MLTL v. ML TQWT

[rjbond3rd]

Originally posted by critofur So again, I ask, assuming standing waves are not an issue, what other benefits might be had from a TL?

Minimally, you eliminate the driver's rear wave so at least it does not cancel with the driver's forward output. More ambitiously, you can harness the cabinet's fundamental resonance to create a standing wave that sums nicely with the driver's forward radiation to create greater LF output.

Whereas standing waves are a sort of "defect" for a "pure" BR (if a BR is idealized as the resonance of two masses of air without taking cab dims into account), standing waves are an essential feature of a quarter-wave cab. Or at least the fundamental is a feature -- the higher harmonics cause peaks and nulls when summed with the driver's forward output, and thus need to be minimized. Or something like that...

 

[planet10]

Well, that's not at all what I do - I place a sheet of a special damping material in certain points in the box which breakup the standing wave without being too restrictive to reduce bass output.

So again, I ask, assuming standing waves are not an issue, what other benefits might be had from a TL?

1st off it is not possible to kill all the standing waves with that damping strategy.

A well designed TL will be much more tolerant of the change of T/S parameters as the drive is changed because the qw resonance is dominant. A traditional BR will go in and out of tune as the volume changes, particularily annoying if the music is particularily dynamic.

dave

 

[Bill poster]

because of the taper on a ML TQWT, roughly what percentage extra does the line length need to be, around 10% ? (obv depending on the flair)

 

[GM]

It'a a function of both its flare factor and frequency, so it depends. Easiest to use Hornresp's Loudspeaker Wizard to 'slide' your way to a solution, then fine tune it in MJK's or similar software.

GM