Wednesday, October 31, 2007

The JBL D44000 Paragon

(This is an archived post from our old blog.)


Paragon image © Harman International
(click image to enlarge)

How about a standing ovation for the folks who created the Lansing Heritage Website?

They've got a ton of great stuff, including this bit about the Voice of the Theatre range.

One of the most fascinating speakers around is the JBL D44000 Paragon

Here's a quote from the Lansing Heritage Website about the Paragon:

A little known fact is that the Paragon was originally envisaged as a center channel speaker to be flanked by separate left and right speakers that would be similar in configuration to the Hartsfield. This was related to research conducted in the 1930's by Bell Labs that purported the most stable stereo image was achieved with a center channel speaker. However the cost and space requirements for such a system would be prohibitive and the concept was revised to be a standalone stereo system.

I always think that the final nail in the coffin of three-channel stereo was the popularity of the LP. But anyone who sells speakers will tell you that three are better than two.

I really suggest reading the whole article.

Okay, again, I realize it's a bit off-topic for us, but the ├╝ber-cool photo pushed me over the edge. Who doesn't want a tan Barcelona chair on a fuzzy white carpet?


Tuesday, October 30, 2007

Lefty Frizzell

(This is an archived post from our old blog.)



Lefty is one of my favorite Country and Western singers.

Smilin' Buck Trent, the guitar player in the TV clip, is still picking and still grinning.

I love it!

In the News: Vinyl will kill off the CD

(This is an archived post from our old blog.)

According to a recent Wired Magazine article vinyl is poised to kill off the CD.

I think this quote is funny:

Golden-eared audiophiles have long testified to vinyl's warmer, richer sound.

I don't have "golden ears" and I don't consider myself an audiophile, but I usually reserve the words "warm" and "rich" for things like Toll-House cookies.

And I vaguely remember hearing that the CD killed vinyl about twenty-five years ago.

I think it's a bit soon to call a winner in the CD/LP/MP3 game. A Spanish language CD store (of the Ritmo Latino chain) just opened a block from my house.

Thursday, October 25, 2007

Alan Blumlein: Inventing Stereo Sound

(This is an archived post from our old blog.)




Alan Blumlein invented a lot of things. Here's a list of his patents. from Dora Media Productions' website where there's also information about Robert Charles Alexander's excellent book about Alan Blumlein.

The book is titled The Inventor of Stereo/The Life and Works of Alan Dower Blumlein and you can order it here.

Alan Blumlein had a lot to do with the fact that most home hifi setups have two speakers. The story goes something like: Alan takes his wife to a movie where he puts together the idea that the sound should follow the actors across the screen. Alan called the idea "Binaural Sound". (We now think of "binaural sound" as a recording specially recorded for listening through headphones... I believe Western Electric coined the term "stereophonic".)

Alan Blumlein described a method of recording sound using two microphones with figure-of-eight patterns arranged at 90 degree angles and a method of playing back the resulting audio using two loudspeakers. If Mr. Blumlein were alive today, I would ask him if he intended for recordings made with the Blumlein Technique to be played back with the speakers placed 90 degrees to each other.

Here's a nice description of how the mics are set up with Blumlein Technique.

According to Chesky Records, all of their recordings are made using Blumlein Technique.

In the early days of stereo recording, some engineers (possibly including Harvey Fletcher at Bell Labs) favored three-channel recordings, but I would guess the eventual dominance of the phonograph record pushed things to favor two-channel recordings.

Here's the Patent Specification for Blumlein's directional sound recording technique (also from Dora Music's excellent webpage.) Note that it's from 1931!

Alan Blumlein also did significant work at EMI on H2S Radar. Sadly, Alan Blumlein was killed in the crash of a Handley Page Halifax aircraft (pictured below) that was involved in H2S Radar tests.



It's amazing that Blumlein was granted 128 patents, especially considering that he died just short of his fortieth birthday.

Wednesday, October 24, 2007

Richard Burwen and his 20,000-watt hifi system

(This is an archived post from our old blog.)


click image to enlarge

(photo from: Audio Magazine/scrounge.org)


click image to enlarge

(photo from Richard Burwen's website.)



Okay, this is pretty fascinating stuff.

I realize it's pretty far off-topic for our single driver speaker blog, but anyway...

Who is Richard Burwen?

Here's his bio.

Here's just a small blurb from his bio in case you skipped the link:

Dick got into a lot of really interesting projects. Among the more challenging projects were ultra-low drift chopper-stabilized DC data amplifiers, IC multipliers and function generators, magnetometers, and low-noise switching power amplifiers. He designed circuitry of the first transistorized blood cell counter, a seizure detector for epilepsy, photoelectric relays, high resolution CRT displays, early projection color TV, a military satellite spin detector, and magnetometers for ground use and aircraft. His spacecraft magnetometer circuits successfully measured the magnetic field of the moon from orbit.

The article about Richard Burwen's 20,000-watt hifi system comes from Wayne's Speaker Building Page. The article is excerpted from Audio magazine, April, 1976. pp. 44-56 and was written by Richard S. Burwen.


click image to enlarge

(photo from: Audio Magazine/scrounge.org)


Here's a blurb about Richard's 20,000-watt hifi system:

Each of the five speaker horns is 13 ft. deep and has about 64 sq. ft. of mouth area. [i.e. 8 foot x 8 foot] The horns are conical, in preference to exponential, in order to produce a gradual low frequency rolloff, instead of a sharp cutoff. As it turned out, due to reinforcement from the room, the average low frequency response on one third octave bands is flat down to 16 Hz without equalization.

Each speaker horn contains 30 Cerwin-Vega tweeters, a midrange horn with two JBL 2440 drivers, and two Empire 16 in. woofers. In addition, the left-front and right-front horns have two 24 in. Cerwin-Vega woofers, mounted on the doors. These woofers are equipped with feedback windings to linearize their acoustic output over their range.


and...

To drive these speakers there are a total of 17 Phase Linear 400 amplifiers [200 watts RMS/channel @ 8 ohms].... Each woofer, midrange horn, and set of 9 or 12 tweeters is driven from one 200 watt amplifier channel. With the electronic crossover at 50, 400 and 5,000 Hz ahead of the amplifier, the speakers can produce the same sound level that would be produced by a single 20,000 watt amplifier.... The crossover filters utilize UM201 modules to produce 6-, 12-, 18-, and 30-db/octave cutoffs for the various drivers. In addition, the crossover provides equalization to lat acoustic response.


click image to enlarge

(photo from: Audio Magazine/scrounge.org)

Here's a great picture of Richard with his first hifi in 1945:


click image to enlarge

(photo from Richard Burwen's website.)

...and here's his 2-watt amplifier with bass and treble controls, 1946.



click image to enlarge

(photo from Richard Burwen's website.)

You can follow this link to Richard Burwen's website. You'll notice that he's been keeping busy.

Thursday, October 18, 2007

Astronomy Picture of the Day

(This is an archived post from our old blog.)




We've had the APOD link up for a while, but it's worth a more detailed mention.

The Astronomy Picture of the Day website
is "originated, written, coordinated, and edited since 1995 by Robert Nemiroff and Jerry Bonnell".

And just as the name promises, there's a new astronomy-related picture every day.

The APOD Archive is a great place to get lost when you're supposed to be working. They've been putting up a new picture every day since June of 1995 so there's a lot to see.

Here are links to the above photos:

Jupiter

Death Valley

Great fun.

Credits: Jupiter: NASA, Johns Hopkins U. APL, SWRI

Death Valley: Dan Duriscoe, U.S. National Park Service

Monday, October 1, 2007

Support Real Stereo

(This is an archived post from our old blog.)


The folks over at TNT-Audio have started the Campaign for Real Stereo.

I'll support that. I only have two ears.

(That doesn't mean I won't be perfectly happy to sell you five speakers!)