genek

A&R Cambridge Limited is Arcam, not Acoustic Research. Moving this to Other Speakers and Electronics, but you'd be better off posting this to Audiokarma's Solid State forum.

As I recall, Zilch was not very happy with his AR-2-based econowave and preferred Advents for his 10" projects. He did econowave a bunch of 8" AR-4s over the years though. Most of those projects were discussed at length in threads over on Audiokarma. Zilch did participate in this CSP discussion about replacing the AR 3/4" dome tweeter with a waveguide, not in The Kitchen, but right here in Mods and Tweaks:

It may end up there eventually. I am intrigued by your impression that the first video (which we now know is "before") sounds better than the second ("after").

Would probably help if you identified what the clips are supposed to be.

I don't have headphones (not counting cellphone earbuds, which I have plenty of but don't consider worthy of being called "high fidelity"). Did you think one sounded better than the other, or were they just "different?"

White discoloration is moisture that has penetrated into the finish but not into the wood. Black discoloration is moisture that has penetrated through the finish into the wood fibers (iron in the water has chemically reacted with tannins in the wood). White comes off with finish removal. Black can only be removed by bleaching. You can't sand it off, because it's essentially dyed the wood fibers all the way through. Your best bet for sandthrough is to apply a topcoat finish rather than a penetrating one. Oil finish over touchup will never look the same as the wood, and if you oil first the oil will make the exposed particle board darker and harder to conceal. Apply a light coat of sanding sealer, followed by a first coat of varnish or lacquer, then touch up the sandthrough with paint or color sticks, toner and graining pens, followed by a second coat of varnish or lacquer. You will never find one single colored cover that will be a match for your base color. Your best bet is to get a kit containing different shades and some toner, apply a lighter shade to cover and then several light applications of toner until you get a good match, then grain. You must apply sealer and a first coat before touchup. You cannot touch up raw wood and get a match when a finish is applied.

My guess is that one is "before," and the other is "after." But since both videos sound identical, either the perceived improvement is too subtle for phone recordings on computers to capture or there isn't any actual improvement and the exercise has simply resulted in a method of reproducing original sound with a new driver and some crossover mods.

The 1974 FTC amplifier rule states that power should be rated at continuous wpc over a specified frequency range with a specified distortion. Like this "100 WPC, 20-20kHz, 0.05% THD). This seems to be widely ignored by retail advertisers (though most manuals do comply), and offhand I can't recall the last time I heard about anyone getting dinged for violating it.

Modern electronic music often goes to down to 20Hz. A 32' pipe organ can produce a C0 note at 16.5Hz. The 64' Boardwalk Hall pipe organ in Atlantic City, NJ can produce a C3 note at 8 Hz (if you ever get a chance to hear it, go to the bathroom first).

To clarify, the criteria is the intent to change the original sound. Otherwise, every instance of someone replacing the tweeter in an AR-3a with a HiVi QiR - or even the tweeter from an AR-11 - could push a discussion over the line. So for this topic, the decisive moment was:

Probably because unlike the dome tweeters, these drivers hardly ever seem to fail.

Have you tried the parts dept at BA?

Jab, there's no time limit. What determines whether a discussion stays here or moves to Mods, Tweaks and Upgrades is whether it's about repairing, restoring and maintaining original speakers or about redesigning them into something else.

It has been well established that there are no "similar drivers" to AR woofers being produced new. Even woofers being offered as "AR replacements" don't meet the specs required to produce original performance. Yes, you could redesign the cabinets and crossovers to work with new drivers. You could also rip apart the spiders and voice coils of new drivers and try to rebuild them to meet original specs. But unless you are an inveterate tinkerer doing it all for fun, that's a lot of time, effort and money to avoid refoaming an old woofer. It'll also get your discussion moved to the Mods, Tweaks and Upgrades forum.

"Locally" is a much bigger factor than it used to be. I'm seeing shipping quotes on many vintage speakers that are higher than what those same models were selling for 3-5 years ago.

Sounds like AR-3s rather than 3a?

If it came with that resistor already attached, then what you have is probably a 4 ohm 1200013-1 tweeter designed for the AR-3a with the resistor added to convert it to a -2 equivalent.

It's always a tough trade-off, whether to expend time, money and effort to produce improvements you're not sure you'd even be able to hear. I decided a while back to hold off on rebuilding tweeters unless/until they actually stop working. What I have sounds good enough to me as it is.

What you experienced is most likely a common psychoacoustic effect. You had expectations of a particular sonic improvement (much higher tweeter output), and didn't appreciate the different one you actually got until you stopped looking for the one you had expected. BTW, those speakers will sound considerably better if you can raise them up off the floor. 10-12 inches is good; double that would be better.

I started a project with a pair of AR-11 cabs I bought cheap from Goodwill (was going to add 3a-style face frames and grills). Put it aside at the start of the pandemic, our cats claimed them as their new kitty condo and I haven't got the heart to take them back. Might as well see if I can find a pair of the real thing.😗

Aren't the inner walls of the cabinet "inside" the cabinet...?

The 1ms cabinets are made of aluminum.

I have two pairs of these (used to have three, sold one to one of our members a while back). I question whether they really added all that much to the higher end AR speakers back in the day, but considering that those old speakers' tweeters are now operating at less than optimal performance, for what I paid for the Microstatics ($50 and $75/pair), they're an obvious alternative to having to rebuild or replace all the old tweeters.

The 1ms is a pretty tight squeeze, but if the foam doesn't make things bind up when trying to fit the internals back in you should be ok. Probably won't make much difference in the sound. BTW, I'm pretty sure the 1cs didn't have an actual cabinet, just a front face with the drivers and crossover attached to it.

I have two pairs of 1ms, and removing the front plate basically turns the open housings into bells. When they're fully assembled and screwed tight, they don't ring.