Multipled tube TML

[Tyimo]

Hi!

Is it possible to split to 4 sections a TML tube? I know it is possible with a chainsaw , but I mean for example:

Driver Sd 132 cm2 and the tubes and the ports would be 4x33cm2??

Greets:

Tyimo

[Tyimo]

I learnt that the TML terminus or port must be equal to the driver's Sd.
So, my question is: should I split the terminus-port to 2 or even to 4 sections??

Maybe it is better to show an example.
Something similar to my question, but it has only 2 sections.

Tyimo

[GM]

Greets!

Yes, though the old rule-of-thumb of the terminus be = Sd isn't 'cast in stone' since it was derived back when drivers had a very large Vas. Today's generally lower Vas drivers work better with 1/4-1/2 Sd.

A single large terminus is more efficient and the TML's length is the shortest for a given Fp than with multiple smaller ones. Note too that the smaller pipes will be more resonant due to their higher cutoff, but more resistive, so all things considered, some folks prefer the one over the other, like a single large vent BR Vs an Onken's multiple smaller vents.

GM

[Tyimo]

Thanks GM!!

I thought that it has some relationship to the BR multipled vents.
What do you think, how could I simulate-calculate the multipled TML ports?

Greets:

Tyimo

[Tyimo]

O.K.!

I was playing with some BR simulations and I saw the lenght difference between 1 and 4 vents (or ducts) was very small. Only a couple of centimeters. Maybe it is also true for the TMLs.

Tyimo

[MJK]

If you design the TL as if it were only one cross-sectional area with a specific length, then you should get basically the same result if you take that area and split it into four equal parallel pipes of the same length. If you make the pipes different lengths, you will have a mess and a very difficult design problem. Depending on how you arrange the four parallel pipes, you could get exactly the same response, or only a slight difference, due to the open end boundary conditions associated with the open end areas and how close they are to each other.

[Tyimo]

Hi Martin!

Thank you very much my Master!!!!

If you design the TL as if it were only one cross-sectional area with a specific length, then you should get basically the same result if you take that area and split it into four equal parallel pipes of the same length.

Yes, of course I would use four equal parallel pipes of the same length.

Greets:

Tyimo

[GM]

Originally posted by Tyimo
O.K.!

I was playing with some BR simulations and I saw the lenght difference between 1 and 4 vents (or ducts) was very small. Only a couple of centimeters. Maybe it is also true for the TMLs.

Tyimo

Greets!

Don't have a program that sims a response using multiple vents, only calc the difference in length, but I do know that a single big vent BR sounds different than multiple small vents that sum to the same area and Fb, though damping can null the latter's more resonant sound, so I prefer to use a single big one and skip the extra woodworking.

WRT your TL layout though, a tube within a tube is a good plan for ease of bracing, so dividing it into four for the second half is what I would do.

GM

[Tyimo]

Thanks GM!