7AUDIO

My first introduction to fullrange speakers was about 4 years ago in a German diy audio magazine which featured a small transmission line speaker project using a Vifa 10 BGS 119/8 driver. I decided to give them a try and was surprised with the sound quality! Of course they did not play as loud as the bigger two-way speakers that I built before, but something else was fascinating. Fullrange drivers seem to play music with more coherence, more life and they sound more direct. However, there are compromises with fullrange drivers; little drivers have disadvantages at the low end and bigger ones at the top end.

Fostex FX120 Transmission Line Speakers

Looking for more information about fullrange drivers, I found the Mathcad worksheets by M.J. King and decided to try a speaker design of my own. My first try was a speaker using the Fostex FE167E, but I never made proper cabinets for them because my wife said “No way, they are too big”. Searching a smaller driver the Fostex FX120, a 12 cm fullrange unit caught my eye. There is not much information available for this driver, but the feedback from people who have used was positive. On the Fostex data sheet they show a flat frequency response without great peaks and drops.

Read more below!