Electronic Design

Bob's Mailbox

Dear Bob:
I had a good laugh at your recent dialog with Allan Hurst (electronic design, Dec. 17, 2001, p. 25) on the subject of speaker wires. Allan was right when he said that the Hi-Fi trade is now 100 times worse than it was in those days!

Consider that the "best" stereo/home-theater systems have power amps mounted just feet away from the speakers. Despite this, they will spend a fortune on massive wires, and even install "equalizers" in that short wiring! Apart from features like Litz wires, they make the cables for all parts of the system—not just the speaker wires—from "Oxygen Free" copper, whatever that is.

Not satisfied with that, these cables are marked with the direction that they're to be connected to—from the source to the destination of the signals! I had a very heated argument with one guy who insisted that if the wires were reversed, he could tell the difference in the sound! I'm in the video biz (Faroudja/Sage), and it's just as crazy.

Get a camcorder to record the details of every test. Bet him $1000 plus his fancy cables that he can't hear the difference, really, in a truly blind test!—RAP

Dear Bob:
I have done miscellaneous audio design for years. Originally, it was just for my own fun, analog synthesizer stuff. But in recent years, it has shifted more and more into the "audiophile" world. So, I will give you more data from an engineer's perspective.

Some of my clients are recording studios with numerous projects that they would like to do. The temptation is quite high because it's always fun to try to assume the role of creating the best device that ever existed—regardless of material and build cost. In my opinion, that's not even engineering, but more of an art. The problem that I notice most prevalently is that the audio people are generally completely flaky. (Exactly! /rap) The terms they use are devoid of any descriptive qualities. This has stimulated me to try to develop a sense of their vocabulary, so that I can go around and sound snooty by using words like "the sound," etc. To date, I still don't know what I mean when I say it. (Neither do they. /rap)

There are noticeable audible differences when changing things such as crummy cable to decent handmade cable. But I can't really aurally quantify the difference. The ear is such a wonderful device, and extremely resolute, but it doesn't seems at all quantitative.

I think that doing custom work in this industry is quite interesting. It presents various unusual problems, bridging descriptive assessment with personal subjective assessment and providing the opportunity to work for the "golden-ears" folks that bar no bucks for the best. It offers the chance to really shine with electronic design and often forces really good engineering. This ultimately results in the simplest and most stable designs, though often ludicrous overkill.

About cables: I'm always up for the opportunity to find some audiophile who wants a custom cable made of high-purity silver wire in Teflon tubes—configured as "spread-spectrum Litz" with welded terminations to insanely expensive connectors. But what I find to be the best at home is a quick trip across the street to the hardware store. It has this nice twin-conductor, stranded-copper extension-cord stuff that's 14 gauge—for about 30 cents a foot. I think it works great. Yes, it has some of the lousy features of stranded copper, but it's fairly heavy duty and real cheap.

Maybe I would use something else if I had some big Martic Logan speakers. But because it drives some ancient Advents that I re-coned, it's great stuff! (I agree. It's pretty good for me. But have you ever heard the results of using those flat arrays of 32-conductor wire? You parallel up all of the even wires for the ground and all of the odd wires for the speaker drive. This wire system has really low inductance. If there's any audible difference between speaker cables, these low-L ones ought to sound different, maybe even good! /rap)

Anyway, I think that participating in the modern audio field is rather amusing. There are good engineering projects for commercial items. There also are really neat custom-design opportunities, which are trying to attain the perfection that never will exist in audio, constantly pushing the audio envelope farther to the asymtotic point. (You just used an interesting phrase: "trying to attain the perfection that never will exist in audio." /rap) It's all pretty much fun, except for the part of trying to communicate with audio people. Perhaps I just have inept communication skills.

No, I think it's the "golden-ear guys" who are inept at showing that they can hear a difference—when they can't. Best wishes in dealing with strange people like that!—RAP

All for now. / Comments invited!

RAP / Robert A. Pease / Engineer
[email protected]—or:

Mail Stop D2597A
National Semiconductor
P.O. Box 58090
Santa Clara, CA 95052-8090

P.S. We had to postpone our bicycle trek around the Annapurnas from last October to June 1 for bureaucratic reasons. We have several people signed up, but a couple had to back out for personal reasons. We have room for one more, so inquire if you're a good, strong mountain biker looking for an excellent adventure. /rap

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