Best speakers circa 77-79'

If your willing to extend the time frame to the very early 80s then you should definitely listen to the Infinity IRS series. I don't know what you are willing to spend or the size of the speaker you are interested in but the biggest sound I have ever heard were from IRS V. Unfortunately they were the most expensive and are 7 feet tall with separate colunms for the woofers with their own 1000 watt amps and big panels for multple emits and and emims for on both sides. They were Arnie Nudell's ultimate speaker to get a picture an there is a link to vintage infinity if you look. A more reasonable smaller facsimle are the RS1 B mentioned above. The IRS Beta are the next one down in the IRS series which are superb. Below that there are several others but the Beta can be bought for about $4,000 used the giant V's are multiple times as expensive but unreal to this day. You use your own amp to power those through an external "servo control crossover". The top of the Genisis also an Arnie Nudel design are similar but you are talking about $50,000 used. Personally I own Klipsch Heresys bought in 1977 and La Scalas vintage 1978 they would be more in line with your system, but your have to like very clean midrange and treble because they are horns, they will play as loud you want but don't expect deep bass. Check out Klipsch Fortes and Choruses for more deep bass.

Dalquist DQ-10..Although this was introduced in 1973, there was clearly few that competed with them through 1980. Many versions exist through 1982 including mirror image pairs (1976), and crossover changes (1977). The only issue is that they need power. I believe they were 89db/1w/1m, but don't hold me to that. They would do well with about 150 watts/channel. Is your reciever high power?

Beveridge 2SW-1 Electrostatics were reviewed by many publications and were considered by some to be the "best in the world". As a very low production, hand built product, they were not sold in large numbers, but they were a fascinating design, and as it turns out, quite reliable. Mine are still making beautiful music, and they were built in 1978.

Bose 601's

mission 770 - have a pair still making music up at my cottage useing a phase linear 300 amp and SAE mk2 pre amp and the very first sony discman as source