DIY Rythmik G22 Cabinet vs. Turn-key Sigberg 10D (Seeking Advice)

[marked sound]

Hi everyone,

I am looking to add a dual subwoofer setup to my high-end system (listening to a lot of pipe organ music, requiring deep extension). My room is relatively small (approx. 12ft x 10.5ft x 9.5ft) in an older home with easily rattled floors and older wiring.

I have an interesting dilemma. Rythmik located a lone, old-stock factory G22 in their warehouse that they will sell me, along with the raw drivers and plate amp to build a second matching unit myself. We all know what an incredible value the G22 is.

However, I am agonizing over the project risk. I know Rythmik’s Direct Servo technology is highly demanding. How risky/difficult is it to source a local woodworker or CNC shop to build a custom cabinet that perfectly matches factory servo specifications? I don't want to end up with a mismatched pair or a pile of expensive parts that aren't utilized properly. Also, since used G22s don't come up for sale often, I don't want to be forever searching for the matching sub.

The alternative path is just buying a pair of turn-key Sigberg Audio 10D subs, which meet my physical room/power constraints, but don't go quite as low, and sit at a COMPLETELY different price point. But at least I'd get two matching high quality subs with no headaches.

Would love to hear from anyone who has tackled a DIY Rythmik build, or engineers who can weigh in on the cabinet tolerances required for the servo system.

Thanks!

 

[Everett T]

Hi everyone,

I am looking to add a dual subwoofer setup to my high-end system (listening to a lot of pipe organ music, requiring deep extension). My room is relatively small (approx. 12ft x 10.5ft x 9.5ft) in an older home with easily rattled floors and older wiring.

I have an interesting dilemma. Rythmik located a lone, old-stock factory G22 in their warehouse that they will sell me, along with the raw drivers and plate amp to build a second matching unit myself. We all know what an incredible value the G22 is.

However, I am agonizing over the project risk. I know Rythmik’s Direct Servo technology is highly demanding. How risky/difficult is it to source a local woodworker or CNC shop to build a custom cabinet that perfectly matches factory servo specifications? I don't want to end up with a mismatched pair or a pile of expensive parts that aren't utilized properly. Also, since used G22s don't come up for sale often, I don't want to be forever searching for the matching sub.

The alternative path is just buying a pair of turn-key Sigberg Audio 10D subs, which meet my physical room/power constraints, but don't go quite as low, and sit at a COMPLETELY different price point. But at least I'd get two matching high quality subs with no headaches.

Would love to hear from anyone who has tackled a DIY Rythmik build, or engineers who can weigh in on the cabinet tolerances required for the servo system.

Thanks!

There is nothing difficult about building a diy sub, especially if sourcing the cabinet with the cutouts.

 

[Timcognito]

Try these guys. They have a lot of know how and might have something close to buy two or custom to match.

Creative Sound Solutions | High End Speakers and Speaker Kits

CSS offers unrivaled audio performance at any price point with creative solutions for the DIY-er, Hobbyist, or Frugal Audiophile

www.css-audio.com

Also get the CAD files from Rythmik if poosible

 

[Redacted]

You're going to get some interesting peaks and nulls in that room, when a 16' pipe blasts off.
You know what? Who cares! - go for tons of power and very big speakers. I would, "I like "behs"", and I cast aside any worries about scrotal safety or flapping trousers.


Now, over to my erudite buddies....

 

[Timcognito]

Lots of companies like this doing sub boxes for cars

Atrend USA | Custom Subwoofer Boxes & Enclosures Made in USA

Atrend USA builds premium subwoofer enclosures for 30+ years. Proudly made in the USA with precision craftsmanship, custom options & nationwide delivery.

atrendusa.com

 

[marked sound]

There is nothing difficult about building a diy sub, especially if sourcing the cabinet with the cutouts.

The massive, glaring caveat you dropped in your reply is "especially if sourcing the cabinet with the cutouts." That "if" is the entire hinge of my dilemma.

If Rythmik or a third-party company like DIYSoundGroup sold a pre-machined, flat-pack cabinet specifically designed for the G22 dual-driver layout, I would be laughing. I’d buy the flat-pack, glue it together over a weekend, and have a perfect match.

However, as far as i am aware, Rythmik doesn't currently offer a flat-pack for the G22. They sell flat-packs for their single-driver models (like the DS1200 or DS1500 CI), but the G22 is a complex, dual-opposed, internally braced enclosure.

So when you say "there is nothing difficult," you are assuming I can just order a pre-cut box. Since I can't, I am back to square one: taking Rythmik's internal volume and bracing blueprints to a local custom woodworker or CNC shop and hoping they cut and seal it to demanding servo standards.

 

[Timcognito]

If you have the CAD files you can. Plus you love this model and they are willing to help you out. You are close, at least get the NOS and I say parts too.

 

[marked sound]

If you have the CAD files you can. Plus you love this model and they are willing to help you out. You are close, at least get the NOS and I say parts too.

From what I know Rythmik is protective of their intellectual property and specific enclosure designs. The odds of Rythmik just handing over proprietary, factory CNC CAD files for a discontinued commercial product to a retail customer are slim to none. They sell DIY components for their Custom Install (CI) single-driver series, but I doubt they hand out blueprints for their premium, fully assembled dual-opposed commercial line. I can ask but I doubt it.

Now, Let's play devil's advocate and assume Rythmik gives me the exact CAD files. Now what? I can't just hand a raw CAD file to a standard local woodworker with a table saw. I have to find a dedicated commercial CNC fabrication shop willing to load a one-off custom job into their schedule.

Most CNC shops don't just hit "print" on a file you bring them. They charge an engineering/setup fee to program their specific machines for your file, select the tooling, and run toolpath simulations. For a single box, that setup fee alone can swallow up a massive chunk of the savings.

Now, even with perfectly CNC-routed panels, I (or a woodworker) still have to glue, clamp, and assemble an airtight, multi-layered dual-opposed chamber with heavy internal bracing. If there is a millimeter of error or a slight leak in the glue joint, the Direct Servo feedback loop is going to misbehave because the internal air pressure dynamics won't match the factory unit.

If you think it is so easy, then great! What do you charge?
I'm serious I'll pay.

 

[Everett T]

The massive, glaring caveat you dropped in your reply is "especially if sourcing the cabinet with the cutouts." That "if" is the entire hinge of my dilemma.

If Rythmik or a third-party company like DIYSoundGroup sold a pre-machined, flat-pack cabinet specifically designed for the G22 dual-driver layout, I would be laughing. I’d buy the flat-pack, glue it together over a weekend, and have a perfect match.

However, as far as i am aware, Rythmik doesn't currently offer a flat-pack for the G22. They sell flat-packs for their single-driver models (like the DS1200 or DS1500 CI), but the G22 is a complex, dual-opposed, internally braced enclosure.

So when you say "there is nothing difficult," you are assuming I can just order a pre-cut box. Since I can't, I am back to square one: taking Rythmik's internal volume and bracing blueprints to a local custom woodworker or CNC shop and hoping they cut and seal it to demanding servo standards.

There is nothing complex about the Rythmik cabinet at all. Any local woodworker can build one for you or handy, you can build it. Subwoofers are just boxes with a driver or two and an amp with DSP/EQ for sealed units.

 

[marked sound]

There is nothing complex about the Rythmik cabinet at all. Any local woodworker can build one for you or handy, you can build it. Subwoofers are just boxes with a driver or two and an amp with DSP/EQ for sealed units.

Reducing a high-performance subwoofer down to 'just a box with a driver and an amp' completely ignores the mechanical engineering required to make it work properly.

If this were a standard open-loop DIY sub where you can just throw DSP at the driver to force a flat response, I would agree with you. But the G22 is a dual-opposed, sealed, Direct Servo system.

In a servo setup, the amplifier relies on a physical sensing wire on the voice coil to instantaneously correct for distortion based on the strict air-spring pressure inside that exact enclosure volume. If a local woodworker builds a cabinet that has even minor internal micro-leaks or structural flex under massive pressure, the internal air compliance changes. The servo loop will actively fight those structural flaws, leading to unpredictable behavior, altered damping, or amplifier instability.

Saying 'any local woodworker can build it' severely underestimates how few standard cabinet makers understand airtight tolerances, internal bracing layout, and driver displacement volumes for high-pressure acoustic applications. There is a massive gulf between a cabinet that looks nice and one that is structurally inert under extreme pneumatic stress.

However, if you think this is so easy. How much would you charge to get this done? I'll pay.

 

[Timcognito]

Now, Let's play devil's advocate and assume Rythmik gives me the exact CAD files. Now what?

Atrend USA | Custom Subwoofer Boxes & Enclosures Made in USA

Atrend USA builds premium subwoofer enclosures for 30+ years. Proudly made in the USA with precision craftsmanship, custom options & nationwide delivery.

atrendusa.com

Prices are there custom may be more. send them a picture

 

[marked sound]

Atrend USA | Custom Subwoofer Boxes & Enclosures Made in USA

Atrend USA builds premium subwoofer enclosures for 30+ years. Proudly made in the USA with precision craftsmanship, custom options & nationwide delivery.

atrendusa.com

Prices are there custom may be more. send them a picture

Assuming i GOT the cad files, and this company COULD build me a FLAWLESS EXACT box down to exact milimeter (two big ifs), who is going to put it together?

Even with perfectly CNC-routed panels, I (or a woodworker) still have to glue, clamp, and assemble an airtight, multi-layered dual-opposed chamber with heavy internal bracing. If there is a millimeter of error or a slight leak in the glue joint, the Direct Servo feedback loop is going to misbehave because the internal air pressure dynamics won't match the factory unit.

You are treating this like a basic sub and it is so not that.
But as I said before, what do you charge?

 

[marked sound]

Atrend USA | Custom Subwoofer Boxes & Enclosures Made in USA

Atrend USA builds premium subwoofer enclosures for 30+ years. Proudly made in the USA with precision craftsmanship, custom options & nationwide delivery.

atrendusa.com

Prices are there custom may be more. send them a picture

I just looked into this company.

Are you seriously suggesting I buy a charcoal-carpeted, mass-produced car audio box from Atrend to house a high-end Rythmik Direct Servo subwoofer in my living room?

First of all, Atrend makes pre-fab enclosures for car trunks and trucks. They don't make dual-opposed, internally braced hifi enclosures designed to sit next to premium audiophile tower speakers.

Second, sending them a 'picture' doesn't magically teach a mass-production car audio shop how to build a cabinet to the exacting pneumatic tolerances required by Rythmik's feedback loop. If the box leaks or flexes, the servo wire on the voice coil misreads the air pressure and the amplifier distorts.

This just proves my exact point: finding an actual high-end precision manufacturer who understands hifi acoustic engineering to build a one-off G22 cabinet is a massive logistical headache. Suggesting a car audio trunk-box company isn't a solution—it just highlights how difficult it is to get a proper enclosure built.

 

[marked sound]

You guys would be better off suggesting a company like Harbottle or Funk Audio, but I doubt they would take on a project using another company's audio parts and subwoofer design.

 

[Timcognito]

You guys would be better off suggesting a company like Harbottle or Funk Audio, but I doubt they would take on a project using another company's audio parts and subwoofer design.

I did suggest CSS or maybe https://www.stewartspeakersystems.com/homeaudio
You could just buy the NOS and parts for repair, then wait for used to show up it will. Good luck. Over and out.

 

[Everett T]

Reducing a high-performance subwoofer down to 'just a box with a driver and an amp' completely ignores the mechanical engineering required to make it work properly.

If this were a standard open-loop DIY sub where you can just throw DSP at the driver to force a flat response, I would agree with you. But the G22 is a dual-opposed, sealed, Direct Servo system.

In a servo setup, the amplifier relies on a physical sensing wire on the voice coil to instantaneously correct for distortion based on the strict air-spring pressure inside that exact enclosure volume. If a local woodworker builds a cabinet that has even minor internal micro-leaks or structural flex under massive pressure, the internal air compliance changes. The servo loop will actively fight those structural flaws, leading to unpredictable behavior, altered damping, or amplifier instability.

Saying 'any local woodworker can build it' severely underestimates how few standard cabinet makers understand airtight tolerances, internal bracing layout, and driver displacement volumes for high-pressure acoustic applications. There is a massive gulf between a cabinet that looks nice and one that is structurally inert under extreme pneumatic stress.

However, if you think this is so easy. How much would you charge to get this done? I'll pay.

I get you think the G22 is a magic subwoofer, it's not, everything I said is true. Sealed subs are EQd for extension, and that's what the Rythmik amp does. The amp has a servo sensor and so does the driver, that's it just an additional cost that does provide a small benefit. There is a reason that there isn't very many servo subs or speakers available and it's not because it's not complex as servo circuits have been around a long time.

I'm not trying to be disparaging, just honest and I'm trying to be helpful for *you*.

Edit: I don't agree with Paul McGowan on very much, but I do here.

 

[Salt]

One more 'Don't feed the Trolls‘.

 

[levimax]

It sounds like, if you have the means, you would be happier going with 2 brand new supported and good looking Sigberg subs.

 

[marked sound]

I did suggest CSS or maybe https://www.stewartspeakersystems.com/homeaudio
You could just buy the NOS and parts for repair, then wait for used to show up it will. Good luck. Over and out.

I appreciate the suggestions. CSS makes great kits for their own drivers, but like Funk or Harbottle, they aren't in the business of doing one-off contract CNC manufacturing for a competitor's proprietary servo tech.

As for Stewart Speaker Systems, they are a small boutique shop out of Indiana. Paying an American shop a massive premium for custom engineering time, paying to freight a heavy, one-off wooden enclosure across the border into Canada, and just hoping a shop that has never handled a Rythmik Direct Servo setup gets the pneumatic tolerances millimeter-perfect is a massive logistical risk.

Buying parts to wait indefinitely for a rare, discontinued cabinet to pop up used isn't a viable strategy for me either. This exchange has just reinforced exactly why the turnkey certainty of a fully engineered factory pair of Sigbergs is the most logical path forward. Thanks for the discussion.

 

[marked sound]

It sounds like, if you have the means, you would be happier going with 2 brand new supported and good looking Sigberg subs.

I really like the extension of the G22 subs and if two were available id jump on them. If I felt a DIY G22 was easy I would jump on it too. Unfortunately neither seems possible. But if you are asking if I like the Sigberg 10D yes. It is just significantly more money and it is a smaller niche sub.