How to make a box with the least imp rise?

[JBGabriel 10+ year member]

Alright I guess ill have to play around with some trial and error

 

[2loud4youmorris 10+ year member]

Alright I guess ill have to play around with some trial and error

Done quite a bit in my past.

Hope you find a setup you like.

 

[JBGabriel 10+ year member]

Done quite a bit in my past.Hope you find a setup you like.

Thanks. Ill prolly go 2.5 cubes @ 36 with a 6 inch aero first and go from there.

 

[hrtbrk1 5,000+ posts]

I've got my eye on you...

lol haha ok

 

[terra 5,000+ posts]

lol haha ok

Keep your hands in sight big guy...//content.invisioncic.com/y282845/emoticons/nono.gif.eca61d170185779e0921b0faa9704973.gif

 

[Toxic Tuan 10+ year member]

Compression = impedance rise. Compression includes any kind of possible loadings such as corners or angles that would create turbulence. To lower the impedance rise, the enclosure must be designed more as a wave guide. On an aerodynamics standpoint, a low impedance rise box will have a Reynolds number of 2300 or lower. Just think about an aerodynamic car...low resistance, low impedance. Let me know if you need an even more detailed explanation.

Tuan

 

[Boomintempo 10+ year member]

I just drill holes in my subz cone to halp with compretion....it enebles my subz to move lik a 10.

Put a whole in the side of ur box. tHats halps the air move outside uv the box

//content.invisioncic.com/y282845/emoticons/fyi.gif.9f1f679348da7204ce960cfc74bca8e0.gif

//content.invisioncic.com/y282845/emoticons/redface.gif.62fdbfe1a101588a808c4cff71bcb942.gif

 

[hrtbrk1 5,000+ posts]

Keep your hands in sight big guy...//content.invisioncic.com/y282845/emoticons/nono.gif.eca61d170185779e0921b0faa9704973.gif

i'm a relatively small guy...u know that...

Compression = impedance rise. Compression includes any kind of possible loadings such as corners or angles that would create turbulence. To lower the impedance rise, the enclosure must be designed more as a wave guide. On an aerodynamics standpoint, a low impedance rise box will have a Reynolds number of 2300 or lower. Just think about an aerodynamic car...low resistance, low impedance. Let me know if you need an even more detailed explanation.
Tuan

how do u calculate the reynolds number...the same way for an airfoil?

 

[Immacomputer 10+ year member]

Your view of impedance rise is like many others who think that it will kill the performance and high rise equals low output. This is not true at all as these spots of high impedance are the resonant points of the system (the points of greatest efficiency). That is why a sealed box can have a flat response even with an impedance rise of more than 30ohms at certain frequencies and be back to 4 for others.

And if you want to make an enclosure with a very flat impedance curve, you have to build a correctly designed and tuned transmission line. Done correctly, they have very flat impedance curves but that doesn't mean that they're loud. It had much better benefits than that.

 

[lilmaniac2 5,000+ posts]

make the box weak, the more the box flexes the less impedence rise.

 

[Toxic Tuan 10+ year member]

i'm a relatively small guy...u know that...

how do u calculate the reynolds number...the same way for an airfoil?

I did a tutorial for this a few years ago...I don't know where it is on my computer....but here:

Re = VD/v (f*ckin Mech. Engineering professor...can't forget this formula even if i wanted to.)

V = velocity of air, D = diameter of circle or diameter equivalent for non circles, v = kine. viscosity (from dyna. viscosity & density)

Tuan

 

[JBGabriel 10+ year member]

Your view of impedance rise is like many others who think that it will kill the performance and high rise equals low output. This is not true at all as these spots of high impedance are the resonant points of the system (the points of greatest efficiency). That is why a sealed box can have a flat response even with an impedance rise of more than 30ohms at certain frequencies and be back to 4 for others.
And if you want to make an enclosure with a very flat impedance curve, you have to build a correctly designed and tuned transmission line. Done correctly, they have very flat impedance curves but that doesn't mean that they're loud. It had much better benefits than that.

Alright I understand better now. Impedance rise is not everything and I am focusing to much on it. I thought it was alot more important than it really is. So basically high rise DOES NOT equal low output, its more a combination of rise and efficiency that determines a box's output characteristics.

 

[boogeyman 10+ year member]

An aperiodic enclosure lowers impedance rise.............But more towards the SQ crowd not the boomers

 

[Immacomputer 10+ year member]

Alright I understand better now. Impedance rise is not everything and I am focusing to much on it. I thought it was alot more important than it really is. So basically high rise DOES NOT equal low output, its more a combination of rise and efficiency that determines a box's output characteristics.

Output is more determined by the efficiency of the enclosure/sub combination and how effectively it couples with the environment. Power plays a very small role in that game but does matter.