Looking at Surround Sound

Surround sound is NOT a new concept, contrary to popular opinion. It has been being developed and toyed with since the 40's or so and has been achieved using several different techniques and formats. The most commonly remembered for the 60's era was "Quad" which was quite simply four speakers placed around the listener in a square pattern to submerse the listener in sound from all directions.

Since then, we have come a long way. Now it is commonplace to see any home stereo system that decodes at least Dolby Pro Logic and 5.1 Dolby Digital Surround. Often even up to 6.1 or 7.1. The trouble is many people don't know how to use it and just have all the speakers piled up in front of the listener with their system.

Just for a quick tutorial on what 5.1, 6.1 and 7.1 actually is, the .1 is the subwoofer, not really considered a "channel" of it's own, it is a LFO for the sound typically the crossover point is at 120Hz - 125Hz, everything over that goes to the satillites. The big differences in surround formats are the placement of the these speakers. With 5.1 the satillites are place with the center channel right in front-center to the listener, front left and right to the left and right in front of the listener and the rear speakers behind to the left and right. This same format is used for Dolby Pro Logic Surround, which is the same as 5.1 with the exception that the rear speakers are both running the same channel and there is not as defined of a subwoofer channel, if one is even used at all. 6.1 adds a rear center channel to the mix. 7.1 has three across the front, one on either side of the listener and two rear speakers on either side.

Formats

OK, with any newish technology there is the obvious format battle to be waged. Currently with surround there are two formats.

• DVD-A - the six surround tracks are 96kHz/24-bit with frequency response of 48kHz and a dynamic range of 120dB. The stereo tracks being a 96kHz frequency response. Though it can be played on any DVD player, that will limit the frequency response to 48kHz, a special DVD-A player will give you full range.
• SACD is kinda crazy, it's actually a layered disc, the first layer being a standard CD, which can be played in any standard CD player (cool, eh?) The second contain two separate tracks, one a typical stereo recording and the other a 5.1 recording. It's frequency response is only 100kHz and a dynamic range of 120dB. The downside is you need an SACD player to play them at that quality.

Both are a vast improvement over the standard CD in terms of quality. Also, they both have room in the format for lyrics and video.

Personally, I hope the SACD wins the battle due to it's better specs and the fact it can play in a CD player. Plus the fact it's proposed by the Sony/Philips alliance makes a good case for it...since they proposed many standards, CD being one, the original S/PDIF being another...

Down the Road

I have talked with people that don't wanna go the 5.1 route because them they will have to redo it all when 7.1, 10.1 or higher become the standard...eh, decent point...but really, the average listening environment, such as a car, livingroom or bedroom really isn't large enough to use or even house some of those bigger systems to any effectiveness, so I have my doubts of how common it will get.

The little bit I have dabbled in surround has been fun, I think it's worth the venture if you have the means, because, like it or not, it IS the next wave...actually, it's the current wave...and it can add a whole new dimension to the way you look at mixing music.

However, one hitch, before going and buying all the hardware, cuz you know your app pans and mixes in 5.1, do yourself a favor and make sure the app ENCODES EXPORTS in 5.1, cuz there is a good chance you will have to buy an extra plugin or something to get the encoding process installed in your software.