The MG-IIIA sentimentally, is like our long lost girlfriend from yesterday. For us, and I’m sure for many others, the MG-IIIA was the speaker that knocked our socks off when we listen to it for the first time. Back in the Eighties when it first appeared on the scene, the MG-IIIA surprised many with its big sound scale, rich mids, effortlessly smooth highs and impressive bass response (especially for a speaker that looks like a big piece of sheetrock and measures only 2″ deep). It does need several conditions to achieve this level of “perfection” – a high current high power amp that could dive down to 4 ohm and a lot of space around the speaker/room that it is being placed in. If you have these two conditions met, the MG-IIIA will bring you audio nirvana…with one caveat – its not for the heavy metal/rock fans. If you listen to lots of vocals, jazz, the Maggies are hard to beat for the money. Imaging is superbly wholesome and 3D like with great depth.
Specs wise, the numbers for the MG-IIIA will blow any comparably priced cone based speakers out of the water. The speaker is a three-way planar-magnetic bass and midrange system, with a ribbon tweeter. The bass driver has a sq area of 620 sq inch which is more then the sq inch of three 8″ woofers or two 10″ woofers. For the midrange panel – 170 sq inch, it is more than two 5.25″ mid-woofers put together. The tweeter itself is 0.25″ wide and 57″ long which is roughly equivalent to four 1″ dome tweeters. Frequency response 37 Hz to 40 KHz with a nominal impedance of 4 ohm and a sensitivity of 85dB. Magnepan recommends driving them with an amp that will put out a minimum of 50W and can dip into 3 ohm. The speakers stand 72″ tall, 23″ wide and 2″ deep (not measuring the feet extension). From what we have experienced, the greater the power, the better the MG-IIIA sounded. The crossover box will accept a regular speaker in where it will “split” the signal to high/mids and bass out into the speaker. Previous owner upgraded the jumper cables to a heavier gauge Monster cables that added more weight to the sound presentation.
Cosmetically, the speakers look very good for its vintage. One very careful since new! No rips or tears in the fabric or any major scuff marks on the wooden side panels. Only issue, which is a minor one, is one of the four locking screws for the extension feet is not locking in but the other three works fine. Speaker stands up straight and fine. We have the original boxes for the speaker panels and the crossover box. Local pickup is highly recommended but if shipping is needed, they will need to go freight.