Harman’s Signal Doctor Gives Your Music Back in Full


Signal Doctor technology from Harman warms your MP3s back to their old analog roots.

Harman wants to send its Signal Doctor out to look at your music, whether you realize it’s sick or not.

MP3s rule the music world. That’s hardly breaking news to most people as they take in their favorite tunes via computers, laptops or in dash systems. While the songs we enjoy were once recordings, now they’re compressed data.

What many listeners don't realize is compression technology limits the size of actual music files, allowing consumers to pack thousands of them on something as small as a thumb drive. Unfortunately, that digitized compression process squeezes sound out of your songs. Even the most generous compression formats that produce the largest data file sizes cut bits of music out of what we hear.

The missing sounds might be a little reverb, an extra tough of percussion or a high end vocal echo. The song might seem complete without these elements, but the ear doesn’t know what it’s missing. The dropped sounds are why many high end stereo fans insist old analog music on polyvinyl and tape had a fuller, warmer sound.

Harman looked at this problem and came up with Signal Doctor, software that restores those lost sounds to MP3s while they’re played using bandwidth extension.

Chris Ludwig, a Chief Engineer with Harman, explained that listeners lose up to 90% of the music in MP3s due to discarded data, tossing out higher frequencies.

“Signal Doctor analyzes for lost frequencies coming in and restores them,” Ludwig said. “The analysis returns percussion, guitars and quirks. Signal Doctor restores musical elements most MP3 players lose. It returns to higher fidelity — as the original recording engineers intended.”

The system’s Real Time Analyzer scales the amount of restoration on the quality of the source signal — never applying the same packaged treatment to every song. And, the same technology works beyond MP3s, adjusting automatically between MP3s, online streaming and songs ripped from CDs.

“The philosophy behind Signal Doctor is “as much as necessary, but as little as possible,” Ludwig said.

Signal Doctor will be an ingredient across the product spectrum. It’ll be launched in JBL’s Authentics line and will find its way into Harman’s automotive systems later this year. In a car, it can be turned on or off by the driver and will be tuned to the individual’s car’s audio.

Headphones will need a small accessory with a chip plugged in between the phones and the source to implement the system.

There’s no word yet if the software might extend beyond Harman or JBL systems to other manufactures, but it’s safe to say 2014 will see discussions begin.