FIRST 66 YEARS
When my amateur radio station W1NMG shut down due to World War II, I became interested in Hi-FI audio. At that time it was an accomplishment to
design a vacuum tube power amplifier having extended frequency response from 30 to 15,000 cycles per second (now called Hertz).
In my first major hi-fi system in 1945, I realized the losses in speaker response at extreme low and high frequencies required frequency response
equalization (EQ) to extend the range. My 3-watt, 6L6G pentode power amplifier design used feedback to boost 30 Hz and 15 kHz for brilliant highs and
deep bass without boom. It had bass and treble controls too.
My successively better audio designs over many years used ever more elaborate, feedback tone controls as a key element in improving the sound. I
learned that the frequency response of the entire system, including the recording, phono preamplifier, power amplifier, speakers, and room is the number
one factor in producing high quality sound.
Besides low distortion and the usual specifications for high fidelity equipment, two other most important elements of fine sound are the acoustics of the
recording environment and the listening room. When sound is reflected from various walls and surfaces, the combined waves cause it to add to or subtract
from the direct (original) sound at different frequencies, producing big ripples in the frequency response. Contrary to many professional opinions that
ripples are bad, I found they are what make music sound really musical. So, I prefer live rooms over dead rooms which are clearer, but too revealing of
For more than 30 years I was privileged to record in what to me is the best hall in the world, Jordan Hall at the New England Conservatory, in Boston,
Massachusetts. I recorded the Boston Philharmonic Orchestra, the Boston Civic Symphony, and Boston Baroque using two omni-directional microphones
pointed at the ceiling. Omni-directional microphones are actually quite directional at 20 kHz and the increased high frequency reflections, together with a
little EQ, made the recordings smoother and more musical.
I always loved the reverberation in recordings made in Jordan Hall, but I hated the artificial reverberation I heard in many commercial recordings. Jordan
Hall's reverberation makes the sound brilliant, full, and musical. Artificial reverberation can turn instruments like cymbals into mush. Newer sampling
reverberation more closely resembles real halls, but I find it is not really what the ear likes to hear.
My 20,000 watt hi-fi system has been in development since my home was designed and built around its five walk-in speaker horns 45 years ago. Before
acquiring modern computers, I used three microphones to pick up the sound from the speakers and add a little of it into the input signal. Due to the 22
milliseconds or so sound travel time from the speakers to the microphones the additions and subtractions at different frequencies caused ripples in the
frequency response that made the sound pleasingly brilliant and very musical.
Although I was equipped for genuine 4-channel analog recording with a mix to 5 channels, I discovered I actually preferred my 2-channel recordings
processed to 5 channels. The contributions from the front left and front right channels to the front center and rear speakers produced a fuller, smoother,
more pleasant, room-filling sound.
When fairly powerful digital signal processing (DSP) chips and circuit boards became available I designed software that used four $7500 processing
boards inside a Pentium 1 computer together with two stereo external digital-to-analog converter (DAC) boxes. The software system replaced the
microphones and the tone controls for my front speakers. It generated simple, but pleasing reverberation for my rear speakers. My analog equipment
was able to mix a little of the rear channel reverberation into the front channels for greater smoothness.
The completed reverberation software, in conjunction with my rear channel tone controls, added subtle ambiance extending to frequencies as high as 20
kHz. For the first time, I got to like artificial reverberation - my own. It didn't sound like reverberation. Not only that, it nicely supplemented the
reverberation already present in phonograph records and CDs.
I realized the improvement my new ambiance software made was just a taste. I wished I had 500 times the processing power to produce many more
sound reflections. In 2002 this became possible with Intel's development of the Pentium 4 processor, which I estimate was equal to 400 of the Motorola
DSP96002 chips used on my old DSP boards.
In the fall of 2002, when I retired from circuit design consulting, I embarked on improving my hi-fi system, and maybe producing a commercial product to
share with others, via new software. After 8 years of intense work, averaging more than 60 hours per week, I now have AUDIO SPLENDOR and its
derivatives BURWEN BOBCAT and BOBCAT MOBILE. What took so long was writing 1,400,000 equations, some, more than 150 characters long, and
making them all work.
Besides improving my sound with new tone controls and ambiance generation in 5 channels a principal objective was to make my sound system easier and
quicker to operate. With the availability of 5-channel SACDs and movies, switching back and forth to 2-channel CDs and optimizing my system had been
a complex task. By the time I finished the setup my audience became bored and often I made a mistake. Now, after saving my settings from a rehearsal,
clicking on a track in the Windows Media Player causes AUDIO SPLENDOR to set up my whole system to play the same sound saved from settings of
310 on-screen sliders and 357 buttons.
When re-mastering music files, settings saved for each musical selection in the TONE library automatically recall from 6 libraries: tone control settings,
reverberation characteristics, the mix, reverberation mix, source compensation, and speaker or headphone compensation. Rehearsing is easy, as most
recordings require setting only 12 controls, affecting all 5 channels. The software also works in 2, 5.1 and 7.1 channels.
Part way through the development of this comprehensive software, I recorded test CDs one of which I mailed to my long-time friend Mark Levinson. For
many years prior, Mark had been telling me how bad and fatiguing CDs and other digital recordings were and why he liked old-fashioned analog
recording. "Dick, solve this problem! If we can't improve CDs I will get out of audio." As I had always used my ever-improving tone controls to rebalance
the sound, almost every CD sounded decent to me, and I was not convinced there was such a problem.
Upon listening to the test recording and others, Mark reported I had indeed solved the problem of listening fatigue. My new ambiance generation, which
had its greatest effect at extreme high frequencies, really smoothed the sound, got rid of irritants, and made transients clearer, all without losing high
frequency resolution. I didn't even know I was working on the problem!
Mark was so enthusiastic that he urged me to make a simplified version of AUDIO SPLENDOR without controls, available and affordable for everyone.
We will call it BURWEN BOBCAT - BURWEN OPERATING SYSTEM, BEST COMPUTER AUDIO TECHNOLOGY. It was all Mark's idea!
Around that time iPods and MP3s were becoming popular. Audiophile magazine writers often derided the quality of MP3s as unlistenable on a good hi-fi
system. Back to phonograph records! Tests we and others made listening to BURWEN BOBCAT processed MP3s showed the processed MP3s were
actually preferable to the original CDs, even SACDs and LPs. Additionally BURWEN BOBCAT processing reduced the audible difference between
processed MP3s and processed CDs from which the MP3s were made.
In 2006 I introduced BURWEN BOBCAT RE which plugs into the Windows Media Player (WMP) for listening. It processes the signal on the way to the
computer's sound card or DAC. BURWEN BOBCAT RE incorporates all the slider and button settings of AUDIO SPLENDOR, pre-set for you, giving you a
simple choice of 19 processing selections on click-buttons for 2-channel stereo. When you listen to BURWEN BOBCAT processed audio you don't hear it
adding what sounds like room reverberation or echo. The reverberation you notice is almost entirely that already present in the recording itself. BURWEN
BOBCAT adds what I describe as ambiance without echo. It includes a lot of what audiophiles call "air". Rough sounding recordings become smoother
and more musical because the extreme high frequency reverberation averages out the grit. Unlike natural reverberation, which tends to obscure transient
sounds, BURWEN BOBCAT stretches transients in time so they are more easily perceived and become clearer. After getting used to this type of
processing many listeners find their original CDs played loud are quite irritating.
Users of BURWEN BOBCAT RE used mostly the Basic processing selections. Mark Levinson said 19 buttons was a mistake because it was possible to
make the sound worse by choosing the wrong button. So now we have two new BURWEN BOBCAT products.
Mark Levinson traveled the world trying to help me license BURWEN BOBCAT to major companies. What we learned was some people do not hear and
appreciate it. The high frequency reverberation is a subtle effect. Musicians appreciate it right away, but company managers just don't get it. They are
looking for a big sound effect. After flunking out at a lot of big companies we got engineers at LG Electronics in Korea interested. We worked with LG for
two years trying Bobcat in various consumer products and cell phones. What finally made BURWEN BOBCAT acceptable to managers was combining
equalization (EQ) for headphones with Bobcat's high frequency reverberation and slight EQ, so they could hear a substantial difference when Bobcat was
switched in and out.
In 2009 LG started shipping its top class Arena phone that incorporates a special version of my software called BOBCAT MOBILE. The phone has nearly
every feature possible in a cell phone and the best sounding music in the mobile market. Mark Levinson became LG's Chief Audio Advisor for two years.
For the cell phone I had redesigned BURWEN BOBCAT to use less processing power so it will fit into spare digital signal processing (DSP) capacity in all
of LG's phones. LG incorporated it in its Viewty2, Andante, and Crystal phones and finally AT&T started selling the KM900 Arena phone in the USA. By
the end of 2010 about 1,500,000 people were using my software but hardly anyone knew it. Aside from naming BOBCAT MOBILE as an option in the
display of the phone, LG did not even mention it.
Just before completing a license agreement with me, LG licensed Dolby, which became another option in the Arena phone. Apparently LG valued the
Dolby name association more than the performance of its phones and their advertising leaves the impression the Arena is a Dolby phone. Fortunately
inside the phones BOBCAT MOBILE is turned on by default and Dolby is off. The phones have enough processing power for only one at a time. Dolby
technology produces a surround effect inappropriate for most stereo recordings which are already too wide for headphones. In contrast BOBCAT
MOBILE deliberately narrows the stereo image to normal and smooths the high frequencies, making the music easy to listen to.
The current audio product has been digested down to AUDIO SPENDOR for professional use and BURWEN BOBCAT TONE BALANCER and BURWEN
BOBCAT TR for home use. The latter two products were derived directly from AUDIO SPLENDOR by omitting some features.
AUDIO SPLENDOR consists of two parts. BURWEN AUDIO performs real-time digital signal processing that mixes, equalizes, and adds high-frequency
reverberation to as many as 8 channels in and 7.1 channels out. AUDIO SPLENDOR.xls is an Excel workbook that calculates and sends new sounds to
BURWEN AUDIO either locally or by remote control. On screen it has the power of a 310 slider, 357 button studio mixing console. Inside it takes all
1,400,000 long equations to create the sounds for 7.1 channels. All settings are saved in 6 libraries.
The BURWEN AUDIO processing part of AUDIO SPLENDOR can become any of three different programs. When it plugs into the Windows Media Player,
it provides three different BURWEN BOBCAT windows full of buttons for fixed processing. These can be overridden by all the mixing controls. Clicking a
track in the Windows Media Player can recall all settings. Dropping music files from Windows Explorer onto a Bobcat window will convert them to stereo
Bobcat processed MP3 or WMA lossless files. Its second application is as a DirectX plug-in for audio editors, providing the fixed and variable sounds the
same as with the Windows Media Player. The third method of use in conjunction with a MOTU 828MK3 FireWire Audio Interface is to process up to 8
analog inputs for TV, SACD, and live recording etc. BURWEN AUDIO has its own Burwen Recorder Player for recording what you hear in MP3, WMA,
WAV, and W64 formats up to 8 channels and at sample rates of 44.1, 48, 88.2, or 96 kHz. It will also convert music files at high speed to Burwen
processed files in a variety of formats and sample rates, including 32-bit floating point accuracy.
BURWEN BOBCAT TR is the simplest possible version of the Windows Media Player plug-in. Its BURWEN BOBCAT window has only two processing
buttons, Pure Bobcat and Smooth Bobcat plus Bypass. It also contains the stereo file converter. Pure use a somewhat more advanced high frequency
reverb than the original Basic. Smooth, in addition to equalizing out shrillness, dynamically reduces screech only during a singer's loudest notes using a
feature of AUDIO SPLENDOR called NO SCREECH.
BURWEN BOBCAT TONE BALANCER.xls is an Excel workbook that has all the mathematics of AUDIO SPLENDOR to generate new sounds that it sends
to BURWEN BOBCAT TR either locally or by remote control. The tone controls have been digested down to only 6 sliders. It converts BURWEN
BOBCAT TR from stereo operation to up to 7 channels. It is much easier to operate than a graphic equalizer, and the controls can produce a huge range
of boost or cut, more than 70 dB, at low and high frequencies. Half of the tone sliders actually contain characteristics of two AUDIO SPLENDOR sliders
operated simultaneously. Most important, the tone settings can all be changed in only 0.1 dB steps to achieve perfect balance. Three buttons select
Basic, Recital, or Extreme high frequency reverberation, plus Off.
Real room reverberation and ordinary electronic reverberation have their greatest effect at middle and low frequencies. When I first discovered the benefit
of my high frequency reverberation, I tried boosting the high frequency content of various sampled reverberation programs to obtain a similar effect. That
did not work at all. No resemblance.
To produce the brilliance and clarity of BURWEN BOBCAT's high frequency reflections in the real world, imagine a saxophone player has a wall-size
reflector with a hole through which the neck of his instrument protrudes and the reflector is only 1/4 inch from the top open valve. The reflector is in a
different position for each different note. Physical dimensions make such high frequency reflections impossible. They have to be produced electronically.
You can't get this effect at a live concert. Yet I find quick, high frequency reflections are what your ear really likes to hear for clear, musical sound. Even
at Jordan Hall, I sometimes think the sound ought to be processed with my new high frequency reverberation technique.
I save my CDS on an external USB drive in WMA lossless format. When I make MP3s there is only one compression degradation, not two. If I want to, I
can apply BURWEN BOBCAT processing when ripping or burning CDs. The efficient file converter can process a whole folder or library of music files in a
When I listen to my own CDs I don't mind changing the sound completely. Frankly, among the 3000 or so CDs in my collection there are very few I care to
hear sounding anything like the unprocessed recording. One reason, I am told, is many older recordings were equalized via monitor speakers that
attenuated the 3500 Hz region where voices become shrill. These recordings now sound screechy when played through more accurate speakers.
I use AUDIO SPLENDOR to augment extreme low frequencies, attenuate piercing high frequencies, sweeten violins, widen the acoustic image, and fill the
room with spacious ambiance via 5 speaker systems. An important lesson I learned is you need to preserve the high harmonics of musical instruments,
but a little too much makes the sound unmusical. For poorer quality CDs and TV audio I often use what I call EXTREME processing which almost
completely substitutes artificial reverberation for the main signal at high frequencies. EXTREME gradually substitutes high frequency reverberation for the
direct signal above 360 Hz. At 20 kHz you hear nothing but electronic reverberation because the direct signal component is less than1/50th the amplitude
of the reverberation component. In contrast the direct signal component of regular reverbs is bigger than the reverb component at 20 kHz.
|GENESIS OF BURWEN BOBCAT
By Dick Burwen