Audio/Video Home Theater Setup Guide

We have other articles which will help you actually connect your home theater system. This article assumes that you are indeed getting sound and video through the components and that you are ready to move on the the next phase of configuring and tweaking the many settings and physical options associated with all of that AV gear.

Once you've got your Home Theater audio system wired and producing sound there are a few simple steps you should take to ensure your system is configured correctly. Home Theater calibration professionals can attest to the fact that a majority of Home Theater systems suffer unnecessary bottlenecks in performance that can be easily overcome with a few minor adjustments. Here is what to look for on your Home Theater system.

• Simplicity: Keep wiring simple but optimized, using as few cables and wires as possible. Keep your lengths short and be sure to use the highest resolution settings - and cable options - that you can. This doesn't mean you have to pay a fortune, but if you just bought a new DVD player with HDMI upconversion, you don't want to use the yellow composite video cable it came with.
• Polarity: Double check speaker wire's polarity (the plus and minus/red and black) for consistency. If you choose the "striped" wire for negative, be sure to keep that consistent with every speaker connection. Typically this means red to red, black to black. Switch them and you're going to ruin your sound and lose your bass response.
• Interconnects: Make sure you have all of your short "interconnect" cabling correct. If you are using analogue cables, make sure you don't switch your left and rights. If you used digital cables, be sure to verify you have that selected in the AV receiver for that input.
• S/PDIF: Use a digital connection (optical or coax) whenever available (except for HDMI).
• HDMI: HDMI carries both audio and video signal in digital form and is the preferred method of connection for most uses. Try to use this type of cable whenever possible as it will deliver the highest audio and video quality in most cases.
  

• Speaker Positioning: Nothing affects the sound of your system like the positioning of your speakers. Experimenting with positioning offers near limitless possibilities for tweaking your sound. In general you want to place the main speakers evenly across the front of the room, with surround speakers slightly elevated and  firing at the listening position from the sides (or from behind if you have no side walls.) The Surround Back channels are meant to be somewhat higher and directly behind the center listening position.
  

Front on top, rear at the bottom. The television/display should face the seating area
from the center speaker position.

Loudspeaker positioning basics

When setting up speakers in a real world living space, it helps to think of invisible cones of sound emanating from the speakers themselves. Anything coming in contact with that cone before and after it reaches the seating position is going to affect the sound. Things likely to come in contact with that cone of sound include plants, bookshelves, couches, chairs and small furry creatures. Try to keep anything from blocking the sound before it reaches the seating area. Obvious problems might include a chair in front of a speaker (even if the chair is below the speaker it will affect the ability to move the air in front of it). The key is to experiment, experiment and then experiment some more with speaker positioning in your home theater room.

Things to pay particular attention to:

• Obstructions: Don't let objects block the path of sound before it reaches the audience. If living space requires such compromises, try a system of temporarily removing blockages for film viewings. Sound travels in waves, and is easily diffracted and dispersed which can contribute to poor intelligibility (causing you to turn up the volume.)
• Speaker Toe-in: "Toe-in" is the angle to which the speakers are pointed at the center listening area. Some speakers do better with more toe-in and some do best when they are firing straight ahead. This is something you'll need to experiment with, but in particular listen for the widest soundstage when the image of the audio opens up (best to use music for this.)
  
• Room Acoustics: Every room is different when it comes to acoustic properties and the room adds much to the sound quality. Learn as much as you can about the interplay between acoustically dampening and reflective materials and how it works in your room. You don't want your room too reflective or lively (lots of reflective materials such as uncovered hardwood floors and glass). This will lead to an overly bright sound. Conversely it is possible to go overboard with acoustic dampening (using excessive drapes, acoustical panels and shag carpet for example.) An anechoic chamber is fine for testing speaker design but doesn't make for the most pleasing home theater!
• Center speaker: Inarticulate dialogue is a common problem. Position the center speaker toward the ears of the audience. If your center speaker small in size and sounds like it's being drowned out by the surround field, adjust the level higher. It should be raised off the ground and pointed to head level of the listening area from above or below the display.

Component Setup and Calibration

There are several things you must do to audio components after they're connected. Most DVD players and A/V receivers have their own way of doing the same things and might even have a different name for certain settings. Consult your owner's manual for exact instructions to apply this checklist to your system.

Receiver setup

• Bass management: Large/Small speaker settings. Set all speakers to small, let your subwoofer handle the low frequencies. Find a comfortable crossover setting, it might not always be THX's recommended 80Hz. We have an article on bass management settings dedicated to this topic in greater detail.
• Dynamic Range: This is a setting for Dolby Digital signals and will condense the difference between loud and soft portions of movie soundtracks. If you find yourself constantly adjusting the volume during loud portions of DVDs then consider setting the level to 'Medium' or 'High'. If you are a home theater purist and/or have a decent room that can handle dynamic sounds, then 'Off' is the setting you want to use.
• DSP modes: We recommend users turn Off all DSP modes with limited exceptions for some THX modes. Only experiment with DSP when you're ready to play with the sound and have everything else buttoned up. 'German Bathroom' can be fun to play with  
• Dolby Pro Logic II or IIx: Dolby PL II and IIx are primarily used for two channel (stereo) sources and PL IIx can also be used for discrete 5.1 sources to expand them to 7.1. Double check to see if the PL II or IIx settings are saved for each input selected. IE: Setup "music" appropriately for CD input, switch to VCR and see if your CD settings carried over to the other inputs. PLII presets and saved settings per input are convenient features and often overlooked when shopping for an A/V receiver.
• Dolby Digital/DTS: Enable automatic detection of Dolby Digital/DTS for digital audio inputs. This should override any Pro Logic II or DSP setting you have chosen. There should be an indicator on your receiver's front panel to let you know which audio format is detected.

DVD Player setup

• Bass Management: Large/Small speaker settings. Only one component should handle bass management. Receiver, DVD player or another specialty component such Outlaw's ICBM. If another component is handling bass management set all speakers to large or turn off bass management.
• S/PDIF: Use your DVD player's digital audio output only (coax or optical). Do not use the RCA stereo output if you already have the digital output connected to the receiver.
• Bitstream/PCM: Set audio output to bitstream. The only reason you wouldn't want to use bitstream is if you're not using the DVD player's digital audio outputs. Almost all DVD players have PCM set as default, PCM will not send Dolby Digital or DTS to the receiver even if the DVD player is compatible with those audio formats. Countless new DVD player owners will listen to stereo PCM transmitted to their receiver over digital outputs, wondering why the receiver isn't detecting Dolby Digital or DTS.
• Audio filtering or effects: Disable any audio noise reduction, filtering, DSPs or any other audio effects your DVD Player might provide. The A/V Receiver can handle these. Experiment with these settings later, after you've heard the "true" sound of your system.
• Aspect Ratio: Enable widescreen mode (16:9) assuming you have a compatible display for this aspect ratio. Disable zoom. Depending on your viewing preferences, zoom/stretch modes may be used on 16:9 displays when watching 4:3 program source material to utilize more screen area. There should be an independent setting on your display to enable these modes when viewing 4:3 program material.
• Video output: Always use the best possible video output available on your TV. If your TV is High Definition you MUST use either Component outputs (R,G,B) or digital video such as DVI or HDMI to get a de-interlaced video signal to your TV. S-Video is your best option for non-digital TV.
• Progressive Scan: Enable progressive scan if your DVD Player has this feature and your TV is Digital or HD.
• Other Video Features: Black level, brightness, filtering etc should all be initially disabled on the DVD Player. In most cases all of the video tweaking should be done on your display. However, if you cannot achieve an accurate picture, you should then look at tweaking using the DVD player video adjustments.

Audio/Video Home Theater Setup Guide - page 2

A lot of money can be spent on a professional audio calibration, but for most people that's just not practical. You can conduct your own Home Theater calibration for a minimal investment of about $60.

You'll need the following tools:

• Avia: Guide to Home Theater (or similar audio calibration DVD)
• SPL meter from Radio Shack.

A calibration should be performed a couple of times a year or anytime new equipment is introduced into your Home Theater system. The Avia DVD has a variety of tests you can perform some of which can be found on THX certified movie DVDs. The basic tests you'll need to perform on your Home Theater's audio system include the following.

Speaker Volume/Channel Identification: Ensure all speakers in your system present audio for the correct channels. THX certified DVD movies will contain this test as do calibration DVDs like Avia. Your speakers receive a pink noise tone one at a time corresponding with the highlighted speaker in a graphic representation of all the channels in your audio system.

The correct speaker should not only be identified by the graphic (i.e. identify the correct channel) but all speakers should present the tone at the same volume level. If you find any speaker is sounding out of sync with the graphic either a speaker or component is wired incorrectly. Also listen for the pitch of the noise, if one channel is noticeably lower than the rest it could be out of phase so you'll need to re-check your speaker wires' polarity. With the master volume level properly adjusted, your system should be able to put out an even 75db of volume from each speaker to the SPL meter according to the standards for THX Home Theater optimization.

Using the SPL meter: Sound Pressure Level meter is a small handheld device you can buy at Radio Shack for around $35. This device will take the guesswork out of the volume of each speaker in your system.

It's critical to get the volume from each channel right from the prime listening spot and the human ear isn't always capable of deciding if two sounds are at the same sound pressure level especially when different speakers have their own timbre. There are some simple rules to help when you're using the SPL meter to calibrate your system.

• Check Battery . It might have been months since the last test, use the meter's own battery check to ensure it tests "good" before you proceed.
• Switch to 70db range. You don't have to listen to movies that loud, but 73 - 75db is widely considered optimal for Home Theater. The 70db setting on the large circular dial will correspond to 0dB on the needle indicator scale. This will give the needle an effective 60dB (-10dB on scale) to 76db range (+6dB on scale).
• Response. Set response to fast to read changes in sound pressure.
• Weight. Set weight to C for full range sounds such as music and most test tones.
• Holding Meter. Hold the meter at about head level in your Home Theater area's sweet spot keeping the microphone pointed diagonally upward and toward the source of the sound.
• Frequency response. When weighting is set to C, frequency response of the meter is flat from ~100Hz to 10kHz, below 100Hz above 10kHz, response of the meter will fall off as per ANSI S1.4-1971 response curve for C-weighed networks.

• Below 100Hz the built-in C-weighting network will cause the scale to read the bass response as lower than it actually is. For instance, if your subwoofer is truly capable of playing flat to 20Hz in your room the Radio Shack meter would indicate -6dB.
• Subwoofer. The sub's measurements should be conducted with pink noise in its range 20 - 120 Hz. Because it is known that the calibration of receivers and processors can vary as much as 4dB, using a test disc of known, accurate test tones such as Avia which already accounts for properly scaling subwoofer levels with +10dB more volume than the other (single) speakers in your system is recommended.

Low frequency sweep. The purpose of a low frequency sweep is to measure the transition from speakers to sub woofer or crossover. A test tone of 200Hz is where low frequency sweep will start. Use the SPL meter to measure the SPL of frequencies from 200Hz all the way down to 20Hz. Select the right combination of crossover frequency, and subwoofer phase to minimize the dips and peaks in response.

Editorial Note

For more information on properly configuring and calibrating system bass response, the reader is advised to review the following article:

Subwoofer Calibration using Rives Audio Test CD

A system that suffers from dips in lower frequencies could be afflicted by any number of problems. The system itself is the first place to look, although not always directly proportionate to cost, a cheaper system with satellite "woofers" smaller than 4" is not likely to be able to reproduce frequencies down to 80Hz. So there will almost always be a dip in the overall system's frequency response between when the subwoofer reaches it's upper 80Hz limit (by a filter inserted with Dolby Digital and DTS software) and the small satellite reaches it's lower bass limit which may be well above 80Hz.

Speaker / subwoofer placement with reference to the primary listening positions is also critical and the reader is advised to read more about this in our Get Good Bass section of the website.

Full range frequency sweep. Using test tones from a DVD like Avia starting at 200Hz, progressing higher, measure the SPL of sound at each frequency. Since the pink noise test has already given you balanced full frequency level, you're looking for the same balanced SPL to be reproduced at each frequency. This is the flat frequency response highly desired but nearly impossible to attain in most Home Theater systems.

It's good to know the strengths and weaknesses of your system, but there is little you can do about fluctuations, which may be inherent in the speaker system itself, outside of using a parametric EQ, replacing speakers and/or manipulating the room's acoustics. Experiment with speaker positioning and room acoustics using acoustic damping and reflective materials (noted above). The science of room acoustics is complex and will require patient experimentation.

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Special thanks to Home Theater Focus.