Dimensions to make the enclosure look tall and slim.

[rakeshln]

The golden ratio donot seem to offer a slim 3.5ft tall floorstander with a single woofer 8"or 10". How abt the ratio 1:1.62:3.82. Is the Fibonacci rule very strict. How does this series eliminate standing waves?

[markp]

you are just scaling the ratio .62:1:1.62 arent you?

[GM]

Golden, or acoustic, ratios do not eliminate, or even attenuate, standing waves. What they do is keep them from summing to a higher magnitude, spreading them apart enough that they average out into a ~uniform, diffuse particle density field.

Once you begin increasing the aspect ratio it all falls apart in the longest dimension and shifts towards a 1/4WL (vented) or 1/2WL (sealed) resonator. Standard box programs don't show the effect this has on the driver/vent location and vent length. AFAIK, only MJK's excellent Mathcad worksheets do this so I highly recommend getting familiar with them if you plan to design/build high aspect ratio cabs.

WRT the other two dimensions that make up the cross sectional area (CSA) of the pipe (SO and SL values in the worksheets), I prefer to use a golden or acoustic ratio just in case it makes a subtle sonic difference since I use construction materials/bracing that yields relatively light, yet extremely rigid cabs, though MJK is of the opinion that the requisite stuffing damps the system enough for this to be a moot point, while some other pipe designers mass load the cabs so much it is a moot point.

GM

[markp]

They also look more 'right' from a aesthetic viewpoint.

[GM]

I assume you mean a golden ratio cab. My fave is the Parthenon's 1:2.25:5.0625, or for a more rectangular cab, the industrial ratio of 1:1.4:2.

GM

[BillFitzmaurice]

When considering the Golden ratio also consider the lowest frequency being reproduced. If the wavelength of the lowest frequency is 4 times or more that of the longest dimension standing waves are pretty much a non-issue; in this case that would limit you to an F3 of about 110 Hz, which could be problematic. The answer: Put a subdivider inside the box to shorten it internally. If you can't do that for volume reasons then put in a 'shelf' or two that doesn't extend fully across the box interior but does serve to shorten the inside pathway dimension. The additional bracing gained won't hurt either.

[rakeshln]

Its the same, 0.62:1:1.62 or 1:1.62:2.62 or 1/x:1:x or x^0:x^1:x^2.

Or x^(n-1):x^(n):x^(n+1), where n is an integer and then applying the Fibonacci rule you get x=1.62.

But, how does this get into dimensions? There has to be some reasoning.

[Colin]

Some years ago, an article in Speaker Builder suggested a better acoustic golden ratio (for cabinet interior) was

1 : 1.26 : 1.59.

Anyone else used this?

Colin

[Jan Dupont]

Many top designers of different stuff (not only speakers),
uses the "almost similar" to power calculation ratio of 1 : 1.43 (= 10:7). The W:H ratio seems to work fine with mine speakers

[rakeshln]

Any material on net which supplies proper reasoning? Cant get a copy of such magazines here in Mumbai. Well which issue of Speaker builder??