AR18s refurbishment

[Guest Oz]

Does anybody have any experience repairing or painting over the AR18s vinyl finish? If removal of the drivers and crossover is necessary is there anybody who could tell me if whether this task is difficult? Any advice would be most appreciated.

[johnieo]

Hi Oz:

We "restored" several AR-18 and AR-18b speakers for our home theater. The term restored is used in quotes. We decided not to retain their original dark finish, as the system would look too massive. Instead, we finished the cabinets in off-white to blend with the wall.

Remove the drivers. The driver seals are flat foam gaskets; the wires are attached with push connectors. If you are not familiar with the color code, simply mark or photograph before disconnecting the wiring.

Place the polyfill from each speaker in a bag and identify the unit from which it was removed.

You may wish to replace the electrolytic capacitor in the tweeter crossover. Its value depends on the speaker (AR-18, -18b, -18s). If the capacitor value is hidden beneath hot glue, I can e-mail you the values for each model. If you do wish replace the caps, consider leaving the old cap embeded in its hot glue. Just clip its leads and solder a new cap in place.

Here are a couple of suggestions for refinishing--others may have different ideas. If you want to retain the vinyl, but do not like its color, consider the use of a spray paint designed for application on plastics. We found it easier to remove the vinyl completely. It is quite easily done. Insert a thin blade under the vinyl and peel it from the entire cabinet. Lightly sand the particle board surface and apply a coat of varnish sealer. Sand again and apply two coats of paint. We used a small trim roller so as to match the wall texture.

The grille is made from a stretch fabric. We removed the black or dark brown fabric and replaced it with white that we dyed slightly off-white. We stretched the new fabric around the plastic frame, and with thread, laced it on the backside to the fabric opposite, shoe-lace fashion. We used a cool soldering iron to thermally weld the fabric to the frame on the backside, as was done at the factory. This is easiest done with a temperature-controlled iron. Cut away the excess fabric when finished.

We appreciate that by now, serious classic collectors have had either a severe stroke or a life-threatening heart attack; however, my wife is quite happy with their new look. Be assured I would never have done this to an AR-3a, -4x, -11, etc.; then again, I never liked vinyl when it was in fashion!

cheers,

[Guest Oz]

Hi John,

Thank you very much for providing me with such a thorough response to my enquiry. I couldn't have asked for more helpful information and appreciate the effort you have invested.

I own a pair of AR18S speakers with shot surrounds. I ordered a surround replacement kit and if I succeed in getting them to sound right I will move on to the cabinets.

I was told that given the age of the speaker there shouldn't be any need to replace crossover components and therefore have not given any consideration to replacing the capacitors. Nevertheless, I would appreciate if you could provide me with the capacitor value for the AR18S in the event that they do need replacing. I am a novice and therefore don't know how to check the current ones? I am assuming that I would have to bring them to a technician with instrumentation. Any advice on this matter would be most appreciated. Also, even if they are still functioning properly can you tell me whether there is any sonic advantage to be had in replacing them with new ones?

Again, thanks so much for your help.

[johnieo]

>I was told that given the age of the speaker there shouldn't

>be any need to replace crossover components and therefore have

>not given any consideration to replacing the capacitors.

The unit was likely mfg around 1980. I personally choose to replace 25+ year old electrolytic capacitors. The AR-18s uses a 5-uF tweeter cap.

>still functioning properly can you tell me whether there is

>any sonic advantage to be had in replacing them with new

>ones?

It depends; not everyone has the same hearing acuity. For sure, a new polypro cap will not drift out of spec before your new surrounds need replacing.