refurbished AR4x- a review...

[ozmoid]

Whew! Sorry to be so confusing, but as you can see I'm really confused. Any help you (or anybody) can give me would be greatly appreciated.

Roy

Roy - ignore all the colors and where they go for the moment.

Take the wire from the center of the pot (feeds the little "wiper" that rotates), and attach it to the pot terminal that corresponds to the highest setting (full increase).

That's it, you're done! :yes: No schematics, no color confusion.

 

[RayW]

Or if you like colors better than components, cut the yellow wire where it goes into the pot and attach it with the blue wire on the pot without disconnecting the blue.

Ray

 

[Roypercy]

Roy - ignore all the colors and where they go for the moment.

Take the wire from the center of the pot (feeds the little "wiper" that rotates), and attach it to the pot terminal that corresponds to the highest setting (full increase).

That's it, you're done! :yes: No schematics, no color confusion.

Sorry to be obtuse - but which is which?

I'm sorry, I'm really hopeless at this.

 

[ozmoid]

Sorry to be obtuse - but which is which?

I'm sorry, I'm really hopeless at this.

Don't be sorry - we all gotta start somewhere. :yes:

Looking at the back of pot, with the terminals at the bottom, full increase is the terminal on the left. :thmbsp:

 

[ozmoid]

In this picture, you're looking at the "top" of the pot in the foreground. The terminal all by itself in the center is the wire you're going to move, and the pair of terminals at the edge is where you're going. From this point-of-view, it is the terminal on the right.

(Sorry if that's confusing, I didn't have a picture of the pot in the same orientation as the first explanation. You are basically moving the wire to where the connection would be if the control were turned to full increase.)

 

[Roypercy]

Let me make sure I get this straight. Here's a diagram I made of how the pot looks on my 4x:

View attachment Pot Diagram PDF.pdf


So the yellow wire on the terminal on the bottom right gets detached from the pot and joined to the blue one? Or vice-versa?

Thanks for all your help with this, once I get it I'll know it from now on, which will be good (teach a man to fish, etc) I'm just a slow learner when it comes to fishing...

Roy

 

[shacky]

Wouldn't it be better to install a resistor of X value in line than completely removing the pot? Even at full on isn't it going to be an inegral part of the crossover? If you eliminate the pot won't it increase the crossover freq?

 

[ozmoid]

Wouldn't it be better to install a resistor of X value in line than completely removing the pot? Even at full on isn't it going to be an inegral part of the crossover? If you eliminate the pot won't it increase the crossover freq?

Shacky, what we're trying to do here is not remove the pot, but permanently wire it so that it is always at "full increase". The wiper is bad, and we need to get it out of the wiring loop without losing the 15 ohm resistor. The pot will still be in the circuit, just the control will be defeated. The internal coil will still be a bridge between the +/common.

Let me make sure I get this straight. Here's a diagram I made of how the pot looks on my 4x:

View attachment 63375


So the yellow wire on the terminal on the bottom right gets detached from the pot and joined to the blue one? Or vice-versa?

Thanks for all your help with this, once I get it I'll know it from now on, which will be good (teach a man to fish, etc) I'm just a slow learner when it comes to fishing...

Roy

Roy, my ARs did not have the same color wiring as yours - happens sometimes with AR. So let's try it this way:

Cast in the ceramic body are identifiers for each terminal: 1, 2, B.

Take B loose, and attach it to 1. Regardless of wire color, that is the fix you're looking for.

 

[shacky]

Shacky, what we're trying to do here is not remove the pot, but permanently wire it so that it is always at "full increase". The wiper is bad, and we need to get it out of the wiring loop without losing the 15 ohm resistor. The pot will still be in the circuit, just the control will be defeated. The internal coil will still be a bridge between the +/common.
Roy, my ARs did not have the same color wiring as yours - happens sometimes with AR. So let's try it this way:

Gotcha! I saw Onplane's diagram and thought thread was going towards bypassing. Leaving it in at max is great idea :yes:

 

[ozmoid]

Gotcha! I saw Onplane's diagram and thought thread was going towards bypassing. Leaving it in at max is great idea :yes:

You know me better than that...

 

[shacky]

You know me better than that...

Yes I do :yes: :thmbsp:

Not to steal this thread but did you recap you KLH 6's? Just received caps and looking for more info.

 

[callmez]

Thanks to all

A big thanks to the many AK'ers who've provided input on refurbing the AR4x in all of the various discussions. I'm now putting the finishing touches on a pair that I'm fixing up for a friend (my first speaker project) and am VERY happy with the results. These little suckers sound awesome -- very detailed, 1000x better than the muffled mess I heard after returning from the thrift store with my new find. Right now they are handling the rear channels of Poncho Sanchez' "Conga Blue" SACD and the various percussive instruments sound amazing.

AR4x (serial #s 400870 & 401057) from thrift store: $15

my approach:
replaced old caps with new Dayton 20 uF polypropylene caps ($11)
woofer surrounds re-sealed with two coats of clear siliconized latex caulk thinned (considerably) with water ($3... worked great!)
bypassed rheostat wiper to full output (free)
old rock wool fill replaced with polyester fill (already had on hand)
old closed cell foam woofer seals replaced with new (cut from used packing material)
restoring walnut cabinets with supplies on hand
replaced grille cloth with leftover from previous project (black, sorry... owner-to-be's preference)

total... about $30.

These two will be used as the front speakers in a HT/surround sound setup driven by a modern Pioneer receiver. No golden ears there, but the new owner & family will be thrilled at the price and the sound, and will get a lot of use out of them.

Now it's off to my Optimus T-120 project discussed in a recent thread, the bug has bitten and the new parts are already here!

Mark Z

 

[Helle]

AR4x (serial #s 400870 & 401057) from thrift store: $15
old rock wool fill replaced with polyester fill (already had on hand)
"callmez"

Hi all,
Reading through this post, I am wanting to replace the rock wool in my AR4x's and I am guessing
the density between polyester and rock wool would be different.
I also remember reading AR filled the boxes with a specific weight of rock wool,
so what weight of polyester is recommended to replace the rock wool in each
cab?

Thanks

 

[archie2]

AR4x (serial #s 400870 & 401057) from thrift store: $15
old rock wool fill replaced with polyester fill (already had on hand)
"callmez"

Hi all,
Reading through this post, I am wanting to replace the rock wool in my AR4x's and I am guessing
the density between polyester and rock wool would be different.
I also remember reading AR filled the boxes with a specific weight of rock wool,
so what weight of polyester is recommended to replace the rock wool in each
cab?

Thanks

Just my 2 cents but I would use fiberglass instead of polyester. You can buy more than enough for the 4x's at Home Depot for 5 or 6 bucks Sorry but I don't know the weight. It's much closer to rock wool than polyfill without having to deal with the high sulfur content and loose fibers of rock wool.

 

[Helle]

Just my 2 cents but I would use fiberglass instead of polyester. You can buy more than enough for the 4x's at Home Depot for 5 or 6 bucks Sorry but I don't know the weight. It's much closer to rock wool than polyfill without having to deal with the high sulfur content and loose fibers of rock wool.

Thanks archie2,
I was trying to steer away from fibre glass as it is also a carcinogenic
material like rock wool...
That being said, in a worse case scenario I guess I'll have to be extra
careful!

Thanks again!

 

[archie2]

Thanks archie2,
I was trying to steer away from fibre glass as it is also a carcinogenic
material like rock wool...
That being said, in a worse case scenario I guess I'll have to be extra
careful!

Thanks again!

True, if any foreign fibers lodge in the lung there is the potential of the irritant stimulating cancer growth. Rock wool fibers are 5000 times more likely to break, float and be inhaled than spun glass fibers. Spun glass has far longer and tougher fibers than rock wool. Also rock wool has a high sulfur content which can be very corrosive to the lungs when inhaled. And wet rock wool promotes the groth of bacteria which one also can inhale. I think if you wear gloves to prevent mechanical irritation and a good face mask, handling fiberglass will be fine.

 

[shacky]

I thought mine had rock wool and it turned out to be old style fiber glass. I've read several posts on CSP's saying new FG is best. Uniformity of particle size seems to be important in the dempneing process.

Also saw weights listed for both early 4X version and late. It all depends on the woofer. Late version is most common. I'll take a look and see if I can find what I was looking at and post another reply if I do.

Here's my recent post showing pictures of my FG that I thought was RW.

http://www.audiokarma.org/forums/showthread.php?t=273736&page=2

 

[shacky]

Here's a CSP post that has reference to JOhn O'Hanlon and Roy's work. 11 oz for the 4X with #5 inductor coil. 17 ox for earlier #4 coil design.

I believe the challenge with using polyester is there is not hard and fast conversion and you may not be able to fit enough inside the 4X cab to get the same dempening as 11 ox FG.

Roy told me the bags of loose pink FG at Home Depot are 11 ox each. I did weigh the two bags I picked up and they were only 7.5 so I'd recommend double checking if you go that route.

http://www.classicspeakerpages.net/IP.Board/index.php?showtopic=5778

 

[archie2]

Home Depot has these, no weight listed but I would think 1 roll per speaker would be more than enough.
http://www.homedepot.com/h_d1/N-5yc...splay?langId=-1&storeId=10051&catalogId=10053

 

[shacky]

Yes that's the one. Would be good if you can to stop by the post office and weigh it. That's where I found they were 7.5 oz. I didn't use them for my 4X - needed extra for my 3a's.

But I was thinking if they are less than 11 oz it would be a shame to use them in 4X assuming they are the correct weight.

If my wiehgt was indicative of "new" packaging then 3 rolls would be needed. 1.5 per speaker would be just right. But best way is to measure to make sure.

BTW my comment on uniformity is a little out of context above. JOhn and others at CSP found new pink FG is more uniform in particle size and may be better than old FG used back in the day. Not that other stuffing like acoustastuff isn't uniform. But FG seems to be best for AR's unles you are willing to go trial and error with polyester.