Wednesday, March 26, 2008

The Importance of Xd

It wasn't long after getting into audio that I realized speakers are the weakest link in the audio playback chain.  At the same time it was clear they also are the key to creating the magic... occasionally.  Listening to the right recording, in the right room and in the right mood shows us that replicating the live performance is possible but only when the stars are aligned a certain way and all the mojo is working.

It makes no sense to me that enthusiasts will fuss over a tenth of a percentage point in amplifier THD, all the while listening through loudspeakers that at their very best produce 10 times more distortion.  These contradictions were the reason I got into the loudspeaker business.  There just had to be a better way.

Every decision made in passive (and most active) speaker designs involves compromise.  Acoustic designers have to prioritize and balance electrical and mechanical distortion, frequency and time domain response, not to mention guessing what the listening room will be like.  This is one reason why they all sound different, and why any speaker will sound different based where it is placed.  Drivers and crossovers are imprecise, clumsy devices and choosing the right combinations rely as much on intuition as science.  While our industry has made some improvements over the years, there is very little we can do to advance the craft as it is.

While NHT was working on analog technologies such as our Focused Image Geometry (a method for minimizing the effect of the room on sonic playback), on the other side of the planet one of early pioneers of DSP and a co-founder of Fairlight was working on digital solutions for improving loudspeaker performance.  We met each other some years later and Xd was born.

The belief that we held in common with our new partners at DEQX is that the speaker really must be corrected first, then room correction was feasible, at least in the low frequency range.  When you can control both frequency and time domain response, and provide steep digital filters through software, most of the compromises we've lived with for years disappear.  Driver design then has one real purpose; to minimize mechanical distortion.

Don't misunderstand.  It still takes a good acoustics engineer to achieve quality results.  The interesting thing about software-based correction is that it gives designers a whole new pallet of tools and possible directions.  It means we can build smaller, affordable systems that will outperform traditional products by huge margins and they can be placed almost anywhere in a room.  In addition, the amazing resolution is so revealing you can actually hear a difference using better quality components.  And while a sub-$1000 dollar DSP corrected system will  blow any existing passive system away, there will be room for higher end systems.  This leaves lots of room for multiple speaker brands and lots of potential choices for us listeners.

So Xd goes on the "shelf" for a while.  Our first effort proved what we wanted it to, but the hardware is outdated, and there are better, faster, cheaper chip sets out there that we need to work with.  Back to the design caves we go, hopefully others in the loudspeaker field will join the effort and advance the technology quickly.
 

2 comments:

minim said...

Sad to see the Xd not fly. Even though my use would be professional, as in mixing and even mastering, at the current selling price of $3000, I am sorely tempted, especially since I will be retiring in a few years and could use these for home speakers after.

My only big concern is the talk of hiss at idle.

Russell

Clifford said...

Just great...I discover this hidden gem and it's discontinued. Snark!