Pre Teledyne AR-9

[Guest tomcat2200]

Hi all. I am new to this board.

I have a pair of AR-9 speakers that I purchased new. I noticed the AR-9 info on this site was for the Teledyne AR-9 speakers.

If I recall correctly, I had purchased these just before Teledyne bought AR. I had thought Teledyne bought them out and introduced the AR-9L which was shorter and had a bit different layout.

The engineering drawings here are stampped with Teledyne.

Does anyone have the original drawings for these speakers.

I am looking to refurb these, due to a recent move and the result of the move damage.

I have always loved these speakers and bought them because at the time they had won the "international Grand Prix, Speaker Competition".

Any suggestions for this process would be appreciated.

At the least the foam around the woofers is starting to deterioriate.

I do not know what to expect as I disassemble them.

Thanks in asvance.

[ar_pro]

Welcome aboard, and congrats on your fine speakers.

Teledyne's acquisition of Acoustic Research predates the AR-9, and to the best of my knowledge, the blueprints in the library section are final drafts.

There are a number of threads regarding rebuilding the AR-9 (we've rebuilt several pairs over the years) that will be of much assistance.

Issues include:

All of the original foam surrounds will be shot, and must be replaced.

The woofers, mids and tweeters are no longer being built, and must be acquired from parted-out systems.

Many here feel that the crossover caps are out-of-spec, and need to be replaced (good luck with the big caps!).

Level control switches should be removed & cleaned.

All crossover repairs/replacements are possible through the woofer holes, which makes evrything pretty easy.

Our most recent restorations have included refinishing the cabinets, removing the glued-on vinyl appliques and Acoustic Blanket, removing the plastic chrome trim from the grille panels, and installation of spiked feet.

Regardless of the level of restoration that you choose, you own the finest full-range speaker that AR ever built, and in restored condition, it's fully competitive with very expensive modern designs.

[Guest tomcat2200]

Thanks so much for the reply.

The only thing that prompted the rebuild was the mover taking off the grille and tearing some of the gasket around the cones on one of the speakers. I have had good luck in the past in shipping the speakers up until now that is.

I only seem to need that foam gasket , and new grille covers on one of the speakers. If I cannot get the match in the cloth, then I guessI will have to do both grilles to match.

Other than a few small marks on the back where it is painted with a flat black the rest of the cabinets are fairley pristine. I lemon oiled the speakers regularly. It seems to preserve them.

My really big question is: Where do I reliablly buy quality parts. I noticed that one online shop actually had factory replacements for the Woofers It was a place called "Simply Speakers" on the internet. They also sold foam kits for that gasket around the cone. That is the area that got damaged in this last move.

Are there better places to shop on-line?

Is it recommend to do your own foam replacement?

The speakers sound fine other than the one that was damaged, should I look for age related problems or just address them as I come across problems?

I am pretty handy in the Lab and in the shop. This kind of stuff does not intimidate me, unless there is sometthing I do not know.

It looked as if I could refoam with the speaker in place.

Thanks for the reply and any further comments.

[rrcrain]

You might pull off refoaming the drivers in place, but it's not a wise idea. I found it incredibly useful to be able to have total access while removing all traces of the old surround and it made gluing and realignment simpler than if I'd left the drivers in place. You absolutely must ensure the coils do not rub on the magnet thru the entire excursion. I it rubs anywhere for any reason, you will hear it, and possibly run the risk of blowing out your amp when the insulation is finally rubbed off. Additionally, you don't want any adhesive solvent dripping into these fine speakers.

While you have the speaker opened, give serious consideration to replacing the caps in the crossover. Electrolytics age badly with time and negatively alter a speakers performance. You don't have to purchase the most expensive caps on the market, but don't get the cheapest either.

If you live near Illinois and simply want to get rid of them, you'll find more than one interested buyer here.

[JKent]

Here are step-by-step refoaming instructions, and I highly recommend this outfit for the kit.

http://www.citlink.net/~msound/refoam/

[ar_pro]

I can't stress enough how unlikely it is that *any* of the foam surrounds on your woofers and lower midrange speakers are OK. Please inspect them carefully, as damage could result from use with deteriorating surrounds. After nearly three decades, gently poking the foam with your finger should cause it to crumble and fail.

There are no equivalent factory replacement parts - no one currently manufactures a woofer (or tweeter, or midrange, for that matter) that will be identical to the original drivers in your AR-9. The part might "fit", and have a similar appearance to the original part, but it's not the same. Don't be tempted to purchase a "new" woofer, and hope that it will give performance identical to your original woofers.

There are many threads on DIY refoaming - it's not difficult, but there is a learning curve. Miller Sound in Montgomeryville, PA is also a well-regarded refoamer, should you decide not to tackle the job. Either way, you'll definitely want to remove the woofers before working on them.

[soundminded]

I bought my AR9s in 1984. They were demos and were fully guaranteed except for any scratches on the cabinets and the grills. AR had to replace all of the drivers before I took delivery. The original woofers had the round magnets but they replaced them with the square ones. Remarkably, the foam on all 4 woofers and one of the lower midranges is still good. The other lower midrange has a small hole in it where the surround became dry and brittle. It doesn't seem to affect the sound. When I do need to have them refoamed, I will take them to Millersound along with a lot of other drivers from other speakers that need refoaming.

I've wondered how AR9s would stack up against Duntech Crown Sovereigns which cost about ten times as much. They are also 4 way tower designs with two 12 AS woofers in something like an MTM arrangement except theirs is a W-LM-UM-T-UM-LM-W configuration. Both woofers fire forwards and one is at the top. This strikes me as clearly inferior to the clever arrangement of the AR9s so well described in Tim Holl's write-up in the library.

On those occasions I've had to move my AR9s, I removed the 12" woofers and boxed them separately. Besides reducing the possibility of damage to them, it makes moving them a lot easier. The gaskets have held up very well. With two or more AS speakers in a cabinet it is very easy to test for air tightness, just gently push one cone in and the other should pop out and stay out until the first one is released. My original Bose 901 still does this too with 9 4" in each sealed cabinet.

[soundminded]

redundant posting removed.

[ar_pro]

Soundminded -

Heard the Duntechs years ago, and to me, the AR-9 was a more complete product, with a better overall balance.

If you're looking to replace your damaged lower mid, there's one currently on ebay, along with the AR-9 dome midrange & tweeter:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewI...em=290173999800

[Guest tomcat2200]

Thanks for the purchase offer but i am in Oregon now, having left Ohio.

I wouldn't sell them until after both children are gone.

I am into classical music, and have never found any speakers to match these.

They are crisp and the imaging is perfect.

Perhaps it is my imagination or lack of experience with these issues but the foam on the surviving speaker seems intact. It is not flakey or falling off. The air seal also seems fine.

I would ask if the Caps in the crossover look fine on the outside, do they need replacement with no obvious apparant damage or leaking.

What should I be looking for, or is this just one of those things to do due to age?

Thanks

[soundminded]

>I would ask if the Caps in the crossover look fine on the

>outside, do they need replacement with no obvious apparant

>damage or leaking.

>What should I be looking for, or is this just one of those

>things to do due to age?

Unlike oil filled capacitors which could leak, failure or changes in values of these capacitors will usually show no outward signs. I think it was Pete B who said that the changes are due to chemical deterioration of the dielectric, inevitable in some types and that capacitance value usually actually increases. This sounds right to me. For the shunt capacitors (those wired in parallel with the drivers) this will result in a FR rolloff at a lower than intended crossover frequency creating an FR dip between the top of that driver's range and the next higher driver. The ones with the potentially more serious consequences however are the series capacitors. When these increase in value, the crossover frequency at the driver's low end decreases putting it at risk of being overdriven at frequencies it was not intended to handle. If you notice distortion from reliable sources which don't deteriorate such as a cd where there was none at the same sound level before and this distortion decreases as the volume is lowered, that's a warning sign to pay attention to. When properly operating, these speakers will not audibly distort at even very loud levels if sufficient amplifier power is available and the source signal is known to be distortion free. If it does, it should be investigated immediately. The only way to know for sure that I'm aware of is to remove the capacitors from the circuit and check them with a capacitor checker. But even here you cannot be 100% certain unless you have a checker which will run up the capacitor to a significant percentage of its rated voltage. Capacitors which check out fine at 1.5 or 3 volts may have problems such as dielectric breakdown at higher voltages. If you do the work of replacing them all yourself, use ordinary non polarized electolytic capacitors, and don't replace the large ones in the woofer circuit, it's not an expensive job even if it is a pain in the neck. Parts Express is a good source for replacements. I think the large ones will run into some money. BTW, if you buy more exotic types such as polypropylenes, many advocates of these feel only the series capacitors make an actual audible difference in sound. Me, personally I'd stick with the plain vanilla variety but then what do I know?