Genesis Advanced Technologies SuperSub Subwoofer

Ron Resnick

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Gary Koh, founder and CEO of Genesis Advanced Technologies, has been working on a new subwoofer, the SuperSub, consisting of two 8" drivers and two 12" drivers and two 15" drivers in one box. Gary's servo control system for the drivers is implemented here.

In Gary's words: “It’s not a 3-way crossover, it’s not that that 15s get the lowest frequency. Instead – I managed to integrate all of this to make each of the drivers (15,12,8) move the same amount of air. The excursion is proportional to the area of the cone. It is the most awesome bass I have ever heard. I was nicely surprised.”

It looks like the SuperSub was designed for the Genesis Quartet (successor to the Genesis 200 and 2.2), but it will be interesting to learn if Gary intends this subwoofer to be usable with any full-range loudspeaker.

The SuperSub can be stacked, apparently, to provide four 8" drivers and four 12" drivers and four 15" drivers per side. That would be a whole lot of woofing going on!

Interestingly, I think Gary is using a high-level signal, tapping the main speaker amplifier's output, to drive the SuperSub's amplifier and servo controllers

Please tell us more about this new product, Gary!

What is your design thinking behind this subwoofer, Gary?

Will the different driver sizes permit smoother integration with full-range speakers?

How, mechanically, would two SuperSubs be stacked?

Is the SuperSub intended for use only with Genesis loudspeakers, or is it designed to be able to be integrated with any full-range speaker?




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LL21

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Ron Resnick

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I knew you would be into this, LL21! :)
 

treitz3

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It looks like the SuperSub was designed for the Genesis Quartet (successor to the Genesis 200 and 2.2), but it will be interesting to learn if Gary intends this subwoofer to be usable with any full-range loudspeaker.

Is the SuperSub intended for use only with Genesis loudspeakers, or is it designed to be able to be integrated with any full-range speaker?

Hi, Ron. Based upon my experience with servo subs, while it may be optimized for a particular set of speakers, unless there is a cable specifically manufactured and wired to only pair with a particular set of speakers? A Direct Servo sub will work with any loudspeaker....and quite well too.

Gary is well respected in my book and I still am thanking him every day because years ago, he turned me onto direct servo subs. After purchasing 2 of them to flank the mains, I have never been happier with the end result as to what hits my ears and haven't worked on improving the bottom end ever since.

Congrat's on your new model, Gary! (and your new shop/phone number)

Tom
 

Ron Resnick

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. . . 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"

This makes its footprint 82% bigger than an XLF!

It's bigger than I guesstimated from the photos as well!

I hope it's very heavy!
 
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LL21

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Ron Resnick

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Yes, that is where I copied Gary's quote from!

Lloyd, it is interesting that in this configuration Gary has the SuperSubs firing side-to-side rather than front-to-back. Hopefully he can tell us his thinking behind that decision.
 
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LL21

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Given that Andy Payor has done side-firing woofers for years until only recently, I do wonder as well...

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?
 

Alrainbow

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I had a long discussion on his new subs. that man has the best controlled bass I ever heard. It’s extremely fast yet very powerful. He explained how each of the three sizes has an advantage. Fir him to achieve his Milestone he needed all 3 sizes. my first thought was why not a line source as they have there place in playing louder at greater distances. Where his subs would be disadvantaged, but in hearing them it’s a seemless sound. I could not tell what driver was where or felt integration could be heard. Gary’s monumental bass was achieved over many years. on his line source woofer towers he has rear firing woofers too.
 
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Alrainbow

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High power sub input is also a discussion I had in noticing my own issues. His reason makes perfect sense to me.
 

LL21

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I had a long discussion on his new subs. that man has the best controlled bass I ever heard. It’s extremely fast yet very powerful. He explained how each of the three sizes has an advantage. Fir him to achieve his Milestone he needed all 3 sizes. my first thought was why not a line source as they have there place in playing louder at greater distances. Where his subs would be disadvantaged, but in hearing them it’s a seemless sound. I could not tell what driver was where or felt integration could be heard. Gary’s monumental bass was achieved over many years. on his line source woofer towers he has rear firing woofers too.

Wow...good to know!! Thanks for the insight.
 
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Folsom

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Yes, that is where I copied Gary's quote from!

Lloyd, it is interesting that in this configuration Gary has the SuperSubs firing side-to-side rather than front-to-back. Hopefully he can tell us his thinking behind that decision.

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.
 

dbeau

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

Folsom

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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.
 

Ron Resnick

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Gary, please enlighten us! :D
 
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garylkoh

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Sorry folks, I had not seen this thread until one of my friends pinged me on FB. I'm rushing to get the new factory set-up to get back into production as soon as we can as I have a big upgrade to ship asap.

Will try to get to answering all your questions above on Sunday when I have a bit of me-time.
 

Ron Resnick

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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!
 

garylkoh

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Thank you all for your interest and your patience in waiting for me to respond. I watch the Genesis forum and would get an email if you post in there. So, if you want to specifically ask about Genesis, and would like my reply quickly, post in there please.

So, this "SuperSub" was not in the product roadmap, or even anything I had in the back of my mind, but it was something that came about out of the blue and out of my insatiable curiosity. It started out innocently enough. I have a customer with a pair of the G-Force (which has 2 x 10" woofers per speaker) who wanted more effortlessness in playing loud rock "live" recordings. So, I designed a "Force Majeure" - a pair of woofer towers the same size as the G-Force with 4 x 10" woofers per speaker.

I was running them in before delivery, and pairing it with my "convertible" bookshelf speakers.

Force Majeure.jpg

And I noticed one thing straight away. Ambience!

The Genesis Primes with their twenty four 12-inch woofers have a particular quality that is not as prominent in my other loudspeakers. On some recordings, at the beginning of the track before the music starts, the walls of your room melt away and you get transported to the recording venue. That is why I say that on my speakers, most of them will bring the musical venue to you, but with the flag-ship Prime/Dragon/G1.2 your music room becomes a holodeck and transports you in time and space to the musical venue.

And at the end of the track, before the mixing engineer fades the music off, you still feel like you are there. On some tracks, when it is ended abruptly instead of the 2 second fade that a good mixing engineer puts at the end, it can be pretty jarring.

The four x 10-inch woofers did it much better than the sixteen x 8-inch woofers in the Quartets. So, I brought in a few 8-inch woofers to mate with the 10-inch woofers.

Force Majeure with Maestros.jpg

Unfortunately, not so good....... This had been my experience anyway. Mixing woofers of different size in the same frequency range usually did not work too well. It was easy to measure why - the impulse measurement was a mess.

Nevertheless, my curiosity was piqued.
 
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garylkoh

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So, what would be the lower limit of woofer size to be able to create this "ambient silence"? Of course, the recording has to be very good to be able to do this. And what frequency do you need to get to to be able to deliver this? Turned out not to be too easy a task to figure out as when I looked at the waveforms of some of the music that seemed to display this, I wouldn't be able to distinguish this from the noise floor. And on records where the noise floor is much higher than CDs, I can detect more of the "ambient silence" than on CDs.

So, I had to build stuff and depend on listening and the "skin-gasm" and not so much measurements.

With the pair of bookshelf speakers (the G7 convertible), the Quartet towers comprising sixteen 8-inch woofers did not do as much as four 12-inch woofers using two G928 subwoofers. Two more G928's (total eight 12-inch woofers) gave me much, much more than the eight 10-inch woofers in the Force Majeure. So, I figure it has to have something to do with cone area and how the woofer couples with the air. With servo-control of the woofer cone (and sufficient power for the servo-loop), I couldn't measure any difference between 8-inch, 10-inch or 12-inch woofers. But they all sound different when presented with music.

So, since I had 8-inch, 12-inch and some 15-inch woofers in-stock, I made a prototype cabinet with two of each. I like using exactly two, and horizontally opposed so that the cabinet doesn't hop around when driven hard. That was over 2 years ago. Along the way, I nearly gave up multiple times, but I am glad I persevered. Because like I said, when I got it, it was really the most awesome bass I had ever heard. And for all kinds of music and recording, not only for jazz or organ music.
 

garylkoh

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Sep 6, 2010
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This design was exclusively for use with Genesis loudspeakers. I don't think anyone is going to buy a $100,000 pair of subwoofers to match a $6,000 pair of bookshelves.

While it can probably be used with other speakers, we would have the same problem integrating the SuperSub to other loudspeakers (may be even more so) as we had trying to integrate the Force Majeure to the Genesis Maestros.

This is one reason why I use a high-level input to the SuperSub (and all our external amplified woofers). If the woofer amplifier is driven by the preamp, there is a one-level disconnect between the high-pass filter for the midrange and the low-pass filter for the woofer - the main power amplifier used. Since this component has a group delay (some tube amps even completely invert phase) the loudspeaker designer has no clue what the customer would use..... and hence he cannot design a crossover between the midrange and the woofer with an unknown element interspersed there.

Making sure that the amplifier is outside the circuit, we can design an active low-pass filter for the woofer and the passive high-pass filter for the midrange that would allow us to perfectly integrate the active woofer to the passive midrange. This way, it will sound completely seamless.

There is another problem with integrating the SuperSub (and even any active sub-woofer) to other full-range loudspeakers. Many large full-range speakers come with a port. If you understand how a port works, the output of the port is out-of-phase with the output of the woofer below the port tuning frequency. That is why the bass output drops out at 12dB per octave at the lower end of the frequency response of the speaker. Any subwoofer used would have to first cancel out this out-of-phase signal from the port before it can produce any significant output.

Then, you will have to match the impulse response of the SuperSub with the woofers of your main loudspeaker. While it is possible (I provide a phase control that can delay the phase by 5 degrees up to 180 degrees) I don't know if I want to be responsible for that system matching.
 

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