Common Questions Sent in by GoldenEar Owners
  
    
One Dolby Atmos recommended speaker setup

We get questions from GoldenEar owners regarding lots of audio related topics. The ones below seem to come up fairly regularly.

1. I've got a large flat screen TV. Can I use multiple center channel speakers (like one above and one below the TV) to set up my surround system? 

You could but it's generally not a good idea. There are interactions between multiple drivers that occur when they're reproducing the same frequency. This isn't such a big deal with woofers and the low frequencies they produce but it gets more important as frequencies rise. 

 
Two drivers reproducing the same frequency can cause peaks and suckouts across the listening area
The result can be upper midrange and high frequency "comb filtering" that creates peaks and suck outs as you move horizontally across, in front of the speakers. If you're the only one listening and you always sit in the "sweet spot" this may not be a major concern. But since home theater is typically a group activity, with people sitting at multiple locations in the room, these peaks and dips can be a real problem, especially for dialogue intelligibility. You're better off getting a higher performance center channel.

2. I noticed the term "Force Cancelling" in the description of the SuperSub XXL. What does it refer to?

There are two extremely powerful 12-inch active drivers in the XXL and they're placed on opposite sides of the enclosure. When they're driven by the 1600-watt internal amplifier the cones move in, towards each other and out away from each other. Top and bottom mounted passive radiators do the same (hence "dual plane"). Because they're mounted opposite each other and moving this way, they cancel out the vibratory impact that they would have on the enclosure if they weren't mounted "back to back". The result is there's less vibration transmitted to the enclosure by the drivers resulting in less "box talk". In effect it's like having an extremely heavy and solid enclosure that's essentially inert. And more of the driver energy goes into creating pressure waves in the room, not vibrating the box.

Our favorite way of demonstrating this is to place a nickel on edge, on the top of the enclosure and play powerful bass content. The coin remains upright because the internal bracing combined with the force cancelling design means the enclosure walls are almost totally inert.

3. I notice when I sit on my couch, up against the back wall in my room, there seems to be lots more bass than when I sit on a chair out, away from the wall. Why is that?

Imagine you're standing in one end of a swimming pool and you're making waves with a 4x8-foot sheet of plywood standing on end in the water. As you continue to do so the waves would continuously slam into the far wall and pressure would build at the wall boundary. This is what happens to the large bass sound pressure waves at every boundary (wall) in your room. If you sit right up close to the wall (less than about 2-feet away) you'll hear exaggerated, thick sounding bass. And it gets even worse at the intersection of multiple boundaries like room corners and the floor/wall/ceiling junctions. If you were to stand or sit in a corner the bass would likely be overpowering. This phenomenon is directly akin to what happens when you put your subwoofer in a corner and you get lots more but inconsistent bass in the room. If at all possible, move that couch out at least a couple feet from the wall for better bass performance.

4. Can you explain the new "object based" surround systems now on the market and why I might want to consider them?

Until recently Dolby Digital and DTS (and their variants) were the most advanced surround formats available. These systems typically consist of 5 to 7.1 channels of sound reproduction. There are also speaker location "rules" for proper performance with these systems. When an engineer mixes a Dolby Digital or DTS soundtrack he puts specific sounds in specific channels, attempting to create an immersive sound field.

In the new object based systems (Dolby Atmos, DTS-X) sounds are considered "objects" and they can be placed throughout the room, not just in specific channels. This is accomplished by telling the Atmos/DTS-X controller how many speakers there are and where they're located. Although there are recommended speaker locations, the processor is smart enough to compensate for differing speaker placement to some extent. Certainly some locations will be better than others but there's more freedom in the number of speakers and where they're placed than in a standard Dolby Digital/DTS system.

The decoder software determines how to "place" the sound objects so they appear to come from the location specified in the mix. Dolby says home Atmos systems should start with 7 speakers and can have as many as 34. Once the decoder knows where the speakers are placed it steers sounds to those speakers that will create the illusion of correct sound placement according to the metadata coded into the soundtrack. Dolby says Atmos "supports up to 128 simultaneous independent audio objects in a mix for rich, realistic, and breathtaking sound".

This is a major advance over the systems that have come before and you can get into it by adding two to four "height" speakers and electronics that include Atmos and/or DTS-X decoding.

5. I've read that using multiple subwoofers can offer real benefits in any system. Yet some people have told me this isn't true. What's the straight scoop?

There's no question that using two or more subwoofers can help you to get smoother more defined bass response in the average residential room. We say this not because it means we'll sell more subs (OK. Selling more subs will make us happy. But we want you to be happy with your system too.) but because it's been scientifically proven. Still, properly locating the subs is critical to their in room performance. We've covered some of this in our Newsletter series, click here for the archive..

A brief reminder of the general recommendations:
 
Recommended multi-subwoofer placements
  • If you've only got a single sub you can try it in a room corner as you'll get the most effective output from it, but at the cost of evenness throughout the room, definition and clarity. If you're using one of our subs, in most residential rooms you shouldn't need the apparent increase in bass volume you'll get from corner placement and best to avoid..
  • Using multiple subs will result in better bass throughout the room. Better bass can be had from placing the subs at the exact center of opposing walls (the middle of the front and back or the left and right walls). Don't guess, measure and place the center of the driver cone exactly at the center of the wall.
  • Using identical subs is better than using different types.
  • You can also try multiple subs placed in multiple corners, but this typically will yield more bass, but less defined.
  • If you can't place the subs in the precise centers of the walls you can try placing them at ¼ or ¾ of the distance from the corners along the walls.

And if possible, don't sit in corners, or at ¼, ¾ or ½ way along any wall. Absolutely try to avoid sitting in the exact center of the room too. You'll be best off sitting at thirds or fifths distances or as close to those distances as possible, to hear the smoothest bass response.

  

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