Great Topic....particularly now that Amir is testing speakers. My nominees have for the most part not been measured, but Amir could easily acquire one of them to test through Craigslist or Yard sales:
1. Any speaker from the 80s/90s that was originally sold with a "rack" or shelf system. Nearly all of them sounded bad...but the budget brand systems by Soundesign, Craig, or department store brands took it to a new (lower) level. Primary design considerations were use of multiple drivers (the more the better) and cabinets with woodgrain and height that matched the accompanying rack.
2. Late 70s/80s speakers that were built to be sold as house brands for unscrupulous stereo stores. Most of these were local...but Ultralinear Speakers
were a national brand that flourished for a few years using this economic model. They were sold exclusively by a single dealer in each market area and most of the material cost seemed to go towards large but very thin woodgrain cabinets, and aluminum speaker trim rings. The crossovers were for the most part just tweeter caps to prevent them from destruction during the 2-3 day return period. I confess to have sold some of these during my troubled youth. The stores that sold them had ingenious ways to make them sound better than the advertised loss leader brand name products during short demo sessions. Google bait and switch.
3. White Van speakers
, multiple brands include Acoustic Response and Acoustic Image. Like #2, they are designed to look impressive...but as they are generally never demoed in the sales process (and have no return option)..they could measure, I suspect, even worse.
Science almost demands tests on one of these examples to establish a baseline