What's special about Maggie 1.6
Maggie 1.6 - basics
The 1.6 has two Quasi Ribbon Panels. The tweeter panel is aluminum foil glued to a mylar membrane. The woofer panel is copper wire glued to a mylar membrane. Quasi ribbons are not as fast acting as true ribbons but have the advantage of being useable for woofer panels. 1.6's, with both panels being QR's, have the advantage of being very uniform in the their "speed" across the full frequency spectrum.
See summary of Jonathan Valin's July 1998 Fi magazine review. Interestingly the cap and inductor upgrade improves on every characteristic of the 1.6 that is not outstanding but only very good or excellent
Crossover Design
The 1.6 has a very simple first order 6 dB per octave filter for the tweeter and a simple second order 12 dB per octave filter for the woofer. The HF panel is in parallel with the LF woofer panel (which has reverse polarity). The crossover is suitable for and will benefit from speaker cable bi-wiring.
The nominal crossover frequency is 600 Hz with the 4 tweeter caps totaling 22 mfd and one woofer inductor having an inductance of 3.5 milli henries with a 25 mfd bypass. See Schematic.
Because the crossover is so simple, with few components, it is an excellent candidate for an economical upgrading with the best components available. By contrast the 3.6 crossover has 16 caps and 5 inductors and is much more expensive to upgrade.
Caps
The stock crossover uses French made Solen MKP "Fastcap" 200 volt 10 mfd + 6.8 mfd + 5.1 mfd caps by passed with an Electrocube 0.1 mfd for a total capacitance of 22 micro farads. Solens are very economical, great value for money caps that cost less than $ 3.00 each and are typically 1.25 " long.
Hovland caps cost 10 times as much as Solens and are about 3.25 " long. Hovland get their polymer film from a special supplier in Germany who has six different film formulations. Hovland caps are used as original equipment by Von Schweikert and Merlin in their highly regarded conventional box speakers. The transparency of Hovland caps are a good match for transparency of Maggie quasi ribbon drivers.
Hovland recommend a cap arrangement of 7 mfd + 7 mfd + 8 mfd with NO bypass cap for the best sonics. Ideally 11 + 11 would be the best, but Hovland's cap winding machines' maximum diameter limit only allows manufacture of caps up to 10 mfd in value.
Hovland Caps are available from many retailers in the US, Canada, Europe and Far East. See Hovland pdf for details.
Jensen caps from Denmark are reported to be excellent. See the report from Phil, also check Paco's web site
Inductor
The stock inductor is a steel cored wire inductor. The advantages of a steel cored inductor are low DC resistance for a given inductance, compact size, and low cost (about about $ 7.00 each). They do suffer from introducing quite noticeable distortion. An air cored inductor has very many more turns and will have a much higher DC resistance than a steel cored inductor of the same wire gauge.
Alpha Core make 12 gauge foil inductors which have almost exactly the same DC resistance as the original steel cored inductor. They are very much larger (4.25" dia x 2" high) weigh about 5 lbs. and cost $50.50 each. This huge weight of copper is necessary to match the DC resistance of the stock inductor and to maintain the woofer loudness (sound pressure level) and crossover frequency. 3.5 mH is not a standard value and has to be special ordered from Alpha Core who will charge you the price for a 3.9 mH inductor.
The woofer bass response using the Alpha Core inductor is typically within +/- 0.5 dB of the original steel cored inductor.
Sonic Changes which can be expected
After the upgrades have been made the following sonic changes have been noted
Timbre is absolutely superb. The improvement in timbre after
the cap / inductor modifications is much greater than the difference in timbre I recall
between the 3.6 and 1.6. Vocals are extremely realistic. Guitars sound
stunning.
Resolution is noticeably improved from the unmodified 1.6's.
Soundstage presence expands beyond the left and right boundaries of the speakers.
You won't hear individual instruments beyond the boundary of the speakers but the echo and
decay appears beyond the boundaries
Increased reverberation and decay time
Bass is sounds 3 dB stronger even though SPL's have not increased !
Summary - The sonic improvement is enormous, bigger than the improvement which is
typically obtained from a PS Audio power plant.. The parts are not inexpensive, but the
benefit / cost ratio is higher than any other upgrade I have tried . This is a must carry
out upgrade for listeners who enjoy detail and transparency in their systems.
Suitable Upstream Equipment
Stock 1.6's are quite tolerant of medium fidelity yet still quite musical components. By contrast, with the upgrade, Maggies will sonically reveal everything that is fed to them. The upstream system needs to be as free as possible from harshness and should be as transparent as possible (no coloration) to take full advantage of the increased transparency and clarity of the upgraded 1.6's.
Click to see a table of Cap and Inductor upgraded systems
Power conditioning, preferably AC synthesis, is highly recommended for digital components.
Room Acoustics and Treatment
Cap and Inductor upgraded 1.6's put out more sonic information which the listener's brain uses for spatial perception. This results in a noticeably improved soundstage when speakers are in poor sonic locations compared to unmodified 1.6's. Also, because there is more spatial cue information. the benefits of room treatments for dispersion and absorption is increased. See Room Treatment
