My name is Philip Clements, Inventor of “H-PAS” loudspeaker technology, the future of sound and loudspeaker sound reproduction technology, today. If one of your passions in life includes listening to and being moved by good music and/or enjoying great home theater video and sound, you will probably be hearing and reading a great deal about “H-PAS”, patent pending. Google “H-PAS” speaker technology even today and you will probably get a quarter million hits on just its beginning over the past year. The following descriptions and information are offered to those with interest in hopes of providing a little greater understanding of what the technology is, what it does to enhance sound enjoyment, and what it means for almost all the sound applications and uses of sound we enjoy today and will in the future.
Why “H-PAS”? In my opinion, the weakest link in sound reproduction today is the lack of real music dynamics, especially those associated with low bass frequencies. To even begin to reproduce low bass frequencies with amplitude and some degree of feel, let’s face it, requires large woofers and even larger enclosures. Even with such, limitations exist that hold back the dynamic impact of low frequencies, such as those like 41.2Hz, which is low E of the Bass, about 27 feet long – the lowest string on a bass guitar, and even lower and longer - 32Hz, low C of the organ. Few speakers at any price really come close to reproducing these frequencies at amplitude, much less with the dynamic impact, feeling the pressure fronts that massage your soul as well as your body.
Powered subwoofers with large woofers were popularized to help in this regard and certainly, do extend low end bass performance. However, such is typically at the cost of greater harmonic distortion, difficulty with placement to obtain a seldom achieved coherent sound field with the satellite speakers, and still require fairly big cabinets if you want to reproduce frequencies from the low 50’s down into the 20’s. Even then large woofers themselves, 10, 12, and 15 inch have heavy moving mass, which slows their ability to react, move and recover unlike smaller woofers, and the louder they play the worse distortion increases. But how do you get smaller woofers, and preferably in smaller cabinets to play loud bass frequencies?
To reproduce these low bass frequencies at all is a major task. To do so with some degree of magnitude and feel – dynamic impact is considerably harder yet. To further do so in relatively smaller enclosures with smaller drivers with such dynamic impact is unheard of, until now with “H-PAS”. “H-PAS” is here to fill this void and give us the low bass amplitude and dynamic impact as enjoyed from live music that has so long been absent in our enjoyment of sound. Such has been one of my goals as an inventor/designer of loudspeakers for over 30 years.
What does “H-PAS” stand for? It means “Hybrid-Pressure Acceleration System”. Effectively, using a unique internal enclosure design, air flow is compressed as it moves through a series of compression chambers. As such compression happens a considerable back-pressure of air is created all the way back from the vent opening of the enclosure to the back of the woofer. The back-pressure through the whole line effectively aids in coupling with the woofer and its movement effectively shooting the compressed air in the enclosure out from the vent opening into the environment or room. It acts in much the same way a nozzle on a hose works with water. If you have ever watered your lawn, hooking up the hose to a water spicket and opening the spicket about half way, what happens? At the other end of the hose you get water flowing out, but typically at a very slow rate, simply falling right to the ground as it exits the hose.
But now, crimp the hose, screw on a nozzle, open up the nozzle about half way, and then un-crimp the hose, what happens? The pressure has increased so much you literally shoot a stream of water out of the hose 20-30-40 feet or more. The point is, did we change the output at all at the spicket? NO! What happened was that we created a back pressure in the line – the hose, and that back pressure in the entire hose line created far more pressure to be released at the end of the nozzle. This pressure resulted in far more dynamic impact of the water against the static, low pressure, high air density outside, and literally threw the water across a street.
Such increased pressure inside an “H-PAS” designed loudspeaker enclosure is all mechanically created to enhance frequencies from 80Hz down. This time, of course, we are using air. Air is much lighter than woofers and much easier to move. The significantly increased air pressure emanating from the vent opening of an “H-PAS” enclosure simply becomes more coupled to the static, low-pressure, high density air in the environment or room. When doing so it takes those frequencies below the woofers resonance point, which typically decrease, roll off, in audible amplitude quite rapidly, and effectively boosts them back up to a balanced output with the rest of the sound from the speaker. Doing so has now extended the frequency range considerably lower. Now, with the low bass frequencies extended and highly audible, the added pressure of the air flow from the enclosure vent against the low pressure, high density air in the room or environment significantly increases the dynamic impact of these frequencies as well. This works in much the same way an acoustic horn acts as an better acoustic transformer to improve output and sensitivity for mid-range and upper frequencies, as many of you may know.
To help understand the increased dynamics and the ability to literally feel the pressure fronts of these lower frequencies image the following. You have swimming pool in your back yard. If you drop a small rock into the pool it will no doubt disturb the water, create a little splash, and not much more. If you then drop a much bigger rock into the water, (greater density), it will create a much bigger splash, displacing more water with added pressure from the bigger rock. If someone was in the pool when this happened, there would probably be enough wave action from the big splash to move that person back and forth with the wave motion created. Such is what happens in a smaller way when one goes from smaller woofers to larger woofers.
Now envision a small rock again, but this time it is a meteor coming in from space at very high velocity, (small density but much greater pressure), and hits the water in the pool. What happens then? Even though a little rock, its velocity creates enormously increased pressure against the density of the water in the pool, which in turn will literally blow all the water out of the pool and the person in the pool with it. Suffice it to say I think the dynamic impact from such would prove to be significantly increased, and definitely felt.
Usual speaker designs that operate at lower pressure against the low pressure, high density of the air in the room or environment require larger woofers, and thus large cabinets, often more than 2 times that used in an H-PAS design to even begin to get pressure sensitivity up. In today’s world where smaller, less conspicuous, and more placement flexibility are paramount lifestyle requirements, H-PAS sound products are today’s and the future’s solution for sound enjoyment. As importantly, they are so without performance compromise, and arguably more so as improved performance designs.
What does “H-PAS” do? It does many things, but it general; one, helps to extend loudspeaker low frequency response well below typical loudspeaker bass designs; two, significantly increases the dynamic range of the presentation of such extended low frequencies; and three, does so using equal size or smaller cabinets and with equal size or smaller woofer drivers than typically used.
What does all this mean? Now, products such as I-Pod docs, desktop and tabletop radios, modern day boom boxes, hifi speakers and high-end loudspeaker designs can all achieve greater extended low frequency range, and do so with more dynamic impact never before available in such products and product categories.
If you go on-line, as mentioned, you will see the name Atlantic Technology. They are wonderful and talented loudspeaker folks themselves. It is Peter Tribeman, the president of the company and a terrific gentleman I have known for many years, who provoked me enough to revisit the forerunner of “H-PAS”, which I developed over 30 years ago. Below in this letter are a few pictures of Clements products developed then and more recently through the 90’s with such previous technology, some models with my proprietary, high-output ribbon drivers as well. When I did pull them out again I was struck by what they still did, and what, after 30 years, the market had not caught up to. I also quickly saw ways, from 30 years ago when there were no computers, no software, and much less of a knowledge base, to make significantly improved changes to fully optimize the technology’s use and performance. Peter wanted a set of towers with the technology and after we listened to a set of new prototypes I built for him we both felt and knew as well, this technology was very special.
At that point it was easy to decide to do a joint venture together, Solus/Clements Loudspeakers and Atlantic Technology, to bring “H-PAS” to the market. In so doing I appointed Atlantic Technology my exclusive “Licensor” to license other speaker manufacturers, and/or other companies that want to use “H-PAS” in their speaker products. This allows me to stay in my lab cage doing creative engineering and design work, make prototypes for our licensees when contracted for such, do the same for ourselves, and continue to further “H-PAS” research and other acoustical development. They come to town once in awhile and throw some raw meat in my cage to keep me going.
Licensing is not the only activity they bring to the table. Myself, while a holder of 4 patents with 2 more coming, and with a longevity of 35 years as an acoustic loudspeaker designer I am not, myself, an advanced acoustical mathematician. As mentioned previously, when I started my speaker design work there were no computers, no software, and very little, hard to find, knowledge base information in acoustic design with which to work. In those days you developed your own theories and formulas on which to base your work results. Certainly, today’s computers and software very much aid and continue to further my 30+ years of loudspeaker design and engineering fulfillment.
Fortunately, in Atlantic’s employ is a gentleman, Boaz Shalev, who most definitely is a very talented mathematician by trade. I fill my day furthering “H-PAS” research here in Phoenix creating and engineering products for my company - Solus/Clements Loudspeakers, Atlantic, Licensees and several others, as well as administering to the daily affairs of SCL. Boaz at Atlantic, in conjunction with Martin King – known properly so as the “King of Quarter Wave”, has developed and continues to work on the advanced math algorithms in support of “H-PAS” extended bass design parameters and performance. These algorithms both mathematically validate “H-PAS” high-performance designs while providing predicable computer performance modeling for the technology and its applications. Having the knowledge base from both our efforts together allows Atlantic to also help with some prototyping as well. It is an honor to work with Peter and Boaz, and all the great folks at Atlantic. Together we look forward to all the wonderful products today and in the future we can bring to the market to further sound enjoyment for all.
Having designed and engineered loudspeakers, and speaker components, such as my proprietary, high output “planar Ribbon” drivers, for many years it is my still my goal to raise the enjoyment level of what sound brings to us all. “H-PAS” extended bass loudspeaker technology is a major bridge to helping reach the fulfillment of this goal.
I hope this “H-PAS” introduction letter has provided a little insight about “H-PAS” speaker technology, how it works, what it means to our enjoyment of sound now and in the future, and a little about us, Solus/Clements Loudspeakers and Atlantic Technology, as the principals involved making “H-PAS” happen in the market. I look forward as we progress to posting updates on our activities, pictures of products with “H-PAS” technology from ourselves as well as our licensees, if allowed, and in general any newsworthy items of interest we can pass along.
Thanks for visiting our website, and remember, there are only 3 things in life folks really want, more love, more money, and more bass.
Philip R. Clements
President: Solus/Clements Loudspeakers
A Completely New — and Better — Way
to Make Serious Bass
H-PAS does not require the use of special drivers, any kind of on-board electronics or outboard equalization -- it is a purely passive system, completely compatible with all AV receivers and stereo amplifiers.
Employing a unique cabinet design, the elements of the different speaker technologies are cascaded one to another in such a manner as to pressurize and accelerate the very lowest frequency back waves as they travel through the cabinet.
These waves are then radiated into the room through a vent at the lower front of the cabinet. There is an “acoustic crossover” from the vent to the bass drivers and the upper bass and midrange regions are propagated directly from the woofer’s cone.
An important additional feature, integral to the design, is an “acoustic bass trap.” Signals travel through this internal passive resonance/harmonic distortion line filter to further reduce unwanted distortion for clean, tight bass. As a result, H-PAS delivers extended deep bass with high output levels, and exceptionally low harmonic distortion.
The central tenet of this new design approach is somewhat counter-intuitive. Instead of using heavy, low-resonance drivers to achieve low bass, H-PAS utilizes quick, high-resonance bass drivers. The internal matrix of the cabinet takes the backwave of the driver below its resonance and pressurizes and accelerates it before it exits the vent. This acceleration increases the impact of the highly pressurized air flow in the enclosure when it leaves the vent. The result is both extended low bass and greatly improved dynamic range at such lower frequencies. The internal workings of the cabinet (using very specific, mathematically-derived ratios between the various cabinet/driver relationships are such that the low frequency efficiency of the system actually increases with decreasing frequency—exactly the opposite of conventional system behavior, where output below resonance drops rapidly. H-PAS produces a reciprocal output of the high-resonance drivers’ natural roll-off, yielding flat acoustic response to well below that of conventional designs using like-sized drivers and cabinets.
The use of lighter, higher-resonance woofers also means that the
H-PAS system exhibits lightning-fast transient response and incredible bass detail compared to the slower high-mass, low-resonance drivers needed to achieve reasonable deep bass extension in ordinary speakers.
In short, H-PAS technology provides greater extended low frequency range, and/or greater output, with increased dynamic range and impact at those extended low frequencies. It can be scaled to fit many size cabinets, small to large. Higher SPL’s are inherent to the design, as is low distortion, which in turn negates any requirement for costly high-power amplification.