Making Tracks: Quad Squad

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FIG. 1: The Show Info dialog in Audio MIDI Setup is where you name a MIDI device and set its properties, including which MIDI channels it will send and receive data on and whether it will transmit or receive MTC.

For years, I''d wanted to record and distribute surround-sound music, but I always figured I''d need a mountain of gear. Then the Zoom H2 arrived. This handheld recorder costs approximately $150, yet it sports four mics to capture sound in 360 degrees, saving it to Front and Rear stereo WAV files. But how can you share those surround recordings with other listeners?

I cooked up an elaborate recipe, splitting the two stereo WAVs into four mono files—for Left, Right, Left Surround, and Right Surround—and creating silent Center and Low-Frequency Effects (LFE or “.1”) files of the same length. I then interleaved the resulting files into a special 6-channel WAV, processed that through a shareware Dolby Digital encoder, and Option-dragged the result onto Roxio Toast to burn surround-sound DVDs. You''ll find details in my tutorial at

The folks at Immersive Media Research read my tutorial, realized their flagship Vortex Surround Encoder program did many of those steps already, and asked if I''d like to help build a streamlined version for H2 owners. The resulting program, Vortex Zoom Encoder (Mac/Win, $29.95; see Fig. 1), imports two stereo WAVs or AIFFs and exports one of three standard surround formats: DTS 5.1 (Digital Theater Systems); a binaural headphone mix; or a 6-channel, interleaved WAV or AIFF. And it does this all with just one click (see Web Clips 1a through 3d).

When the Zoom H4n came out, we discovered that Vortex Zoom Encoder (VZE) also worked with its 4-channel recordings. In fact, you can load any two stereo WAVs or AIFFs into VZE, as long as they''re 16-bit, 44.1kHz. (A future version should support more resolutions.) Here''s how to create your own surround-sound productions (see Step-by-Step Instructions on the next page).

Choose Your Perspective
VZE has two drop zones for stereo files: Front and Rear. The program will route the Front file to the Left and Right channels in the output file and the Rear file to the Left and Right Surround channels. To preserve imaging, VZE doesn''t synthesize anything for the center channel; home theater systems will allocate low frequencies to the LFE as needed on playback.

If you''re using H2 files, you''ll typically load the front WAV (SR***F.wav) into VZE''s Front zone and the rear WAV (SR***R.wav) into the Rear zone, but it depends which perspective you want to emphasize. The H2''s rear mics are angled farther apart so they produce a more ambient sound. If you have four speakers and a multichannel audio interface, you can preview both options in VZE before encoding.

With the H4n, many recordists use the built-in mics to capture concert-hall ambience while recording the stereo board mix to the H4n''s line inputs. In that case, you''d assign the line-input WAV (4CH***I.wav) to VZE''s Front zone and the mic WAV (4CH***M.wav) to the Rear. Another approach is to close-mike a source with the H4n''s built-in mics and connect external mics for ambience. In that situation, you''d assign the internal mics'' WAV (4CH***M.wav) to the Front zone.

For quadraphonic records, tracks exported from a DAW, and other sources, listen and swap until you like the effect.

Digital Theater Systems
VZE''s officially licensed DTS encoder creates 2-channel, 44.1kHz WAV files that sound like static when played directly but expand into 4-channel surround when played through the DTS decoder in a home theater system. Click the DTS button to begin encoding.

Next, load the DTS files into your favorite CD-authoring program and burn a CD, being sure not to alter levels, which may corrupt the data. This DTS Music Disc should play in most DVD players; the Sony PlayStation 3 plays DTS CDs, as well. Connect the player''s S/PDIF or HDMI output to a surround receiver''s digital input and you''ll be in surround city. If your computer audio interface has a bit-perfect S/PDIF output, you can also play the DTS file from iTunes into a home theater system without first burning a disc. Check out the VZE help file and my blog at for details.

MP3 Surround
To make MP3 Surround files, start by clicking the 6 CH button. VZE will produce a 6-channel interleaved file you can load into Fraunhofer MP3 Surround encoder (; free). MP3 Surround files are about 10-percent larger than normal MP3s yet are completely backward-compatible: They play like normal MP3s on normal players, but expand into six channels (or binaural surround) on new players. Fraunhofer offers a free player, as well.

Drag the 6-channel WAV (Win) or AIFF (Mac) onto Fraunhofer MP3 Surround encoder and select an output folder. After a few moments, an MP3 Surround file will pop out. You can play it in the Fraunhofer MP3 Surround player, Winamp, a PS3, or other compatible players in 5.1 or binaural mode. VZE''s own binaural encoder creates a 2-channel WAV or AIFF that doesn''t require special decoding to hear.

VZE runs in full-feature mode for 30 days before requesting payment, so testing the surround waters is easier than ever.

David Battino ( designed the user interface for Vortex Zoom Encoder. He also consults on iPhone music apps.



Step 1: Record in 4-channel mode on the Zoom H2 or H4n, producing two stereo WAVs, or choose two WAVs of your own.

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Step 2: Convert the WAVs to 16-bit, 44.1kHz resolution if necessary and then drag them onto Vortex Zoom Encoder.

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Step 3A: Click the DTS button to create a 2-channel DTS-encoded WAV you can burn to CD.

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Step 3B: Click the Headphone button to create a binaural WAV.

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Step 3C: Click the 6 CH button to create a 6-channel interleaves WAV or AIFF.

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Step 4: Drag the interleaves WAV or AIFF from Step 3C onto Fraunhofer MP3 Surround encoder to create an MP3 Surround file.

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