Meade's Tuning, Location Consideration?

[kryptonitewhite]

I think the statement "keep your port at least 1 port diameter away from any surface" is misleading.

If you have a 4"x4" port, remember that if you make a slot port and 1 side of the box is used for a port wall, you add 1/2 the port diameter for end correction, as the air 1/2 the diameter away still acts as if it were port.

Now, if your 4"x4" port is 10" long, and you have your enclosure 4" from a hard flat surface, and your box is 20" tall above that, the air after exiting the port then must travel up the 4" space between the enclosure and the surface. (of course, it's prolly not 4" wide as well, but say your port is 32" wide and the enclosure is too....so maybe it's more of a bell effect, or aero effect, but it still needs to be accounted for!) This would make the 4"x4" port that's only 10" long actually another 20", unless the flat hard surface continues on as well, then there's more end correction, adding another 2" (1/2 port dia)

With Meade's port being right up against the rear gate, it is elongated...however, it is much wider than the port, so not 100%, but still.

So Is he really tuned lower than 27Hz??

[Derrick824]

I think you're over-analyzing it.

[Boon]

I have found it doesn't make much difference except for pure SPL when yes, especially if the port is very large then the gap between port and surface can act as an extension to the port and lower the tuning of the system as a whole.

There's no point trying to calculate it either as trim panels behave rather differently to slabs of MDF

[dwright27]

i thought meade was tuned to mid 30s??

[kryptonitewhite]

27Hz if I'm not mistaken. (so I'm gonna guess factor in in-car as placed, 21.78Hz )

[EricM9104]

27Hz if I'm not mistaken. (so I'm gonna guess factor in in-car as placed, 21.78Hz )

How the fuck are you gonna know just from the pictures?

What? You have a little tape measure on your computer that measures the distance between the port and the hatch?

[AI James]

hes stated before about 34hz hes tuned to

[Ray]

Absolutely the wall effects his tuning.

Trying to figure out just how much is a waste of time imo.

It just makes it lower, that and the transfer function works very well for him