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AR-9 Refurbishment


SHOKDU

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I have started my refurbishment process for the AR9's, and am almost finished. At this point I am only waiting on one last piece of foam for a woofer, and I want to find replacement foam surrounds for the tweeters and UMR's. I will be driving these with Emotiva XPA-1's!

Sorry for the low quality pics, but I'll share them anyway!

Before starting any work:

post-120327-0-15026000-1353009601_thumb.

Drivers pulled and ready for foam:

post-120327-0-34602000-1353009766_thumb.

No pics of the new foam, sorry.

Parts for the job:

post-120327-0-88323100-1353009823_thumb.

Crossovers with new caps:

post-120327-0-51180900-1353009704_thumb.

post-120327-0-07984600-1353009786_thumb.

post-120327-0-76335000-1353009880_thumb.

post-120327-0-52470500-1353009918_thumb.

post-120327-0-56530300-1353010524_thumb.

Cabinets during refurb process (left is restored, right is the way they came out of storage):

post-120327-0-70166200-1353009685_thumb.

post-120327-0-42593700-1353009723_thumb.

Old grille vs new grille (times 6 grilles):

post-120327-0-21011900-1353009738_thumb.

post-120327-0-52843900-1353009806_thumb.

Overall this has been a moderately easy job. Some may consider it quite challenging though, it depends on your level of mechanical ability.

I'm building myself a new amp/tv rack now, when that is done I'll get the new amps set up and start pouring some dB's through these speakers!

I hope you've enjoyed seeing the pics so far!

BTW, all the capacitors, and these schematics, have been right on with my factory cabinets:

Actual_AR9_crossover_circuit.pdf

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Thanks for the compliment!

A couple more upgrades that I decided to do was;

I upgraded the woofer binding post to a Vampire BPHEX unit. I see no real need to upgrade the upper range binding posts. I just left in the jumper as I intend to run monoblocks. This upgrade will allow me to use banana jacks and a bit heavier wiring coming from my amplifier.

I've added about a foot of extra wiring to go to the LMR and the woofers. This will allow me to rotate the drivers by 180 degrees and prevent sagging spiders.

I coated each of the drivers baskets with a product similar to dynamat. The cost of dynamat is crazy, so I found a product at lowes that is very similar in design, but it's meant for sealing roofs. It's about 1/8" thick, it's got adhesive on one side, with a soft rubber compound, and, has an aluminum backing. I've used this product a lot before and it has never let me down. The tin like ringing of the baskets is gone. When I tap on them now it's a soft, thud. Very effective.

I cleaned the switches with DeOxit. If this proves insufficient, I may replace the switches all together at some point. As of right now, I'm going to see how the DeOxit treated things.

One upgrade I'm contemplating doing is, JB Welding all the magnets. I may do this after I've played the speakers for a couple weeks, just to make sure that everything is working properly with the drivers.

Is there any other upgrades that anybody can suggest for these speakers?

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They look great!

Your going to love 'em.

I rebuilt my original 9's about 4 years ago and they still sound great.

I'll be waiting your review of the 9's with the Emotiva amps.

I certainly don't need anymore equipment at the moment but I've looked at Emotiva and keep thinking I'd like to try some of their stuff.

Good luck with your setup.

John

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I've thought about spiked feet, but my opinion on them is that they are not an efficient way to isolate. I believe that in fact they may more effectively bond the speaker direct to your floorboards in your house as they poke right through carpet when 140 pounds is applied to them. This is just my opinion of course. I have my own idea of how to isolate. I have 3' by 3' by 1/2" granite pieces which I will lay on the floor, and I have a bunch of 1/8" rubber to lay between the speaker and the granite. A cheaper option to the granite would have been concrete, but I got a good deal on the granite.

I have an emotiva pre, cd player, and dac currently working in my place...and I love them. The XDA-1 amps get a lot of shining reviews, and I doubt I'll have anything bad to say about them, but we shall see and I will certainly write a review.

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Good work - I am intrigued with your suggestion of using rubber and granite for a plinth. I do not believe in spikes either - but I have had success with plinth like approaches.

One important thing; Did you make sure that the "Wooden Can" behind the 8" driver is securely in place? These often come loose and are merely being held in place with the speaker wires. This "can" like thing is the air suspension chamber for the 8". I had to brace mine in place by adding a member behind it.

I see you left your attenuator pack in place. I took mine out. Didn't want those switches in the circuit. Not sure that this makes any sonic difference.

I also notice that you did not rewire the speaker. I completely replaced all the wiring in mine - I used doubled runs of 14 gauge to the woofers. Single runs of 14 gauge to everything else.

Great suggestion on the "material" to damp your woofer baskets - very good. I will be going to Lowes shortly myself and will be doing the same thing.

And thanks again for confirming the values of the crossover caps.

Great Work - very impressive.

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Shokdu,

The schematic that you posted at the bottom of the page was the SAME one I brought to your attention during the discussion of which caps were correct for that crossover.

Are you saying that the "published" values (the ones in the "factory" schematic) are the same as what you removed? Or are you saying that you too found differences in the values? I know for a pretty solid fact that the factory schematic for the cap in parallel with the UMR should be an 8uF and NOT a 6 per the factory schematic. Same with the extra coil in shunt for the UMR (not on the factory schematic).

Please advise.

BTW: I have been considering the Emotiva "stereo" amp - I am very interested in your evaluation of how the Emotiva amplifier sounds. Right now I am running Odyssey Khartago mono-blocks - but they are only 110 wpc and I think I am running out of power at higher volume levels.

thanks in advance,

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Thank you very much for bringing the 8" woofer enclosure to my attention! Sure enough, one of the enclosures rear had come loose and was only being held up by wires. I'm going to use wood glue to secure the rear in place again, and then may seal the inside with hot glue or jb weld. I will consider adding a brace to the rear.

I see no need to upgrade wiring. AR build the speaker knowing what amperage and voltage would flow through the wires, an it's not as though wire is better now than it was at time of manufacturing. If I find out that the speakers are capable of handling more wattage than AR published, I may consider upgrading wiring just to be safe.

I did not check actual values of the caps as I pulled them, I thought it was a waste of time. I did verify that every capacitor was the same value as the schematic I posted, which they were. It was in fact a 6 uF capacitor.

I did not check values of the coils. The only reason I would have done that is to replace one, and coils really don't fail. The kapton coating was fine and still very much so working, so there was no need to replace any. If you want values checked, I could certainly do so though.

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Wow, kudos to you Shokdu. Very nice job indeed. Should you ever again come across a decent pair of AR9 - keep me in mind.. lol ;-) Regards and glad you're posting your progress. Very nice indeed. I had the idea of, should I find a pair, taking them down to my friend who is a furniture restoration specialist and have him finish the cabinets in "Red Violin"; the same as the new Sonus Faber Amati Anniversario...

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Thanks Mar! It has been a lot of work. I ally coming to an end though. I am actively seeking another set of AR9's to refurbish as this has been a lot of fun, but I think shipping them from Alaska could get quite expensive! I am going to reveneer these in rosewood at some point. The veneer isn't perfect on these, but not bad enough at the time to justify replacing.

Today I reattached the broken enclosure back for the 8" mid. This was by far the most frustrating endeavor in the refurbishment of these speakers. Whatever glue AR used to attach these things is nearly impossible to clean off. Its a very akward area to reach into as well. To fix them I used a glue to reattach the back, and am going to silicone the insides, and jb weld the seam on the exterior of the enclosure. This should seal and keep them in place for good.

The project is almost done...for now. In a couple years I am going to recone all the drivers as all the spiders are sagging.

Wednesday is D-day. My entertainment rack will be ready by then. It's a nice flexy rack system. I'll have to post pictures of it as well as the finished speakers.

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Shokdu,

The idea of the spiked feet is actually to couple the cabinet to the floor, not to isolate it. I installed spiked feet on my AR90s, which on carpet, and the effect was rather noticable. For me and where my speeakers sit, it was an improvement I don't regret.

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I was reading a posting on AudioKarma about a fellow using marble/stone slabs as a base for his AR9 rather then spikes. He says it does something to the sound of the bass drivers by lifting the speakers off the floor an inch or two.

I'm anctious to hear your review of the emotiva xpa-1 monos. The look nice. Are they made in the USA and how, in your opinion, would the compare with the older Rowland Model 7 mk III? I was thinking of the Krell, Bryston or even Conrad Johnson but after speaking to my friend here who owns a pair of the Model 7 mk I he speaks very highly but says the mk III are much improved over the previous generations...

Just read a few threads on the Emotiva products. A very mixed bag to be honest. I guess it will come down to personal prefrence...

Cheers...

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rrcrain, I suggest you read this; http://www.audioholics.com/education/loudspeaker-basics/speaker-spikes-and-cones-2013-what2019s-the-point

Emotiva designs in the USA and assembles abroad, and you buy direct from Emotiva. That is how they keep costs low. I suspect with the changing world and manufacturing costs that production may eventually be moved back to the states.

A lot of reviews about emotiva products are extremely biased, in my opinion. When people are accustomed to spending 5k to 30k on amplifiers then they check out a amp that's $1k or under with the same specs or better specs than their expensive amp, they go into listening and essentially have already talked themselves out of Emotiva before even listening to the product. In my experience the two channel stereo equipment they offer is phenomenal. I doubt my opinion of the XPA-1's will be any different.

For the real stories behind true Emotiva users go check out the Emotiva Lounge. You can access it by going to Emotiva and clicking on the community link.

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Does this mean there isn't any benefit if the speakers are on hardwood floors (like mine)?

-Joel

Shokdu,

The idea of the spiked feet is actually to couple the cabinet to the floor, not to isolate it. I installed spiked feet on my AR90s, which on carpet, and the effect was rather noticable. For me and where my speeakers sit, it was an improvement I don't regret.

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Does this mean there isn't any benefit if the speakers are on hardwood floors (like mine)?

-Joel

I can't answer that and claim to know what I'm talking about.

I installed thread inserts into the base of my speakers similar to this:

http://www.grainger....0121120203716:s

This way, I can install or remove the spikes as their location requires. Doing it this way also made it easy to remove the spikes if I didn't care for the effect.

If you do decide to try spikes on hardwood flooring, make darn sure you put metal disks under te spikes first unless you like holes in your flooring.

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I take it neither of you actually read the link I submitted.

Basically the idea of spikes is to minimize contact area and to isolate the speaker, or whatever component you've got spikes under. Spikes are not meant to act as a direct coupling, that is what you want to avoid. You always want isolation. If you could build a component rack out of solid concrete, it'd be the best thing you could have. If you have concrete floors, they would be the best thing to set your speakers directly onto. Concrete does not carry vibration or resonate, neither does granite.

Setting speakers on a wood floor is devistating to the speaker acoustics. You typically want carpet and non reflective surfaces surrounding your speakers. A "soft" room will always sound better than a "hard" room.

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Yes you are correct. I guess it is all taste. Personally, it pisses me off this crime of "Free Trade" came along kicking out all our manufacturing to China and artificially building up such an anti-West regime - with our money, natural resources, jobs and tax dollers. Sorry this is my area of expertise speaking. This is why I never, whenever I can help it, purchase anything made in any non-Western nation. We're sinking like the Titanic while they've got pots of our wealth to "re-invest" in our countries and whereby manipulate politics/ians... A sad state all the elitist crooks lead us down into eh?

With that, I think I'll stick to the AR-9 and Rowlands. ;-) But I will not hold anything against ya...lol

Cheers..

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One speaker done. The enclosure sealing compounds I used cured, so I finished the speaker up by returning the drivers to their homes.

You can not feed these things enough power.

Crystal clear, no matter what the volume. So far, very impressed with the Daytons, and all the bypasses.

Wow, these speakers will spoil me.

Haven't even hooked up the big monoblocks yet! Currently running at ~250 WPC.

More updates tomorrow.

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For years, I listened to various AR-9 systems in different environments, just as they had come from the factory, with their nubby little "feet".

They were adequate, unless the system was on a carpet, or uneven wooden floor, as that could allow the speaker to stand off-plumb, or tilted, ever-so-much in one direction.

On about our 3rd AR-9 rebuild, my son suggested installing spiked feet to abate the tilting issue, and we've never looked back.

Focusing the system's weight on those four tiny points have improved what was already a pretty "locked-in" focus, and extreme low-frequency reproduction is now visceral, with plenty of tonality in even the lowest notes.

Our listening room is an addition built onto the rear of a 110 year-old house, and runs the full width, with an 18' multi-angled ceiling and suspended wood floors over a 4' high crawlspace. Irregular walls, upholstered furniture, carpets, a fireplace, and two raised entrances do an excellent job of making it a true "music room", and serving as a reliable tool to evaluate changes in the system.

Based on these factors, spiking the feet of the AR-9 provided as remarkable a change as running them without their Acoustic Blankets - I'd go so far as to say it trumped our last amplifier upgrade, and was considerably less expensive, making my wife happy, too. ;)

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I take it neither of you actually read the link I submitted.

Basically the idea of spikes is to minimize contact area and to isolate the speaker, or whatever component you've got spikes under. Spikes are not meant to act as a direct coupling, that is what you want to avoid. You always want isolation. If you could build a component rack out of solid concrete, it'd be the best thing you could have. If you have concrete floors, they would be the best thing to set your speakers directly onto. Concrete does not carry vibration or resonate, neither does granite.

Setting speakers on a wood floor is devistating to the speaker acoustics. You typically want carpet and non reflective surfaces surrounding your speakers. A "soft" room will always sound better than a "hard" room.

Actually, it's a case where I don't agree with it.

A speaker sitting on carpeting is already isolated from the floor or subfloor. Spikes penetrate the carpeting effectively coupling the speaker cabinet to the floor and reduces cabinet resonance.

Even the link you provided states in the authors own round about way that spikes couple a speaker to the floor, NOT isolate it.

"By having spikes on the base of the stand (as illustrated in diagram 1) we allow the speaker stand to ‘grip’ the floor under the carpet. As a result, we can expect the spikes to reduce how much the speaker and stand wobble around, particularly at low frequencies. Unwanted vibrations or shaking of the speaker box and stand at low frequencies could then be reduced. By holding the speaker more firmly we may alter or assist its ability to radiate low frequencies. In addition, the floor may now act as a secondary radiator or medium to convey sound vibrations to the listener. Hence spikes under a stand may well have an effect we can sense, not because they “isolate” vibrations, but for precisely the opposite reason!"

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I am going to give the spikes a try on my AR9's. I see that Partsexpress has several different versions- which one is appropriate for the AR9? Also, how hard are they to install? Will I need to drill into the bottoms of the speakers?

This is a great thread- lots of really useful info.

-Joel

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You will need to drill into the bottom of the base so be neat with your layout. Use the inserts on the link I provided or something similar to them and follow the directions for their installation. Spikes will have a machine thread not a wood screw thread (the ones I bought did in any event). and aren't suitable to be installed directly into wood.

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Parts Express #240-730 requires a 1/2" hole that accepts the included threaded insert - you need a 10mm allen wrench to screw the insert into the hole.

The spiked foot then threads right into the insert.

http://www.parts-express.com/pe/showdetl.cfm?partnumber=240-730

Be sure to read some of the comments for valuable pointers (pun!) on installing the feet.

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