Genesis Advanced Technologies SuperSub Subwoofer

[garylkoh]

Hey Ron,

Also very interested in learning more. This is a big sub, bigger than i guestimated based on the cone size and photos. From Gary's Technical Specs on his website:

SuperSub (optional): H 41” x W 26” x D 38”

https://www.genesisloudspeakers.com/products/quartet/quartet-technical-specifications/

This makes its footprint 82% bigger than an XLF!

Hi Lloyd, It is a BIG subwoofer. In addition to that footprint, it also has a 3-chassis ServoBass amplifier. The sub weighs about 195lbs and then add another 70lbs for the amplifiers.

 

[garylkoh]

To a degree (maybe large) but many find that orientation of direction subs face does make a perceived difference at various listening positions.

There is a little bit if power response deviance but it also varies with the type of subwoofer a fair bit.

These are bipolar so they don’t get baffle step loss. They will be pretty even. The simplest way to describe facing them the way they do is space connivence and less reflections from main towers.

But they really are not firing side to side if they’re only playing low frequencies. At the low frequencies they fire in all directions, as the frequencies are MUCH longer than the size of the woofers so the sound goes in all directions.

You are both correct. I found that if you have a low-pass filter that is greater than 18dB/octave there will be absolutely zero difference sonically facing side-to-side or front-to-back. Even the reflections from the main tower is negligible if there is no high-frequency component in the output.

Even the 7-ft tall woofer towers in the Prime act as a point source. However, since they are not hanging in free space, but they sit on the floor - it would be better to describe them as a hemispherical source and not a point source. This makes for an interesting mental exercise as you have to imagine the sound waves spreading like a donut.

 

[garylkoh]

Best of luck getting the new factory set up, Gary!

No rush on answering these questions. Please put this at the bottom of your list!

Thanks, Ron. It's mostly there. We've been unpacking and organizing for nearly 4 weeks straight already. Hope I managed to answer some of your questions.

 

[garylkoh]

What actually intrigued me the most in this article is that Gary has actually eliminated the 2 woofer towers in this configuration. The main speakers we see are actually part of the Quartet, a 4-tower speaker (6' tall each speaker) which sits directly below the main Genesis Prime massive 7.5' tall x 4' wide 4-tower flagship. But in this case the 2 x 6' sub towers are removed and ONLY the SuperSub is being used (which was originally shown as a further add-on to the Quartet).

Clearly, Gary has designed these to crossover across quite a wide range which is intriguing in terms of flexibility as well...if it can be used either as supplementary to the 2 x 6' sub towers or IN LIEU of them...I suppose that bodes extremely well for their ability to be used with other non-Genesis speaker systems?

The SuperSub comes with our standard ServoControl Crossover Module. The low-pass is adjustable from 80Hz to 135Hz (in 1 Hz steps), and phase from 0 to -180 degrees in 5 deg delay (phase cannot be advanced as we wouldn't know what is going to happen in the future).

So, you can use it to supplement the 8-inch woofer towers of the Quartet, or the 12-inch woofer towers of the Prime, or it can replace them.

The SuperSub sits on my usual suspension system. As the woofers are horizontally opposed, the cabinet hardly vibrates. Any vibration is generated from the internal air pressure in the cavity. To control this, the cabinet is constructed using my usual carbon-fiber/composite sandwich. So, they would stack with an additional suspension between the top and the bottom cabinet.

 

[Ron Resnick]

Wow! Thank you very, very much, Gary, for answering all of our questions, and for taking the time to explain the history behind, and the evolution of, your SuperSub!

 

[LL21]

Wow...thank you, Gary!!! I have to say that your "ambience of the hall descripton" is a near-copy of something I posted earlier when trying to describe to people why i focus so much on deep bass. It is absolutely a 'rude awakening' as soon as you press pause on the jazz track...your breathing, the sound of your clothes in your actual room with the sound bouncing off the walls, etc makes you realize you are in your living room...but as soon as you release the pause button, the overwhelming sense of venue puts you back in the jazz club. Its like the air has changed and your sense of distance/space and everything else gets thrown back on course into the venue and not into your room. It fools your ear into thinking it is somewhere else somehow.

That ONLY happens when the Velodyne is ON. If you turn if off...all you have is the sound coming from 2 speakers at the far end of the room. That's it.

This is why i always insisted on the big Velodyne in the system and why i would not part with it as part of a system design.

And why I am seriously trying to explore what happens if, instead of 1 x 18" servo sub...we went with 4 x 18" subs...in the same location...and NOT try to get too complicated with all the implications of a multi-sub/multi-location setup. Just take what we have...and use a bigger/badder version of a 1-sub set up which has far greater air displacement, more effortlessness, and lower distortion to see if it improves the sense of venue even better and makes it even more solid, more real.

 

[Ron Resnick]

It is very interesting that in Gary's experience and experiments the "you are there"/hall ambiance effect is created not just by increasing very low frequency driver surface, but primarily by big drivers per se (two 15" woofers create the effect more fully than about the same driver surface area of eight 8" woofers).

Maybe two 18" drivers create this effect more fully than the equivalent driver surface area of 15" drivers?

But is the implication of this that to create specifically this very low frequency "you are there"/hall ambience effect we should focus on huge drivers and not worry as much as we usually do about light and "fast" drivers or about tight servo control? (In car parlance does this mean we focus on cubic inches/displacement and not so much on high RPM or "finesse"? (Dodge Hellcat, not McLaren?)

If so, Lloyd, you are on the right track with your 4 X 18" behemoth! (Although I would prefer (at least visually and psychologically) a stereo pair of whatever size boxes you can accommodate.)

 

[LL21]

It is very interesting that in Gary's experience and experiments the "you are there"/hall ambiance effect is created not just by increasing low frequency driver surface, but primarily by big drivers per se (two 15" woofers create the effect more fully than about the same driver surface area of eight 8" woofers).

Hey Ron,

Someone here recently said something that really 'resonated' with me (pardon the pun)...which is that a series of multiple smaller drivers with the same surface area as 1-2 larger drivers has the "potential" of less excursion capability...so that they actually displace less air. And outright air displacement (particularly in bass) has to be critical I think.

Furthermore, if we are NOT talking about 50-180hz...but about 10hz-35hz, then we are not going to be looking for outright alacrity or certain tonal qualities (ie, plucking of a string, or the snap of a drum snare). We are probably looking for outright sheer scale, effortlessness, low distortion at 10hz-35hz...in which case, I wonder if the big cones are at least as valid an option.

Certainly, having spoken off-line with a few professional sub designers, when asked to deliver subterranean signals for big standalone full range speakers, they seem consistently driven towards bigger cones rather than arrays of smaller ones.

 

[Folsom]

Hey Ron,

Someone here recently said something that really 'resonated' with me (pardon the pun)...which is that a series of multiple smaller drivers with the same surface area as 1-2 larger drivers has the "potential" of less excursion capability...so that they actually displace less air. And outright air displacement (particularly in bass) has to be critical I think.

Furthermore, if we are NOT talking about 50-180hz...but about 10hz-35hz, then we are not going to be looking for outright alacrity or certain tonal qualities (ie, plucking of a string, or the snap of a drum snare). We are probably looking for outright sheer scale, effortlessness, low distortion at 10hz-35hz...in which case, I wonder if the big cones are at least as valid an option.

Certainly, having spoken off-line with a few professional sub designers, when asked to deliver subterranean signals for big standalone full range speakers, they seem consistently driven towards bigger cones rather than arrays of smaller ones.

The answer would be no, to all of it. But that doesn’t mean large cones aren’t still special.

Smaller drivers move the exact same amount of air if the SPL is the same. The individual drivers use less excursion to achieve that SPL because there are so many of them playing. However the larger driver will have more distortion and a bit different wave pattern. More distortion in this case may sound considerably more correct. On stereos where you can adjust the Q for subs turning it up is the likely solution to make it bloom and sound normal, which means increasing distortion to some degree. But you may be reducing a bit of distortion at the same time that was smaller. The reason is because there are limits to how much control an amplifier can have on a bass driver. You can correct it to a point but beyond that it isn’t lowering distortion; it’s just wasted energy that might make it sound different.

And to the second paragraph, no, larger drivers that have to move farther will always have more distortion because they have to more farther. The farther the movement, the more the distortion. But as said before that distortion may be a benefit. It’s not like the frequencies that tell you a pluck of a bass string is indeed a string are even remotely near the bass region... And what big drivers do is have more SPL capability. I would note that a lot of big drivers or ones in certain enclosures could have low distortion because of barely moving - similar to a bunch of smaller ones.

I’m not sure what stock I’d put into fullranger stuff, since I have yet to hear an actually good fullrange speaker.

 

[LL21]

The answer would be no, to all of it. But that doesn’t mean large cones aren’t still special.

Smaller drivers move the exact same amount of air if the SPL is the same. The individual drivers use less excursion to achieve that SPL because there are so many of them playing. However the larger driver will have more distortion and a bit different wave pattern. More distortion in this case may sound considerably more correct. On stereos where you can adjust the Q for subs turning it up is the likely solution to make it bloom and sound normal, which means increasing distortion to some degree. But you may be reducing a bit of distortion at the same time that was smaller. The reason is because there are limits to how much control an amplifier can have on a bass driver. You can correct it to a point but beyond that it isn’t lowering distortion; it’s just wasted energy that might make it sound different.

And to the second paragraph, no, larger drivers that have to move farther will always have more distortion because they have to more farther. The farther the movement, the more the distortion. But as said before that distortion may be a benefit. It’s not like the frequencies that tell you a pluck of a bass string is indeed a string are even remotely near the bass region... And what big drivers do is have more SPL capability. I would note that a lot of big drivers or ones in certain enclosures could have low distortion because of barely moving - similar to a bunch of smaller ones.

I’m not sure what stock I’d put into fullranger stuff, since I have yet to hear an actually good fullrange speaker.

Thanks Folsom. In regards to small cones vs large cones, if the square inch coverage of 8 x 9" cones is the same as 2 x 18" cones...given the physical specs of a smaller cone, would the smaller cones normally have less excursion than the larger cone? That was where I was coming from in terms of large vs small.

For some reason, I assumed that with the smaller diameter, the construction of the smaller cones would result (all else being equal) in a generally lower excursion? So less air displacement...and therefore one might need more than 8 x 9" cones to equal 2 x 18" even if the square inches is the same?

Clearly, I know zilch about technicals but trying to understand some basics here as I try to get my ahead around the general direction of travel for a sub solution for our system.

 

[Folsom]

Square inch to square inch is an interesting question. Without knowing the exact drivers it’s a little hard to say but likely the smaller ones would have to travel more. That’s because they put out less of the low frequency due to size and suspension etc. Either way you still adjust the SPL to match.

It would seem possible to be equal but smaller drivers have a few more normal constraints due to construction, so I suspect you have to drive them a little harder when square inches are equal.

 

[LL21]

Hi Folsom,

The other one that occurs to me in looking at smaller cones vs larger is:
1. the excursion being linked to the surround.
2. the same excursion (say 3") being lower distortion in an 18" cone than the same excursion in an 8" cone

Take the 1st one, clearly a 2" surround on a 2" cone is absurd...the diamter of a 2" cone does not lend itself to such a massive surround. And I imagine that the excursion capability of the cone is linked to this element of the design? So presumably a larger cone can more easily accept a larger surround...and more easily accept greater excursion?

On the second one, if we take a 20' cone...and move it 4 inches, the vast majority of the cone barely moves because at that angle...10 feet from the center, a movement of 4 inches barely registers for most of the cone. By logic then, would an 18" cone where the center is designed to have 4" of excursion capability have lower distortion on this one aspect than an 8" cone that also has 4" excursion capability?

 

[LL21]

Square inch to square inch is an interesting question. Without knowing the exact drivers it’s a little hard to say but likely the smaller ones would have to travel more. That’s because they put out less of the low frequency due to size and suspension etc. Either way you still adjust the SPL to match.

It would seem possible to be equal but smaller drivers have a few more normal constraints due to construction, so I suspect you have to drive them a little harder when square inches are equal.

Thank you! Sorry you are being asked to teach audio kindergarten, but I appreciate your time!

 

[Folsom]

Hi Folsom,

The other one that occurs to me in looking at smaller cones vs larger is:
1. the excursion being linked to the surround.
2. the same excursion (say 3") being lower distortion in an 18" cone than the same excursion in an 8" cone

Take the 1st one, clearly a 2" surround on a 2" cone is absurd...the diamter of a 2" cone does not lend itself to such a massive surround. And I imagine that the excursion capability of the cone is linked to this element of the design? So presumably a larger cone can more easily accept a larger surround...and more easily accept greater excursion?

On the second one, if we take a 20' cone...and move it 4 inches, the vast majority of the cone barely moves because at that angle...10 feet from the center, a movement of 4 inches barely registers for most of the cone. By logic then, would an 18" cone where the center is designed to have 4" of excursion capability have lower distortion on this one aspect than an 8" cone that also has 4" excursion capability?

An 8” cone at 4” excursion would be a fascinating thing to see. I suspect the overall dimensions of the drivers spider would be near a 18”’s...

I’m not sure why you are asking. The whole discussion is predicted on having more smaller drivers to have more surface area than the 18. Smaller drivers weigh less in the cone and are more controlled. In most of these situations the designer would probably exceed the amount of square inch you’d get from a larger driver, like by doing a line array.

So why compare excursion measurements, if all other things are not equal?

 

[dbeau]

An 8” cone at 4” excursion would be a fascinating thing to see. I suspect the overall dimensions of the drivers spider would be near a 18”’s...

I’m not sure why you are asking. The whole discussion is predicted on having more smaller drivers to have more surface area than the 18. Smaller drivers weigh less in the cone and are more controlled. In most of these situations the designer would probably exceed the amount of square inch you’d get from a larger driver, like by doing a line array.

And to the second paragraph, no, larger drivers that have to move farther will always have more distortion because they have to more farther. The farther the movement, the more the distortion. But as said before that distortion may be a benefit. It’s not like the frequencies that tell you a pluck of a bass string is indeed a string are even remotely near the bass region... And what big drivers do is have more SPL capability. I would note that a lot of big drivers or ones in certain enclosures could have low distortion because of barely moving - similar to a bunch of smaller ones.

I’m not sure what stock I’d put into fullranger stuff, since I have yet to hear an actually good fullrange speaker.

 

[dbeau]

Just an observation as I've been deep diving into REL videos, etc. and they apparently agree with a lot of this as they claim 'ambiance' using their 25 model using a single 15" cone (recommend 2+) correctly 'tuned'. REL relates that first efforts were with 18" and larger cones but without good results and came back to 15" and attention to speed (filters) cone design and materials and of course always the claim of 'box' construction. i am trialing a pair of 25s and yes 'ambiance' is more 'there' although my initial settings are near 20 hz for the cross over point and I'm thinking of going lower with WA X1s and I also agree that at least my speakers are not sufficient, in my room and limitations of placement, of providing all desired.

 

[LL21]

An 8” cone at 4” excursion would be a fascinating thing to see. I suspect the overall dimensions of the drivers spider would be near a 18”’s...

I’m not sure why you are asking. The whole discussion is predicted on having more smaller drivers to have more surface area than the 18. Smaller drivers weigh less in the cone and are more controlled. In most of these situations the designer would probably exceed the amount of square inch you’d get from a larger driver, like by doing a line array.

So why compare excursion measurements, if all other things are not equal?

The reason is because given a fixed amount of real estate in the room...i am trying to understand the broad direction of travel. As I try to get my head around the basics...I 'think' multiple smaller cones that would equate to fewer bigger cones strikes me intuitively as requiring more real estate (square footage and/or height).

Hence my inclination to focus on larger drivers, ideally with servo, and powerfully driven and (it goes without saying) a really high quality crossover/setup for adjusting to the system and room.

 

[LL21]

Just an observation as I've been deep diving into REL videos, etc. and they apparently agree with a lot of this as they claim 'ambiance' using their 25 model using a single 15" cone (recommend 2+) correctly 'tuned'. REL relates that first efforts were with 18" and larger cones but without good results and came back to 15" and attention to speed (filters) cone design and materials and of course always the claim of 'box' construction. i am trialing a pair of 25s and yes 'ambiance' is more 'there' although my initial settings are near 20 hz for the cross over point and I'm thinking of going lower with WA X1s and I also agree that at least my speakers are not sufficient, in my room and limitations of placement, of providing all desired.

Great stuff...thanks for the update on the 25s. I think looking at where Wilson has gone (from dual 15" to 3 x 12")...it is interesting to see.

Meanwhile, the Rockport Lyra is 2 x 10" vs the Altair at 1 x 15". The difference of course being that these cones are being asked to play a much wider band than a subwoofer cut off above 35 hz or so...let alone your 20hz.

 

[Folsom]

The reason is because given a fixed amount of real estate in the room...i am trying to understand the broad direction of travel. As I try to get my head around the basics...I 'think' multiple smaller cones that would equate to fewer bigger cones strikes me intuitively as requiring more real estate (square footage and/or height).

Hence my inclination to focus on larger drivers, ideally with servo, and powerfully driven and (it goes without saying) a really high quality crossover/setup for adjusting to the system and room.

Calculate how many 15" or 18" drivers you can fit into 2 foot cubed, now do the same for 8" drivers. You simply get a lot more configuration, and they don't have to be nearly as wide so you have options. The larger the drivers the more difficult box size and room placement will be.

 

[LL21]

Calculate how many 15" or 18" drivers you can fit into 2 foot cubed, now do the same for 8" drivers. You simply get a lot more configuration, and they don't have to be nearly as wide so you have options. The larger the drivers the more difficult box size and room placement will be.

Thank you! Yes, fair point. My super-crude approach was to look at roughly 2 feet cubed as you say:

- Funk 18.2: Dual opposed 18" drivers in the cabinet and 509 square inches of cone surface area
- Paradigm Sub 2: 6 x 10" woofers and 471 square inches of cones surface are
- Epoque Mini: 8 x 9" drivers and 509 square inches of cone surface area

Clearly the difference in surface area is less than 7% so its more about execution and implementation. Based on the measurements I have seen, the Funk dual-18" seems to reach further into the sub-20hz region with greater db and very low distortion than the Sub 2. While I am sure implementation counts for a lot, I was also thinking that perhaps some of the physics of the larger drivers might have also come into play.

FWIW, I have asked 1 or 2 sub designers about going with 8 x 9" vs 2 x 18", and for some reason, based on my requirements (basically 10hz-15hz up to 38hz+/-), they both seemed to feel that the execution was more straightforward and the results would be better, more powerful with the 2 x 18".