Magneplanars and EnABL

[BudP]

Hi all,

It is now your turn to argue about and debunk and try EnABL.

I recently had an opportunity to begin the process of applying EnABL to a pair of Maggie 2.6r speakers. I have no intention of touching any of the driver surfaces. All work will be applied to the side trim panels on the front (already finished), across top and bottom, though the exact location is up for debate, and on the backside, in locations that correspond to the front side treatment.

For a general description of the process and a template to show you spacing and also where the EnABL blocks go here.

http://www.diyaudio.com/forums/showt...27#post1900327

These EnABL blocks were made from 0.003" thick clear acrylic contact paper, with a stick and remove adhesive, so they can be removed without damage to the wood trim, should you want to do so.

Bud

[Alex from Oz]

No replies?

A little surprising given that folk in this forum seek audio perfection beyond the traditional moving coil and box approach...

[Ed Holland]

Originally Posted by Alex from Oz

No replies?

A little surprising given that folk in this forum seek audio perfection beyond the traditional moving coil and box approach...

Hard to know what to say. This subject has caused such a riotous debate elsewhere, I'm not sure I want to be the first to comment - Even as a Magnepan owner...

[Alex from Oz]

G'day Ed,

Thankyou for your reply!

Your description of 'riotous' debate regarding EnABL is probably a little conservative.

Logically, the descriptions of the audible changes EnABL brings are difficult to comprehend.
I have spent the last 18 months exploring EnABL on fixed surfaces - ports, baffles, vents, inside cabinets and even room corners. My work is simply an extension of Bud's invention.
EnABL is effective, the audible changes are real and attainable using ridiculously simple materials and a process that is completely reversible.

So, I would like to make you a proposition.
Let's discuss a 'hypothetical' EnABL treatment for your Maggies.
I will describe in detail how one might (hypothetically) EnABL the fixed surfaces based on your particular speakers.

There is no requirement for you to actually do any of this or report your listening impressions if you do - because it's just hypothetical.

What do you say?

Cheers,

Alex

[Ed Holland]

OK then, hypothetical debate is usually a healthy excersise.

I have a pair of SMGa speakers, that I stripped and rewired using materials supplied by Magnepan last year. The intention was to restore them to original condition, or as near as I could manage. They now seem to have settled down, and present music very nicely.

I don't understand how EnABL additions to fixed surfaces will alter or improve what I hear. The wooden sides are well damped - they are fixed over the fabric "sock" that covers the baffle.

More later - have to go to work!

Cheers,

Ed

[Alex from Oz]

Originally Posted by Ed Holland

I don't understand how EnABL additions to fixed surfaces will alter or improve what I hear.

My current thoughts on how this works is here:
http://www.diyaudio.com/forums/showp...&postcount=402

The wooden sides are well damped - they are fixed over the fabric "sock" that covers the baffle.

So the wooden sides are on top of the fabric.
Can you post a photo with the outside edge dimensions and the dimensions around the edge of the driver?

I can then draw up a picture of a hypothetical application.

Cheers,

Alex

PS: Found this pic of a 'sockless' SMGa...

[planet10]

Originally Posted by Ed Holland

I don't understand how EnABL additions to fixed surfaces will alter or improve what I hear.

So far that is a mystery to everybody. But the empirical evidence cannot be discounted, further investigation is required (and slowly happening).

I am encouraged by what i am reading in Toole's latest book (i'm going to paraphrase since i can't find a direct quote quickly, but he says it over & over again): "a microphone and an analyzer does not have nearly the capability of 2 ears and a brain".

dave

[Ed Holland]

Originally Posted by Alex from Oz

My current thoughts on how this works is here:
http://www.diyaudio.com/forums/showp...&postcount=402




So the wooden sides are on top of the fabric.
Can you post a photo with the outside edge dimensions and the dimensions around the edge of the driver?

I can then draw up a picture of a hypothetical application.

Cheers,

Alex

PS: Found this pic of a 'sockless' SMGa...

Ha, yes they're less than attractive without their socks on, but then so are many of us.

No photo, but the baffles are 18" wide x 48" tall, within which the driver aperture of 9.5" x 39" is centered across the width, but 6" from the bottom, and 3" from the top. The gap between the inside edges of the wooden side is approx 17.5", and these are proud of the baffle face by about 1/2". The wood sides are 3/4" by 2" and give the assembly considerable extra rigidity.

I read quite a lot from the threads regarding EnABL, its application to transducer surfaces and its application to baffles/enclosures etc. I will admit to struggling with the reasoning and physics behind the latter, though I'm not looking to start a fight or offer an opinion on something I haven't heard "first ear". I'm not even sure I could find the time to experiment with these speakers even if I found the motivation to do so.

The SMGa speakers are one of the best pieces of equipment I have ever heard, and certainly the best speakers I have owned and it is lucky that they suit the acoustics of our living room very well. I'm a total convert to box free speakers now. Recently I re-foamed & repaired some Infinity Kappa 7 3-way speakers owned by my father in law, and had a chance to compare them to the Maggies in the same room - the boxes were much less enjoyable.

If there were any comparison I'd like to make it would be against an open baffle design constructed from conventional cone speakers. The Maggies are oft touted as a harsh load, but they are largely resistive, and compared to "conventional" speakers, the weak "motor" doesn't provide much back e.m.f. to the amplifier, minimising that interaction. Furthermore, the distributed planar drive should mean that voicecoil heating problems and subsequent resistance variations are minimised. I guess this could (should) be the subject of another thread....

Ed

[BudP]

All comments about flat panels are just fine here Ed. We do not worry about off topic in EnABL threads, just like in the beyond the Ariel thread, all is grist eventually.

I agree about the mental concussion you get from trying to understand how something that those "who know" can only accept as mass loading of a diaphragm, can possibly migrate to hard, incidental, surfaces. No worries, it will all come clear some day.

In the mean time, the description I gave in the listening thread of the 2.6R Maggies of Rene' Jaeger, has been read and seconded by him. His actual comment recently was "no, I haven't torn the damn patches off, I am not going to, the speakers have disappeared" "I am not certain that it wasn't all just down to us having moved the maggies either... except, they didn't do this the last time they were there"

His wife is very happy, as there is now center channel for movie voices and extremely deep bass, and again, these could all be due to placement, since that is of paramount importance with all OB speakers and horns and anything else too for that matter.

To treat your side panels with invisible tape would take about an hour, cost about $4, and is easily removed. Then you would know if the patches were staying on or not.

Google Rene' to find out who he is.

Bud

[Alex from Oz]

Originally Posted by Ed Holland

Ha, yes they're less than attractive without their socks on, but then so are many of us.

G'day Ed,

Forgive me for not finding an image that was suitably dressed.
It was late and this was the only image I could find.

I read quite a lot from the threads regarding EnABL, its application to transducer surfaces and its application to baffles/enclosures etc. I will admit to struggling with the reasoning and physics behind the latter, though I'm not looking to start a fight or offer an opinion on something I haven't heard "first ear". I'm not even sure I could find the time to experiment with these speakers even if I found the motivation to do so.

"First ear" experience is nothing short of a revelation.
Doesn't make things easier for the logically minded though...

Thankyou for the description of your speakers.
Based on that, I will post a drawing and description of an EnABL application I would use.

Cheers,

Alex