Double Front Planars

[bubslewis]

Hypothetical scenario here:

Out of curiosity I was wondering what the sonic result would be if one were to employ two planar speakers each for front left and front right. I'm curious about this because I had a similar setup in my old system when using conventional speakers.

I had bought a new A/V receiver and was running a pair of self powered fronts out of the preamp section of the A/V. This left the front speaker amps idle in the A/V receiver. One day I decided to hook up my old BOSE speakers to the front terminals and run them outside and a bit behind the self powered fronts. After comparison, I found I liked it better, so I kept the setup.

Today, BOSE's are gone, self powered fronts moved to the back, and a pair of Magnepan 1.6's are front left and right, again via the A/V pre-outs into a separate amplifier. Once again this leaves the front amps idle in the A/V receiver.

The A/V receiver amps (130 W) could not probably handle 1.6's, but might be able to do OK with a less demanding planar like Magnepan 1.2 or MMG or MC1. Question is what would it sound like.

To a non educated one like myself, I would think this "horizontal stacking" would result in a wider sound stage and an expanded sweet spot listening area. It would be like having one very large planar speaker on each side. Or would it? Or would they cancel each other or result in other negative effects beyond my knowledge to describe.

Just a wonderin'

Bill

[E-Stat]

Out of curiosity I was wondering what the sonic result would be if one were to employ two planar speakers each for front left and front right. I'm curious about this because I had a similar setup in my old system when using conventional speakers.

I have different answers depending upon the type of planar speaker. Using multi-way Maggies, there would be some good news and some bad news. The good news would be greater panel area which is generally a good thing with respect to dynamic range. The bad news would be that the collective speaker would no longer have a line source tweeter. There would be two sets offset horizontally. Think about any number of large cone speaker arrays. They are most often vertically oriented, not horizontally for this reason. I stack the Double Advents in my vintage system vertically and invert the top pair in a quasi D'Appolito arrangement.

With full range electrostats, however, the entire panel becomes the line source and would not automatically suffer as do multi-driver designs. The 20.1 has greater panel area overall, but still a single tweeter line source (a very sweet ribbon one at that) Having said that, some designs like the flat array approach found in Acoustats end up narrowing the sweet spot with a wider panel configuration. From the original three panel side-by-side model X, I upgraded those to the Monitor Four having four panels side by side. While adding the panel helped bass and dynamics in general, imaging suffered. I later replaced them with 2+2s which used the four panels in a stacked, two panel side-by-side approach. My current Sound Labs solve that problem by faceting a very large single panel in a staggered approach which offers a 90 degree radiation angle. This win-win approach gives you the best of both worlds.

rw

[bubslewis]

. "The bad news would be that the collective speaker would no longer have a line source tweeter. There would be two sets offset horizontally. Think about any number of large cone speaker arrays. They are most often vertically oriented, not horizontally for this reason. I stack the Double Advents in my vintage system vertically and invert the top pair in a quasi D'Appolito arrangement".

I don't suppose that turning the outside pair 180 degrees (kinda like inverting your top pair of Advents) would be a satisfactory solution. However, this would eliminate the horizontal offset for the tweeters. This would also be aesthetically feasible, since the back of maggies look pretty much the same as the front.

[E-Stat]

I don't suppose that turning the outside pair 180 degrees (kinda like inverting your top pair of Advents) would be a satisfactory solution. However, this would eliminate the horizontal offset for the tweeters.

I don't see how. There will still be two discrete verical tweeter slits offset by a number of inches. Reversing them merely changes that distance. Stacking them, however, WOULD put them in the same horizontal plane.

Even with the multi-panel Tympani series, Magnepan used a single tweeter line source.

rw

[bubslewis]

I don't see how. There will still be two discrete verical tweeter slits offset by a number of inches. Reversing them merely changes that distance. Stacking them, however, WOULD put them in the same horizontal plane.

Even with the multi-panel Tympani series, Magnepan used a single tweeter line source.

rw

Thanks for your input. Not having a great deal of knowledge in this field (I majored in history!), after reading your responses I spent a couple of hours on the internet reading up on line source speaker principles and other related info. Very complicated stuff.

But at least now I have a rudimentary understanding of how a line source tweeter works (particularly as opposed to a point source tweeter). Bottom line: based on your feedback and the stuff I read, it seems like the bads might outweigh the goods in placing Magnepan style planars side by side. Sacrifice of imaging and cohesiveness of sound not a worthwhile trade-off for wider sound stage, improved dynamics.

thanks again,
Bill

[Geoffcin]

Hypothetical scenario here:
, I would think this "horizontal stacking" would result in a wider sound stage and an expanded sweet spot listening area. It would be like having one very large planar speaker on each side. Or would it? Or would they cancel each other or result in other negative effects beyond my knowledge to describe.

Just a wonderin'

Bill

But you would have to disconnect one of the tweeter sections of your speakers.

The real benefit of stacking speakers is increased uncompressed dynamics, and the ability to play lower bass. Also lower distortion at the same SPL. Paradoxically, the soundstage does NOT get bigger with stacked panel speakers (unless vertically stacked like quads).

Rather than going the stacked route, I would suggest going up the ladder in performance to the Magnepan 3.6r. With the 3.6r your going to get a bigger panel, with better bass and dynamics, but more importantly your going to get the Magnepan true ribbon tweeter, widely regarded as one of the best high frequency drivers ever made.

[bubslewis]

But you would have to disconnect one of the tweeter sections of your speakers.

The real benefit of stacking speakers is increased uncompressed dynamics, and the ability to play lower bass. Also lower distortion at the same SPL. Paradoxically, the soundstage does NOT get bigger with stacked panel speakers (unless vertically stacked like quads).

Rather than going the stacked route, I would suggest going up the ladder in performance to the Magnepan 3.6r. With the 3.6r your going to get a bigger panel, with better bass and dynamics, but more importantly your going to get the Magnepan true ribbon tweeter, widely regarded as one of the best high frequency drivers ever made.

Gee I don't know.... I've only had the 1.6's for ten days.

If I sneak them out and trade up to 3.6's with same grill cloth color, maybe the wife won't notice the difference......
Dang, will have to upgrade the amp too, also had for ten days. If I get a better one that looks the same I'm sure she won't notice.......

Seriously though, I would love to have gotten the 3.6's and a solid amp to drive them if I could only have squeezed a bit more $ out of the budget. My stacking question was mostly in the hypothetical realm.

Bill

[Florian]

My tip is the following

1. Give them 2 more month of break in
2. Same for the electronics
3. Trash the ****ty crossover and make a new one (cheap and easy)
4. Tune your room
5. Tune your placement

In a small room the 1.6 is easier then the 3.6 with driver integration. The 1.6 is a lovely speakers but planar dipoles are either made or broken with placement.

[bubslewis]

My tip is the following

1. Give them 2 more month of break in
2. Same for the electronics
3. Trash the ****ty crossover and make a new one (cheap and easy)
4. Tune your room
5. Tune your placement

In a small room the 1.6 is easier then the 3.6 with driver integration. The 1.6 is a lovely speakers but planar dipoles are either made or broken with placement.

ummm............uncertain here. While not being a total klutz as far as having the ability to modify/replace speaker components, I would face a certain amount of trepidation at tinkering with brand new, relatively expensive equipment.

Modifying the existing crossover would probably void the warranty in the unlikely event that I had to return the speakers. What exactly don't you like about the existing crossover? Poor quality? Poor design? Poor application?

I would think the Magnepan people, with years of intimate knowledge of their speaker line, would have sound and valid reasons for doing what they did with the existing crossover.

[Florian]

The crossovers are crap, they are trash in the Magnepans, Almost trash in the Apogees and even worse in the Acoustats. Many people upgrade their crossovers and so do i, if you open up your 1.6 you will find a cheap spool, cheap cable and a cheap capacitor. My friend upgrades the crossovers on his 20R because they are junk. Magnepan saves money on all ends, so dont worry.

[Rick Vansloneker]

The internals of my SMGa. Looks poor imho.

[bubslewis]

The crossovers are crap, they are trash in the Magnepans, Almost trash in the Apogees and even worse in the Acoustats. Many people upgrade their crossovers and so do i, if you open up your 1.6 you will find a cheap spool, cheap cable and a cheap capacitor. My friend upgrades the crossovers on his 20R because they are junk. Magnepan saves money on all ends, so dont worry.

Came across an article while I was boning up on crossovers. It's from a guy who modifies speakers. Looks like he has the same opinion as you concerning the quality of Magnepan crossovers. He really likes the speakers , but hates the crossover equipment.

He was upgrading a Magnepan 3.6 (including new speaker stands). Pretty interesting stuff. Trouble is he spent an arm and a leg to do it (Looks like about $2,000 not including new stands).

http://www.newaudiosociety.com/reviews/speakers4.htm

[Florian]

Well its not an opinion but a fact. Many upgrade their crossovers or ditch it entirely and go active, my new crossovers are in an even higher price realm and the difference is huge.

-Flo

PS: Good components are a must, they are the last stand between the amp and speaker.

[E-Stat]

I would think the Magnepan people, with years of intimate knowledge of their speaker line, would have sound and valid reasons for doing what they did with the existing crossover.

They're not villains, but do manufacture to a price point. I guess I was surprised to see electrolytics used today (they were common in the days of my old Advents).

Perhaps they could offer an extra cost "hot rod" option with the 3.6s and 20.1s for upgraded crossover components like Sound Labs does. I paid an additional $950 for Jensen caps, Vishay resistors, and Sledgehammer chokes.

rw