Sony SS-G7a

By 1980, Sony had sold in excess of 10,000 pairs of SS-G7. Yes, indeed, no mistyping here: ten thousand pairs !

So a little revision was deemed necessary : added were boron carbide coating on the titanium tweeter, a new voice coil design for the mid driver and the crossover frequencies between the bass and mid drivers was lowered by 50Hz (500Hz instead of 550Hz).
Also, a second bass-reflex port was added to keep symmetry... symmetric.

The rest is the same : 94dB/W/m SPL, 8 Ohm nominal impedance and... still 52kg on the balance.

However, by 1980, the SS-G7 was an "old" design dating from the almost prehistoric year of 1976 so, unlike the original G7, this revised version didn't sell much... if at all : 158,000¥ probably was too much for such an old thing, whatever its recognized excellence.

Launched at the same moment, the SS-G4 did benefit from the updates made on the SS-G7a.