An ML-TL should never require stuffing beyond the first half of the line's length. A negatively tapered TL should not need stuffing beyond the first 60-65% of the line's length, depending on the taper ratio. I've found this to work quite well most of the time with a stuffing density of 0.75 lb/ft3 and using polyester fiber. Note, there's nothing magical about long-fiber wool. It and poly fiber and fiberglass do the very same thing but do need different stuffing densities to do so.
Paul
Paul
Looks like an end loaded line. That will maximize the ripple and you will have to use more damping.
Damping is always a trade off between ripple & extension. Hence why you often see an offset driver and a mass loaded terminus, both helping to deal with riple in their own way, and allowing for less fibrous damping. You will note the Woden design uses no volume fill (althou you can).
dave
Damping is always a trade off between ripple & extension. Hence why you often see an offset driver and a mass loaded terminus, both helping to deal with riple in their own way, and allowing for less fibrous damping. You will note the Woden design uses no volume fill (althou you can).
dave
Well this thread has been a really jolly romp through the Land of Theory. For some data, see:
17 foot pipe sub 12-230 Hz ±5dB
(OK, I've posted that two-dozen times since.)
There are bumps in the lower end of the freq response which arise from tuning. It is one of the several respects in which a TL is cousin to the BR. But a boost from tuning is the last thing you want to hear, yet it is all but inevitable in creating speakers out of Rice-Kellogg (1920) drivers unless you use a true horn.
What resonance hath given, pillow-stuffing hath taken away. Which seems to be just the trade-off you want to be available. In practice, the trick is to design the box so that you can add stuffing as you please.
17 foot pipe sub 12-230 Hz ±5dB
(OK, I've posted that two-dozen times since.)
There are bumps in the lower end of the freq response which arise from tuning. It is one of the several respects in which a TL is cousin to the BR. But a boost from tuning is the last thing you want to hear, yet it is all but inevitable in creating speakers out of Rice-Kellogg (1920) drivers unless you use a true horn.
What resonance hath given, pillow-stuffing hath taken away. Which seems to be just the trade-off you want to be available. In practice, the trick is to design the box so that you can add stuffing as you please.