Reply to thread

Message

<blockquote data-quote="Art Welter" data-source="post: 84283" data-attributes="member: 52">Re: PK SoundTim,The sub on the PK site is the only one they manufacture for sale presently, for good reasons.A bit of history:Very few of us had ever heard as much LF as was produced by the Cerwin Vega L-48SE Sensurround subs for Earthquake in 1974,&nbsp; that movie (moving) experience brought subwoofers to the mainstream.Eugene &quot;Gene&quot; Czerwinski (who passed away in 2010) sub designs influenced Tom Danley, who&#039;s Servodrive drivers in a similar &quot;W&quot; bin of a similar size to the L-48SE, but had even more output due to the increased driver excursion. Later Servodrive horns of the same standard truck pack size of 45 x 45 x 22.5 increased the horn path length by using a spiral, rather than &quot;W&quot; path. Spiral horns have been used in amplified audio for nearly a century.The availability of commercial high excursion drivers and the increasing cost of servo motors ended their dominance as the most powerful sub drive.After Tom Danley had developed his Tapped Horns, which pack more LF output in to a smaller package, he provided plans for the LabHorn, very similar to the SDL BT7.Although large horns are quite efficient, with the high excursion drivers and high power amplifiers available today, more SPL per cubic foot of truck space can be achieved with ported cabinets than horn loaded cabinets.Technology marches on, the Lab 12 at 13mm Xmax (maximum linear excursion) was quite an achievement for a low cost driver around the turn of last century. As a growing company, easy to see why PK would have started with an inexpensive, yet potent style of horn.The JBL 2269, with 19 mm Xmax, also was quite potent in an era when 6-8 mm was considered high excursion.Those drivers displacement have now been eclipsed by the likes of the neodymium magnet B&amp;C 21SW115-8, a 21&quot; driver, or the ferrite slab magnet TC Sounds LMS Ultra 5400 which has 33.66mm Xmax. If JBL&#039;s&nbsp; 2269 is their most potent 18&quot; driver, they have a lot of catch up to do, regardless of which continent their manufacturing and design work takes place.Art</blockquote>

[QUOTE="Art Welter, post: 84283, member: 52"] Re: PK Sound Tim, The sub on the PK site is the only one they manufacture for sale presently, for good reasons. A bit of history: Very few of us had ever heard as much LF as was produced by the Cerwin Vega L-48SE Sensurround subs for Earthquake in 1974, that movie (moving) experience brought subwoofers to the mainstream. Eugene "Gene" Czerwinski (who passed away in 2010) sub designs influenced Tom Danley, who's Servodrive drivers in a similar "W" bin of a similar size to the L-48SE, but had even more output due to the increased driver excursion. Later Servodrive horns of the same standard truck pack size of 45 x 45 x 22.5 increased the horn path length by using a spiral, rather than "W" path. Spiral horns have been used in amplified audio for nearly a century. The availability of commercial high excursion drivers and the increasing cost of servo motors ended their dominance as the most powerful sub drive. After Tom Danley had developed his Tapped Horns, which pack more LF output in to a smaller package, he provided plans for the LabHorn, very similar to the SDL BT7. Although large horns are quite efficient, with the high excursion drivers and high power amplifiers available today, more SPL per cubic foot of truck space can be achieved with ported cabinets than horn loaded cabinets. Technology marches on, the Lab 12 at 13mm Xmax (maximum linear excursion) was quite an achievement for a low cost driver around the turn of last century. As a growing company, easy to see why PK would have started with an inexpensive, yet potent style of horn. The JBL 2269, with 19 mm Xmax, also was quite potent in an era when 6-8 mm was considered high excursion. Those drivers displacement have now been eclipsed by the likes of the neodymium magnet B&C 21SW115-8, a 21" driver, or the ferrite slab magnet TC Sounds LMS Ultra 5400 which has 33.66mm Xmax. If JBL's 2269 is their most potent 18" driver, they have a lot of catch up to do, regardless of which continent their manufacturing and design work takes place. Art [/QUOTE]

Verification