AudioCircle
Industry Circles => Hollis Audio Labs => Topic started by: HAL on 22 Sep 2023, 12:02 pm
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To go with the MG10/QR DSP Crossover project, worked with folks to develop a modular 8in Servo Sub OB H-Frame 4x8 stack. These are for the GR-Research 8in servo subs from the latest design. These will work below the 80Hz cutoff of the planars down to 30Hz.
These are the flat packs being test fitted before glue-up and then off to be painted.
Getting them ready for CAF2023.
(https://www.audiocircle.com/image.php?id=256856)
(https://www.audiocircle.com/image.php?id=256857)
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Please keep us informed as this product is developed and brought to market - with pictures and data along the way!
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Please keep us informed as this product is developed and brought to market - with pictures and data along the way!
Yes, please do so. I'm also interested in these. Will these cabinets fit the old 8" OB drivers as well?
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You would need to ask Danny, but I believe they are the same size as the original 8in servo sub drivers.
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Checked out the grill frames that insert into the OB H-Frame module face.
Then glued and clamped the first module to do a test fit of the 8in servo woofer.
Will wire up the driver connections before installing. It is a tight fit in the module.
(https://www.audiocircle.com/image.php?id=256918)
(https://www.audiocircle.com/image.php?id=256921)
(https://www.audiocircle.com/image.php?id=256920)
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Rich, I'm super excited to see how these turn out. Could you elaborate to the outside dimensions of the modules?
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Hal, is there anything you cannot make. One talented Man.
charles
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Rich, I'm super excited to see how these turn out. Could you elaborate to the outside dimensions of the modules?
nlitworld,
The outer dimensions are approximately 12.25inW x 12.25inD x 11.5inH. For when they stack the tops and bottoms of each module are 1/2 thickness of the sides.
Charles,
I know talented people that can do great work. I just come up with some ideas.
Rich
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Two of the 8in OB H-Frames with the sub drivers installed and wired.
Time for some testing.
(https://www.audiocircle.com/image.php?id=256960)
(https://www.audiocircle.com/image.php?id=256961)
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Building two more of the 8in sub modules today and install the servo drivers tomorrow.
Waiting on more Neutrik connectors to arrive today to be ready for the next 4x8 stack being done.
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Can you run 3 of them stacked and use them as stands for bookshelf sized speakers?
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Tyson,
That would be a 5.3 Ohm load and fine for any Rythmik Audio servo amp.
With the bass and top would be about 38in high.
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Finished the 4th sub module and the rest of the wiring for the 8in servo subs.
Once the 4th module glue has set, then install the next two servo woofers and wire them up.
(https://www.audiocircle.com/image.php?id=257015)
(https://www.audiocircle.com/image.php?id=257016)
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The first 4x8 H-Frame stack is complete. The glue for module#4 will be dry by tonight to install the last 8in servo woofer.
The 3x8 H-Frame stack is either 36.75" tall or 35.75" tall depending on if the top cap is installed. A bit lower for putting a small 2-way monitor on to add extension to 30Hz.
(https://www.audiocircle.com/image.php?id=257027)
(https://www.audiocircle.com/image.php?id=257026)
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Assembling the last 2 modules this week and then getting a finishing estimate for the two 4x8in stacks.
Will be testing them soon with hopefully the latest generation Rythmik Audio HX series amps customized for these drivers.
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Last sub module assembled and drying overnight.
Also received the reworked Magna Risers for the larger bolts in the MG10/QR's with the new stainless steel machine screws.
(https://www.audiocircle.com/image.php?id=257180)
(https://www.audiocircle.com/image.php?id=257181)
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Both 4x8in servo sub towers are complete.
This is the idea with the MG10/QR's with the Magna Risers stands installed.
Now for some measurements to see what is needed for the DSP crossover.
(https://www.audiocircle.com/image.php?id=257204)
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Very cool. Are you running the MG10's active, or just the subs?
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The system will be entirely active with the dspNexus 2x8 as the control system. The MQ10/QR's will be driven from 80Hz up with a pair of Orchard Audio Starkrimson Monos as 2-way active.
Even the sub crossovers are being modified in the DSP for better response to crossover with the MG10/QR's. Did this with the Magnetar II speakers and 3x12 servo subs. Made a big difference using the AVR input setting.
Then time delay the mains to match the subs in their best locations.
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Oh man, that's gonna be nice!
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Wiring has occurred.
Now to get the Music Server PC setup and start Audio Weaver to download the new DSP crossover prototype to the dspNexus 2x8.
Next is measurements of the MG10/QR drivers for an updated DSP crossover design.
(https://www.audiocircle.com/image.php?id=257238)
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The two 4x8in OB servo sub cabinets are off to finishing at the cabinet shop.
Going to be a semigloss black finish, but not the Hot Rod Black. It will be waterproof.
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Is this for a customer or are you doing purely as a HAL project?
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Tyson,
These are prototype 8in servo subs that will lead to production systems.
These should work well for most planar systems to add low end down to 30Hz. The stack size depends on the room.
Most people say the 12in size servo subs look or are too big for their rooms. These should solve that problem.
Rythmik Audio will be the deciding factor. I am looking at the HX310 servo amps as they can be modified for balanced input and 8in OB systems. We shall see what happens with those inputs to them.
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Can you run 4 subs on a single amp? I know the 12 inch subs are limited to 3 drivers per amp.
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Something else that might be fun is lay the subs sideways and set the planars on top of them. That would be REALLY space efficient, lol.
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Tyson,
My understanding is that the new batch of 8in servo subs have higher impedance so a 4x8in stack will run on one amp.
That will be tried once prototype servo amps arrive. It should work correctly.
Yes, with modules it is easy to experiment with different sub configuration. The limitation will be length of the inter sub wiring to the servo amps.
Might try that with the MG10/QR's with either all lying down as a stand or maybe two one each side of the speaker. :)
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:thumb:
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Looks like the prototype servo amps for the 8in servo subs will be here this week. :D
Time to build some amp cabinets.
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The servo amps need boxes, so these are captainhemo's HX style flat pack boxes.
Box #1 it glued and clamped to dry. Then on to box #2 assembly.
(https://www.audiocircle.com/image.php?id=257732)
(https://www.audiocircle.com/image.php?id=257733)
(https://www.audiocircle.com/image.php?id=257734)
(https://www.audiocircle.com/image.php?id=257735)
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The custom modified HX300-8OB servo amps are here and now in their boxes to get wired to the servo subs. This is not the original HX300-8OB.
Using the Neutrik 4-pole Speakon connectors on the cabinets and wiring harness for simple connections.
Wiring the cable harness is ongoing as the parts arrived today to complete the wiring.
The 4x8in OB cabinets are to be finished this week and delivered.
Getting closer!
(https://www.audiocircle.com/image.php?id=257859)
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The servo amps are wired and ready for testing.
Next step is to wire the cable harness to the individual modules.
(https://www.audiocircle.com/image.php?id=257860)
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(https://c.tenor.com/Xw-PgnWOUBYAAAAC/tenor.gif)
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The servo amps are wired and ready for testing.
Next step is to wire the cable harness to the individual modules.
(https://www.audiocircle.com/image.php?id=257860)
On the speaker side of cabling, why not put terminals in the wood box so customers can use whatever cable brand they like/have clean looking wiring?
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The latest version of these amp boxes can have the Neutrik connector mounted in the box. The wiring is directly from the amp board without any other connections before the cable. This was just convenient to put the Neutrik connector on the existing cables.
These are early versions of the mounting boxes that did not have the mounting hole drilled. They can be made with or without the mounting hole.
The servo amps requires a 4 wire connection to the servo sub drivers for the servo amp to work correctly.
The customer can purchase them either way as flat packs, or as built.
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The HX300-8OB servo amps are wired to the two sets of 4x8in servo subs. They are now working as expected.
The finished 4x8in OB H-Frames should be here on Friday to finish the install of the drivers and wiring.
(https://www.audiocircle.com/image.php?id=257941)
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That room looks like an audio laboratory. Love it!!
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Tyson,
It is an audio lab. Wait until I have the two new 6x12's servo subs built and take two more 3x12's to the rear of the room! :o
That is going to be an experiment! :)
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Tyson,
It is an audio lab. Wait until I have the two new 6x12's servo subs built and take two more 3x12's to the rear of the room! :o
That is going to be an experiment! :)
I have 2 towers of 3x12 OB subs in my basement, so 6 bass woofers total, and that's already insane amounts (and quality) of bass. I can't even imagine having 18!!!!
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Tyson,
It is an audio lab. Wait until I have the two new 6x12's servo subs built and take two more 3x12's to the rear of the room! :o
That is going to be an experiment! :)
And how soon til you replace the foundation to your house? Sheesh, all that shaking will register on the Richter scale for sure!
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And how soon til you replace the foundation to your house? Sheesh, all that shaking will register on the Richter scale for sure!
Luckily the house and audio room are on a 6in slab of concrete. Will be interesting to hear the results! :)
Maybe use it for massage therapy as well! :)
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Both 4x8in servo sub wiring harnesses are complete and working.
The two 4x8in modular sub cabinets are to be finished and deliverd Tuesday. Then time to install the servo drivers and start measurements and listening.
(https://www.audiocircle.com/image.php?id=258159)
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The Scientist at work
charles
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You forgot the "MAD" part :P
The Scientist at work
charles
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BWAHAHAHAHAHAHA! :D
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The 4x8" servo sub H-Frames are back from painting. These were done with cabinet grade semigloss black paint, not the automotive Hot Rod Black like the 3x12" cabinets.
Now to install the drivers and wiring to test and listen.
(https://www.audiocircle.com/image.php?id=258236)
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Make your bed. We should be able to bounce a quarter.
:nono:
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Talk to my wife about that. She did it. :nono:
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How many pizza boxes fit under the bed?
Alan
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At least four.
Four of the pizza boxes make two 250W Class D monoblocks amps. :D
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And... servo sub stack #1 is complete.
Servo sub stack #2 is half done. Easy to see how the modules stack.
Stack #2 will be complete tomorrow then testing and listening. :)
(https://www.audiocircle.com/image.php?id=258258)
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The two open baffle 4x8in modular sub stacks are complete and now making music.
Will be doing another round of measurements to integrate the MG10/QR's and sub stacks to get ready for CAF2023.
(https://www.audiocircle.com/image.php?id=258273)
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Question - how do you make a wimpy looking speaker more badass?
Answer - add intimidating looking subwoofer towers.
:thumb:
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:weights: :beer:
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How low would stacks of 3 of these 8" woofers play, rather than stacks of 4?
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They still play to 30Hz, but they will be 3dB lower in max SPL.
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They still play to 30Hz, but they will be 3dB lower in max SPL.
Thank you. And I think I see that each module is 11.5"H. So a stack of 3 would be ~34.5"H?
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With the base and top about 37in. Those can be adapted if shorter subs are needed. They add about 2in.
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Here are the 4x8in servo subs at CAF2023 last weekend.
Even the Magnepan folks came in for a listen to their upgraded 30 year old pair of MG10/QR's. We got Magnepan buttons for the room. :)
(https://www.audiocircle.com/image.php?id=258677)
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TAS YT Video:
https://www.youtube.com/watch?v=G2aRzygAOgI (https://www.youtube.com/watch?v=G2aRzygAOgI)