not zero beat against the ceisiums at the NIST so we went out and bought three ceisiums. When we brought them up and went to lock them against NIST we were way out of sync. So we called CBS against whom whe had been zero beating and asked them who they were locked to. They said. "ABC." So we called ABC and asked them, "You" was their reply. The three networks had been locked in a free floating circle, difting along in sync with each other!

Grayson