Acoustic Research AR9LSi restoration

[leesonic]

These speakers have been in my storage unit for a while, so I figured it was time to get to work on them. The cabinets are in excellent shape, as are the grills, and if this wasn't enough, they came with a brand new set of grills still in boxes. All the woofers need refoaming though, they had been removed when I bought the speakers, and carefully packed in boxes.

Here are the cabinets, they're HUGE!



Here is the crossover, no evidence of any caps, they must be on the other side of the circuit board. I'm guessing I'll have to de-solder all the inductors first, then the binding posts, in order to remove the central PCB.



Woofers needing refoaming. Interestingly enough, the mid-bass woofers look exactly like the lower woofers in my old AR94S speakers. One of the 12" woofers has a cone that looks browner than the other, I wonder if this speaker was standing somewhere exposed to sunlight? There's no evidence of this with the other woofers or the grill.





Lee.

 

[RS Steve]

Looks like the refoam job should keep you busy for a little while. I bet they will sound great when finished. :thmbsp:

 

[EPI-Center]

I got the circuit board out because the glue on the caps was "broken" but the other side wasn't and I followed this method, which made me a little sore operating through the hole but it worked.

http://www.google.com/url?sa=t&rct=...=Qvxldas-dUsIPdDsM-vwhg&bvm=bv.48293060,d.dmg

 

[EPI-Center]

Looks like the refoam job should keep you busy for a little while. I bet they will sound great when finished. :thmbsp:

I have been playing bass for about 30 years and these speakers have the most realistic palpable bass I've ever experienced. The high end was a tad harsh until I redid the caps. They sound great on anything but if you like drums and bass there is no equal IMO except maybe the AR9

 

[Tetrode]

Absolutely beautiful.

 

[dhanson64]

Hi I own 4 pair's of AR 9ls's and had 1 pair is Ar9lsi's I sold. The best thing about those 9lsi is there Cabinets nice wood on all side's , 9ls has the black formica front baffle . But In my opinion the true WEAK POINT on these is the Xorver's. They have very Small cap's in them and can't handle the current as. Well as the older Original 9ls there xover's have Much bigger caps in them more heavy duty and are easy to replace there not sandwich and glued right in between the partical board an electric cross over circuit board Very Very hard to work on 9lsi cross overs caps when there's a problem, and those glued on tiny little cap explode very easy like a frozen pop can when you run some juice through them. 9lsi very nice cabinets poor x overs design 9ls ok/ not. As nice cabinets but way beeter x over parts in. Them and way easy to fix .. they look great by the way! :thmbsp:

 

[Smallies]

Yes the AR-9LSI lower midrange and 12 inch just laughs at any Polk(only quality speaker I've heard) To assume the yuppies selling these beasts have prevented them from havoc is rediculous.

 

[dhanson64]

I have been playing bass for about 30 years and these speakers have the most realistic palpable bass I've ever experienced. The high end was a tad harsh until I redid the caps. They sound great on anything but if you like drums and bass there is no equal IMO except maybe the AR9

Hi have you ever herd the DLK 4's with ALNICO mags on thee. Twin 12" woofers? Unbelievable ultra low bass, there also a 4 ohm speeakers. Check out my thread showing a pic of 1 of the pairs I own. on that pair in the pic There not the CTS Alnico's they have the twin 12" Heppener woofers with ceramic mags still hit very hard n go low. I just prefer the sound of the ALNICO much warmer an sound deeper bass. Both kick some A@@. I like the dlk's better than my Ar 9ls''s. :yes:

 

[leesonic]

8" midwoofer refoam

After I ordered some new surrounds for these speakers, I set to work. For some reason, I knew this 8" midwoofer would give me problems because it's the same woofer as used in the AR94S. In this speaker (the 94S), there are two 8" woofers that are a different design, the top one uses a pressed cone, and the bottom one uses a folded cone, which is smaller in diameter. In the end, I used surrounds intended for JBL speakers as they have more "meat" on the inside edge where it attaches to the cone. I ordered a set of these surrounds for this 9LSi midwoofer. I got them from Tom over at myaudioaddiction.

Take a look at the following pictures, these show the difference between the two surrounds. "Surround A" is the one that most people sell for these speakers. "Surround B" is for an 8" JBL woofer. From the front, you can see that surround B has a slightly smaller inner diameter, there is less gap between the surround roll and the edge of the cone. From the rear, you can see that surround A does not cover where the old glue line was, whereas surround B covers it completely.




Here they are all pegged up waiting for the glue to dry.

 

[allsmith]

How is your AR project coming along?

 

[leesonic]

Here are a couple of shots of one of the ten inch woofers, the ones that sit in the bottom of the cabinet and fire downwards. I only had enough clothespegs to do one at a time.

 

[leesonic]

I got the last of the woofers refoamed over the weekend, these being the 11.5" ones. They have an interesting frame design, the surround sits on a little raised lip that goes all the way around, and then the "gasket" sits around the outside of this. "Gasket" being in quotes, since it doesn't actually function as a gasket, being on the front of the basket and the woofers being front mounted.

What this meant was I couldn't use my favorite clothes peg method to hold the surround down to the frame. I got out my router, and made a ring out of 3/4" MDF to hold the surround flat while it dried. My clothes pegs didn't have to worry though, as one of the "gaskets" had been mounted incorrectly from the factory. I carefully removed it used an Xacto knife, and glued it back on, using the clothes pegs to hold it in place.

Here is a picture of the wooden ring on the left, and the gasket being glued back in place on the right.



All done.



Now I just have to attack the crossovers...

 

[Pandovski]

Brilliant! Keep it up.

 

[leesonic]

I did some work on the crossovers today. I managed to break the board in two getting it out of the back of the cabinet, it doesn't help that the caps are hot-melt glued to the back panel.



What I wanted to do is make some crossovers without having to remove the whole crossover panel from inside the speaker. I figured I could remove the three small inductors, and mount them on a strip of wood along with the new caps and existing resistors. I did a design on paper first, and then transferred it onto a piece of wood. Here is is with the components mounted. I haven't wired up them up on the other side of the board, and a still have to figure out some terminals for the remaining inductors (inside the cabinet) and for the wires to all the drivers.



Hold on! That's not supposed to be in there. The previous owner must have fitted these Radio Shack woofers in the bottom when the foam on the originals rotted out. The original design has two eight ohm woofers in parallel, putting this four ohm woofer in it's place must have made the speaker even harder to drive.

 

[GoRNR]

Lookin' good Lee! Good that you had all the original drivers to refoam. Now the RS woofs can go away. Question-- are you thinking about replacing the cabinet gaskets for the woofers?? I've done new surrounds for my midwoofs and large woofers for a pair of AR-9's, and the gaskets are pretty compressed/crushed. I've read some guys are using rope caulk, but I thought a new 1/8" thick foam gasket -- either tape or cut from sheet-- would be a possibility. To get optimum performance, that bass bin on the cabinet needs to be tightly sealed. Any thoughts you can share?? Interested in what your final crossover arrangement turns out to be. Keep at it! :yes:

 

[Gang-Twanger]

OPTIMUS performance...

Yeah, it's nice that you have all the woofers, including the two downfiring tens. You're doing a hell of a job on those. Keep us updated. I know the AR9-types are supposed to be game-changers.

 

[poortom]

That's some beautiful work.

 

[spkrdtr]

If you have the means to test those Culver caps I think you'll find they weren't far from spec. If you can, pls let us know how they measured. You know, uF, ESR,.....

 

[shacky]

Wow! Just wow!

 

[spkrdtr]

Here they are all pegged up waiting for the glue to dry.

If you (or others here) do a lot of refoaming, you should consider acquiring a set of plastic clamp rings specially made for speaker repair. I've had mine for years and most time they fit nicely. With a set of these you give the clothes pins to your significant other.
Here is where you can get them....

http://www.recone.com/FSR.htm