Need help identifying speakers: year was 1978/1979. The enclosures were metal, front was slanted back with the front perforated(holes). They were 5 maybe 6 inches tall, 7 or 8 inches long, 5 inches deep ? And very heavy. I was in high school and the audio shop in the midwest had a pair and played Sentimental Lady by Bob Welch. Those speakers shook the place & yet were quite smooth at lower volumes. I have been searching for 2 years but thus far have come up empty. Would appreciate any help, thank you.