The passing of a spaceship, a big explosion or the low notes of an ominous soundtrack are all reproduced by subwoofers in a modern home theater. Oddly shaped or large rooms often present difficulties in placement of a single subwoofer. Many rooms have peaks and nulls where bass response is either too strong or nonexistent. One way to solve this problem is to use two subwoofers in the space. Not only will the primary listening position experience better bass, but all seating areas in the room should have a more even low frequency response.
Turn around the receiver so the back panel is facing you. Locate the "SUB" RCA jack in the "Pre-Out" cluster.
Connect the RCA splitter cable to the single pre-out connector. Connect each RCA cable to the individual leads on the splitter. If your receiver has two subwoofer outputs, forego the splitter and connect each RCA directly to the two outputs.
Place one sub along the front wall, 1/4 the distance of the width of the wall. Place the second sub in the a spot along the front wall, mirroring the other subwoofer at the 3/4 position.
Turn on the receiver and subwoofer. Press the "Menu" button on the receiver's remote. Scroll through the menu until you find the "Test Tone" option. Select the tone for the subwoofer and press "Enter."
Adjust the volume to the midpoint on each subwoofer's amplifier. Adjust the phase control to its position relative to your seating position. For example, if the sub is directly in front of you, set the phase to "0" degrees. If it is directly to the side, set it to "90" degrees and so on.
Evaluate the performance of the two subs. Experiment with placing the subs directly across from one another on the side walls, or in opposing corners. Your room's response will vary, so trial and error will be involved.
Turn down the volume of one subwoofer from the control on the rear of the unit. Set your sound pressure level meter to 70 decibels. Set the weighting switch to "C." Flip the response switch to "Slow." Both adjustments keep the needle on the meter from jumping around, making adjustment easier.
Adjust the volume on the receiver's test tone screen until the needle points to its vertical position. There may be slight movement; this is normal. Repeat the process for the second sub.
- Always select two identical subwoofers or two very similar models. Using a high quality and low quality subwoofer together limits overall performance.
- It may prove easier to daisy-chain one subwoofer's RCA output jack, connecting to the second sub. Prior to committing to this course of action, look to see if at least one of your subs has this feature.
- Home theater receiver
- RCA splitter
- Sound pressure level meter
- RCA cable (x2)
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