Mixing For Surround Sound

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		Mixing For Surround Sound Prev 1 2 3 4 5 6 7 Next

			We've talked about how to pan your inputs into the Surround soundfield. There are some parameters that we can use to define the general soundfield itself, and this will be our topic here. Setting the Size of the Soundstage [an error occurred while processing this directive] When you are pushing that sound around the room with the joystick, just how does the joystick location relate to the sound location? Turns out that you can define the relationship between the joystick position and the sound position. In Mx51, the adjustment is found by right-clicking on the Surround panner. When you select this, you get a slider control: This slider adjusts the panning algorithm. It is defined as setting how the center soundfield volume compares to the corner soundfield volume. When you move the slider to "1", the volume for a sound panned to the center of the soundfield is the same as the volume if you panned the sound to a corner speaker. Sonically, this has the effect of making the corner speakers prominent compared to the center, and tends to "pull them in" and make them sound close to the listener. When you push the slider up to "4", a sound panned to the center now has 4 times the sonic power as the same sound panned to the corner. This makes the corners sound more distant. In effect, then, *this control sets the size of your soundstage!!!* This is a very important parameter for the overall listening experience, and one you will want to play with in order to get a good feel for it. You can set all Surround panners to the same soundstage size by setting the default value for the Surround Center control, in the Options menu under "Surround defaults." But you can also set this level independently for each Surround panner. Once again, the best thing to do is experiment. How Real Is Your Center? Try real hard to think back to the days of stereo, and remember how we got a center image. "Gee, there was no speaker in the middle, yet I heard sounds in the middle, between the two speakers." The way we got a center image in stereo was to put exactly the same sound in both speakers. This created a "phantom" center or "virtual" center. It worked fairly well, although the image in the center was always big and never tightly focused. Now, with 5.1 Surround, we actually have a real speaker in the front center. If we place a sound in this speaker, and this speaker alone, we will have a sharply focused sound from the front center of the soundfield. So we have a new option for placing sound that didn't exist in stereo. But we also still have the option of creating a virtual center, also. Mx51 lets you choose between real center and virtual center, with a shutter on the Surround panner. Just grab the edge of the shutter with the mouse, and pull it in or out. You can not only select between real center and virtual center, but you can in fact make a blend of the two. This way you can adjust the size of the image for sounds panned to the front center of the soundstage. Bass Management Warning: This is the most highly debated topic in Surround mixing. With 5.1 Surround, we are now surrounded with 5 full-range speakers, and we also have a subwoofer. Do we send all the bass to the subwoofer? Do we ignore the subwoofer and send all the bass to the full-range speakers? Do we send bass to both the full-range speaker AND the subwoofer? Actually, different recording engineers try doing different things with the bass. More than anything, though, what is determining the direction of this debate is the playback equipment that is going into home theater systems. Here is how home theater Surround decoders and receivers work: They send any information from the subwoofer channel of the recording (called the LFE channel, for "Low Frequency Enhancement") directly to the subwoofer. It also filters the low bass out of the other 5 channels, and sends it to the subwoofer also. Some decoders and receivers use a fixed crossover frequency for filtering the low bass. Others allow the user to tell it if your system has "big" speakers or "small" speakers, and they adjust the bass crossover frequency by guessing how low your 5 full-range speakers can go. So, as a recording engineer, you have to pay close attention to where you send the bass. In Mx51, you can drop a SubBass crossover onto any input channel. The SubBass crossover component is on the component toolbox, labeled "sub". When you drop this on a channel, it gives you a "SubBass" button. When you click on the button, you can adjust the crossover parameters. With the SubBass crossover, you can extract the low bass from any input channel and send it to the LFE channel, for playback on the subwoofer. You can also send the low bass out to the full-range speakers if you want (by selecting "Thru" under "Surround channels") or you can remove the low bass from the full-range speakers (by selecting "High Pass"). For some really high-power low frequencies, try sending the low bass out to all channels, and let the home decoder/receiver filter it out of the 5 full-range channels and send it to the subwoofer along with your LFE bass. You can rock the house! Prev 1 2 3 4 5 6 7 Next [an error occurred while processing this directive]

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