Jump to content

Get rid of your Autoformers


drewb

Recommended Posts

I have found a way to eliminate the Autoformer from the midrange portion of the crossover. If your cornerhorns, heresy's etc. have an autoformer you can bypass it. Just add old magnets harvested from thrown away computer hard disks. These can be removed from the old hard disk by unscrewing the cover and removing the ceramic piece that your screwdriver just stuck to. The magnets will attach themselves to the squaker driver. I find that 3 of them equal spaced is just perfect.

The result is a sound that is more magnetic with a certain hard to put your finger on ceramic tingle. The magnets reduce the db output of the midrange just like the autoformer did but without that nasty autoformer distortion.

Caution: I am not sure what this would do to the warranty.

Link to comment
Share on other sites

BAD IDEA!

You may have reduced the magnetic strength of the speaker magnet. If that is what you have done you have upset the design of the driver, not just it's sensitivity. Besides: A transformer is a GOOD THING. It holds a constant attenuation to spite a verying load. It also holds the amps damping factor to the driver. A "L pad" won't even do that, but a L pad is a much better way then goofing up the magnet! In truth, I don't see how sticking magnets outside a driver could do anyhting at all!

Al K.

Link to comment
Share on other sites

I gotta say, IMO, Al's right. I've heard that autoformers are BAD, etc., so I thought that I'd test it out...

I tried L-pads. REAL BAD. Sort of sharp and "tinny"; just plain "not right".

Back to the stock ALK autoformer. Results: GOOD. Sounds natural.

DM2.gif

Link to comment
Share on other sites

The research from Lirpa Labs shows that Drew's approach has much merit.

Generally, the most effective parts are harvested from the disks on 20 megabite drives from early PCs. Seagates are the best --- causing an increase in midrange warmth while maintaining bass slam.

It is well understood that the combination of the size of the hard disk and the magnetic permeablity of the material is critical for best results.

There is, admittedly, a minority cadre which contends that a stacked matrix of 5.25 floppy disks, removed from their sleeves, should be applied to woofer magnets. This has some support from general physics.

Like bucking magnets, these (in either theory) concentrate the magnetic field back into the voice coil with some balanced anomalies. Because the magnetic permiablity of the disks mimic those of the the original recording tape, there is a type of common mode rejection. Therefore, the application of recording media to the driver magnet cancels out short comings of the original media.

In this, it is very important to find matching media with the same magnetic cross section and transfer function characteristics as the source program.

I believe this is nonesense. Rather, the bucking media must be the same as the source material.

For example. Historic recording of Sgt. Pepper (Beatles) and Crosby, Stills, Nash (later Young too), were created before the computer revolution. Therefore we can no find computer based media as a sample. None the less, these historic recording do exist on 8 track or cassette.

Therefore the same common mode rejection of inherent noise and distortion can be accomplished by taking apart an 8 track or cassette, wrapping the tape around the present day drivers, and then playing the same recording off an LP.

Child's play.

In the era of digital recording, much the same logic applies. We all know the deleterious effect of digital processing. Microprocessors taken from computeres can also be carefully applied to the back of drivers and excited by the magnetic fields to counteract jitter.

There is also an inherent funciton from pasteing a 8088 chip to the back of a big magnet which counteracts the need for inducing low level noise to obviate false coding at low levels which is otherwise called dithering.

Of course this is April 1. Smile.

Gil

Link to comment
Share on other sites

Gil, now that it is April 2nd, please be advised that that was one of the most charming "dis"ortations that I have heard in a long while. Thanks for making "Poissons D'Avril" work in the Klipsch backwaters with a McDermott spin casting reel-to-real approach. -HornEd

Link to comment
Share on other sites

Yes, April fools!

I wouldn't have tried this one anywhere else for fear of becoming the source of the latest tweek fad. We have great defenders (like Al) of what is real and sensible. I am beginging to wonder about Gil. His reply shows a dangerous understanding of the tweekers mentality.

Adding Autoformers to my system (the dreaded Speakerlab's) was the best upgrade I have done. PWK showed his true genuis when he added these to the crossovers. They are overlooked as fundimental part of Klipsch design. Thanks to Al for finding a source of quality Autoformers for new crossovers.

Link to comment
Share on other sites

For best results, the computer media should first be overwritten with random characters. Any program on analog tape should be recorded over with noise.

Otherwise some very odd, and dangerous, results can be expected. For example "Highway to Hell" was played though a system which magnetic tape applied. Unfortunately, the tape had the residual magnetic field from "Stairway to Heaven". Listening was pure purgatory.

(I need a room with a two-drink minimum. Maybe this is one. Ta-Dum.)

But seriously folks. The best April 1 article I saw was in a computer magazine reporting on a breakthrough in modems using Russian vacuum tubes which reportedly had better bandwidth than otherwise possible. The only tip off was that is was called yllissihttnsi technology. I almost bought it. So don't feel bad, Al.

QST, the ham radio magazine, has at least one interesting article in the April edition. At least I'm wise to one; there might be more.

April next year is going to be fun around here. Stay tuned.

Best,

Gil

Link to comment
Share on other sites

This is unrelated to audio, but remember the Sports Illustrated article on the pitcher named Sidd Finch who could supposedly throw 160+ MPH fastball and such?? This was back in 1985, when the original story in Sports Illustrated - written by George Plimpton - was headed as follows:

"He's a pitcher, part yogi and part recluse. Impressively liberated from our opulent life-style, Sidd's deciding about yoga and his future in baseball."

The article then went on to explain that he was from Tibet, a master of yoga - that Finch had learned "the art of the pitch" and tales of him trying out in Florida with the Mets.

SI floated this for a couple of weeks, then finally admitted that it was a hoax - and telling us that it was in black and white - all along.

"He's A Pitcher, Part Yogi And Part Recluse. Impressively Liberated From Our Opulent Life-style, Sidd's Deciding About Yoga and his future in baseball."

This will go down as an all-timer9.gif

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...