Dolby Digital and Digital Theater System (DTS) are the top contenders in the surround-sound arena, and they represent impressive technical achievements.

Dolby Digital and Digital Theater System (DTS) are the top contenders in the surround-sound arena, and they represent impressive technical achievements. Dolby Digital software offers a reasonably priced option for producing surround mixes, but if you want to distribute your music on commercial CDs, you are out of luck if it's all you have. That's because DTS owns the exclusive licensing rights to put compressed surround data on audio CDs. In fact, if you wanted to produce DTS-encoded material in the past, you had to send your music to DTS to have it encoded. Fortunately for desktop musicians and personal-studio owners, that is no longer the case.

Minnesota-based Minnetonka has just released its new SurCode CD Professional DTS-encoding software, which lets you produce DTS surround mixes simply and reliably. Moreover, purchasing SurCode CD Professional gives you the right to publish and sell surround-mix CDs.

SurCode CD Professional uses lossy compression to encode six audio channels with a playback streaming rate of 1,234 kbps. The sophisticated compression scheme lets you fit as many minutes of DTS-encoded audio on a CD as you get with a normal stereo CD. (For a brief overview of surround technologies, see the sidebar, “Surround About.”)


To realize your surround-sound ideas, you need a 5.1 decoder or 5.1 receiver, a set of speakers, and 5.1-mixing software such as Digidesign's Pro Tools, Steinberg's Nuendo, or Minnetonka's Mx51 surround mixer.

Before you can use SurCode CD Professional, you must click on its Options menu and select the sound-card outputs for monitoring. The program is easy to use and centers on a single window that presents the necessary parameter settings at a glance (see Fig. 1).

Because Windows audio devices are allocated in stereo pairs, it's necessary to assign three MME drivers for the six outputs in your 5.1 mix: left-front, right-front, center, subbass LFE, left-rear, and right-rear. If you assign fewer than three pairs of drivers, the source files are mixed to the available devices. Besides assigning the three pairs of drivers for the six channels, you can assign a driver through which you can send the encoded mix to a decoder for preburn auditioning.

Once the hardware assignments are set, it's a simple matter to select sound files for encoding. SurCode CD Professional accepts WAV and AIFF files at 44.1 kHz. You choose the files by clicking on the buttons marked with the names of the six channels and selecting from a standard Windows browse menu. The name of the selected sound file for a given channel then appears in the window next to the corresponding button. Each channel has Mute and Solo buttons as well as a Clear button to remove the selected file if you change your mind or make a mistake.

The next step is to pick a destination for the encoded file using the Destination button at the top of the window. The encoded file is written as a WAV file, which you can easily burn onto a CD with several popular programs such as Roxio's Easy CD Creator. A session with all of its input sound files and its destination sound file can be archived or reopened with the Save or Open commands, respectively.

You don't have to select all six channels to encode. For one mix, I selected a computer-music piece and encoded it in four channels: left-front, right-front, left-rear, and right-rear.

Two sections labeled Encode and Playback appear at the bottom of the window. Clicking on the Encode button in the lower-left corner starts the encoding process. The Start and End displays mark the locations in the source files where encoding begins and ends.

A five-button transport in the Playback section lets you play and navigate the source files or the encoded WAV file. A time display beneath the transport buttons serves only as an indicator of elapsed time for the source files or the encoded file; it doesn't accept typed-in values for setting the playback point.

You enter start and stop points for encoding by typing numbers into the Encode section's Start and End displays before you hit the Encode button. Start and stop points can also be set by playing the music with the transport controls: after locating the appropriate point in the music and stopping playback, hit the S (Set) button in the Encode section to transfer the current time to the Start or End display. The R (Reset) button returns the display to its default setting.

If you have a sound card with at least six analog outputs or an ADAT Optical port, SurCode CD Professional lets you monitor your pre-encoded mix by clicking on the Source radio button beneath the transport controls. To do a preburn audition of the DTS-encoded WAV file, click on the Destination radio button and send the mix through your sound card's S/PDIF outputs to the decoder. Be aware, however, that many sound-card drivers include a software volume control, which corrupts the data on its way to the decoder. If it can't be bypassed (as is the case with Creative Labs' Sound Blaster Live, for example) your audio output will end up sounding like static or white noise. If your sound card has a driver designed for streaming encoded files (such as the Sound Blaster Platinum or the Digital Audio Labs CardDeluxe), you should have no problem.

The 16-page SurCode CD Professional user manual is a hard-copy version of the online document distributed with the software. It is attractive, well laid out, and designed to get you up and encoding quickly. However, it left me wanting more, especially in the sections about how DTS works and where you can obtain further information. Also, specific hints about using the encoder with particular sound cards to test a DTS encoding prior to burning would have made a nice addition.


For this review, I used Nuendo to prepare examples for testing. The mixes were from various sources: contemporary classical chamber works, jazz, and 4-channel computer music. I auditioned the mixes on an Infinity Prelude MTS surround speaker system driven by a Sony model STR DE-935 consumer 5.1 receiver along with a Hsu subwoofer.

I was impressed with how good the DTS algorithm sounded. Most of my musician and recording-engineer colleagues couldn't tell the difference between a 6-channel ADAT classical-music recording and its DTS-encoded counterpart. Some preferred the DTS-encoded mixes to a Dolby Digital-encoded version that I also prepared.

You can experience for yourself how SurCode CD Professional sounds by downloading from Minnetonka's Web site two free sound files that were produced with the software. All you have to do is burn the WAV files onto a CD and play them through a DTS decoder.

If you want to hear more 5.1 mixes, DTS (www.dtsonline.com) markets a large number of surround-audio CDs featuring artists and composers from Steely Dan to Messiaen. The DTS mixes I have heard from that collection are quite impressive and are clearly the work of talented recording engineers.


About 60 companies are licensed to manufacture DTS-compatible surround equipment, such as A/V receivers, discrete decoders, and DVD players with built-in decoders. Most units are built for video home entertainment but will play DTS surround-audio CDs just fine.

The fact that more DVD movies are being released with Dolby Digital and DTS audio tracks speaks to DTS's acceptance and viability. In addition, the large installed base of DTS theater systems (about 19,000 compared with about 25,000 for Dolby Digital) says something positive for the future of DTS.

If you want an entrée into surround sound and wish to release multichannel mixes on audio CDs, I can't think of a better solution than Minnetonka's easy-to-use SurCode CD Professional.

Minimum System Requirements
SurCode CD Professional

Pentium II; Windows 95/98/2000/NT;


Multichannel sound production has been around a long time and has gone through many incarnations, including the pioneering multichannel soundtrack of Disney's Fantasia in the 1940s, multichannel electroacoustic compositions from the '50s, the interest in quad sound on LP and 4-channel tape in the late '60s and '70s, and Dolby ProLogic in the '80s and '90s. Now the two biggest surround-sound contenders are Dolby Digital and DTS. (Although Sony Dynamic Digital Sound [SDDS] is an important system in wide use, no SDDS software encoders are available.)

The question of which digital surround format — Dolby Digital or DTS — is superior remains a hot-button issue in audio circles. Both surround systems are certainly impressive. Of the two competing formats, Dolby took the lead in 1992 with the release of Batman Returns; DTS followed the next year with the release of Jurassic Park.

Until now, if you wanted to get involved in making your own surround mixes, Dolby Digital software encoding was the only reasonably priced game in town. However, making surround CDs with a Dolby Digital software encoder can be fairly dicey. (For more about the process of creating surround-sound mixes, see “You're Surrounded” in the October 2000 issue and “Mixing in the Round” in the May 2001 issue.)

If you plan to release your surround-sound music on commercial CDs, you'll have to use DTS encoding. DTS has the exclusive rights to surround-encoded audio for commercial CD distribution.


SurCode CD Professional 1.0.2 (Win)
surround-sound encoding software



PROS: Simple, easy-to-use interface. Excellent sound quality.

CONS: Documentation a bit sparse. Can't directly enter playback start time.


Minnetonka Audio Software, Inc.
tel. (952) 449-6481
e-mail info@minnetonkaaudio.com
Web www.minnetonkaaudio.com