Extreme BIB cabinet EnABL

[Alex from Oz]

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

[Alex from Oz]

This is an alternative for those of you who already have BIBs that are glued up or you just can't face the extreme option!

[OzMikeH]

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.

[Alex from Oz]

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

[JeroenR]

Originally posted by Alex from Oz


...

- 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

[nicoch58]

adhesive vinyl line for car ?

remove the protection of adhesive, cutting out the spaces, and paste perfectly aligned

[Alex from Oz]

Originally posted by JeroenR

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

[Bigun]

One day we're going to get fed up with this block pattern (no disrespect intended to anyone here) so I do wonder what other patterns would work - is there an understanding of why this particular pattern is a good one ?

[rjbond3rd]

Hi Bigun, check out the rationale (with diagrams) here: http://www.positive-feedback.com/Iss...ndingwaves.htm

[Alex from Oz]

G'day,

For clarification of the pic in post #1, the pattern needs to cover the inside of the side panels also.

See revised pic below.

Cheers,

Alex