How to setup a home theatre?

A typical 5.1 speaker setup

Setting up home theatre involves certain basic knowledge about where & how things work and a little common sense. Basically, 4 components are required to achieve the a home theatre setup for movies & music.

1) Source: CD/DVD/BluRay/HD Media player

2) Amplifier: Audio/Video Receiver (AVR)
3) Speakers & Subwoofer
4) Display Unit: Plasma/LCD/Projector
5) Setup, Connectivity & Cables
6) Tips & Tricks

Lets discuss the above points in detail to setup an amazing home theatre.



Courtesy: Sony BluRay Player

 1) Source: To view a movie or to listen to music we require a player which can play different types of media like CD/DVD/BluRay etc. Nowadays, BluRay players are becoming cheaper day by day to the increasing demand for BluRay movies and hence mass production of the same. You can get a Sony BluRay player for Rs.9,990/- which earlier cost in the range of 30 to 40k. The cost should further reduce in the coming days and DVD would be phased out completely due to the need of storage in higher capacities to maintain high definition picture and sound quality.
Few infos...

An audio compact disc (or music CD) can store upto 700MB of data i.e. maximum 16 tracks/songs or 80 minutes of audio or video data.

A DVD (Digital Versatile Disc) media comes in 2 forms - Single (4.7GB) & Double layer (8.5GB). Both forms are used to store Standard definition video (720 x 576 resolution). With the double layer DVD retaining maximum upto 9MBps bitrate of video. Even a single layer DVD can also retain the same 9MBps quality but not for very lengthy movies where the quality has to be compromised to accomodate the length of the movie in a single layer. In a double layer DVD, extra features, interviews can be added to the main movies additionally.

HD-DVD is High Definition DVD, which is now phased out after losing the war with BluRay. A HD-DVD also has 2 forms like in a DVD - single (15GB) & double (30GB), which can store High Definition video (1980 x 1080 resolution)  retaining around 29.4MBps and high definition audio track.

The upcoming BluRay disc comes as similar in 2 forms - single (25GB) & double (50GB) capacities. BluRay almost similiar to HD-DVD can store high definition video (1980 x 1080 resolution) but with bitrate achieving around 40MBps and at the same holding high definition audio soundtrack.




  Physically, all these different medias looks the same at 12cm diameter, but what distinguishes between them is the lase technology used in writing the data onto these discs using different wavelength and thickness. As you see in the fig. on the left, the various wavelength and thickness used by the laser for different media and how the data is accomodated more in a bluray though physically it appears like a audio CD.

Some DVD/BluRay players have built-in onboard decoders for Dolby & DTS (or only Dolby which is very common). In a DVD/BluRay disc the audio & videos track are separately written. The laser in the DVD/BluRay player picks these audio/video data signals and converts from optical to electrical signals and send to the analyser, where the analyser splits the audio & video signals and sends them to the respective decoders.

Fig.1

 A video decoder decodes the signal and send to the video outputs of the DVD/BluRay player. Similarly, the audio decoder decodes the encoded signal of Dolby or DTS audio and splits the audio to 6 tracks and send these signals to the analog multichannels 5.1 outputs of the DVD/Player. As you see in the above Fig. you will notice "Digital Audio Out = 1" which send the raw digital signals of Dolby/Dts to the AVR. "Multichannel 5.1 analog output = 2" outputs the processed audio from the onboard decoderin the DVD/BluRay player to 5.1 analog outputs. From these multichannel outputs individual cables are connected to the AVRs multichannel input to amplify these signals to the speakers. "HDMI = 3" this is the newly introduced connector for transmitting high definition audio/video to the AVR. By the way, what is HDMI?
   HDMI is High Definition Multimedia Interface which is used to transmit and receive high definition audio & video signals between devices like DVD/BluRay player to AVR or vice versa.

Typically, a DVD or BluRay player will be able to play your music audio CDs without any hassel hence need not require a separate standalone CD player (unless you are an audio purist who wants perfection in sound clarity). If you are choosing a BluRay player over a DVD player then there is no requirement for a separate CD/DVD player as it supports all formats like Audio CD, DVD, Photo CD, SACD, DVD-Audio, DTS Audio CD and ofcourse BluRay discs. Based on your budget and individual preference one is free to decide what player he/she wants.



Courtesy: Onkyo TX-SR608 AVR

 2) Amplifier or typically called as AVR: An AVR or Audio Video Receiver is similar like an amplifier which amplifies the signal received from a DVD/BluRay player and then send to speakers. An AVR has few extra job to do than a typical amplifier. The AVR is like a media hub where it helps to connect between any devices like CD player, Phono Turntable, Cassette Deck, VCR, Video Camera, DVD/BluRay player, Plasma/LCD/CRT/Projector etc. Apart from the amplification process,  an AVR has the ability to decode the incoming digital signals  received from the DVD/Bluray player to either Dolby or DTS formats which then amplifies and outputs to the speakers. To stay with the current trend, it is advisable to buy an AVR with the ability to decode the latest high definition audio Dolby TrueHD & DTS Master Audio formats as this will become standard during the course of time just as how Dolby Digital & DTS Surround has become. As how there is a vast difference in the picture quality from a Standard Definition to todays High Definition, the high definition audio does make a huge impact in the sound quality.

3) Speakers: Choosing speakers to match the AVR definitely play a great role in sound reproduction. Speakers comes in different sizes and shapes and in different budgets  which makes buying easy for the consumer. The important factor one has to note while buying speakers are the following.
  a) Size of the room
  b) AVR power matching with Speaker handling
  c) Obviously, your budget that don't burn a hole in your pocket.

Lets discuss about the different types of speakers available in the market. Basically, speakers are classified under Satellite, Bookshelf and Floor Standing speakers.

Satellite Speakers: These speakers are cute little speakers usually having only one or maximum 2 drivers (speakers) in a wooden or fibre enclosure. These type of speakers can handle frequency maximum upto 150Hz and can't go beyond. Wherein the so called LFE (".1") or typically called as Subwoofer does the job of reproducing those bass shakes & explosions to support these small satellite speakers. We have a separate discussion later in this article with regard to Subwoofers. Satellite speakers inspite of their small size doesn't compromise on the sound quality and can reproduce the sound in detail with clarity and thereby handing over the job to the subwoofer for reproducing the deep bass sound under 125Hz frequency range. These speakers are suitable for small rooms and as well medium rooms where space & style is consideration and can be wall mounted. Satellite speakers comes in different styles and merge with the interiors of a living room or decor without compromising sound quality. Nevertheless to say, Satellite speakers do have limitations in reproducing the full range of sound due to their physical size and can be only considered if one is very keen on space or decor issues.

Bookshelf Speakers: Bookshelf speakers are the big brothers of satellite speakers which are physically more bigger than the satellite, normally has 2 or 3 drivers (1 tweeter, 1 or 2 mid/woofer). Bookshelf is manufactured keeping in mind the pure music listeners  for stereo channel reproduction. Trend has changed and bookshelf speakers are now widely used in 5.1/7.1 channel home theatre setups for movies & music. Typical bookshelf speakers have wooden enclosures to ensure proper imaging & sound reproduction and there are bookshelf speakers which has drivers of size 8inch which can handle below 100Hz bass frequency eliminating the need of subwoofer. In a home theatre speaker package, bookshelf speakers comes in the range of 4", 5¼", 6½" driver sizes accompanied by 1inch tweeter. Driver sizes upto 6½" can handle bass frequency upto 100Hz and gives very good sound reproduction. Adding the subwoofer to the setup helps to reproduce very low notes below 100Hz. Though bookshelf are physically bigger than satellite they are still smaller in size and can placed in a shelf (so the name its been called), wall mounted and can be invisible in your living room eliminating the need for more space and are suitable for small to medium room sizes.

Floorstanding Speakers (or Tower Speakers): These speakers are constructed as per the law of sound. These are typically large speakers which doesn't require any mounting plates and made to stand on the floor as you in Fig. on the left. These consists of the typical 3 way sound reproduction technology covering the full range of frequency thus eliminating any compromise in the sound quality. Normally, 3 way speakers are classified into Tweeter - for reproducing the high frequency (range: 2KHz to 20KHz), Mid-range - for reproducing middle range frequency (range: 200Hz to 5KHz) and Woofer - for reproducing the bass frequency (range: 20Hz to 200Hz). The combination of these 3 types of speakers into a single wooden enclosure reproduces the full spectrum in sound reproduction. Typically, a 3-way speaker system can be divided into 4 or 6 speaker system by dividing the midrange to 3 speakers and bass range t 2 speakers, thereby equalising the sound distortions/reflections created from a single speakers. These floorstanding speakers require more space depending speaker system it is constructed. These floorstanding speakers gives the ultimate sound quality in a home theatre setup having very less job to do for the subwoofer to produce those deep impacts. These speaker packages are expensive when compared to bookshelf and are available in various price ranges.

Subwoofers: Subwoofers or LFE (Low Frequency Effect, the ".1" in a 5.1 or 7.1 setup) delivers only the bass frequency from 20Hz to200Hz depending on the type of speaker setup one has. Subwoofer consists of a single or even 3 speakers (I should say Woofer for more understanding) constructed in a Wooden or fibre enclosure using a separate amplifier within the enclosure or as a separate unit to create those deep bass sounds. Typically, subwoofer speaker size varies from 8inch to 21inch diameter based on the room size and sound output required for the setup. We would see common sizes of 8 to 10 inch for home use and > 10inch for dedicated home theatre setups.
   As said earlier, the subwoofer is conncted from the AVR using a sub-pre out which send the unamplified signals from the AVR to the subwoofer. The amplifier inside the subwoofer will then amplifies these signals from the AVR  and sends to the Woofer reproduce those bass sounds. The subwoofer has separate controls for adjusting the volume, cross-over, phase etc. to give the perfect matching bass for any kind of spealer setups. I will discuss what Volume, Cross-over and Phase means to you.

  Everyone would be aware of a "Volume" control in a subwoofer, which is used to increase or decrease the bass output. Now, this should be new to you "Cross-over" or "Cut off frequency". It is actually not crossing over but sounds similar with respect to frequency. This adjusts the frequency range that has to send to the amplifier in the subwoofer for a balanced bass output matching with the speaker setup. For eg. Lets say, one has 5 satellite speaker and it can reproduce bass upto 150Hz. So, the cross-over frequency has to be set to 150Hz in the subwoofer for reproducing those bass sound below 150Hz which are unable to reproduce by the satellite speakers.The cross-over frequency varies with different speaker types and driver sizes and has to be referred to the respective manuals for perfect adjustments. So, lets discuss about "Phase" and what is does to the output of the subwoofer. Changing the phase means giving delay to subwoofer thereby matching the sound with the main front speakers. There are some instances that you find a bass sound hearing first from the main front speakers and then after a fraction delay from the subwoofer. This means that the subwoofer is not in sync with the main speakers for reproducing the correct bass sound when required and plays it out of phase. The "Phase" control ensure that the subwoofer sound perfect in phase with the front main speakers.

Subwoofer are classified under 2 types - Active and Passive subwoofers. Active subwoofer consists of an built-in amplifier, whereas a Passive subwoofer is without the amplifier inside the subwoofer enclosure and depends either on the AVRs amplifier or a separate amplifier unit. Normally, an AVR does not amplifies sound for the LFE (or ".1") channel in a 5.1/7.1 system. Nowadays, you can notice in many entry level home theatre systems called as HTiB (Home Theatre in a Box) meaning an AVR with a 5.1 or 7.1 matching with respective speakers system as a whole package. This eliminates the need for buying separate speakers for a 5.1/7.1 AVR system and the company takes care of matching the speakers for the AVR perfectly. In HTiB packages, you can more easily find passive subwoofer used instead of active subwoofer to reduce cost and also making it a single driven box for all speakers. There are disadvantages in a passive subwoofer when compared to active subwoofers. The AVR has to amplify the 5 or 7 channels and also the ".1" of the LFE making it strain at higher volume levels. The main concept of the HTiBs is introduce the consumer to 5.1/7.1 setups within a very limited budget. So, if an AVR has to do amplification for ".1" channel, it has to require more power to balance the 5 or 7 channels bass management. Obviously, the quality suffers for all 5 or 7 channels inclusing the LFE or  ".1" channel when played at higher volumes. On the contrary, an active subwoofer takes half the load of the AVR in amplifying the bass and powering the speakers. In an action movie, where bass is involved more requires more power for amplification than a mid or high frequency amplification requires thereby straining the AVR when playint at higher volumes thus affecting the sound quality on all 5 or 7 channels. I would suggest to buy an active subwoofer which is worth the money for the extra bucks.

4) Display Unit: However powerful the sound is, it should be accompanied by a decent display unit to create the effect of a movie theatre at home. Nowadays, Plasma/LCD prices have drastically reduced making it affordable for most homes and available in various screen sizes from 26inch to 60inch. And for more than 60inch screen sizes the projector will be the best buy for money subject to setting it up in a dedicated home theatre room to control light. I would personally suggest that upto 50inch you can buy either Plasma/LCD and beyond opt for projector to give the theatre like feel and also to save your pocket. Now, the question arises between Plasma and LCD TV, which is the best? Earlier days, I would have personally recommended Plasma TVs beating the LCD in every department say, black levels, contrast, color reproduction, fast scenes. But, now time has turned around for LCD to prove that they are not meaner and does whatever the Plasma was doing before. Yes, nowadays the technology has improved a lot more featuring the same trump cards that Plasma possessed earlier. LED now plays a vital role in LCD for boosting that extra contrast, color uniformity, black levels, power consumption and obviously life of the TV. So, I won't be suggesting you any TV between Plasma or LCD because it is now become a personal preference and the individuals eye is the best judge. Likewise, in projectors there are many brands which offers different types of projectors, a detailed article will be discussed separately.

5) Setup, Connectivity & Cables:  Now connecting all the above devices perfectly and positioning plays a pivot role in the success of a home theatre setup. Choosing the best connectivity options from our devices certainly improves the viewing/listening experience. Like we said, HDMI provides the highest quality standard for passing High Definition audio & video signals to TV/projector, AVR etc. There are also other options in a DVD/BluRay player as seen in Fig.1 HDMI, Component Out, S-Video out and Composite out, begining with the highest quality to the least quality respectively. Similarly, an AVR does have inputs for receiving signals for all types connectivity as described in DVD/BluRay player. The same goes with a Plasma/LCD TV or projector. Since, the current market trend is focussing more on High Definition picture & sound, we will discuss more about the highest quality connectivity in this article. As you see in Fig.2 a sample connectivity of different devices to the AVR. Like you can see a DVD/BluRay player, CD audio player, HD DTH cable all connected to the AVR using the respective connectivity inputs/outputs. And the final picture output is connected to through the HDMI out from the AVR to the Plasma/LCD TV.

Fig.2



Fig.3

 As you see in Fig.2, in DVD/BluRay player there are two types of connector for passing the sound signals to the AVR, one as I have already mentioned the HDMI connector and the other connector is the Digital Audio. The main difference between the HDMI and Digital Audio connector is in a HDMI it can send and receive High Definition audio & video signals whereas Digital Audio can pass through only the RAW Digital signal of Dolby & DTS audio outputs. Meaning, the latest High Definition audio formats like Dolby TrueHD and DTS Master Audio cannot be passed through the Digital Audio output. Whereas, in a HDMI it supports along with HD video signals making HDMI a single cable for High Definition connectivity. The Digital Audio connectivity  option is provided in the DVD/BluRay player and AVR for supporting older audio formats like Dolby Digital and DTS Surround. I believe, you would have got an insight about the HDMI and its advantages. The AVR then process the audio signals either from the HDMI or the Digital Audio and process it to 5.1/7.1 Dolby or DTS signals and then amplifies and pass it to the speakers as seen in Fig.3. thus completing the full audio department. Similarly, from AVR respective HDMI out signal is connected to the HDTV or projector as seen Fig.2.

Lastly, we shouldn't forget the carriers of these signals called as "Cables" from DVD/BluRay player to AVR, HDTV etc. Because, the quality of the cable determines that the signals are carried with 100% quality to the AVR or HDTV etc. So, care should be given in selecting good quality cables to achieve the maximum quality transfers  for between your devices. There are lot of branded cables/interconnects respectively for each purpose and a detailed research in the market should help you in selecting a good quality based on your budget.

Fig.4

6) Tips & Tricks: As we discussed from Source to AVR to Speakers and more important the cables, every link in this chain plays an important role in forming the complete setup to gives the best picture & sound output. If we compromise any of these, then we are not doing justice to the components we buy. This doesn't mean that we need to buy the best of the best, but buy the best matching components within your budget for a awesome surround sound experience.

Fig.5

   Certain tips about positioning of speakers/display unit are critical in a home theatre setup to achieve the best  audio/visual experience. As you would be now familiar about the 5.1/7.1 setups as discussed earlier in this article. Lets now discuss the placement of the display unit matching with our 5.1 or 7.1 setup. Take in the case of a Plasma/LCD TV as seen in Fig.4, the angle of seating shouldn't exceed 178 degree, otherwise the person sitting at the extreme corner would unable to enjoy the visual with full color/light uniformity. Likewise in Fig.5, the TV should be placed not more than 15 degree angle of height, prolonged viewing when TV placed higher than the permissible limits will develop strain to neck and spoils the experience. This is applicable for HDTVs as well for projectors.

Fig.6

   Now coming to the speaker placement which plays the important role to achieve a realistic surround sound as intended by the film director. The Front Left and Right speakers should be place only on the respective left and right sides of the HDTV or projector screen. Say in the case of Satellite or Bookshelf speaker types, these speakers should be placed in the line with the ear level of the listeners ear thus providing good sound imaging to the surround setup. As for the Floorstanding speakers, it has to be placed on the floor as what it means to. The front speakers whether it is Satellite, Bookshelf or Floorstanding types these speakers have to angled towards the listening area as shown in Fig.6. Similarly, the Centre speaker should be placed either on the top or bottom of the HDTV or projector screen. As this channel is critical in reproducing the dialogue delivery in any movie. If this speaker is placed elsewhere, it would sound awkward where the dialogue would be out of sync from the visual. As for the Surround speakers, side surrounds in the case of 5.1 and additional back surrounds in the case of 7.1 channel setup should be placed atleast 2 feet above the listeners ear level to create a more realistic surround sound effect. Otherwise, placing the speakers straight to ear level very nearby to the listener gives an artificial feeling and spoils the surround sound. I have at times turned by head back during certain scenes of some movies were surround sound is so enveloping that creates a very realistic surround effect. This effect can be only achieved if all the speakers are placed as intended. As for the LFE channel or ".1" in a 5.1 or 7.1 setup, bass is unidirectional can be placed anywhere in the home theatre setup room. But thats how the theory goes, whereas practically subwoofer placement is critical in producing those bass effect with more depth rather than sounding it very boomy due to improper placement. A subwoofer should never be placed in the extreme corner, which will accumulates boominess to the total sound and feels artificial during explosions. Whereas, placing it with necessary space on all sides and angling onto either corner of the room or in the centre of front speakers would give exceptional bass effect matched to your front, centre & surround speakers. When you hear bass explosion, you should not be able to make out from where the bass sound is coming and should confuse whether the subwoofer is working or sitting idle. A subwoofer should merge with the main sound stage and should not be audibly noticeable during those explosions etc. this makes a very good placement.

Some tips you can consider in your setup.

  1) Please avoid bright light in your home theatre setup area and use only dim light  for HDTVs or completely dark room in the case of projector

  2) The Plasma/LCD/projector screen shouldn't be placed way above 15 degree angle as it will create strain in the neck on continuous viewing.

  3) Similarly. the HDTV/screen should be viewed within the 178 degree viewing angle or else the audience would experience less uniformity/color in the picture.

  4) The front speakers should be angled towards the listening position and in line with the ear level for better sound stage.

  5) Centre speaker should placed either top/bottom of HDTV or behind the screen (acoustic transparent) in the case of projector

  6) Surround speakers should never be placed very near to the listening position and it should be atleast 5 feet away and 2 feet above the listeners ear level. 

  7) Subwoofer shouldn't be placed in the extreme corner of the room, which creates boominess in sound and should be placed either leaving necessary space in the corner of the room or in the centre of the front speakers to create a tight bass.

  8) Always ensure quality cables are used to experience good audio and video reproduction thus doing justice to your electronic devices.

Now, many would have got confused which setup to choose between 5.1 and 7.1. I personally recommend to stick with a 5.1 setup as the 7.1 audio in BluRays are not so common and available in a very very few movies. It is always better to be tuned to the current trend in technology, so I would suggest to go for an AVR that supports the latest High Definition audio formats like Dolby TrueHD & DTS Master Audio with 7.1 decoding capability and configuring as a 5.1 setup. Later on, when 7.1 audio track becomes popular and is available in BluRay, then you add an additional pair of surround back speakers and change the 5.1 speaker config to 7.1 setup in the AVR. Moreover, 3D market is coming up slowly with entry of 3D HDTVs, BluRay players and which are 3D supported by the latest AVRs onboard. Keeping watching this space for more updates.

In case of any comments please do post your views for improving this article.