UPCOMING: Basspig Audiophile Society Social, March 30, 2019!
It's been a few years, but we're finally
going to run another audiophile get together here at the Lair. For
those that are unable to attend, it will be viewable on a life
stream, visible further down this page.
This year's event will feature a lab demo, audio demo, and
DCI 4K projection with 3D material and 2D material that we shot in
various countries. This is the meet for audiophiles who are also
into home theater tech. RSVP to let us know if you can attend.
Basspig Goes 4K!
For nine years, I have been wanting to
fill my screen with a full 4K image and 2.4:1 ratio for movies. This
year, I finally realized that goal, with the addition of the Sony
VPL VW-765ES projector, which provides full DCI 4K (4096 pixels
wide) and 17:9 native aspect ratio.
Here is the finished result:
Here is the rough wood assembly, out of poplar, before sanding and
Here is the interface plate that will attach the box enclosure to a
mount on the carrying beam:
Here is that interface, after painting with Duratex paint:
Here is the interface mount. Critical is the leveling of this mount,
so fine shimming is done here:
Here is the interface plate, attached to the mount. The plate has
four M-8 T-nuts to which the box shelf will attached by four M-8 x
30 mm bolts.
This took some planning, because I have a vertical support column in
the way, necessitating the offset from the beam.
This is the result. Incidentally, this footage was shot in 16x9 on
35mb/s MPEG XDCam in 2008. I found that I could use the projector's
lens memory and blanking to create a 2.35:1 widescreen image and it
still looks clean and detailed.
This project has been long in the planning and there are not many
projectors that meet my requirements of both wide enough lens and
DCI 4K (not UHD), as well as brightness, gamut, and deep color.
A Look Behind the Scenes
The Bass Pig's electronics laboratory. Here is where I design, build, modify,
and repair audio equipment. There's too much to list (I get a case of "Crow
Epistemology" when I try to recall all the model numbers), but the highlights
are the Tektronix AA-501 Distortion Analyzer and the HP 3585A Spectrum Analyzer,
which are two important tools that I use for analyzing the performance of audio
and RF amplifiers. I have an assortment of function generators, ultra low
distortion oscillators, power supplies, digital multimeters, temperature probes,
and a Tektronix 576 Curve Tracer. That last item is my tool of choice for
testing vacuum tubes. I have also found it useful, with a pair of probes, for
troubleshooting in-circuit components. Electronics has been my profession for
over forty years.
Phase Linear D-500 Hum
Reduction Modification - $750 I'm now officially
making my D-500 modification service available to the audiophile community,
after many requests. I've refined the modifications and added a few tweaks to
make the amp topology more stable. On top of that, I tune the amp on a spectrum
analyzer for lowest distortion. I've
written about this modification on my own D-500 a few years back. You can
find out what it entails. The purpose is to fix some wiring topology problems
that prevent this otherwise amazing amplifier from reaching its full musical
potential. If your D-500 suffers from hum and buzz (especially from light
dimmers) and the problem is more severe in the left channel, then my
modification will eliminate the interference. In addition, I replace any aging
capacitors, particularly the one in the low voltage control board PCB assembly,
which is known to fail often. The D-500 is also a bit unstable and tends to
oscillate ultrasonically, especially if driven to clipping. I add parasitic
filter capacitors to the B+/- busses to prevent this condition, which could
damage your speakers, if severe enough. Enough people have begged me to offer
this service, so here it is. Contact me at
domain name basspig.com)
to make arrangements. If you live in the northeast, walk in drop off pickup is
often the best and safest way to deliver your D-500.
$2500 Projection Screen
I built a projection
system/theater for only $2500 in total expenses, including screen, projector
(purchased on eBay), fabrics, wood framing and three chairs. See the results:
As of 8/14/2009--finally, done hanging
See it in action:
Equipment racks are divided into signal
sources and power amps/speaker management:
The analog equalizers are no longer in use, due
to my tighter restrictions on noise floor of devices in the External Processor
Loop. I am solely using the DEQ2496 for this purpose, as it contributes less
hiss to the overall chain.
April 2017 Audio amplifier racks
see the addition of Hafler XL600 amplifiers. These went through a
thorough upgrading and received all new capacitors with the
addition of upgraded power supply capacitors and some
modifications to make the amplifier more stable.
For more photos and to see photos that
have been moved from the front page, go to the More Photos section and select
Square Wave Response
Recently, I became curious about
reproducing square waves, acoustically. I knew that this is generally an
exercise in futility, given that there are so many factors ranging from driver
alignment, phase rotation vs. frequency, room reflections/acoustics and even
audio electronics, particularly audio player DACs.
My first step was to find a good square
wave source. My Oppo BDP-83 failed miserably at that, producing a generally
square-shaped wave with higher frequency sine waves riding on top, decaying to
near zero by the zero crossing of the fundamental wave. I ended up using a high
quality DAC that I use for recording professionally, to produce a decent enough
square wave. That was fed through a mixing desk and 40' of cheap coax to the
Carver C4000. This is the output of the C4000 (top trace). Bottom trace is what
a Behringer ECM8000 omnidirectional measuring mic picked up in the center seat
of the front row. Needless to say, it wasn't as bad as expected. It indicates
that room reflections are well controlled, even from the live (rear) end of the
studio. From a listener standpoint, it was always apparent that the system
presents excellent transient response, but I like to confirm what I hear with
500Hz in room square wave response measurement at listener position.
About Planning of Bass Pig's New Projection
plan denotes a 'false wall' which supports a new perforated screen material from
Seymour AV, which is highly-rated for audio transparency and visual performance.
The frame supports a sub-frame with the screen, which is secured by deadbolts
for easy removal for cleaning and maintenance and is
tilted down slightly to maintain perfect alignment with the projector's image
plane, which has a fixed 36% offset. I purchased an InFocus IN82 projector,
which provides 1920x1080 native HD resolution.
Theater enthusiasts will notice that the screen is a
2.35:1 aspect ratio. The new screen and false wall completely conceals my not-so-pretty array
of speakers, and finalizes my 25-year dream of turning this into a theater. Why
did I wait so long? Because until last week, I did not see a projection system
that would rival direct-view plasma screens. What I saw at a friend's house in
July 2009 (I went there to help him calibrate his projector and achieve dark, inky
blacks with great success) totally changed my perception of projection
technology. This new DLP stuff has contrast ratios that exceed my LCD TV screen
by 5:1! I was seeing deeper blacks on the big screen than I saw on my LCD.
Hence, a milestone was reached. So I immediately researched projectors, found
one with even better shadow detail, based on screen shots and reviewer comments,
and looked on eBay and lo and behold, I snagged a $5,400 projector for $1,425
open box with 76 hours on it! I immediately went to work on designing a screen
and making a materials list.
So here is what the final concept
is expected to look like. I expect to be able to use a lightweight velvet
material for the drapes, in as dark a burgundy red as I can find.
The projection (active) area of the screen
is 12 feet wide by 5 feet high.
A pixel of 1920x1080 will be 0.043", or about the size of the period on a
typewriter keyboard. After seeing my XDCam footage from a Blu-ray disc that I
authored on my friend's projection system, I developed a new respect for the
CineAlta line of cameras!
PHILOSOPHY -- To prove that LOUD and HI-FIDELITY are not
(While defining a whole new set of terms, starting with "sonic violence.")
FRONT MAIN SPEAKERS... Six E-V EVX-180Bs and four Bassmaxx ZR-18s (June 2006)
It may not look like much, but thanks to long-stroke, it displaces over
8,000 cu in of air.
[October 2009, Update]
much has changed here since my last writing. The addition of a
screen and projector arose out of a visit to a friend's home
theater, to tweak the colors on his new projector. I was a skeptic
on projectors for years, as none of what I'd seen 'til recently was
even close to a cinematic experience. I came away from that session,
forever a changed man!
the changes you see here are a direct result of my experience of
July 2009. I finally decided that the technology had reached the
milestone where I was willing to invest. A series of events fell
together so easily, that it could almost be said that "divine
intervention" wanted this theater project to happen. The appearance
of a very expensive projector on eBay, at the right time, and at an
unbelievably low bid price due to a lack of bidders, the help I
received from family and the speed and smoothness with which I
planned the construction, all made this a reality in just three
I'm writing about in this column is about the audio side of things.
Given that I was erecting a semi-permanent screen wall, I wanted to
address some acoustic treatment issues once and for all, which I had
been procrastinating on for more than 25 years. I bought many boxes
of acoustic fiberglass panels and finished the treatment of the wall
behind the speakers. The screen arrangement begged for a tighter
speaker arrangement. With the LCD panel removed, I could populate
that space with the mid-bass cabinets. (I had tested the effect of
putting one double 18" cabinet in that central position about 15
years ago and the result was a visceral increase in bass.) Recalling
past experience, I knew there would be some benefits to having all
the woofers close-coupled.
Getting all the cabinets down to a sixteen foot-wide footprint
proved to be very beneficial. The former arrangement with the four
foot gap in the center was inefficient because it created a
situation where the woofers acted as two separate sound sources,
introducing cancellations of low frequency energy down the center.
Moving them all together created a unified sound source, eliminated
the cancellations and also gave the benefit of mutual coupling,
making the whole cluster act like one sixteen foot woofer. At a
given reference power level, the increase in SPL was about 6dB, just
from moving the cabinets together to form one unified source!
biggest challenge to deal with is that the seating is located dead
middle of the room's length. Since the room acts as a waveguide,
it's apparent that 2X the wavelength of the room will be the
frequency at which the back wall's reflected wave will cancel the
front incidental wave. That frequency is 36Hz in the center of this room. The dip
was especially deep and narrow, in this case. I later discovered
that the dividing wall between this room and the next was resonant
at... you guessed it--36Hz! I mass-loaded it with concrete panels
from the other side, and added a 4x6" brace in the middle, to bring
the resonance up to 55Hz. Lo and behold, the dip at 36Hz is not
nearly as deep and not so narrow anymore.
next step to solve the reflected energy is to add plywood resonant
panels to the back wall. These panels will be tuned to 36Hz and
their function will be to absorb only that frequency so that it
won't be reflected back to the center of the room where it causes
cancellation. I've already built some bass traps, and a friend of
mine donated a couple of bass traps that his
Acoustically, the room sounds quite neutral now. If Bob Carver could