by Jim Holtz & Curt Campbell
Jim: Jim: The design goals I established for this project were to challenge my full-sized Statements overall performance in a smaller monitor sized speaker with a special focus on the midrange. This isn’t a cost no object design but rather a high value design that controls costs but still provides top notch performance that will equal or challenge the best.
Curt and I have talked frequently over the past few years about what is the secret ingredient in a speaker that makes a listener go “WOW”? It always comes back to the midrange. It’s got to be right to have a truly enjoyable speaker that accurately reproduces a live acoustic performance. Every top end driver design has its virtues. However, the best drivers all share one characteristic, hard and stiff cones regardless of the material used in its construction. We also agreed that the ones we liked the best were often based on a form of advanced paper construction. Not always, but often. J There is a naturalness to the mid-range sound of a high tech paper cone driver when combined with a well-designed crossover that takes you to the original performance with a realism that is hard to duplicate.
A 3-way vented design with The Dayton RS225-8 aluminum cone woofer, the Dayton RS28F fabric dome tweeter, and the Vifa NE149W-04 reed paper cone neodymium driver housed in an open back cylindrical enclosure.
I'll call this one 6 ohms as the impedance curve flirts with, but never quite reaches 4 ohms at any frequency, and spends as much of its time above 6 ohms as it does below. The impedance is above 7 ohms below 60 H. The minima is 4.3 ohms at 100 Hz, and again dips below 5 ohms between 500 and 1000 Hz, but then increases to above 7 ohms at higher frequencies. The worst amplifier load is 5.4 ohms and -40 degrees at 73 Hz. This suggests an easy load for any reputable 6 ohm rated amplifier.
Dimensions: external: 11" wide, 24" tall, 15.5" deep
Basic Sensitivity: Approximately 84 dB / 2.83v / 1 meter
Max SPL: (Modeled at woofer published Xmax) 104 dB / 1 meter
Statement II performance in a smaller, more cost effective package?
You be the judge...
Jim: Jim: Since this was a design intended to give top performance in a monitor sized cabinet at an affordable price, we chose the NE149 based on feedback from others that have compared it favorably to its high-end siblings from Scan-Speak. The NE149 was an unknown quantity, so I even went so far as to size the mid cut out to accommodate SB Acoustics, Scan Revelator and Seas Excel 5 ½” drivers in case we were not satisfied with the NE149 performance. The NE149 exceeded my expectations. It tested great and sounded better.
We also chose a Dayton RS28F tweeter and the trusty Dayton RS225-8 woofer to support the mid-range. The two Dayton drivers are proven performers whose sound quality far exceeds their price point. Both are superb drivers when used as designed that would require several times their cost to better their performance, IMHO. I keep looking for a better 8” woofer that is low distortion, has a low F/3 and decent xmax that requires a reasonable sized cabinet for bass extension, and I can’t find one that doesn’t cost several times the cost of the new RS225-8. I also find the RS28F to be a real over achiever. Both offer superb performance at affordable prices.
Curt: The advanced frame design of the NE149 made it look like an excellent candidate for the 6" tunnel mid enclosure Jim and I had in mind. Our concern was that a large magnet assembly would impede the rear pressure wave and cause cavity resonance in the cylindrical enclosure. During testing with the SB15 with its larger ferrite magnet, this proved not to be the case, however. The design certainly could have moved ahead using the SB15, but at that point we were too enamored by the Vifa's midrange and elected to keep it in the midrange slot.
Jim: The Finalists offer the same huge atmospheric soundstage and layered depth the Statements are known for. Depending on the recording the performers begin at the rear of the speakers and are layered to the rear and sides with the soundstage extending well beyond the width of the speakers if recorded that way. The speakers disappear leaving only the performance. BIG sound from small speakers.
The Finalists are copyright 2012 by Jim Holtz and Curt Campbell