TL quandry (post is not the project )

[Grandma´s_SUB]

I use a standard T/S vented box calculator to determine my pipe design's net volume (Vb), which BTW proves Sd isn't a factor in speaker cab design per se since all that's required is Fs, Vas, Qts.

If I know properly,Vb is volume of vented box.What has Vb deal with Volume of pipe?

-All what I know from "standard vented" design,is that max. speed of sound from pipe can be 17m/s(to avoid whistling..)?,where do you see solution?

-Rules of Thumb arent so useful in my case,because I cant have 2.1m(lets say 1.9m-stuffing) pipe in my room with 13*13cm Sd,mum will kick my a**

 

[GM]

Greets!

A pipe is a vented cab in that the driver 'feels' an air 'spring', the only difference between a true BR and pipe is that the pipe's 'spring' has lots of harmonics, whereas the BR cab only has a fundamental (Fb).

Yes, a BR's or ML-TL's vent needs to have a low mach speed so it won't 'whistle', but this isn't an issue with a TL.

So build a ML-TL instead of a TL. The vent will allow a much shorter pipe, with its cross sectional area (CSA) dependent on net Vb divided by its length.

GM

 

[Grandma´s_SUB]

So build a ML-TL instead of a TL. The vent will allow a much shorter pipe, with its cross sectional area (CSA) dependent on net Vb divided by its length.

OK.

Problem is,that I cant find what is Mass Loaded TL-If I am right,its like BR pipe on the end of main pipe.

Of course, I read MJK´s theory and look at t-linespeakers,but dont to differentiate between MLTL and TL, TQWT... a lot of designs..

Is there any page,that there are desecribed all designs "shortly and to the point".

 

[GM]

Greets!

ML-TL (AKA 'tower' designs) are essentially BR designs stretched in one dimension to cause strong enough 1/4WL resonances to affect vent tuning. You know it's morphed into a mass loaded pipe when the vent length causes a lower Fb than when it's a typical golden or acoustic ratio cab design.

Positive tapering of the ML-TL (AKA ML-TQWT) allows for the potential of even more loading based on its flare rate and a quicker decay of vent pipe resonances, so is preferred when the vent would otherwise be big and/or long enough for its harmonics to have a negative audible affect on the frequency response (FR).

From this it's obvious that the basic ML-TL design can be calc'd with any basic vented box program to get the Vb/Fb/vent diameter required for a low vent mach, then use MJK's PORTED WS to find the best compromise between height, driver and vent location/length.

FWIW, I favor putting the driver down where it suppresses the pipe's 3rd harmonic, which puts the vent near/at the bottom, but most other folks just put it wherever they want it and find the best vent location. This causes more FR uneveness, but never having compared the different design philosophies I don't know if it's audible. My SWAG is that I can get by with less stuffing, but I doubt it's audible except possibly in a single driver design.

GM

 

[Grandma´s_SUB]

From this it's obvious that the basic ML-TL design can be calc'd with any basic vented box program to get the Vb/Fb/vent diameter required for a low vent mach, then use MJK's PORTED WS to find the best compromise between height, driver and vent location/length.

I usually design vented boxes with WinISDpro.I have 1st peoject now,that I switched on TLs.So Volume of vented box(Vb)=Volume of pipe and tunning freq is same...But there is no sense al all..like building normal vented box?Is there any demonstration on the net(MJK has a whole story there,but 1st basics and then advanced things..)?