Fostex FE208E Sigma
Comments: I would have assumed that the FE208E Sigma was intended to be a direct replacement for the FE208E, but the mid and top end make me rethink that. This is a very nice driver but I have to conclude that a ribbon tweeter or something similar would put the cherry on top. Taken alone, it rolls off a bit much for my taste. The 4KHz peak of the uncorrected driver is easily taken care off and it's pretty inoffensive. With a 120-watt rating and a 97dB sensitivity, you can get a lot of sound out of this $175 driver.


Fostex FF165K
Comments: Another nice unit for $61. Stock, it lacks some treble but this is easily improved upon. I notice that Fostex seems to have three approaches for getting full-range performance in the treble. The FE series uses 'whizzer' cones to good effect and the FF series uses an aluminum center. I can't figure out what the FE Sigmas are doing but they look cool. In any case, the FF165K has 94dB sensitivity, works well as a full-range driver, betters its bigger brother in the treble but of course is not as good in the bass.


Fostex FF225K
Comments: I look at this driver and remember the JBL LE8. Well, if you've always wanted the LE8, maybe you'll want to put down $94 on this very efficient and fairly neutral device. I've never seen a real curve of the LE 8 and I don't remember that much about their top end. This one, however, needs some kind of tweeter and while I think the real maximum excursion is bigger than the spec, I would treat it gently with the "Jurassic Park" sound track. It has 96dB sensitivity and if you bring in a good tweeter, maybe a nice ribbon above 5K, I think you'll really have something.


Jordan J92S
Comments: The J92s is not considered a high-efficiency driver at what appears to be less than 90dB/watt, but it is very, very smooth and a wonderful speaker. It excels at one very difficult thing - to still sound good after the honeymoon is over. We got ours at $70 each and I understand they are twice the price now but still worth it. Magnetically shielded, they also make great computer speakers. You'll notice here that the response curves are extremely similar. As pointed out before, it appears that the high-efficiency drivers make the most out of a current source and here we don't see any particular advantage. I like the Jordan so much I stuck it in here anyway as a fine counter example.