Atlantic Technology SP-8000 instruction manual Subwoofer Placement, System Setup and Operation

10 Placement & Setup

SP-8000 Subwoofer Preamplifier

Subwoofer Placement

Single Subwoofers

If you are using a single subwoofer, then, generally speaking, the ideal location would be in the front of the room, between the LRs, or close to or in a corner (see Figure 8). Every room has its own unique sound characteristics, and flexibility in the exact placement of subwoofers is always desirable.The closer a subwoofer is placed to a wall and especially a corner, the more and deeper the bass response you will hear. However, in some rooms, corner placement can produce too much bass or a “one

System Setup and Operation

When using the SP-8000, your subwoofer's controls are of a secondary nature. They will be left at a nominal position, and all adjustments to your system will then be via the SP-8000. Preset your subwoofer as fol- lows:

Level - THX / Preset or approx 1/3 up from minimum Lowpass - THX / External or set to highest frequency Phase - Normal / 0 Degrees

note” boomy effect.Under such circumstances the subwoofer may work

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The LOW PASS Control

better away from the wall or corner.You should experiment to find the best position in your room.

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When used with a complete THX Certified speaker system, the Sp-8000's system’s LOW PASS control should be set to 80Hz, unless you are using a pro-

Figure 8

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Helpful Hint: A particularly useful experiment is to place the sub- woofer right at the prime listening position (move the couch or chair out of the way and put the sub in its place). Then play something with lots of good bass (preferably music), and walk around the room, listening to the subwoofer’s response. When you locate an area that has ample amounts of well-defined bass, you have found a potentially good place to locate the sub.

Dual Subwoofers

When two subwoofers are used you may wish to place them asymmetri- cally; that is,in slightly different positions in the room (Figure 9).This will reduce common mode room resonances that typically occur with sym- metrically placed subwoofers. Another good option is to place the sub- woofers in the same corner. Several tests have shown this to be a viable means of producing smooth bass response in many rooms.

Figure 9

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	THX certified or has a built-in crossover, bypass the

Preamplifier's amplifier’s LOW PASS control by setting it to the THX/EXT setting. All THX certified satellites have been optimized to work with an 80 Hz crossover point.

If your Processor/Receiver has no internal crossover (a fairly rare occur- rence these days) the SP-8000's Low Pass Control should be used to opti- mize the performance of the system,by ensuring that the subwoofer and satellites produce a cohesive and well integrated sound picture.

Higher crossover frequencies pass more bass to the subwoofer but can quickly begin to sound boomy. They also make it easier to localize the subwoofer sonically, which is highly undesirable. Higher crossover fre- quencies may be suitable, however, when using very small satellites that have no real low frequency performance.Settings lower than 80Hz should be employed if you are using larger speakers that have extended bass response. This way, the subwoofer will only reproduce the very lowest bass frequencies that are in the range where the main speakers begin to roll off. It’s generally undesirable to have the main speakers and the subwoofer overlap too much.Larger speakers means a lower LOW PASS crossover frequency,smaller speakers means a higher LOW PASS cross- over frequency. You may also contact the manufacturer of your satellite speakers for their specified low frequency response to determine the appropriate LOW PASS setting on your subwoofer amplifier. In the end, however, a little time spent experimenting will generally result in dra- matically better bass response.

A Word About Bass, Center Channel Modes, and System Setup: Many Dolby Pro Logic surround processors and surround receivers provide a choice between “Wide” (full fre- quency range) and “Normal” (restricted low frequency) mode for the center channel speaker. Atlantic Technology recommends that the center channel be operated in the Normal mode when using a powered subwoofer. The center channel speaker will sound more dynamic and the intelligibility of the system will generally be improved when in the Normal mode.

Bass Management

Today, many processors and receivers offer Bass Management capa- bility. If yours does it will ask you to choose between Large and Small loudspeakers during the system setup procedure.When speakers are set