Bass Management Developed For DVD-Audio, SACD

Select audio suppliers have developed bass-management solutions to make sure that owners of multichannel subwoofer/satellite systems get all the bass they're supposed to get when they play back multichannel SACD and DVD-Audio discs.

Two companies — M&K and Outlaw Audio — will soon deliver consumer-oriented bass-management boxes, which will connect between a DVD-Audio or SACD player's six analog outputs and the six direct analog inputs of a receiver, amp or preamp.

For its part, Kenwood became the first company to announce plans to incorporate built-in bass-management controls in DVD-Audio/Video players.

In the SACD market, Sony said all of its current multichannel SACD players feature bass management, as will all future models. On the other hand, Philips doesn't offer bass management for multichannel-SACD playback in its currently available $2,000-suggested SACD/DVD-Video player, but the company said it will include SACD bass management in lower priced second-generation models. Their launch has been pushed back until January 2002, in part to add bass-management functionality.

The bass-management functions in these companies' products are designed mainly for consumers planning to add multichannel-SACD or DVD-Audio players to surround-sound systems built around small satellite speakers and a separate powered subwoofer, suppliers said.

Owners of current DVD-Audio players and the Philips SACD player can't take advantage of their receiver's built-in bass-management functions when playing multichannel SACD or DVD-Audio discs, the suppliers explained. That's because the 5.1-channel direct analog inputs of today's receivers bypass the receivers' bass-management systems and other preamp-level processing, except volume. As a result, low-bass frequencies from the discs' five full-range channels can't be redirected to a subwoofer that can reproduce them, the suppliers said.

"There's no way to get the bass in the direct inputs to a subwoofer," said a spokesman for Outlaw Audio.

Missing bass is also a problem in systems using outboard amps and preamps, few of which incorporate bass management on their analog inputs, said Outlaw.

Consumers could also be shortchanged if they use five tower speakers and a subwoofer, suppliers agreed. That's because most tower speakers don't deliver bass below 40Hz, and even more robust towers would be hard-pressed to deliver output down to 20Hz because of a room's acoustical properties, said M&K VP Chuck Back.

Even if they play a DVD-Audio disc mixed with a 0.1 bass effects channel, consumers could still be shortchanged, suppliers noted. Even though the bass channel's output will be funneled to a subwoofer in a sub/sat system, the effects channel is intended only to supplement the full-range audio content of the five satellite channels. The bass content of those channels will still be curtailed when played through small satellites, Back noted.

Some DVD-Audio discs are mixed with a 0.1 bass-effects channel, and some are not, Outlaw and M&K agreed.

Another downside to the absence of DVD-Audio/SACD bass management is the potential for small satellite speakers to distort when driven with full-range content, Outlaw said.

The absence of bass management, said Outlaw, has triggered "several early reports from consumers that the first DVD-Audio discs sound thin and edgy because there's no bass."

"When they play the backup Dolby Digital 5.1 tracks, it sound better to them because [the Dolby Digital tracks deliver] full frequency response," Outlaw said. That's because receivers are able to manage the bass of lower bandwidth Dolby Digital and DTS tracks, which enter through a receiver's digital input.

M&K agreed that some consumers are complaining. "Some consumers — the early adopters — and dealers have contacted us asking for a bass management product," Back said. Nonetheless, he said, "there's not a wealth of customers who are frustrated."

The number could grow later in the year, however, as DVD-Audio and multichannel-SACD prices enter the mainstream and more consumers buy into the technologies, he said.

On that point, Kenwood national product manager Brian Towne agreed. Although "we haven't received one complaint" from consumers or dealers, he said, the company is adding bass management to two DVD-A/V players to "to prevent future complaints as the products go mainstream." Mainstream customers, he noted, are more likely to use sub/sat systems that feature small satellites.

"We want to play back what the music companies put on the disc," Towne said.