Acoustic Research AR-4x Rehab

This rehab project was another garage sale find. The AR-4x are not sought-after like their AR-3a sibling so I had no qualms with making changes to the speaker both inside and out. The cabinet was structurally sound but the finish was very poor. This model originally came in oiled walnut, pine, and birch and the one I got was walnut. Deep scratches were all over the exterior and some surfaces were water stained. The bulk of the restoration involved carefully sanding the veneer and applying new stain and oil for a rich looking finish. Here are both speakers sitting over a Fisher MC-3010 receiver (with 8-track tape!).

Here's what the business end of the two speakers looked like intially. The baffle doesn't look very different before and after. I don't have "before" pictures of the cabinet exterior.

The tweeters were both bad. Modern replacement tweeters can easily be found online but I found used original tweeters online (~$30) for a more faithful restoration. The woofers were fine - the fabric surround meant no foam to rot. The gasket on both tweeter and woofer were replaced (left). The original stuffing was put back along with the fabric that separated the stuffing from the woofer's back (right).

The original potentiometer in the crossover (left) was also bad and rather than replace it, I added a fixed resistor (right) electrically in its place for better reliability. The potentiometer is now unused but still physically there.

The grill was discolored and had numerous holes so I replaced it entirely with modern black acoustic fabric stretched over the old frame. One of the original AR badges on the grill was missing so I opted not to put the remaining one back to keep the two speakers the same.

Here's what the finished front, side and rear look like.

12-April-2020

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