- TRANSMISSION LINE SPEAKER ENCLOSURE DESIGN HOW TO
- TRANSMISSION LINE SPEAKER ENCLOSURE DESIGN DRIVER
- TRANSMISSION LINE SPEAKER ENCLOSURE DESIGN PROFESSIONAL
Many TLs are tapered pipes, true - but most of them involve folds or bends which B&W's design does not. They clearly don't refer to this solution as a transmission line but rather, a tapered pipe. Because of the shorter HF wavelengths involved, complete attenuation would be far easier achieved than with woofers, though I'm not sure whether B&W claims complete absorption. Exceptions? Perhaps the Nautilus tweeter loading tunnels employed by B&W. They all depart from the original requirement, of complete & sealed absorption of a driver's rear wave. Truth be told, nearly all present-day TLs are hybrids. By affixing the term 'hybrid' to said loading scheme, Von Schweikert distinguishes his approach from the kind of discretely partitioned labyrinths other TL designers achieve with extensive internal cross-bracing. It separates a highly stuffed upper portion from a lesser stuffed lower portion which, in conjunction, are said to operate as a third chamber venting into the room via a port. He claims fulfillment of this definition by creating two internal chambers with a suspended stuffing blanket.
TRANSMISSION LINE SPEAKER ENCLOSURE DESIGN HOW TO
It severely minimizes excursion demands on the driver, by adding requisite acoustical gain via the cabinet loading.Ī Von Schweikert Audio VR-2 customer's recent removal of a woofer, to inspect what the product propaganda referred to as a triple-chambered transmission line, and his subsequent Internet post and resultant threads all pointed at our collective confusion over how to answer today's opening question: What defines a transmission line, exactly? The VR-2's designer defines it as a non-resonant enclosure with highly damped impedance peaks. It combines a radial TL with a port in what is considered a unique form of woofer loading. Subwoofer specialist VBT recently acquired a patent for its hybrid invention. All of these companies incorporate some form of physical line as indicated by the raw term transmission line.
![transmission line speaker enclosure design transmission line speaker enclosure design](https://www.diysubwoofers.org/tls/images/2018-02-14.png)
TRANSMISSION LINE SPEAKER ENCLOSURE DESIGN PROFESSIONAL
Looking at companies who produce commercial designs dubbed TLs, we find Bud Fried's IMF and now-defunct TDL offspring B&W in its showcase Nautilus and continued use of tapered-tube tweeter loading Morel's Renaissance Prelude Shahinian's Hawk and Double Eagle subwoofers Chapman Sound Company Buggtussel Professional Monitor Company aka PMC InnerSound with its hybrid woofer loading Meadowlark Audio RA Audio. If such a heavily damped vented box acted like a TL in that particular regard, does it constitute a proper transmission line? However, heavy stuffing of a vented alignment too can suppress this resonant ringing to measure as shallower impedance peaks. By exhausting much of the input energy through absorption (via a combination of damping and captive internal reflections), the severity of these electrical impedance peaks is minimized. The presence of a terminus introduces a cabinet resonance which, just like a vented alignment, shows up as the lower impedance peak of the famous "saddle" of twin spikes, one for the driver, one for the port. Therein lies the crux of fixing what defines a true transmission line.
TRANSMISSION LINE SPEAKER ENCLOSURE DESIGN DRIVER
While nearly all current amateur and commercial TL designs employ variations on Bailey's theme - a heavily damped, often folded and tapered line, pipe or tunnel that absorbs most of the energy input of its driver and vents the remainder, heavily attenuated, through what is called a terminus to distinguish it from the port of a vented alignment box - none of them could be called a true TL if held rigorously to the original definition - that of a sealed line that attenuates all incoming energy to completely zero like a black hole.
![transmission line speaker enclosure design transmission line speaker enclosure design](https://i.ytimg.com/vi/2Ivqy9BvmgI/maxresdefault.jpg)
![transmission line speaker enclosure design transmission line speaker enclosure design](http://www.hans-adelt.de/hans/hifi/fidelio1.jpg)
However, the appearance of a terminus compromised the former ideal of the perfect non-resonant transmission line.
![transmission line speaker enclosure design transmission line speaker enclosure design](https://audioxpress.com/assets/upload/images/1/20160724172010_Figure1A-DAppolitoThor.jpg)
The stuffing inside increased air density, slowed sound propagation and made the line behave longer than it physically was. This signaled the launch of more practical TLs which now became shorter to fit into smaller cabinets. īy 1965, Bailey designed a line with a terminus and used fibrous stuffing rather than the absorptive lining of his predecessors. King shows on his website, a full-length line for a driver with an F1 (resonant frequency) of 29.3Hz would have to be 11.7 meters. Pioneering inventors like Olney (1930) and Stromberg-Carlson (1950) accomplished this with huge and very large sealed labyrinths behind their drivers. Regardless of whom you ask, everyone agrees on the theoretical ideal of a TL (the short-form moniker for a transmission line): A virtual black hole behind a driver absorbing all its rear-firing out-of-phase energy. industry features: Terminus LongusĪ recent Internet thread began with the query "What defines a transmission line?" Though it might seem obvious at first - most of us have certain notions about what constitutes a loudspeaker transmission line - upon further inspection, this question is far more trying than apparent.