Stimpy

Hey Darren, We don't mean to be confusing. We're just enthusiastic. But, remember, whether you choose film or NPE, or a mix, they'll be an upgrade. Don't stress too much over it, as there is no wrong choice. As to your questions, yes the parallel shunt caps are "second level". NPE is fine. The 4.0 and 24uF caps are the series caps. To me, they deserve "top notch". Though, as mentioned, electrolytic is fine too. But, even inexpensive poly's are great. And they won't ever need to be replaced. Good luck. P.S. I literally read and researched for months, when deciding on caps for my AR-90s. So, you're not alone.

I don't necessarily disagree with this statement, but I also don't completely understand the thought process involved? And I'm not bashing you either, as I read this type of statement in almost every recap thread I see. For me, bang for the buck isn't just using film for the small values and NPE for the big stuff. For me, if cost is a concern, I always use film for the series capacitors and NPE for the rest. That guarantees good parts where they make the most audible difference, and the cost effective parts where audible differences are more subtle. So, in my head, that's spending for bang for the buck results.

I can't really quote a value. But, if you're certain to sell, I'd leave the speakers as-is. To many, your speakers are true collector's items, and any changes from stock, would hurt resell value. Wipe them down, to dust them, get good pictures, then leave them be! GLWTS

Hey, don't blame me...! But, those new crossovers look great. Very clean work too. Well done. I like your cap and resistor choices. All very good, and reasonably priced. As I noted above, I used ClarityCaps and Bennics. When I recap the 91 boards, I might switch to E-Caps. I hadn't tried those when I first modded the 58s, but I've used E-Caps since, and they're very good. Oh, I use those same Dayton film & foil bypass caps and like them. They do an awesome job. One other thing, my AR91 boards turned out to be AR92 boards. I guess people get confused by the labeling, and think they're the same and interchangeable? Oh, before you recap the 2nd crossover, you should A/B them. You'll be shocked how much better the new board will sound. I just wired my boards to an amp, and used a dome mid on each. There was a crazy difference, with the new crossover sounding so much better.

The 91s and 58s use the same crossover. My AR-58S order from Madisound. $65.68 total for both speakers. Items in this shipment Bennic 40 mfd Non-Polar Electrolytic Capacitor 100V m40 $1.50 (Not Taxable) 2 $3.00 Bennic 100 mfd Non-Polar Electrolytic Capacitor 100V m100 $2.40 (Not Taxable) 2 $4.80 ClarityCap 25 mfd ESA Range Polypropylene Capacitor 250V ESA250V-25 $17.49 (Not Taxable) 2 $34.98 ClarityCap 3.9 mfd CSA CopperConnect Poly Cap 250V CSA-3.9 $9.10 (Not Taxable) 2 $18.20 Carli MET 8.0 mfd Non-Polar Mylar Capacitor 150V m8 $2.35 (Not Taxable) 2 $4.70

All poly film is great. But, you can also just use poly for the 4.0 and 24uF caps, to save money. They're the series caps, in line with the drivers, and have the greatest audible impact. Electrolytic can be used on the rest, if desired?

ClarityCaps and Erse...! Nice. I have a set of AR91 crossover boards that I want to swap into my 58S speakers, one of these days. That'd give me level switches too.

I'd definitely replace the "black and red" caps. They tend to drift out of spec, and often leak. Those same caps, in my 90s, were sounding very veiled and opaque. Distorted too. The metal caps seem to hold up a bit better. Most report that they usually test ok. But, to me, they're still very old, and I replaced those as well. No need to go in twice. Now, the controversial part, which caps to use? They used NPE's, and new NPE's will be fine. Sound great, though they can sound better than great. I own AR-90's, AR-58S's, AR-1MS's, AR-92's, and AR-18's. I once had TSW410's. On the 90s, I used Mundorf film. The 58S got ClarityCaps, the 92's have a mix of Dayton and Mundorf NPE's, and the 1MS, Dayton as well. The Mundorf film sound best to me. Very clean and clear. Huge depth and presence. No distortion. The Clarity's are next. But they sound very different to the Mundorf caps. The ClarityCaps are much warmer in tone. Relaxed. Not as resolving as the Mundorf's, but no one will consider them too bright. The Dayton's split the difference. They sound balanced to me. Not too warm or too bright. In the middle. Very good sound, for the price, but for me, occasionally sibilant. Spitty. Not on all music, just every once in a while, enough to be noticeable and annoying. I added a film and foil bypass cap, which helped clear that up. All only my opinion. Not all agree with using expensive caps. I guess I like to play around, out of curiosity. Compare, to hear any differences. For fun, and more importantly, for a love of music. So, go as crazy as you want. Spend a little or a lot. I won't judge. But, our AR's are worth the effort.

Congratulations. Great speakers. As to capacitors, if your 91s have the red/black Callins caps, I'd replace those, as they usually didn't hold up well. AR also used Unicon caps, and they still sounded fine, in my AR-58S speakers. Your speakers have 4.0, 8.0, 24, 40 and 100uF capacitors. The series caps are the 4.0 tweeter cap, and the 24 mid dome cap. The others are shunt caps. I usually use poly for the series caps, and electrolytic for the stunts. To me, that's the best bang for the buck recap solution. Parts Express, Parts Connexion, Sonic Craft, Meniscus Audio, and Madisound are all good sources for capacitors; electrolytic and film. Good luck!

Oh, one other thought on detail. The AR-90 lower midrange, is very smooth and natural, but I felt the Kappa 8 lower mid polygraph dome had the better midbass detail of the two. Better transient speed, if you will. But, the AR-90 upper midrange dome had much more resolution than the Kappa 8 polydome. It's a very revealing driver. And thankfully, it's dome material won't deteriorate like the Infinity upper dome. A shame that the Infinity upper dome ages so poorly. I even had a spare Infinity Kappa dome, boxed, and stored in my parts closet, and it still clouded over and hardened. No heat or UV exposure, and it still died.

Infinity Kappa 8's vs Acoustic Research AR-90's? West Coast vs East Coast? To me, this might be a tough decision. And I own AR90's, and Infinity's. Personally, this might be a lateral move. Both fine speakers, and similar in some ways, as both are 4-ways, with upper midrange domes. When I've heard Kappa 8's, I thought they were very musical, with a soft, enjoyable midrange presence. Not at all West Coast bright, as I was expecting. I also thought the 8's had a bit more detail than my 90's, but of course, equipment was different too, and I was hearing a newer speaker, with newer components inside. Bass was equal, with no bass boom or overhang, in either speaker. Very smooth through the crossover transitions between drivers. The Kappa was much better in this regard, than Kappa 7's, which I didn't like. It also sounds like you're good to go on gear. Very much so, in fact! Some fine pieces, that should work well. I even owned an Acurus L10 pre, at one point, and it was a great match with my 90's. A real taste of high end. More than acceptable. As to crossover mods? I did. Some don't like or agree with what I did, which is fine. But, I set out to bring out the highest level of performance the speakers were capable of, but not change the balance. Just to let the drivers shine, with much higher quality components than stock. As such, I changed out all capacitors and resistors, plus installed new binding posts. Mainly, all Mundorf film capacitors and Mills resistors. Afterwards, much better presence. More palpable. Plus, very clean and clear, with a layer of static distortion and grunge removed, that I didn't even realize as being there, until it was gone. So, your call (sorry), on speakers. Honestly, you can't go wrong with either model. They both are that good.

They look nice! $800 firm...!

Eight hundred and fifty bucks, would probably be a top amount, for refreshed 90s. Personally, I wouldn't pay more, unless the restoration were first-class, and well documented. Boutique capacitors a given, if the seller has a top dollar asking price.

Good to know Roy. Thanks! Also, I assume that's why Midwest offers both 4 and 8 Ohm versions. Two different versions, that could cross-pollinate most any model of AR speaker.

To me at least, the Mid West tweeter looks like an AR-9/90 tweeter, with the face plate removed. I'd use their tweeter, along with the face plate from an AR-9 tweeter. The Mid West unit doesn't have the 4 inner mounting holes, but the 3 outer holes would still hold everything together. That would give the tweeter the slight horn recess too.

I hand solder 1 Mil 99.9% gold wire at work. Not easy, but proper technique is key. We use Weller irons, at around 700F. They're equipped with the smallest Weller tip. The most important thing is not to apply direct heat to the wire. I lightly touch the tip with the solder, to get just a small drop of solder in place on the end. That drop of solder gets touched to the well-fluxed wire joint. On and off very quickly. The wires need to be stationary too, with as little movement as possible.

Oh, a beautiful room and system too!

Congratulations on the 90s. A great pair of speakers, regardless of their vintage. As far as being refreshed, I'd recommend replacing the high range capacitors. Especially, if your 90s use the black/red Callins brand of electrolytic capacitor like mine. While I never measured my capacitors, the performance of my speakers had most certainly degraded. Replacing the stock capacitors made an easily heard improvement in sound. As to which capacitors to replace, I always suggest series capacitors first, as they'll have the biggest sonic impact. They're the 4.0, 6.0, 24.0, and 80.0uF caps. NPE or Poly is fine for those. But personally, I like Poly, and that's what I used in my recap. There are several great vendors where you can shop for capacitors. I've used the following without issue: Madisound Parts Connexion Parts Express Sonic Craft While I've never shopped through these sites, they're also good parts suppliers: Erse Audio Meniscus Good luck, and Welcome...!

Any reaction from staff or store customers?

At least the AR3a's show up on a list, of the best, for some. The Absolute Sound: The 12 Most Significant Loudspeakers of All Time

Hi quattroatl, Welcome and congratulations. A nice pick up. Even if they are a 2nd pair...! I wish. Also, did your woofers have the Masonite spacer rings? Hard to tell from the pictures.

I did my AR58S and AR92 crossovers, with the boards in place. No issues, and fairly simple. I even changed the stock binding posts, which some of us hate...! New caps too...! 'Nuff said.

For posterity...

If your 91's have Unicon branded caps, they could still be good and sound good. My 58s speakers had them, and they sound great. But, as already noted, if they are the black & red Callins brand of capacitors, I'd rip those out and burn them! They do not hold up well at all.

First and foremost, a big Congratulations Bill...! I'm so glad that your speaker search landed in the past, with the AR-9's. Some of the best ever. Enjoy, and keep us updated on how they work out. Also, ar_pro, I absolutely love those Naked-9's! Absolutely gorgeous. If I ever find a pair, I'm definitely going to do the same thing. I wish my 90's had a veneered front, and I'd strip them down.