The Plumber's Delight (InDIYana Nanotech winners)

[4thtry]

I put together a PDF summary for my Nanotech design. I got a error message trying to upload it, so here are
the individual pages in highly compressed jpeg format. I'll be bringing these to MWAF next month to see how they
compare to much larger, floor standing designs. Bill S.

[4thtry]

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[4thtry]

Crossover schematic and HD measurements:

[tomzarbo]

They sounded fantastic at Indiana. It's hard to believe how good actually. 3 liters isn't much to work with as I now know!
You deserved the win! It will be interesting to hear them compared with other larger floorstanders.

TomZ

[randyohoh]

I think that the cabinet work looks great and with a black paint job would look futuristic like something out of a sci-fi movie. Very, very cool!

[randyohoh]

Can you confirm the outside dimensions? The height seems to be taller that the 12" noted.

[4thtry]

Thanks Tom & Randy. Do you mean black instead of the burgundy or black instead of the gold? I was thinking about re-painting them before MWAF because the gold that I used was some cheap rattle can stuff that I was using just to get rid of it. I got finger prints all over the gold, which was the top coat over the burgundy, and when I tried to buff out the prints the burgundy started to show through a little. These pictures were taken before this happened.

Bill

[4thtry]

Can you confirm the outside dimensions? The height seems to be taller that the 12" noted.

It is precisely 12"

[randyohoh]

The existing cabinet work and paint is exquisite and unique as is the use of brass screws. My thought was if it were all black it would look industrial and futuristic although the very nice facet work wouldn't be as pronounced. The drivers look like they were made for each other. I made a drawing in SketchUp of the cabinet with the drivers approximately placed but without the facets. It looks as if the actual width might be less than 11.875. Now that you have the port all worked out to eliminate the resonances it would seem to be possible to use a square or rectangular wooden port built into a cavity on the rear of the cabinet and maintain a "normal" shaped box. A 1.4" square port would have approximately the same area as the 1-1/2" pvc pipe and the cabinet would get only slightly deeper. The sketch uses 1/2" material for the port. My retired engineer mind and 40 years of CAD work won't go away.

[4thtry]

Randy,

You will need to adjust your dimensions somewhat. The internal dimensions of my box were 5.3" wide by 3.55" deep by 9.75" high.
I used 1.125" thick particle board for the entire box, so if you increase these dimensions by 2.25" each, then the exact outside
dimensions of the box are: 7.55" wide by 5.80" deep by 12.000" inches high.

When I listed the exterior dimensions above as 12" high by 11.875" wide by 11.875" deep, I was including the external crossover
and port. The port trap sticks out at an angle, but stays within the 12" cube competition requirements by 1/8". Very close, but still
within the rules. The flare at the end of my 26" long port sticks out the back but stays within the 12" cube by 1/8" Again, very close,
but still within the rules. Sorry for the confusion.

Regarding the port area and length, please note that that I used schedule 40 1.5" diameter PVC, which has an internal diameter
of 1.6 inches; not 1.5 inches. Also, I used three of the larger type 90 degree elbows that have an internal dimension that increases
to about 1.7 to 1.8" around the bend. So, you may have some difficulty trying to match my exact internal dimensions and length.
This should not be a major problem, as the BR tuning will probably come out fairly close to 40Hz or so. But the trap is somewhat
touchy, and you will need to be able to adjust the trap's length and stuffing density while doing a NF measurement in order to
knock out the 1st and 2nd port resonance. So you need to figure out how to make an internal trap that is easily adjustable.

Hope this helps,

Bill

[randyohoh]

Thanks for the detailed explanation, I was somewhat confused and didn't realize that you were constrained by rules. You must have had to hog away some of the material on the top and / or bottom to fit the drivers, it seems pretty tight. With the correct dimensions the port and trap barely fit within a "normal" box. I assumed a 1.400 square port which has approximately the same area as 1-1/2" pvc pipe and the trap is 1.40 x 1.50 just because that's the way it came out using the original width dimension..The majority of the box is drawn with 1-1/8" material but the rear, port dividers, and false rear are drawn at 1/2". The parts would need to be changed slightly to allow assembly and adjusting the trap length and stuffing. Conceptually, it seems as if this could work and offer the all important improved WAF. The more that I look at your cabinet the more I like it. For some reason it reminds me of the movie "The Terminator", and with the required trap the name kind of fits. Thanks again for the help.

[randyohoh]

Thanks for the detailed explanation, I was somewhat confused and didn't realize that you were constrained by rules. You must have had to hog away some of the material on the top and / or bottom to fit the drivers, it seems pretty tight. With the correct dimensions the port and trap barely fit within a "normal" box. I assumed a 1.400 square port which has approximately the same area as 1-1/2" pvc pipe and the trap is 1.40 x 1.50 just because that's the way it came out using the original width dimension..The majority of the box is drawn with 1-1/8" material but the rear, port dividers, and false rear are drawn at 1/2". The parts would need to be changed slightly to allow assembly and adjusting the trap length and stuffing. Conceptually, it seems as if this could work and offer the all important improved WAF. The more that I look at your cabinet the more I like it. For some reason it reminds me of the movie "The Terminator", and with the required trap the name kind of fits. Thanks again for the help.

[4thtry]

Your adjusted drawing should work just fine. If you make the back removable then you can keep micro adjusting the trap partition and
stuffing density in the trap area until the 1st & 2nd port resonances disappear. Good luck!

[Sigil]

Nice speaker. Great colouring!
I was thinking of something similar a few weeks ago.
That if the tubing was hidden in the stand.
But it have to be easily connected for a performance boost!! I haven't heard any speakers of this type.
I think there called horn loaded, ports for fullrange drivers.
So I decided on sealed because I didn't want my speakers sounding like the typical gettio blasters!!

[ani_101]

Not sure I understand. There is no horn or full range drivers used. It is a simple ported box, except that a small box with a low tune requires a long port. A thin and long port has resonance issues which Bill solved using a trap.

Due to contest rules the port was outside the cabinet. Tou can have the port and trap inside the cabinet adjusting for the tube volume, build a separate compartment to hide it or have it in the stand.... All acceptable solutions

These speakers sound very good and sounds way bigger than they look.