[ifanpayne]

I have Megnepan 3.7i speakers. Most of the room placement and treatment discussions that I have read concern more conventional floor standing box enclosures. Since the planar speakers radiate from the rear as well as the from the front, what differences need to be taken into consideration with regard to room treatment? For example, should the front wall (i.e., the wall behind the speaker) reflect rather than absorb the sound?

[DSkip]

Treat the area in front of the speaker.  First reflection points are critical as always, but do nothing behind them or directly beside them.  These are needed for full effect and are big reasons why Magnepans need space to breathe.

[ifanpayne]

Thanks. I presume that by "do nothing" you mean leave bare sheet dry wall boards or whatever normal finish material was used.

[Tyson]

How close are the speakers to the rear wall and how close are they to the side wall?

[DSkip]

Correct.  You want reflections from the rear.  They do need to be a good distance from those walls though which is why Tyson is asking about it.

[ifanpayne]

My room is 21ft x 40ft with high cathedral ceiling.

I started with a more conventional layout, with Maggies about 5" 6" from the front (21ft) wall (with respect to the listening position, that is, the wall behind the speakers) but gradually worked my way to the Rule of Two Thirds (29% version) - http://noaudiophile.com/speakercalc/ - so now they are 12ft from the front wall and 6ft from the side walls (to center of speaker). I get a really interesting holographic soundstage in which a single instrument (guitar, piano) is place between but behind the line of the speakers as though the instrument were located in the space between the speakers and the front wall. While, in terms of depth, the soundstage of a full orchestra is from in front of the speakers right back almost to the front wall, the width is more constrained to the width of the speakers.

[youngho]

That's a pretty big room. I was just going to post http://www.linkwitzlab.com/rooms.htm#D, but what you're writing suggests that you may be experiencing some degree of the Haas precedence effect, specifically summing localization. In short, the rear wave reflection is arriving at your ears within a short enough time interval (about 20 ms) of the front wave that your brain only perceives one sound but combines the two signals localizes it as further than the distance to the speakers (further sound sources take longer to arrive at your ear, so your brain may interpret the delay as an increased distance). Absorption may result in bringing the sound source forward, though the comb filter intrinsic to stereo reproduction tends to recess the center imaging behind the plane between the speakers.

Bipolar speakers tend to have relatively little lateral dispersion, reducing sidewall reflections, so there would be less summing localization in that direction, which may explain your perception.

[ifanpayne]

Thank you for the link - very interesting. I'll have to digest the Haas precedence effect when I have a clearer head tomorrow morning

[Tyson]

Your speakers are far enough away from the walls that you're not getting smear from early reflections, which is good.  On the other hand, IME a quiet room always sounds better than a lively room with regard to audio.  My advice is treat with absorption along the sides of the speakers and the front wall (behind the speakers).  You will be surprised how much it improves your sound quality.

[rollo]

One would want a dead front wall and diffusion at rear wall. Rule of thirds with Maggies. A rectangular room is best suited. That is what Harry Pearson did in his home and I must say the best Maggie set up I ever heard. Rest your Soul Harry.


charles

[Tyson]

One would want a dead front wall and diffusion at rear wall. Rule of thirds with Maggies. A rectangular room is best suited. That is what Harry Pearson did in his home and I must say the best Maggie set up I ever heard. Rest your Soul Harry.


charles

Agreed - hence my rec to damp the front & side walls but not the rear wall. 

[A_shah]

Treat the area in front of the speaker.  First reflection points are critical as always, but do nothing behind them or directly beside them.  These are needed for full effect and are big reasons why Magnepans need space to breathe.

Plus 1 I have the 1.7i have pretty much made speaker placement of  Maggi's to science  form , I have used laser measure, SPL meter , mirror for first reflection( very important) , you can put some artificial flower pots or a floor lamp , behind ,  but Maggie's need to breath, I find them to sound best when  there is nothing  behind them

[ifanpayne]

Charles, with the rule of thirds your maggies must also be quite far from the wall behind them. How far is your listening position in front of the speakers?

A_shah, since you have made a science of the placement, can you give us some detail of that placement? Room size, distance from walls, listening position?

[josh358]

One would want a dead front wall and diffusion at rear wall. Rule of thirds with Maggies. A rectangular room is best suited. That is what Harry Pearson did in his home and I must say the best Maggie set up I ever heard. Rest your Soul Harry.


charles

So HP had a dead front wall and diffusion behind, or are you just referring to his rule of thirds?

I've always heard that that was a great room for Maggies, so curious about what he did . . . as I recall, the room had a bay window and the listeners were at the back of the room?