Speaker Placement: Setup Tips for Upgraded Home Theater Systems
or "I Upgraded My System, But I Can't Hear the Benefits. Why?"
We received numerous emails from fellow Audioholics who recently upgraded their home theater systems to find that the sonic improvements were less than expected.
This is a topic that comes up more often than you think when the DIY Home Theater enthusiast upgrades his or her equipment. There are a few factors you need to consider to solve this issue. First you need to get used to the new receiver sounding different. The older receivers and processors did not have the same processing power as the new receivers. Even the high end receivers of just a few years ago funneled off sound from the Left and Right speakers to the center channel. They just were not as discrete as the processors in even the lower end receivers today. It may sound as though your center is not working as hard or your center is not "filling the room up" but this is how it is supposed to be thus you will be treated to a much better center dialog, smoother pans and better Foley and sound effects. In order to take advantage of a more discrete sounding processor, set up and calibration become more critical.
Here is a list of items you will need to do this correctly:
1 Radio Shack (analog preferred) SPL meter
1 25ft tape measure
1 pen type laser pointer
1 pair of rubber pie shaped door stops (Home Depot)
1 package small square rubber stick-on feet (Home Depot)
Step 1: Center Speaker Positioning
First stick two rubber feet on the bottom front of your center speaker. Then place the pie shaped doorstops under the back of the center so the back is angled down toward the listening position. Next, place the laser pointer on the top of the center speaker pointed at the listening position. Then aim and adjust the beam of the laser pointer so it is just above the ear level at the listening position. Adjust the rubber door stops until the correct height is obtained. This effectively aims the tweeter at the listening position between your ears.
Step 2: Main Speakers Positioning
Position your front main speakers at least a foot off each back and side wall and you are close to the "Golden Triangle Rule" ( Example: speakers 8ft apart from listening position and 8 ft back). Make sure that the speakers are the same distance off the back wall with the tape measure, then place the laser pointer on the inside panel of the speaker enclosure at the height of the tweeter.
With the laser pointer beam active, rotate the speaker inward until the laser pointer beam is about 6" away (outside) from the center of your listening position. This will effectively toe in the speaker to a close position according to the dispersion patterns of your speakers. If your speakers have an unusually wide dispersion pattern, you may wish to experiment with the degree of toe in for optimal performance.
for installs where there are multiple seats, we recommend an 80% triangle rule (IE. speaker distance is 80% of distance to seated area). So if your seated area is 10ft away, the front speakers should be 8ft apart. Less toe-in would be required, thus allowing for broader dispersion while also taking advantage of sidewall early reflections which are beneficial to the listening experience.
Step 3: Surround Sound Speakers Positioning
Bipolar/Dipole surrounds usually perform best when placed on the side walls directly across or slightly behind the seated listening position and at approximately 18-28" above the seated ear level position.
Quadpolar surrounds, similar to Bipoles, usually perform best when placed on sidewalls, but closer to the backwalls, for rear wall reflection of the side mounted tweeter. Their height should be about 4-6 feet above the seated position, but greater than 1 foot away from the ceiling to not obscure the top mounted woofer.
Direct Radiating surrounds usually perform best when placed behind and slightly higher than the listening position, spread apart the same distance as the mains and slightly toed in.
Step 4: Subwoofer Positioning
Subwoofer placement is adequately covered in our article: Crawling for Bass.
Step 5: Speaker Configuration Set-Up In The A/V Receiver
Enter the setup menu of the Denon AVR-2802, or any modern Surround Sound Receiver, and select all speakers set to small and subwoofer crossover to 80 Hz. Set the crossover on the Subwoofer to its maximum position or if it has a crossover bypass select bypass. Next, use the tape measure to accurately enter the feet or meters your speakers are from the listening position.
For a more in-depth look, we recommend: Bass Management Basics: Settings Made Simple
Step 6: Checking the Phase of the Speaker System
A) Electrical Phase
Make sure all your speakers are in electrical phase (positive from amp to positive to speaker, negative from amp to negative to speaker). A speaker system out of phase will defeat your calibration and may result in poor imaging, bass response, or both.
B) Acoustical Phase
Next check to see if your main speakers and subwoofer are in acoustical phase by sweeping a test tone from 20Hz to 100Hz using a popular set-up disc such as Avia or THX. Listen for any nulls or bumps in the frequency response. The bass response should sound smooth and uniform throughout the entire swept frequency range. If it doesn't try setting the phase switch on your subwoofer to 180 degrees, or if the phase feature is a rotary dial, rotate it in 20 degree steps and listen for the bass to smooth out between the mains and subwoofer. If this still doesn't solve the problem, set the phase on the subwoofer back to the 0 position, and vary the subwoofer distance in the Receiver set-up menu ± a few feet until it does. You may need to experiment between these suggestions and the placement suggestions for your subwoofer previously mentioned in Step 4. Be patient, it is worth the extra time now as it's a one time investment to ensure great sound.
Step 7 Sound Pressure Level (SPL) Calibration
Place the SPL Meter at the listening position at ear level with the Mic end pointed toward the ceiling. Select "C" weighting, response slow then, turn the dB dial to 70. Activate the internal pink noise generator of your Receiver and select manual test tone. Now adjust each speaker to +75 dB reference. When you are adjusting the surrounds make sure your body is not in a direct path of the speaker and make sure the house is quiet. When doing the calibration, only the test tone should be heard (A/C, ceiling fans, ect. should be turned off). We like to adjust the subwoofer level to + 80dB for wow effect. Your taste may vary.
Step 8 Enjoy!
Put in a good flick with lots of hard simultaneous pans and dialog, and plenty of dynamic swings. "Contact" Lift off chapter or "The Phantom Menace" Pod race, or "U571" Depth Charges, work well. IF YOU DON'T SAY WOW AFTER THE VIEWING, START OVER!