How long should the ribbon tweeter on the Magneplanar 1.7i roughly last?

[Mike Gillespie]

A friend who is a prominent tube amplifier and speaker designer (mostly horns but some box speakers) had Maggies in the 70's and 80's and said that every year, to get them to sound good, he had to open them up and stretch and tighten the ribbons. That normal temperature changes from hot to cold, and just normal playing weaken the ribbons and stretch them out to the point they become lax. As they stretch, the sound quality diminishes.

I have a pair of new 1.7i's on trial, and I'm concerned about how much of an issue this really is with the newer Maggies.

How many years have you been able to still get great sound out of your Maggies? What vintage are they?

Any further thoughts would be much appreciated.

Mike

[Mark J]

First, we have to discuss the build of the speakers.

Magnepan used to use round wires glued to Mylar for their speakers. There were the early two-way speakers with a bass section with thick wire and a treble section with thin wire. The higher end Tympani multi-panel speakers used a third medium sized wire for the three-way speaker.

The Tympani III came out in 82 with their first true ribbon tweeter, so there were no true ribbons in Magneplanars before that. The tweeter went down to the MG-III and other 3-series and into two models of the 2-series, the 2.5 and 2.6. The 2.7 moved from the 2-series being a 2-way to being a three-way with quasi-ribbon tweeter.

The quasi-ribbon speaker is simply a flat wire conductor glued to the Mylar. This is really a planar magnetic speaker, a Mylar sheet with the voice coil wire in rows where the gap where a pair of bar magnets are located. These magnets mounted to a perforated sheet metal frame on the other side of the Mylar, numerous ones for the different sections of the speakers.

I don't know what your friend is talking about, stretching the ribbons. The ribbon tweeters would be a real mess to do this, possible but not something to do annually. Replacement (exchange basis for about $100 each plus shipping) would be the better method. The Mylar is stretched on a frame in the speaker and maybe, but I don't know how, he was tweaking this. It would for most of the speakers affect the bass response, too. Breaking in a Magneplanar is usually getting the Mylar to loosen over use for a few months to extend the bass response.

The usual issues with Magneplanars is the loosening of the glue holding the round wires. Much smaller surface area of the wire to hold it to the Mylar. Repairing this is common and with that repair the speakers are fine again. Unless the wires corroded or the aluminum foil in true ribbon tweeters breaks and looses conduction. Then the wire or the tweeter need to be replaced.

I don't think the newest models have issues with the glue as I haven't heard about a quasi-ribbon wire coming loose. Better gluing and more surface area to glue I'm sure helps with this. Probably nothing to worry about in those speakers for about 15-20 years.

[McPlanar]

I still have my original pair of Maggie MG-1.0 imp that I bought in 1982 and they are still humming along. I also just took a pair of MG-1.5/qr's out of service having been replaced by a pair of MG-1.6/qr in my surround system. I bought the MG-1.5's in 1998 and they too still function fine. My 2-chan system has a pair of MG-12/qr's that were built in 2007. These have been modified by Magnestand and show no signs of reduced joy in sound. I think you will have many years of service with your new MG-1.7's.

[Barry1]

Originally Posted by Mike Gillespie

A friend who had Maggies in the 70's and 80' said that every year, to get them to sound good, he had to open them up and stretch and tighten the ribbons. As they stretch, the sound quality diminishes.

How many years have you been able to still get great sound out of your Maggies? What vintage are they?

Mike

Old thread but people should appreciate Magnepan speaker reliability.

First, no one could have "stretched" ribbons back in the 70's because no Maggies had true ribbon tweeters back then.

I have owned Maggies since about 1981 starting with the T-1Ds, then the 3.5s and now the 3.6s. I blew a tweeter once when the speaker fell over! I have blown tweeter fuses twice, but it's been at least 10 years. Oddly, the more power you have the less likely the tweeters are to be damaged because the amplifier will not clip/overload and destroy them. I'm running 440 watts on the combined tweeter/mid panels and the same amount on the bass panels using 2 custom-built stereo hybrid tube amps with no problems.

Yes, the ribbon tweeters can sag a bit, but you could easily go for 5-7 years or more without any noticeable visible changes. These speakers require NO maintenance unless they are abused.

I don't know who your friend is but sorry, "No", the sound does not change with moderate tweeter stretching. It's not audible!

[ehoove]

First the 1.7i does not use a true ribbon which is what your friend was discussing. The 1.7i and most of the newest models have gone to a Quasi Ribbon which other than coming loose from the mylar should have no issues. I have used the true ribbons in my MGIIIa's for 7 years or so. When I refurbished them I replaced both ribbons for around $250.00 including shipping. They are fragile to sudden air movement, but if you use the supplied magnetic strips to protect them when moving them they are fine. I have only seen sag on very old models and don't know what caused it age, use, or climate. I replaced my ribbons last year after one was destroyed during a get together at my house. I have no idea what happened, but the good one had no sag in it after almost 7 years of heavy daily use. FWIW
Regards,
Jim

[mgard]

Thanks Berry, Jim and Mark. Very good information as I wondered what the expected life of my 3.7i's would be. I see I have nothing to worry about. My Maggie's sure sound sweet!

~Mike