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Thomas suggested we start a thread for planar mids so here is the first entry…“Fun with Maggie”.
SWEET! It is easy to see why music lovers love their Magnepans. They have a very relaxed presentation and commit far fewer sins than most speakers on the market.
The MMG W is a fantastic value at $299 per pair. As a stand-alone speaker, limitations include a gently rolled off top end and inadequate bass output. The top end can be easily cured with a tall ribbon, and a pair of panels wide per side might support output down to 200Hz or so. I already had BMS 18N850s in U-baffles, and have built several ribbons…so the temptation was simply too great!
The amps in this system have plenty of swing (+/- 80 volt rails) so the 5 ohm MMG Ws were wired in series for an easy load and, for openers, the panels are allowed to roll off naturally on the top end. The ribbon uses a simple opposed pole motor with a homogenous half-inch gap of about 0.6 Tesla. Ribbon sensitivity is high enough that a matching transformer is unnecessary...the only thing between the ribbon foil and the amp is a resistor in series with a small cap. This low-order filter yields very good integration with the panels.
The low-end of the MMG W is not so simple. Out in a large room, even in pairs, the Maggies roll off below 400 Hz. I had to bite the bullet, bump the xo up to 250Hz, and dial in EQ for the low-end of the panels. EQ boost on the bottom end might have destroyed dynamic range, but the 250Hz xo prevents that problem.
Because of line/point source transition, close measurements of line sources (and panels) are downright misleading so, if we have a heat wave over Thanksgiving, I’ll take them outside for measurements. In-room RTA measurements will do for now.
The end result is extremely pleasant. The panels are not as incisive as the Seas Excels…they are more forgiving of poor sources like some recordings and HDTV material. The Maggie mids were just fired up yesterday but the sound is so darned sweet I listened to K.D. Lang’s “Invincible Summer” DVD-A three times straight through!
Here is what I don’t like about them (or more accurately, the room). The speakers are positioned about 6’ out from a pair of 8’ x 8’ glass doors so the dipole reflection is overbearing. I like a large soundstage, but with fairly precise imaging. These speakers throw a huge stage with vague imaging. The cure could be heavy drapes (not happening) or wool felt and/or foam damping on the back of the ribbon and panels like some of the newer ESLs.
One interesting effect of the spacious sound is that some instruments are clearly located left and right of the speakers, still others are centered behind the listening position. At one point I literally checked to make sure the surround amp was turned off!
As you see from the scrap MDF base, rather than long-term use, these were built as an experiment (and just plain fun). The theory is that the Maggie panels work well enough, high enough, to manage the directivity of a narrow ribbon as well as provide directivity in their range. So, no abrupt directivity changes with frequency. In this case, the crossover is the key, so that will be my focus for the next few days. We’ll see.
Other applications for the MMG W panels might include a 2-tall line array with 9 RS180’s and a ribbon, or the RS180’s in a low 3x3 array, or an RS390, or 4-10”….or?
Let your imagination run free and share the results!
Paul
Edit by moderator to upload pics as attachments
SWEET! It is easy to see why music lovers love their Magnepans. They have a very relaxed presentation and commit far fewer sins than most speakers on the market.
The MMG W is a fantastic value at $299 per pair. As a stand-alone speaker, limitations include a gently rolled off top end and inadequate bass output. The top end can be easily cured with a tall ribbon, and a pair of panels wide per side might support output down to 200Hz or so. I already had BMS 18N850s in U-baffles, and have built several ribbons…so the temptation was simply too great!
The amps in this system have plenty of swing (+/- 80 volt rails) so the 5 ohm MMG Ws were wired in series for an easy load and, for openers, the panels are allowed to roll off naturally on the top end. The ribbon uses a simple opposed pole motor with a homogenous half-inch gap of about 0.6 Tesla. Ribbon sensitivity is high enough that a matching transformer is unnecessary...the only thing between the ribbon foil and the amp is a resistor in series with a small cap. This low-order filter yields very good integration with the panels.
The low-end of the MMG W is not so simple. Out in a large room, even in pairs, the Maggies roll off below 400 Hz. I had to bite the bullet, bump the xo up to 250Hz, and dial in EQ for the low-end of the panels. EQ boost on the bottom end might have destroyed dynamic range, but the 250Hz xo prevents that problem.
Because of line/point source transition, close measurements of line sources (and panels) are downright misleading so, if we have a heat wave over Thanksgiving, I’ll take them outside for measurements. In-room RTA measurements will do for now.
The end result is extremely pleasant. The panels are not as incisive as the Seas Excels…they are more forgiving of poor sources like some recordings and HDTV material. The Maggie mids were just fired up yesterday but the sound is so darned sweet I listened to K.D. Lang’s “Invincible Summer” DVD-A three times straight through!
Here is what I don’t like about them (or more accurately, the room). The speakers are positioned about 6’ out from a pair of 8’ x 8’ glass doors so the dipole reflection is overbearing. I like a large soundstage, but with fairly precise imaging. These speakers throw a huge stage with vague imaging. The cure could be heavy drapes (not happening) or wool felt and/or foam damping on the back of the ribbon and panels like some of the newer ESLs.
One interesting effect of the spacious sound is that some instruments are clearly located left and right of the speakers, still others are centered behind the listening position. At one point I literally checked to make sure the surround amp was turned off!
As you see from the scrap MDF base, rather than long-term use, these were built as an experiment (and just plain fun). The theory is that the Maggie panels work well enough, high enough, to manage the directivity of a narrow ribbon as well as provide directivity in their range. So, no abrupt directivity changes with frequency. In this case, the crossover is the key, so that will be my focus for the next few days. We’ll see.
Other applications for the MMG W panels might include a 2-tall line array with 9 RS180’s and a ribbon, or the RS180’s in a low 3x3 array, or an RS390, or 4-10”….or?
Let your imagination run free and share the results!
Paul
Edit by moderator to upload pics as attachments
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! Thomas, where are your priorities?
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