Blvdre

No, you need a ESR meter that will measure the cap's ESR (equivalent series resistance). The issue is typically that a cap's ESR increases over time (certain types of caps are more prone to this), rather than the capacitance value changing.

How did you drop down the voltage; an output pot adjust (like most switchers)?

Smooth off-axis response is still important for balanced reflected sound, though, even if you're in the sweet spot.

A picture, for those who may be reading, but not familiar with that JBL design:

Do you have pics of the actual unit?

Link............

What an old codger says, Alex. I'm 53, and I know better than that. Does that make me a young 53? 😄

It's bad (also macbook + safari)

Have they behaved this was since day one? That sounds like a connection issue, maybe a bad solder joint, crimp, contaminated connector, etc. Are you willing to investigate the driver & crossover hardware/connections?

That's the pea-shooter.

Agree with Edgar and John. I work in a manufacturing environment, and its always helpful to get failed parts back for analysis. Your phone call should have also prompted them to evaluate their current stock & processes, as well. Give them another call first, to check in; they may have already sorted out the problem.

Maybe an OTL design? Transcendent Sound

I'll reinforce what Bubo said; don't purchase any old piece of gear without it having been recapped (or w/intention of DIY). That means at least every electrolytic. A friend just finished a recap/refurb of a Kenwood KA-7300, and let me run it for a few days (nice dual-mono design). I could be happy with this piece (I'm not giving up my Don Allens, though). I checked some reviews of this integrated, and one of the complaints was noise floor. Bullshit. This thing was dead quiet with my La Scalas. The problem is people are commenting on stock units. My friend said the sound quality was night and day after servicing. Refurb is a must.

Solen also makes a poly film and foil that is reasonably priced. John, I believe Solen caps are manufactured in Ontario, Canada, and distributed out of St. Hubert (just outside of Montreal). They have a french language option on their website, so that might explain the misunderstanding. Sonic Craft has good prices on AudioCap Theta film and foil caps, and I believe they ship internationally: http://www.soniccraft.com/index.php/film-capacitors-audiocap-theta-c-301_33

My suggestion would be to spend the money on music or elsewhere in your system. Your speaker cable is fine, IMO.