I have built a few TL subs with pretty good results, all using a basic formula, relating to Sd & Fs.
For my next project I am trying to make a really small TL sub and was wondering what the most important factors are.
For example line cross sectional area as a ratio to SD - can it go below SD? If so by how much?
Can the length of the line be reduced & stuffing increased to compensate - again by how much - for example is an 1/8 of Fs feasible?
Thanks all.
For my next project I am trying to make a really small TL sub and was wondering what the most important factors are.
For example line cross sectional area as a ratio to SD - can it go below SD? If so by how much?
Can the length of the line be reduced & stuffing increased to compensate - again by how much - for example is an 1/8 of Fs feasible?
Thanks all.
Greets!
You can do whatever you want, but when it comes to moving mass quantities of air, 'small is as small does'
and no amount of stuffing is going to offset it much. As you drop below Sd in CSA, the motor's strength needs to increase (lower Qes) with increasing compression ratio, raising the mass corner, F3, so corner loading is mandatory. I don't recommend >2:1, though if you load the front of the driver to make it a bandpass ala the B*** Cannon, then 3:1 if the desired HF corner frequency is low enough. To get an 1/8 WL pipe to work OK will require reverse tapering (TQWT), making it a mass loaded pipe, so a MLTL may be a better solution depending on the driver.
GM
You can do whatever you want, but when it comes to moving mass quantities of air, 'small is as small does'
and no amount of stuffing is going to offset it much. As you drop below Sd in CSA, the motor's strength needs to increase (lower Qes) with increasing compression ratio, raising the mass corner, F3, so corner loading is mandatory. I don't recommend >2:1, though if you load the front of the driver to make it a bandpass ala the B*** Cannon, then 3:1 if the desired HF corner frequency is low enough. To get an 1/8 WL pipe to work OK will require reverse tapering (TQWT), making it a mass loaded pipe, so a MLTL may be a better solution depending on the driver.GM
Thanks for the reply - I was thinking of reducing Sd down to about 0.8 at exit, not quite as severe as 2:1 or 3:1.
I understand an MLTL is basically a lot of stuffing behind driver then open volume with a port - any ideas on where to get equations for modelling them?
Also, can you clarify reverse tapering in referrence to the 1/8 TL.
Thanks.
I understand an MLTL is basically a lot of stuffing behind driver then open volume with a port - any ideas on where to get equations for modelling them?
Also, can you clarify reverse tapering in referrence to the 1/8 TL.
Thanks.
Greets!
You're welcome!
Hmm, since you've been a member for so long and have prior TL experience I just assumed you were familiar with MJK's work: http://www.quarter-wave.com/ Anyway, a well designed MLTL will only need minimal stuffing (none for a LF/sub app) and his various tutorial docs will cover TL theory/design pretty much from A-Z, including reverse tapered, or line CSA at the closed end being >at the terminus. His Classic TL Alignment Tables yields good first approximations and 'good enough' for most folk's apps.
GM
You're welcome!
Hmm, since you've been a member for so long and have prior TL experience I just assumed you were familiar with MJK's work: http://www.quarter-wave.com/ Anyway, a well designed MLTL will only need minimal stuffing (none for a LF/sub app) and his various tutorial docs will cover TL theory/design pretty much from A-Z, including reverse tapered, or line CSA at the closed end being >at the terminus. His Classic TL Alignment Tables yields good first approximations and 'good enough' for most folk's apps.
GM
Yeah I was going through his site the other day & all the info I need is there, its just that the docs are over 40 pages each and I was looking for a quick answer (just being lazy!)
Guess I'll bite the bullet and sit down & read them all, at least then I will be one step closer to being a guru!
Thanks.
Guess I'll bite the bullet and sit down & read them all, at least then I will be one step closer to being a guru!
Thanks.
Hi Ap, I can reccomend Martin J. King for DUMMIES on
http://www.t-linespeakers.org/
Guess, who wrote it
Hi from Bjorn
Wonderfull Copenhagen
http://www.t-linespeakers.org/
Guess, who wrote it
Hi from Bjorn
Wonderfull Copenhagen
Greets!
Yeah, well, AFAIK there's no 'quick' answer's to your Qs other than what I gave.
Nice write-up, thanks for the effort! Anyway, the salient points are that with his alignment tables and the adjustable BSC doc, you can skip the rest of his work for most apps.
GM
Ap said:
Yeah, well, AFAIK there's no 'quick' answer's to your Qs other than what I gave.
Bjohannesen said:
Nice write-up, thanks for the effort! Anyway, the salient points are that with his alignment tables and the adjustable BSC doc, you can skip the rest of his work for most apps.
GM
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