Here are Some Original Test Pics..

Here are some original test pics of the theater that I have taken soon after firing up the projector for the first time after installing the screen..

You can see my hacked xbox in it's full glory acting as the "Srivij" media center giving me access to all my media files stored on remote file servers upstairs..

Tuning the system and First Impressions

Starting last weekend and for the most part of this weekend, I have been working on setting up the components, calibrating and tuning the audio system. I just got most of them working now. First, hooking up all the components to the brand new Denon 3806 receiver and making the HDMI switching work correctly proved to be a challenging task in itself. On the right side, you see the picture of the 'sound level meter' the key instrument that I used for tuning the system..


I could not believe my ears when I heard the first test scene after I finished tuning the system. My jaws dropped hearing to the opening scene from the movie "Godavari". I saw this movie twice in a theater in Belmont but I never heard the details before that I just heard in my theater. Ascend Acoustics 340SEs are producing amazingly tight sound stage. In the opening dream scene, I can hear the song "Chowdavika chand ho" crystal clearly from the Left front speaker, and heroine's clanking bangles sound is faithfully reproduced from the Center channel. And before she walks into the living room, there is "Bhaja Govindam" playing in the background from the Right Surround channel, and as she was stepping into the temple alongwith her mother, I now hear birds chirping and temple bells reverberating very clearly from the Left front, and a group singing a devotional song from the Right Front channel..wow! I am blown away by the clean, clear and quality sound that filled the entire room.. There was a natural warmth to the dialogs and even mere whispers are more intelligible than ever before.

Ofcourse, what can I say about the HSU sub and it's breathtaking impact? Wow! I never heard base so tight, so strong and so heavy. I always wondered about the controlled base one gets to experience in good movie theaters and never in any of the homes I know. In almost all good home theater setups I've heard so far, base always sounded so different from the one you experince in theaters. In a theater, base has a distinct heavy and controlled feel to it (and it is not about how 'loud' it sounds). In homes, it is always a loud, boomy, rattling and resonating experience. Not any more. I always wanted the base to sound the way it was in a theater, and finally I now have it!! Listening to the battle scene from chapter 37 of the "Lord of the Rings - Return of the King.. what can I say..I felt the elephants stomping straight down in the theater room. As they say - you got to hear it to believe it!!

Yes, finally I may dare say..the experience of watching the movie "Godavari" in the SriVij theater is way too better than watching it in a theater!!

I still have some more fine tuning left to do, but I am already loving (and finally relived about) how good this theater is sounding :)

Also, I worked on the automation this weekend. Since my contractor left me on the middle of the road a couple of weeks ago, I have taken up finishing the electrical wiring job also into my hands and made new wiring runs, installed the X10 switches, and installed the complete automation system as I described in this post earlier. All the components of the automation system are working as planned. Now I am able to control all my remotely hidden equipment from the theater room by pointing the amazing harmony remote at the micro IR sensor that I installed on top of the screen.

Room Acoustics (Part II of II)

As mentioned in the part I of this topic acoustical treatment is a major part of the theater construction. I don't claim to know the subject, but from what I gather, here is why you should care to consider acoustical treatment of the room. Put in layman's terms.. Some of the sound waves reflecting (bouncing) off of the room walls that intersect with a listener position may cause sound distortion or echo. Also, sound reflecting off a surface suffers timber shift. So, it helps to tame those early reflections by applying acoustical treatment to those positions of the wall that cause these early reflections.

So, simply stated, acoustic treatment involves strategically applying sound absorption material to the wall surfaces. There is complex theory behind and generally you need professional help in finding exactly how and what to treat.

In general, for a multi-channel home theater experience (different from a 2-channel music listening), general practice is to treat the entire screen wall behind the front speakers (see the pic on the right). This helps control the back reflections from overlaying on to the surround field. Depending on the speaker placement, this treatment is brought along to the side walls (upto a certain height, not to the entire wall). Bottom of the soffits are also treated for similar different reasons.

A good material for sound insulation is what generally known as Owens Corning Fiberglass 703 series "Duct Insulation". There are several other choices like Johns Manville Insul-Shield or Knauf Duct liner/board.

In my case, finding one of these materials proved to be a difficult challenge. Despite trying very hard, I could not locate any of them. After months of trying and calling numerous people, I finally found a local supplier who luckily had a roll of (see pic) Johns Manville Insul-Shield.

These materials are typically made from fiberglass and if left uncovered is not only unsafe but also a nightmare for the interior designers and has zero WAF (wife approval facto). It just looks plain and ugly if left uncovered. So, it is customary to cover this material with 'special' kind of fabric that is acoustically transparent and "fire retartdant". So be carfeful, all the materials have to be fire safe and hence "any cloth" will not cut it. Most theaters use fabric from Guilford Of Maine .

Beyond treating the walls, it is upto your (and your designer) personal taste to define the look of the room. In my case, instead of putting the insulation on the walls and covering plainly with the fabric, I went with a painful process of builidng individual small wooden frames and installing one by one on the wall. End result is a great looking room. But, during construction, there was not a single day that I did not regret my painful decision to build these farbic frames. In the end, it not only costed me a lot of money but we all at home ended up working like hell to get these frames finished and installed. But I must admit, all that agony is vanished once after looking at the end result though.

Automation

My plan is to automate the control of lighting and A/V equipment installed in the room. Besides the convenience of one switch operation for controlling multiple pieces of equipment, this should also bring that extra wow factor to the room. So, the key automation specs are:

a) should be able to turn on all audio (receiver) and video (dvd/xbox/projector) equipment with a single remote button push and additionally tune them all to the right channel

b) be able to create and control lighting scenaries (For example, when the movie starts then turn off all in-ceiling lights, dim the under soffit low voltage lights to 10%, turn off the rope lights, dim the screen column lights to 50%, turn off the two on screen lights). These lighting macros will be created for different situations such as movie starting, movie ending and interval etc.,

c) a distributed remote IR system since all the equipment is going to be hidden behind a wall

So, based on the above requirements, I have designed a solution using the following components.

1) Harmony 880 remote - key component that allows to create 'activities' and provides the ability to send IR commands adn control multiple equipment with a single remote click.

2) X10 PowerLinc Controller - to create and control the lighting scene macros

3) IR X10 Command Control - to convert IR signals from the remote to X10 trigger signal (sent to X10 powerlinc controller to trigger a scene)

4) Micro IR sensor -- sits on the front screen wall receiveing IR signals from the harmony remote and sending them over the connected cable to the IR distribution block hidden inside the equipment cabinet.

5) IR Emitter block - receives IR signal from the Micro IR sensor and distributes individual audio video equipement via the connected IR emitters.

6) Stick on IR emitters - connects to the IR emitter block on one end and to individual IR equipment on other end thus distributing the IR signal from the emitter block to the equipment.



Here is the system block diagram showing all these components in action in my HT room:

Room Acoustics and sound proofing (part I of II)

Majority of consumers (including your's truely) don't realize how important role a room plays in creating a great sounding theater experience.

One can spend thousands of dollars on a great speaker system, but still end up sounding like crap due to bad room acoustics that leads to all kinds of acoustical problems like bad echo/reverberation.

So, planning a home theater room begins with proper sizing and getting it's dimensional proportions right. Certain room shapes cause acoustical problems. I verified my room plans with a software tool and made sure i got the dimensions right.

Sound Isolation and Sound Proofing:
Generally home theaters generate a lot of low frequency noise that could really rattle rest of the house while you are enjoying your favourite movie in the basement. After spending so much money, you don't want to turn down the volume and waterdown the effect of the battle scene from the "Master and the Commander". Do you?

So, here are the basic principles:

i) Increase the mass of the walls
It is a simple principle. It is hard for the sound to shake a heavy thing than a very light thing. Normal rooms in the house are built with single layer of drywall. My theater room walls have two layers of sheetrock. Also, I am building double stud walls (twice as thick as standard 2"x4" stud wall) with staggered studs (see pic on right) )
Also, these extra thick wall cavities are filled with the R30 thermal insulation material which also doubles as well, as extra the mass barrier.

Also, if you notice carefully, I am using metal studs instead of the traditional wooden studs. Numerous tests have proven that metal stud walls provide superior sound control performance compared to the equivalent wooden stud construction.

ii) Decouple the walls and the ceiling
Staggered studs (see pic above) and double stud walls mechanically decouples the walls and inhibits movement of sound freely via coupled surfaces. I couldn't do much about the ceiling (except for adding two layers of drywall) as I am working with a low ceiling height to begin with (one thing I really miss in this room is the height).

iii) Increase the level of sound absorption
In my case, all that insulation inside double thick wall cavities help increase the sound absorption. It's effectiveness is increased in staggered, double studded wall.

iv) add mechanical damping to the system
When an airborne sound wave hits a surface like a room wall, it becomes structure borne and travel through the structure. At resonance frequencies even these decoupled walls will start vibrating. To stop this phenomenon, we need to damp the resonance.

To improve the damping properties of the HT room surfaces, I am using a specially formulated product for this purpose called "GreenGlue". GreenGlue is what the name suggests..it is a very sticky green glue compound that comes in large tubes. You need to apply this between the two layers of the drywall. So, it is like making a sheetrock sandwich. This is one of the reasons (besides increasing the mass), I have two layers of sheet rock walls.

See in the right hand side picture, second layer of sheet rock with green glue getting ready to be 'sandwiched' against another layer of sheet rock already in place and standing..




Also, last but not the least, I have sealed every conceivable joint, hole, crack..everything with an acoustic caulk (picture on the right..)

The Audio System

No..I don't have a "Bose" system (!!)

Now that question is out of the way..let's talk about some real audio stuff..

As we all know, one thing that makes a movie theater to provide such excitement compared to viewing movies on TV tube is..that SOUND! (besides the life size images ofcourse). So, I wondered how can a room in the basement can sound like a theater that takes your breath away and immerses you in the scene?

As I started researching, I learned a lot about the things I never knew befor such as room acoustics, audio instrumentation and tuning etc., etc., So, my preparations for my home theater audio began much before the first stud is laid on the floor, let alone the room is ready.

The key elements of my integrated audio system strategy are:

1) Room Acoustics and sound proofing
2) Speakers
3) A clean, powerful (may I dare say earth shaking!) Bass
4) Digital Audio processing and amplification
5) Instrumenting and tuning

I will go into the details of each of the above in seperate posts..

Dreaming a Home Theater

The name of our theater is - "SRIVIJ Dream Theater". Let me explain..

SRIVIJ stands for both of us "Srini and Vijaya".

The "Dream" part comes from the fact that having a theater quality movie watching experience in the comfort of your own home is certainly a dream come true for me. Years ago when I was in college, VCR technology became a rage and used to be expensive to own (specially if you are a student). So, a couple of friends used to get together in someone's room (whom ever's landlord is kind..) and rent a VCR and a bunch of movies and watch them all day and night long for a day or two in a row. We did this countless times and it used to be a fun experience, while also an exhausting one in the end. So, everytime when I used to pass by the video rental place, being a movie buff, I used to tell myself..'soon I am going to buy my very own VCR unit and movie casettes and watch them at my will'. Little I know then how soon VCR will become extinct and how the dreams take a shape of their own as you grow older..

So, two years after we built our home and as I started hatching plans to finish our basement (mainly for accomodating my growing interest in my simulation hobby..), my wife vijaya put the thought into my mind that we should really be building a theater instead. That's how it all started as they say..

Now that I am a grown up, my itch for 'cool toys' has been stronger than ever and this time I am not content with simply owning a VCR or a DVD player but instead I wanted it all..the whole enchillada..I want a theater that looks and sounds just like a real movie theater, if not better..