Dipole Speakers like Quad ELS or Magnapan

[Radioham]

Hi All,

Been having a bit of a think about Dipole Speakers like Quad ELS or Magnapan.

The main stumbling block is WAF in that the speakers have to be a far distance away from the wall (esp behind).

In my listening room, I have the TV,HiFi, Speakers and fish tank along the length of the room, and I sit opposite on a 3 seater settee. This settee backs onto an open plan staircase. The treads are not open, but the space under the stairs and the banister above are open to quite a high ceiling upto the landing.

Rather than try to bring any future speaker forwards into the room, I been toying with the idea of reversing the listening position, in that the settee could face the stair case and perhaps the speakers and TV could be quite close to the open plan stairs.

In this configuration there would be about 4 to 5 feet behind the speakers. Would that be enough for an ELS or Magnaplaner ? One speaker would see very little or none of the rising stairs behind it, but the other would have the stairs running behind it.

Currently I have a full length curtain (Floor to Ceiling) hanging in front of the stairs, to stop the downdraught and hide some junk stored under the stairs.

The other thought, is would it be feasable to create a stud partition wall to close off the stairs completly and cut say an opening large enough to accomodate the pair of ELS (or similar) or do you need the reflected sound to come back at you ?

I see that Magnapan/Magnaplaner are now making a return to the UK and some of the dealers now have demo stock, Apart from the pair I hear most years at Scalford, and thoughts on the newer models. I guess I would be looking at the "entry level" MG12 . The amp would be Marantz-KI-Pear Lite. Current speakers are Rega RS5.

http://hifilounge.co.uk/magnepan?gclid=CNjI0df9rbkCFfLHtAodkXAAxg

Regards

Alan

 

[HoopsOnToast]

I would have thought that 4-5 feet would have been fine in my experience with the MMGs.

The MG12 are certainly the best value, can be had for £1k ex-demo.

With Dipole speakers, they like to have space behind them but space to the side is less critical due to the 'figure of eight' radiation pattern, so you could have them firing down the room with the hifi at the far end, they work well in long/narrow rooms.

Best thing would be to get a home demo, Midland Audio Exchange also sell Magnepan.

With Quad 57s, it will be harder to get a demo but I was very impressed when I heard a pair in my room, personally they did most of what I would need a speaker to do.

Up there with the Maggies and other Open Baffle (Di-Pole) speakers that I have had as being the best soundstage and midrange, as well as the main advantage of very good bass quality that you naturally get at the expense of the very bottom range.

 

[MrSammy]

I have my Maggies about 1 metre from the wall. I've run ESLs even closer to the wall. They benefit from having a bit a space but if you have curtains or soft furnishing behind rather than a flat wall you can reduce the distance. Even a slightly compromised dipole can sound good for me I prefer this to a conventional box speaker. The Maggies are "handed" speakers. Experiment with swapping them over.

 

[Valvebloke]

I'd agree with the others. A few feet behind should be plenty. Quad say you shouldn't have the ESLs within two feet of the wall behind and, if possible, you should keep them away from corners too. I think building the speakers into a stud wall is unlikely to work well. Peter Walker experimented with this during the ESL's development phase but apparently he ended up with an enormous brick tunnel stretching out backwards from the speaker and even then it influenced the sound for the worse. The beauty of these speakers is that they are dipoles and any attempt to confine the sound from one face will degrade that.

VB

 

[Tenson]

Ditto here, i've run dynamic di-pole speakers with about 3 feet behind them and not much problem. They were also quite close to the corners and some porus absorbers (foam bass traps) helped greatly as you get much more mid freq. energy from the back of di-poles than box speakers.

 

[stewartwen]

There is of course an alternative, they were the Musical Fidelity MC7. This was a dipole l/s using conventional drive units. They were about 3foot 6 inches tall about 10 inches wide and about 15 inches deep. They used Seas drivers, they had about five drivers mounted on the front baffle and, I think, three drivers on the rear facing baffle. They were designed to be as immune as possible to room placement, so worked near room boundaries very well. Although the design work that took place was certainly very difficult and resulted in a crossover that was hugely complex! Not many pairs were built but they did sound rather good.

S

 

[Tenson]

I can't find much about those, but from your description they sound like a bi-pole?

 

[HoopsOnToast]

I can't find much about those, but from your description they sound like a bi-pole?

I guess it depends on the phase of the rear facing drivers?

I thought Bi-Pole (In Phase with front) Di-Pole (Out of Phase with front)?

 

[Tenson]

I think it is just a mono-pole if the front and back drivers are in phase. A bi-pole I understand to using drivers on the front and the back but out of phase with each other. A di-pole is a driver with the rear radiation allowed out.

It would be tempting then to call those Vivid Audio speakers a bi-pole but actually I think they are a mono-pole as the rear drivers are in phase with the front ones and their reason for being is force cancellation of the mechanical vibration. That's exactly like the AudioSmile Advantage which is also a mono-pole sealed design but with two woofers back-to-back in a continuous and perfectly matched tug of war.

You can't exactly see in either of these pictures but there are identical woofers on two faces.

 

[Werner]

Sorry Tenson, but conventionally a bipole denotes drivers in phase, and dipole drivers out of phase (or open baffle, of course). Once you factor in directivity you'll see that two drivers in phase quickly are all but a monopole. The same drivers out of phase only are an approximation of a true dipole, of course.

 

[Tenson]

I've always thought it referred to how many 'poles' or sources of sound there are. For example is a subwoofer with two drivers back to back but in phase a bi-pole even though the wavelength over it's range of operation is large enough to couple fully? To me this is a mono-pole for sure. Similarly the Advantage is a mono-pole in my mind because it cuts-off at 120Hz and the output from both drivers fully couple to form a single source of sound.

Perhaps it is a bi-pole for the Vivid Audio speakers as, like you say, when the woofers are run higher up they will no longer couple fully and present as two mainly independent sources.

Food for thought - Must a di-pole have a figure-of-eight pattern? If we consider a typical open baffle dynamic speaker we actually don't get very good side cancellation above the baffle step frequency.

 

[Burning Sounds]

To answer the OP's original question I don't think you will have a problem with your room. I've owned Maggies for more than 30 years and as long as you can have 3ft or so behind the smaller models you should be fine. Just remember that although they are an easy load to drive they are inefficient -best if your amp can double its output into 4 ohms.

They have a superb midrange, articulate bass and have a detailed but non-fatiguing treble. Try and get a listen with your amp if possible. They are very good value for money, too.

Gordon

 

[Werner]

I've always thought it referred to how many 'poles' or sources of sound there are.

It is more a convention than anything else. During the advent of multichannel home cinema the industry and press agreed (!) that front+back firing speakers with the drivers in phase would be called 'bipole', as opposed to the established configuration of panel speakers and attempts to mimick their radiation pattern with out of phase drivers.

 

[Chumpy]

Very interesting.

Although I have often heard intimately this sort of stuff, I have not for enjoyment bought.

 

[rabski]

To answer the OP. I had ESL57s here for a fair while and I still think that anyone who is remotely interested in serious music listening needs to own a pair at least once.

Four of five feet behind is massive. IME, the trick is to try not to have anything equal. By which, I mean try and break up the reflected sound from the back as far as is possible. Unequal distance behind for each speaker. Also, and against what others suggest, I found that a bit more room to the side was a help. A couple of carefully positioned traps also can work wonders (the foam column type).

Do it if you can. Perfect they are not. However, in some ways they are sensational.

 

[Radioham]

Hi all,

As the OP thank for the replies.Its food for thought.

However any thought of speaker changing is on hold for a while.For two reason, one is my current setup sounds very good,especialy since i used rega speaker cable,and changed the crossover capacitor to paper in oil.

I also took a close look at our timber framed double glazed windows and they are not a pretty sight, so its time for UPVC.

Alan

 

[Tenson]

Wooden frames can't just be sanded and stained?

 

[Jazzman53]

Placing a V-section beam splitter diffuser behind a dipole ESL would enable placing it much closer to the wall, as long as it isn't close to a side wall.