Being the designer of the Pharos and Archos, both of which are higher efficiency designs, maybe I should comment.
First, what makes a speaker efficient is primarily in the driver design itself. But there are always trade-offs - and those trade between Fs, Vas, and Qes, which are driver parameters. In other words, they lock you into what is called Hoffman's Iron Law, which basically tells us that you can not have high efficiency, low bass, and a small box at the same time. One of those has to go in order for the other two to exist. When we targeted a high efficiency design we had to set a target for each of these. In the Pharos I targeted 95dB sensitivity. Then I had to compromise between acceptable low bass extension and enclosure size. The JBL woofer allowed me to hit the sensitivity mark and get 40Hz extension out of a reasonably sized box at the same time. It offered the best compromise available at the time.
For the Archos, the newly redesigned Lambda woofer gave us lower bass extension in a smaller box, and we kept the sensitivity close to that of the Pharos, but it is a little lower.
Then there is the matter of the impedance. This is tricky. It is not easy to design a three-way speaker with flat response and flat resistive impedance at the same time. However, this goal was accomplished with the Pharos. The impedance curve with it is nearly a flat line above the bass peaks (above 100Hz).This makes the Pharos a perfect match for the most demanding SET amps. The Archos has a fairly well-controlled impedance that varies only from a low of about 5 ohms to a high of 9 ohms across this same range. In most cases this is stable enough that most any amp will be fine with it too, but it is not quite as flat (resistive) as the Pharos impedance is.
The Pharos also has an extremely flat frequency response as well. Apart from not having really deep bass extension it does everything else extremely well. The Archos, by virtue of the open baffle midrange, is a little more dependent on the room set-up and placement, but can also offer very flat response when set-up well. I have listened to both, but I probably should keep my personal opinions on which I would pick to myself.
What I am getting at is - you can ask us to design you a high efficiency speaker with great bass response that comes in a reasonably small box, and unfortunately, it just can't be done. Something has to give somewhere in one of those requirements. As a result we have tried to offer what we felt was the best and most widely appreciated combination of those characteristics in the speakers that were offered. We felt that what we had arrived at would have the widest possible appeal - compared to a refrigerator sized speaker or one that only reached down to 70Hz before it started rolling off.
I'll tell you this; if Jim were located in Japan he would be selling Pharos' like crazy. Both this JBL woofer and the PHL midrange has a cult following over there, and they love ribbon tweeters too. This speaker would have some real impact in that market. Also, beware of some commercial speakers that advertise high sensitivity and low bass. A lot of tests show that many of these do not measure up to their claims in either category. We have tried to be conservative in our ratings so that everything was out there on the table and lived up to the claims made.
Jeff B.
