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AR 18 B restoration


Guest philparis
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Guest philparis

Hello to all!

i am new here so forgive me if i post already asked questions.

I am a sound engineer and had the pleasure to record years ago on site two jazz records with my personal pair of AR 18, one of these records won a prize !

This pair of speakers was lost during movings so i searched for a new one on Ebay and found a pair of AR 18B that i bought. My intention is to restore it at the best.

I found a pair of new tweeters, i may have found a pair of woofers (can someone recommend OEM replacement or must i find a real original speaker ?)

Do you think that these should fit ?: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewI...cTODAY.m238.lVI

or should i go this way ? : http://cgi.ebay.com/ACOUSTIC-RESEARCH-AR-4...7QQcmdZViewItem

Also does someone here have the schematical diagram of the crossover for the AR18B ? I searched on the site and could'nt find it.

Thank you everyone !

Philippe, Paris, France

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I found a pair of new tweeters, i may have found a pair of woofers (can someone recommend OEM replacement or must i find a real original speaker ?)

Hi Philippe

Why do you need new drivers? If you want the best sound from your 18B, it is important to use original drivers. If it is only the foam surround failing on your woofers, it can easily be replaced.

If the woofers are destroyed/damaged beyond repair, I might have a set of the original woofers for AR 18B, but they might also need to be refoamed, I will have to check the parts number when I get home, it should be something like 1210037-0, according to the 1986 parts list in the library.

BRgds Klaus

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I will have to check the parts number when I get home, it should be something like 1210037-0, according to the 1986 parts list in the library.

Hi Philippe

It is the 1210037-0 I have, they are in good working condition with OK foams. Pls let me know if you are interested

BRgds Klaus

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Guest philparis
Hello Philippe:

Voila, the crossover for the AR-18b -18s

Cheers,

John, thank you very much.

I can't believe it ! a simple capacitor et voilà !!!! (of course i know that this is the simplest crossover existing, but i never thought possible to find it in a such good sounding speaker, maybe this IS the reason !)

Do you think the result could be improved by using the 18 BX crossover diagram ? :

http://www.classicspeakerpages.net/library..._schematic.html

Philippe, Paris

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Guest philparis
Hi Philippe

It is the 1210037-0 I have, they are in good working condition with OK foams. Pls let me know if you are interested

BRgds Klaus

Dear Klaus

i am interested, what means OK foams exactly (i am wondering if they are "like new" or " can last two or three years" or whatever ?) and what would be the cost for a pair including shipping cost to France (zipcode 75005) ?

Thank you very much

Philippe

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Guest philparis

Dear Klaus

i also found on Ebay some very cheap 8" AR woofers, their part # is apparently 330-004R

Do you think they can fit the AR 18B or is this something else ?

Thank you

Philippe

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Dear Philippe

If you want to be sure to have the correct AR-18B sound, you should use 18B components, also the woofer since the cross-over frequency for the woofer relies completely on the natural roll-off of the driver. I would not advise to change the cross-over either, I think the simplicity of the AR-18B cross-over is an important reason for the excellent sound, this speaker is reputed with.

The woofers I have are not new, and I do not know how old they are; I found them in a set of AR-6 (where they definitely do not belong). Therefore, I cannot tell you how long the foam surrounds will last, but probably like 2-5 years, also depending on how much UV-light they will have. Again, if you have the correct and working woofers from your speakers, a refoam would fully restore the function of your woofers.

If you are stiil interested, send me an email

BRgds Klaus

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Do you think the result could be improved by using the 18 BX crossover diagram ? :

Philippe, Paris

Hello Philippe:

Please do not change the crossover circuit or change either the woofer part number or the tweeter part number. I would be best to use the woofers offered by Klaus.

A very long time ago someone, I believe it was Steve F., posted comments about the relative merits of the AR-18 series. The poster indicated that the AR-18bx is the next to the lowest in quality of the series, with the AR-18bxi considered ti be the lowest quality. The AR-18bx used a generic tweeter, and a lower quality woofer than was used in the AR-18b. Further, the crossover frequency was increased to 3,000 Hz, widening the range over which the woofer was asked to speak. Also, the AR-18bx use an AR-1200068-0C woofer, which was stated to be not as good sounding as the woofer used in the AR-18 or -18b.

In a nutshell, the AR-18b has both good sounding woofer and tweeter, which are matched to its crossover, so it would be prudent to replace parts with original AR-part numbers, and retain the same value crossover capacitor. It's a nice sounding speaker; I have several and enjoy their sound. It is worth the effort to maintain their authenticity.

Hope this helps,

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Guest philparis
Hello Philippe:

Please do not change the crossover circuit or change either the woofer part number or the tweeter part number. I would be best to use the woofers offered by Klaus.

A very long time ago someone, I believe it was Steve F., posted comments about the relative merits of the AR-18 series. The poster indicated that the AR-18bx is the next to the lowest in quality of the series, with the AR-18bxi considered ti be the lowest quality. The AR-18bx used a generic tweeter, and a lower quality woofer than was used in the AR-18b. Further, the crossover frequency was increased to 3,000 Hz, widening the range over which the woofer was asked to speak. Also, the AR-18bx use an AR-1200068-0C woofer, which was stated to be not as good sounding as the woofer used in the AR-18 or -18b.

In a nutshell, the AR-18b has both good sounding woofer and tweeter, which are matched to its crossover, so it would be prudent to replace parts with original AR-part numbers, and retain the same value crossover capacitor. It's a nice sounding speaker; I have several and enjoy their sound. It is worth the effort to maintain their authenticity.

Hope this helps,

John

i will follow you and not change anything unless i am sure of what i am doing

Thanks a lot for the advice

Regarding the tweeters, mine appear to be working but are smashed and deformed so i found these original AR parts on Ebay the box is labelled HR 1 1/4" and 200014-3

I made a search on this site and found that the tweeters for the 18 models are HR (high range) 1 1/4" # 1200014-3

I assume that they dropped the #1 on the box label, because if you look at the 1986 listing you will notice that every reference starts with a 1

What do you think ?

Philippe

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Regarding the tweeters, mine appear to be working but are smashed and deformed so i found these original AR parts on Ebay the box is labelled HR 1 1/4" and 200014-3

I made a search on this site and found that the tweeters for the 18 models are HR (high range) 1 1/4" # 1200014-3

I assume that they dropped the #1 on the box label, because if you look at the 1986 listing you will notice that every reference starts with a 1

What do you think ?

Philippe

Hi Philippe:

Before you purchase new tweeters, I would try to pull the dome out to about its original position - either with a small flexible plastic hose and a bit of vacuum, or with a sharp pin and lift carefully. If the voice coil is good and you can get the big dents out, then I am told it is not necessary to replace the tweeters.

The #1 in front of the part number was added by AR at some point to allow for more part numbers.

My AR-18 tweeters are part number 200014-3. I think these are what you see listed on eBay.

My AR-18b tweeters are part number 200034-0, but the AR parts list gives their number as 200038-0. I think both numbers are correct.

Why not try to work the tweeter domes back into approximate shape gently. If they sound good, why replace them? Either refoam the woofers or obtain a pair from Klaus. If you purchase his pair, someone will purchase your pair and refoam them - so don't throw them away! These drivers cannot be replaced.

Cheers,

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Hello Philippe:

Please do not change the crossover circuit or change either the woofer part number or the tweeter part number. I would be best to use the woofers offered by Klaus.

A very long time ago someone, I believe it was Steve F., posted comments about the relative merits of the AR-18 series. The poster indicated that the AR-18bx is the next to the lowest in quality of the series, with the AR-18bxi considered ti be the lowest quality. The AR-18bx used a generic tweeter, and a lower quality woofer than was used in the AR-18b. Further, the crossover frequency was increased to 3,000 Hz, widening the range over which the woofer was asked to speak. Also, the AR-18bx use an AR-1200068-0C woofer, which was stated to be not as good sounding as the woofer used in the AR-18 or -18b.

In a nutshell, the AR-18b has both good sounding woofer and tweeter, which are matched to its crossover, so it would be prudent to replace parts with original AR-part numbers, and retain the same value crossover capacitor. It's a nice sounding speaker; I have several and enjoy their sound. It is worth the effort to maintain their authenticity.

Hope this helps,

I don't remember seeing this thread, but I totally concur. The original 18 was a great speaker. Its biggest weakness was that the tweeters blew a lot. This problem, no doubt, was compounded by the 18's affordable price, which meant it tended to show up in dorm rooms, etc, driven much harder than originally expected. Also, at this time, amps were starting to get more powerful. Later versions of the 18 were attempts to increase tweeter longevity, at the expense of the elegance of the first iteration.

The 18 is also an important product, IMO, because it represented a conceptual shift in AR's general approach to product development. Prior to the 18, AR's product development philosophy was always purely "top down." Flagships were established, then technology and ethos trickled down to low price points in subsequent models. The 18, in contrast, really set the standard by which the 28, 38, 48, etc, were judged.

-k

www.kenkantor.com

www.ztamplifiers.com

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Guest philparis
Ken's rarely wrong... <grin Ken, it's o.k.>

I would hurry to take advantage of Klaus's offer. If you don't, I might.

Bret

Thank you all

you are very reassuring to me!

Klaus, i sent you a PM, did you get it ?

Philippe

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Guest philparis

I decided to go the refoam way with the precious advice of Klaus

Bert you could ask him for the 8" woofers !

I was playing with idea of restoring the crossover by using much better quality speaker wires and changing the capacity for an audiophile grade one.

The original component value is 5 microfarads electrolytic , but do you think ( i am speaking to anyone, or to everybody who was kind enough to answer me) i can use the MKP quality (non polarized) ?

Also the values are not exactly 5 microfarads but 4,7, should i combine differents values to obtain exactly 5 ? Maybe this is a question for John ?

Philippe, Paris

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Also the values are not exactly 5 microfarads but 4,7, should i combine differents values to obtain exactly 5 ? Maybe this is a question for John ?

Philippe, Paris

Hello Philippe:

All of the comments I have seen from crossover designers say that +/- 10% is fine. In fact most of the electrolyic are +/- 20% so 4,7 would be fine for a 5,0 uF.

Hope this helps,

John

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John,

I'm quite impressed and most flattered that you are citing such an old post of mine.

It dates from Feb 18, 2003.

Here it is again:

"Hi Guys,

Here's the info that I think you're looking for:

The original 18 was essentially an AR-7 with the liquid-cooled version of AR's superb 1 1/4" cone tweeter. It had a crossover frequency of 2000Hz, the same as the 7, but with the new tweeter's greater power handling capability, the 18's power response was somewhat flatter than the 7. The 18 was a truly exceptional small speaker and a great match for the 9.

The 18s was pretty much the same, save for some slight cosmetic differences, and is also highly recommended.

The 18B had a bull-nosed vinyl cabinet , the same 1 1/4" cone tweeter, 2000Hz crossover, but the tweeter was now centered on the baffle above the woofer, instead of being offset as in the earlier 18's. The woofer also changed, and used a shiny black plastic dustcap.

The big change took place with the switch from the B to the BX series. The cabinet got bigger (from 6 5/8" deep to 8 1/4" deep), and the tweeter changed from that great original AR-built 1 1/4" cone to some randomly purchased 1" dome. The crossover went from 2000Hz to 3000Hz, with the expected roughening in power response that physics predicts with an 8" 2-way system.

The BXi was similar to the BX, but the crossover rose to 3200Hz. The BX and BXi had stated LF -3dB points of 52Hz vs. the older 18's 62Hz, indicating a change in the design intent for these speakers to a more full-range design.

The 18 or 18s is the model you want. The 18B is ok, but stay far away from the BX and BXi."

Steve F.

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The 18s was pretty much the same, save for some slight cosmetic differences, and is also highly recommended.

The 18B had a bull-nosed vinyl cabinet , the same 1 1/4" cone tweeter, 2000Hz crossover, but the tweeter was now centered on the baffle above the woofer, instead of being offset as in the earlier 18's.

A minor AR-18/18s information supplement/correction!

The tweeter placement change, from offset to centred, was seen in the transition from the AR-18 to the AR-18s.

Also, the capacitor value changed: 6 uF for the 18, 5 uF for the 18s. The 18s used the 200038-0 tweeter (featuring S-shaped leadouts for "added protection during peak power surges"), the 18 had the 200014-3 (also seen in the AR-7x).

Incidentally, having both UK and USA assembled models of the AR-18s, I was surprised to see a difference in the cabinet width: USA made are 255 mm wide, UK are 244 mm.

The AR-18s remains a 'cult classic', here in the UK, and is still much sought-after for use as a near-field studio monitor, by those 'in the know'.

Robert_S

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Bonjour Philippe,

If you decide to replace the tweeters, or wish to acquire spares, the following link might be of interest:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewI...em=280208539544

post-101656-1205415751.jpg

Regarding the AR 1.25" liquid-cooled cone tweeter, my guess is that the 200038-0 and the 200034-0 are the same (except for the '34s addition of the plastic front-plate, and mesh); both would be correct for the AR-18B. The earlier 200014-3 may have lower power handling capabilities; it lacks the S-shaped leadouts, described by AR as giving "added protection during peak power surges".

For (polypropylene) capacitors matching the original 5 uF value, here are two possible sources:

http://www.cricklewoodelectronics.com/Cric...ome.php?cat=155

http://www.iplacoustics.co.uk/ipl_crossover_components.htm

Hope that helps.

Robert_S

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  • 12 years later...

Recapped my AR 18bs and the improvement was quite noticeable.

I have been moving toward using these Pin Connectors for all of my speaker wires (See picture) so I can quickly test and break-in a number of different speakers. They are good for all types of speaker terminal plates with their various connector styles. The eBay pricing is reasonable for the 20-piece sets 

For this project, I upgraded the Connection Cup that has these spring-loaded connection points and It was a good choice...I really like these with the speaker wire Pin Connectors and the existing screw holes in the AR cabinet line up perfectly.

("Parts Express" Round Speaker Wire Terminal Cup 2-15/16" Gold Spring-Loaded (Part # 260-276))

There is one down side

The round lip will cover the factory applied serial number label. Careful application of a Heat Gun will allow safe removal and reapplication of the label in a slightly higher location to preserve this important document.  

 

 

989660214113019.jpg

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37882CA34E9C63C1C67002EA8BECA427.app1_1601940247429_L1800.jpeg

20200927_114737.jpg

20200927_155103.jpg

20200927_160825.jpg

AR18b after.jpg

Pin connectors off EBAY.JPG

 

 

100226514113021.jpg

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