Extreme BIB cabinet EnABL

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G'day,

Firstly, hats off to Bud Purvine (BudP).
Bud owns the patent for EnABL and has very generously made his technology available to the DIY audio community.

I have been exploring application of the EnABL pattern to baffles, ports, mouths and inside speaker cabinets for over 12 months now.
This is a different process to the EnABL application used for drivers.

This is an extreme application of cabinet EnABL as I would apply it to a BIB.

BLOCK MATERIALS
Materials that have successfully been used for cabinet EnABL include:
- PVC duct tape
- Norton 'All Weather Tape' - clear tape, thicker than duct tape
- Pin stripe tape

There are probably many other materials that are just as effective, they just haven't been tried yet.


BLOCK SIZE
You will need to use the EnABL block size calculator.

For baffle and external edges
- enter 18 block pairs
- enter 4 x baffle width as the circumference.
The calculator with give you the ideal block size for the baffle and all external edges.

For the internal block size
- enter 18 block pairs
- enter 4 x internal cabinet width as the circumference.

For internal cabinet EnABL, I have laid the EnABL block pattern onto sheets of clear contact (self adhesive stuff you use to cover school books) and then stuck the sheets to the inside walls of the cabinet.
Alternatively, you may find it easier to cut strips of tape to the appropriate thickness, stick them in place on the internal panels, then cut the blocks with a blade.


BLOCK POSITIONING
Please note that the EnABL pattern needs to be positioned one block width from the edge of the panel

Have a look at the attached pic.
Note that the blocks are NOT drawn to scale.


WHAT TO EXPECT
You're probably wondering what to expect sound wise?
Based on experiences
- lightning fast bass
- usually deeper bass
- clearer midrange
- a 'no box' sound
- cabinets will almost disappear sonically - more than you would ever expect with something the size of a BIB!
- oh and you may find that you will need to change the amount and positioning of stuffing.

Cheers,

Alex
 

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Have you experimented much with different materials?
If so which work better and why do you think so?

Cut vinyl sign material may be an easy way to get the patten made. Just go see a van sticker company and get them to cut this out for you.

Other materials I'm wondering about:
Synthetic felt tape as used for sticking under furniture feet.
Stick-on rubber feet. (probably WAY too expensive)
Single sided foam tape
Double sided foam tape with the backing paper left on
Gaffa or Gaffer cloth reinforced tape.
Bits of guillotine cut steel or aluminium glued on with silicone sealant.
Small ceramic tiles glued on with silicone sealant.

Making a stamp of a pattern element, bashing it into the plywood then filling with plaster or putty and sanding it off.
 
G'day OzMikeH,

Most of my experimentation has been using materials that are able to be removed without damage to the speaker cabinet.
I have had to do some arm twisting with friends and associates so I could get them to agree to let me EnABL there precious hi-fi and HT gear.
They all thought I was nuts but agreed to let me try because it was removable.
Interesting though, when I applied the EnABL none of them wanted to take it off!!

I have used the sticky sides of plastic bandaid strips as blocks for EnABLing ports.
Double sided tape and aluminium foil worked for the baffle and as a temporary way to EnABL drivers.
NOTE: Please use Bud's method for treating drivers properly - he's spent 30 years perfecting this!

Some thoughts on EnABL pattern material:
- blocks must be proud of the surface
- block material must allow for good airflow over them
- thicker blocks seem more effective than thinner, although I suspect that there is a point where you can get too thick and create problems, especially with ports and mouths.
- the edge of the blocks should be square (see pic)

Vinyl sign material will work.
Synthetic felt tape - not sure about felt
Stick-on rubber feet - probably yes
Single sided foam tape - not sure about the foam
Double sided foam tape with the backing paper left on - again not sure
Gaffa or Gaffer cloth reinforced tape - Gaffer tape yes, cloth tape not sure

Steel, aluminium or ceramic tiles glued on with silicone sealant - very interesting idea, perhaps you can try this and let us know?

Making a stamp of a pattern element, bashing it into the plywood then filling with plaster or putty and sanding it off - probably no effect because the pattern is flush with the surface.

Hope this helps.

Cheers,

Alex
 

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Alex from Oz said:


...

- the edge of the blocks should be square (see pic)

...


How important is this square edge? When EnABLing a driver with a pen or a brush (like I did) it will be hard to get those square edges. If I look at my drivers then the edges are not sharp. Also when using the pens from Ed's kit I realy wonder if that gives square edges.

Do the square edges also apply when looking from the top at the pattern? Where the pattern gets real small I resorted to dots...

Thanks,

Jeroen
 
JeroenR said:
How important is this square edge? When EnABLing a driver with a pen or a brush (like I did) it will be hard to get those square edges. If I look at my drivers then the edges are not sharp. Also when using the pens from Ed's kit I realy wonder if that gives square edges.

Do the square edges also apply when looking from the top at the pattern? Where the pattern gets real small I resorted to dots...

Thanks,

Jeroen

G'day Jeroen,

The cabinet EnABL that is being described in this thread is a completely separate process to Bud's driver EnABL.

The square edge comment relates to cabinet EnABL only.

I know it can be confusing, but it's important to view the two as separate processes.
Things that may be relevant to one do not necessarily apply to the other.

Cheers,

Alex
 
Some thoughts....


Speed of sound in WOOD. Feet per second. From an old piano book.
(Along Fibre - Across Rings - Along Rings)

Acacia 15,467 4,840 4,436
Oak 12,662 5,036 4,229
Pine 10,900 4,611 2,605
Ash 16,677 5,297 2,987
Maple 14,472 5,047 3,401

The different speeds in different directions are most interesting. In plywood there is a natural cross-wise diffusion of sound energy in the material as it travels between layers. This is why Ply is so much better than MDF.


Speed of Sound in Various Solids at 20 degrees Centigrade.
Velocity units are Metres per second (sorry for the mixed units)
I have deleted materials that are impractical, expensive or very close to the speed of sound in wood.

aluminum 6420
beryllium 12,890 (not that you have any of this laying around but WOW)
brick 3650
cork 500
glass, crown 5100
glass, pyrex 5640
granite 5950
iron 5950
lead 2160
lucite 2680
marble 3810
rubber, butyl 1830
rubber, vulc. 54
mild steel 5960
s/steel 5790
wood, ash 4670 (direction unknown)
wood, elm 4120
wood, maple 4110
wood, oak 3850
RTV silicone 900 - 1050
Neoprene 1510
perspex 2700
Polycarbonate 2220
PVC 2330
Teflon 1400

I assume the greatest differential in apeed of sound is the most beneficial This would maximise the diffusion of the sound waves through the cabinet material.

In which case there are a few methods I can think of that might be very effective.
1: making a template out of thick polyethylene sheet (thin cutting board) and smearing RTV silicone through it silk-screen style.
2: Cutting blocks of cork floor tile.
3: cutting Vulcanized rubber blocks.


Blocks of thin neoprene (cheap wetsuit) have the additional property of being a foam which may be useful.
Glass is no better than mild steel.
Marble and brick like materials aren't worth the effort of cutting them.
 
G'day OzMikeH,

Nice post! This is really interesting.

From my understanding of EnABL, you want to have the sound wave accelerating as it crosses the EnABL pattern - ie. faster than sound transmission in air.

For cabinet EnABL I think an ideal block material needs to be as fast (or faster) than PVC and not prone to ringing.

Do you know what the speed of MDF and particle board are?

Cheers,

Alex
 
The speed of sound within the materials is perhaps misleading. You my miss an important understanding by limiting your thoughts in this way.

In the giant thread and later split to the technical thread, the two most prevalent doubters were absolutely unable to come to terms with the pattern causing ANY effect upon an incidental surface. For the diaphragm surfaces they were adamant that the energy could only be within the diaphragm material and that the mass of the EnABL blocks was too insignificant to effect the level of change claimed. Various tests were run and purported to show these analysis to be correct.

At this point the doubters assumed they had eliminated any possibility of the EnABL pattern being anything but a hoax. In a thread from Parts Express they had actually claimed that was what they intended to prove, and shortly there after they showed up, determined to do so.

The activities Alex is involved in are a clear and present danger to these folks, because the only way they can be working on a solid surface, not directly attached and being driven by the speaker's motor, is through incidental interruption of boundary layer energy, traveling across the surfaces and being forced to not diffract at the edges. And also being forced not to form standing waves between parallel incident surfaces.

I have maintained all along that a boundary layer phenomena is all I could come up with to explain what I was finding. And, I agree with them that currently accepted physical explanations will not account for what is being claimed. The doubters did prove, to their dismay that there was an actual measurable effect and they will now allow that. However none will allow that it is of any importance at all and certainly cannot be providing what those of us who have actually experimented with it, can quite clearly hear.

Here is a link to the test run by John K on an aluminum coned driver. It is the first time I have seen actual, measurable evidence, of what EnABL does, outside of that original test series provided in the initial document on line.

http://planet10-hifi.com/johnK-test/

Please take note of the alarming periodicity of the two major resonance nodes left on the treated cone, as shown in blue, compared to their generally diffuse character on the clean cone, shown in red.

I say all of this to allow you to entertain that you are experimenting in untrodden ground. There are no rules here. No one knows what materials might prove useful, or which will be most useful. What we do know is that there must be an interruption preceding an edge or corner. That the interruption on a solid surface should be proud to one degree or another. And that the height does seem to determine how profound an effect is obtained.

In my own uses, I have never used any more than the paint I use on speaker diaphragms. The overall effect is subtle and when all box surfaces are treated, the box audibly disappears from the sound field. The sounds actually seems to be arising from the wall behind the speakers. This is not the case of course, but even a 0.002 inch high paint block pattern is enough to control a box, when applied to every external edge.

Alex says there is more to be had than this subtle disappearing act and I hope all of you experiment with as few restrictions as you can muster.

Bud
 
G'day Bud,

Thankyou for setting us straight on a couple of things.
I for one would appreciate any insight you might be able to share.

- - - - - - - - - - - -

G'day Phil,

So are you suggesting milling the entire panel and leaving the pattern proud of the surface?
If you have access to some CNC gear then go for it!

As Bud has said, we are on untrodden ground.

Cheers,

Alex
 
G'day Phil,

Be mindful of the EnABL pattern height - don't make the pattern too high - at least not at first.
Based on what I hear with different material thicknesses my gut feel says that it may be possible to introduce some unwanted problems if your pattern is too high. Just a hunch.

My intuition tells me that Bud's invention does more than just address boundary layer issues. I suspect the block material has a roll to play in the EnABL effect but I have nothing sensible to base this on.
I do have this crazy mental image of the panels of a cabinet being like a very stiff and massive diaphragm with very stiff suspension all round (being where it meets the other panels).

Bud, do you have any thoughts?

Cheers,

Alex
 
OzMikeH,

I would not disagree with your understanding. As John K taught, a diaphragm is comprised of particulate masses, suspended to one another. The energy travealing through this suspended mesh of masses is a transverse wave and the speed of it's propagation ranges from slower than the speed of sound through air, at lower frequencies to many times faster than that speed, at higher frequencies.

Taken as a set, this relationship is then modified by the various factors introduced by the physical properties of the diaphragms. Titanium vs plastic film vs paper as an example. Each will have a range of traverse speeds, but the stop points of the specific range of frequencies will differ.

Given the same physical size, for diaphragms made of each material, the EnABL pattern will be applied with the same amount of material, in mass, and at the same locations, at either end of the radial distance of the diaphragm. The same effects will be heard and they will be to the same degree, amongst the three materials.

The overall character of the differing drivers will not be altered, they will sound the same as before. Same spectral distributions, with the same emphasis and de-emphasis will occur. The in room propagation characteristics and the depth of comprehensible information will be greatly altered and expanded.

The mass loading of the diaphragms in each case is essentially insignificant. The patterns placement cannot pre-inform an energy wave of of it's existence. So, the pattern cannot alter the emission of energy from the cone, except at it's specific location.

This is the conundrum of EnABL,in a nutshell. According to classical physics and the test data that supports that model, these patterns cannot have more than a slight change on the overall energy propagated by the diaphragm. So, something else must be in play here, or we are all vastly deluded.

None of these points are new to me. I do appreciate the critique's provided, they confirm what I already knew. I appreciate John K's mesh of suspended masses most especially, as it eliminates any possibility that the pattern is mass loading the entire diaphragm and thereby controlling it. If I were still the only person involved, as was true for some 30 years, self delusion would be high on my list of probable causes here.

Having given EnABL away, within those boundaries permitted with a patented process, I now have a small army of equally deluded sycophants, or, something else really is going on. Something that corrects the transform of energy, from the diaphragm, to the adjacent air, in such a way that information is preserved that otherwise would be disrupted and dispersed.

We are not adding clarity here. We are not adding anything. We are not damping or removing anything either. The objective test data clearly shows this to be true.

We are removing a transformation obstacle. Disallowing a whole range of storage and entropy loss mechanisms, at the boundary between a vibrating diaphragm and the energy structures in air, those vibrations are producing.

My original explanation, of a wave arising upon the diaphragm surface, from the energy being emitted by the transverse waves within the diaphragm, and the elimination of further standing waves within this "boundary layer" of local energy transformation were not well received. A much more direct expression of energy, from each suspended mass, directly into the adjacent air, was the only view found acceptable by the critics. The only view allowed by classical physics, as applied to vibrating membranes.

This is fine with me, but it does beg the question of how much more improbable it is, for this pattern to be controlling the loss and storage mechanisms of these individual transformations, once the energy has exited the diaphragm surface and is in the room?

Once again, delusion is the only answer available to EnABL's critics. I really enjoy the idea that hearing, clarity in detail, coherence in perceived fields of musical instrument reproduction, near infinite expression of internal note details and decay structures, and pure tone structure, can only be a delusion. Perhaps we are similarly deluded, when listening to actual instruments, played within physical venues immediately adjacent to our bodies, by other "live" activators.

Perhaps all of you out there really are only cardboard cut outs, propped up to help me enjoy my own personal "movie".

Bud
 
You know as I read Bud's post I realise that I still really have no idea why EnABL does what it does.
I know where and how to apply it and the audible changes that happen as a result.
And, I know that I'm not deluded.

It seems to me that the deluded ones are those who refuse to allow themselves ANY aural exposure to EnABL.
They continue to label those of us who have as "true believers" and cry "placebo" or "delusion".

Try it, listen to it for yourself and answer the following:
1) Is there an audible difference? YES/NO
2) If yes, do I like what I hear? YES/NO

Oh and Bud, rest assured, those of us who embrace EnABL are defintely not cardboard cut outs!

Cheers,

Alex
 
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