To Sub Or Not To Sub, That Is The Question

The patent number is available on the site!
I could not find it. A new patent is mentioned in the story but I saw no patent numbers, could you please provide a link?

You really can’t see the improvement made by subwoofer you must experience it.
Clearly. Though I should be able to measure it and see as well as hear the results. Some things are more difficult to measure and analyze than others, but your claim of taking the room out of the picture no matter the room or where the subwoofer is placed (I think you said that earlier but have lost track), and enhanced output for lower power with lower distortion, should be easy to measure.

Damping, really critical damping is not there. When you say that the current subwoofer is not base on resonance well I have to disagree! For a subwoofer driver as presently used is requiring excessive moving mass to have resonance at the desired frequency.
Damping is an engineering term and is most certainly there, perhaps not in the amount you desire. When you say critical damping, are you using Q = 0.7071? Any driver requires moving mass; it is only "excessive" if the voice coil, magnet assembly, and amplifier cannot drive it within desired parameters. There is no "resonance at the desired frequency", it is a driven system, typically highly overdamped due to very low amplifier driving-point impedance. There is also much research into producing lighter, stiffer cone materials.

This moving mass must move back and forth and the more mass the slower the response! Please tell me that I’m not wrong here!
My understanding is you are advocating use of smaller drivers, 6.5" diameter, to reduce mass. You must still produce the desired acoustic power output from the smaller driver, so it would presumably be a long-throw design. A dual-driver "push-pull" system could be used to help counter air inside the box, but current subs achieve low distortion at high output through large, stiff cones, large voice coil and magnet structures, and large amplifiers with low output impedance to drive them. You claim to have achieved that with much less power and much smaller drivers, but other than repeated use of the words "innovation" and "resonance" have not explained how you have accomplished that while dismissing any technical discussion. That leaves me, and likely others, curious about how you are achieving the performance, particularly in light of the claims that the room no longer matters. That would be awesome but seems as-yet unproven (a listening review without controls is interesting but not necessarily definitive, and nothing I have read in the reviews so far says the room is taken out of the picture).

As for slower, no, it works as a system and overall response is determined by the amplifier, voice coil, magnet, spider and surround, and so forth. Cone mass is just one variable. More mass may take more driving power but is not automatically slower in the sense you seem to be saying.

Resonance is also a timed event to develop and decay! It’s the wrong way perhaps the only way known to this point! I’m spreading information.
I do not treat a speaker as a resonant system like a tuned RF amplifier or oscillator. It is simply a driven electromechanical driver, not a resonator. Any system that does not have infinite bandwidth requires finite time to start and stop. How does your design circumvent physics?

Regardless of who is right here I see too many failures of desired subwoofer results on this forum! To sub or not to sub shouldn’t even be a question as everyone wants a solution that works. You want to extend your bass in your room while maintaining the integrity of your system. It’s possible now through 21st century innovation. Innovation is so scarce for loudspeakers until our local university “Georgia Tech” has removed it from their curriculum! They used to be the center of loudspeaker research.
I agree with @sigbergaudio audio that the barriers to including subwoofers have little to do with the subwoofers themselves. There is resistance to adding subwoofers to a stereo system (HT systems accept them routinely) out of fear they will corrupt the sound, resistance to adding additional boxes and placing them appropriately (since beside the main speakers is rarely the best place for the subs), and integration concerns since, although the science is well-known, its application can be challenging especially trying to tune (dial in) the system by ear.

Dirac Live and Trinnov have both introduced new bass schemes recently so innovation is not completely dead. I suspect audio will always be a very niche curriculum for any university. Of 200+ college hours I took, less than 10 semester hours were for a couple of graduate engineering courses on acoustics, and most of the "audio" oriented courses were targeting either the music or theater departments rather than engineering or physics departments.
 
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I could not find it. A new patent is mentioned in the story but I saw no patent numbers, could you please provide a link?


Clearly. Though I should be able to measure it and see as well as hear the results. Some things are more difficult to measure and analyze than others, but your claim of taking the room out of the picture no matter the room or where the subwoofer is placed (I think you said that earlier but have lost track), and enhanced output for lower power with lower distortion, should be easy to measure.


Damping is an engineering term and is most certainly there, perhaps not in the amount you desire. When you say critical damping, are you using Q = 0.7071? Any driver requires moving mass; it is only "excessive" if the voice coil, magnet assembly, and amplifier cannot drive it within desired parameters. There is no "resonance at the desired frequency", it is a driven system, typically highly overdamped due to very low amplifier driving-point impedance. There is also much research into producing lighter, stiffer cone materials.


My understanding is you are advocating use of smaller drivers, 6.5" diameter, to reduce mass. You must still produce the desired acoustic power output from the smaller driver, so it would presumably be a long-throw design. A dual-driver "push-pull" system could be used to help counter air inside the box, but current subs achieve low distortion at high output through large, stiff cones, large voice coil and magnet structures, and large amplifiers with low output impedance to drive them. You claim to have achieved that with much less power and much smaller drivers, but other than repeated use of the words "innovation" and "resonance" have not explained how you have accomplished that while dismissing any technical discussion. That leaves me, and likely others, curious about how you are achieving the performance, particularly in light of the claims that the room no longer matters. That would be awesome but seems as-yet unproven (a listening review without controls is interesting but not necessarily definitive, and nothing I have read in the reviews so far says the room is taken out of the picture).

As for slower, no, it works as a system and overall response is determined by the amplifier, voice coil, magnet, spider and surround, and so forth. Cone mass is just one variable. More mass may take more driving power but is not automatically slower in the sense you seem to be saying.


I do not treat a speaker as a resonant system like a tuned RF amplifier or oscillator. It is simply a driven electromechanical driver, not a resonator. Any system that does not have infinite bandwidth requires finite time to start and stop. How does your design circumvent physics?


I agree with @sigbergaudio audio that the barriers to including subwoofers have little to do with the subwoofers themselves. There is resistance to adding subwoofers to a stereo system (HT systems accept them routinely) out of fear they will corrupt the sound, resistance to adding additional boxes and placing them appropriately (since beside the main speakers is rarely the best place for the subs), and integration concerns since, although the science is well-known, its application can be challenging especially trying to tune (dial in) the system by ear.

Dirac Live and Trinnov have both introduced new bass schemes recently so innovation is not completely dead. I suspect audio will always be a very niche curriculum for any university. Of 200+ college hours I took, less than 10 semester hours were for a couple of graduate engineering courses on acoustics, and most of the "audio" oriented courses were targeting either the music or theater departments rather than engineering or physics departments.
I am not discussing the tech at this point due to the apprehension that I’m facing just for suggesting that there is a solution. I suggested that you Google TBI Magellan subwoofers and read what professional reviewers say about those models. It’s not the measurements to absorb but what kind of results do you have. The new subs are more effective. The tech involved is a branch of physics that would seem to have no relevance.
Patent number is on the page showing the MS-6P plate amp detail!

We do want to take advantage of forums and other social media for customers to give reviews that hopefully are consistent. We will also approach familiar internet reviewers. Upon stumbling upon this forum and realizing that folks are voicing their concerns about subwoofer issues I want to participate.
 
I am not discussing the tech at this point due to the apprehension that I’m facing just for suggesting that there is a solution. I suggested that you Google TBI Magellan subwoofers and read what professional reviewers say about those models. It’s not the measurements to absorb but what kind of results do you have. The new subs are more effective. The tech involved is a branch of physics that would seem to have no relevance.
Patent number is on the page showing the MS-6P plate amp detail!

We do want to take advantage of forums and other social media for customers to give reviews that hopefully are consistent. We will also approach familiar internet reviewers. Upon stumbling upon this forum and realizing that folks are voicing their concerns about subwoofer issues I want to participate.
We are asking for the technical description, what is the apprehension? The solution seems fantastic but too good to be true, so we're interested in learning more. I am not particularly interested in reviews, more about the technology. I'll deal with the physics, plenty of it in my day job.

I was expecting patent numbers listed, not from a picture of the plate amp.
 
Interesting subject here. I have found (finally) that I like the lack of room interaction (or reduced interaction) I am getting with Open Backed speakers, as opposed to years of traditional cones in cabinet types.

My next question would thus be - how do Open Backed subs sound? There are some around, mainly as kits. I would really like to know. I note OCD Mikey uses OB subs, and it is these I am wondering about.
You may have associated your preference as room interaction, when it was something else.

One gets more room interaction with an open back.
But it is a 1st order box, and they have better transcient response and lower group delay than a 2nd order box, and low than higher order boxes.
 
We are asking for the technical description, what is the apprehension? The solution seems fantastic but too good to be true, so we're interested in learning more. I am not particularly interested in reviews, more about the technology. I'll deal with the physics, plenty of it in my day job.

I was expecting patent numbers listed, not from a picture of the plate amp.
 
Innovation! When you say regardless of how the subwoofer is designed can you be sure? You are saying that room and subwoofer must coexist with these effects. I didn’t say that room modes didn’t exist only that the resonance based subwoofer design is sensitive to the modes and increases/decreases its output when it is exposed to these external pressures. The subwoofer has to be acoustically grounded to avoid the effects. That is our contribution and it works.

Before contradicting your claim I'd like to make sure I understand it. Are you saying that a subwoofers native output (as in its frequency response) is affected by the room modes? So that due to the standing waves in the room, the actual frequency response of the subwoofer driver changes? And this is what you have eliminated with your patent?
 
This is the patent: https://ppubs.uspto.gov/dirsearch-p...2LTRkMzgtOThmOC1jMmQyMDNiZTA3MmMiLCJleHAiOjB9

It is a Spotify patent. The claims relate to automatic mixing of multimedia sources so apparently they have applied this mixing technique to the subwoofer design. I have not read it in detail yet so it is not clear how it helps them counter room reflections, driver distortion, and so forth. Perhaps just using the patent to describe the feedback scheme they are using.

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This is not a TBI patent!
 
Before contradicting your claim I'd like to make sure I understand it. Are you saying that a subwoofers native output (as in its frequency response) is affected by the room modes? So that due to the standing waves in the room, the actual frequency response of the subwoofer driver changes? And this is what you have eliminated with your patent?
The driver is critically broadband critically damped! I mentioned earlier that a loudspeaker diaphragm is also a microphone. The resonant state is high impedance therefore easy to modulate from external pressures like room modes. At higher frequencies it’s audible feedback. Subwoofers and turntables can have feedback occurring due to this sensitivity. Any questions on how this works after reading the patent? It’s how the driver is loaded so the compression is modulated by an attached 2-D turbulent volume that dissipates energy as heat due to viscous dissipation at its boundary layer. It’s akin to a virtual 3-D volume behind the driver that allows it to operate to lower frequencies avoiding resonance. The enclosure vibration is much less with this process. Free air for the driver is 40 Hz not the typical subwoofer Fa. It would be impossible to output 20 Hz without this modulation in a tiny enclosure! You wouldn’t use this 6.5” diameter in a large enclosure. It goes beyond just preventing feedback because this critical damping/loading affects the full range of the driver. Google the basic physics involved “Two Dimensional Turbulence” for a better understanding how it increases the entropy of a system. This action is that of keeping work done on a previous cycle from affecting a current work cycle. It is a universal concept!
 
The driver is critically broadband critically damped! I mentioned earlier that a loudspeaker diaphragm is also a microphone. The resonant state is high impedance therefore easy to modulate from external pressures like room modes. At higher frequencies it’s audible feedback. Subwoofers and turntables can have feedback occurring due to this sensitivity. Any questions on how this works after reading the patent? It’s how the driver is loaded so the compression is modulated by an attached 2-D turbulent volume that dissipates energy as heat due to viscous dissipation at its boundary layer. It’s akin to a virtual 3-D volume behind the driver that allows it to operate to lower frequencies avoiding resonance. The enclosure vibration is much less with this process. Free air for the driver is 40 Hz not the typical subwoofer Fa. It would be impossible to output 20 Hz without this modulation in a tiny enclosure! You wouldn’t use this 6.5” diameter in a large enclosure. It goes beyond just preventing feedback because this critical damping/loading affects the full range of the driver. Google the basic physics involved “Two Dimensional Turbulence” for a better understanding how it increases the entropy of a system. This action is that of keeping work done on a previous cycle from affecting a current work cycle. It is a universal concept!
Critically was used twice by accident in the first sentence.
 
The driver is critically broadband critically damped! I mentioned earlier that a loudspeaker diaphragm is also a microphone. The resonant state is high impedance therefore easy to modulate from external pressures like room modes. At higher frequencies it’s audible feedback. Subwoofers and turntables can have feedback occurring due to this sensitivity. Any questions on how this works after reading the patent? It’s how the driver is loaded so the compression is modulated by an attached 2-D turbulent volume that dissipates energy as heat due to viscous dissipation at its boundary layer. It’s akin to a virtual 3-D volume behind the driver that allows it to operate to lower frequencies avoiding resonance. The enclosure vibration is much less with this process. Free air for the driver is 40 Hz not the typical subwoofer Fa. It would be impossible to output 20 Hz without this modulation in a tiny enclosure! You wouldn’t use this 6.5” diameter in a large enclosure. It goes beyond just preventing feedback because this critical damping/loading affects the full range of the driver. Google the basic physics involved “Two Dimensional Turbulence” for a better understanding how it increases the entropy of a system. This action is that of keeping work done on a previous cycle from affecting a current work cycle. It is a universal concept!

I guess all this in theory fine, the thing I can't get around, is that earlier you stated (unless I misunderstood you), that this subwoofer will in principle ignore room modes, so you will get an even response at the listening position. Nothing you said here (or that I could find in the patent) explains how that is possible.

But re-reading this: "When it is critically damped the room reflections are ignored so the driver can track the signal. There are always room modes relative to its dimensions where bass can be stronger or weaker but the driver in our MS-6P does not respond to it." - I guess you're not saying that the room modes goes away, just that the driver doesn't react to it.

That feels like a solution looking for a problem to me. If I do a nearfield measurement of any of our subs (and probably most other subs), the frequency response will be perfectly fine, and not visibly affected by the room. Which means any impact the room modes have on the driver will be minimal at best (my guess would be non-existant) - and unlikely to create audible issues.
 
I am not discussing the tech at this point due to the apprehension that I’m facing just for suggesting that there is a solution.
Good morning to you. I'd just like to point out that one cannot come onto a forum and make a bold claim or claims without comments or questions being asked. If you say that there is a solution, then offer it to us and be prepared for more questions/answers. Otherwise, your posts seemingly come across as trolling our forum, while advertising for your innovative product that still has not been explained.

Please note - I say this as a member of this forum and not a moderator. My comments are not reflective of the moderation team, nor is it the WBF's stance.

Tom
 
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I guess all this in theory fine, the thing I can't get around, is that earlier you stated (unless I misunderstood you), that this subwoofer will in principle ignore room modes, so you will get an even response at the listening position. Nothing you said here (or that I could find in the patent) explains how that is possible.

But re-reading this: "When it is critically damped the room reflections are ignored so the driver can track the signal. There are always room modes relative to its dimensions where bass can be stronger or weaker but the driver in our MS-6P does not respond to it." - I guess you're not saying that the room modes goes away, just that the driver doesn't react to it.

That feels like a solution looking for a problem to me. If I do a nearfield measurement of any of our subs (and probably most other subs), the frequency response will be perfectly fine, and not visibly affected by the room. Which means any impact the room modes have on the driver will be minimal at best (my guess would be non-existant) - and unlikely to create audible issues.
Glad that we are communicating! Now the solution that we are offering is keeping the system out of the high impedance state of resonance. Think about the volume of air behind the driver as a 3 dimensional volume. The internal boundaries of that volume is where the pressure should terminate for each motion of the diaphragm.This is not what happens in a conventional enclosure. The pressure reflects back to the diaphragm while flexing the walls.

Now imagine a frequency independent reservoir is attached wherein the reflected pressures would enter this reservoir ( in real time) creating forced vortices that dissipate that energy via viscous forces at its boundary. If this is the case the diaphragm would not exist in a state that alters its work cycle (velocity). The existence of a stable boundary layer is a condition considered as an acoustical ground.[ A stable boundary layer at the wing surface is what keeps a plane in the sky!] It’s a more complex process because of the matrix of levels and wavelength's involved but it works when properly executed. As there are a positive and negative diaphragm excursions the pressure established at negative cycle supports the positive cycle. Enclosure vibration is greatly reduced as this occurs with a proper loading of the diaphragm for all its motions. We can (and will) extend this process to larger and smaller driver diameters but with a typical enclosure volume reduction of 75%.
 
Glad that we are communicating! Now the solution that we are offering is keeping the system out of the high impedance state of resonance. Think about the volume of air behind the driver as a 3 dimensional volume. The internal boundaries of that volume is where the pressure should terminate for each motion of the diaphragm.This is not what happens in a conventional enclosure. The pressure reflects back to the diaphragm while flexing the walls.

Now imagine a frequency independent reservoir is attached wherein the reflected pressures would enter this reservoir ( in real time) creating forced vortices that dissipate that energy via viscous forces at its boundary. If this is the case the diaphragm would not exist in a state that alters its work cycle (velocity). The existence of a stable boundary layer is a condition considered as an acoustical ground.[ A stable boundary layer at the wing surface is what keeps a plane in the sky!] It’s a more complex process because of the matrix of levels and wavelength's involved but it works when properly executed. As there are a positive and negative diaphragm excursions the pressure established at negative cycle supports the positive cycle. Enclosure vibration is greatly reduced as this occurs with a proper loading of the diaphragm for all its motions. We can (and will) extend this process to larger and smaller driver diameters but with a typical enclosure volume reduction of 75%.
We are using chaos to create order. It’s classic entropy typically used by Mother Nature think tornados and hurricanes!
 
I guess you're not saying that the room modes goes away, just that the driver doesn't react to it.
...but does the ear/body react? Or why doesn't the ear/body react? I might except that you found a way to benefit the speaker (enclosure) but doesn't the room energy still exist?
 
We are using chaos to create order. It’s classic entropy typically used by Mother Nature think tornados and hurricanes!
Now what does this have to do with the rooms acoustics? Well actual usage in various rooms shows that the room boundaries mimic the grounded boundaries of the enclosure! Actual measurements show a mild increase in level at the walls with bass response even in the room. Corners increase the bass level but no real modes or dips and peaks as would be the normal case.
 
Now what does this have to do with the rooms acoustics? Well actual usage in various rooms shows that the room boundaries mimic the grounded boundaries of the enclosure! Actual measurements show a mild increase in level at the walls with bass response even in the room. Corners increase the bass level but no real modes or dips and peaks as would be the normal case.
I hope that I answered your question concerning the benefit of the room relative to enclosure grounding!
 
Now what does this have to do with the rooms acoustics? Well actual usage in various rooms shows that the room boundaries mimic the grounded boundaries of the enclosure! Actual measurements show a mild increase in level at the walls with bass response even in the room. Corners increase the bass level but no real modes or dips and peaks as would be the normal case.
Ah. How about showing us those measurements along with a description of the context?
 
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