Jeff Bagby's Helios CM Bookshelf Speaker Kit

stangman67
stangman67 Posts: 2,179
edited April 2022 in DIY, Mods & Tweaks
Fellow polkies,

I am going to use this thread to chronicle my progress and lessons learned on a DIY speaker project I am undertaking.

A few months back, I was looking for a project/challenge to keep myself busy. I have done basic woodworking in the past and I really enjoy it so I decided to mix that with the audiophile bug. Been gathering parts and pieces and tools over the past few weeks and I officially began the project today.

Details on the project, kit and components are from Meniscus audio https://meniscusaudio.com/product/the-helios-cm-loudspeaker-kit/. It is a large "bookshelf" with a 8" SB acoustics woofer, a SB soft dome tweeter with a badass waveguide and a 10" SB acoustics passive radiator.

Here is one of the designers (Javid Shadzi) finish build. His will be way way nicer than mine but gives an idea of the makeup of the speaker

m792lqbck16f.jpg

I will be using 3/4 MDF with a 1.5" baffle and internal bracing, and I will be doing an automotive quality paint job on the speakers. I will probably be painting them either British Racing Green or a Cementy Gray. This will be my first attempt at doing a high quality paint job, so plenty of opportunities to screw up and learn!

Anyway, progress pics thus far

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96lbqsmozr35.jpeg



Pretty happy with the fit and finish considering I don't have a table or track saw and am making all cuts with a circular saw and guide. These will notionally be going into my garage powered by a NAD C 368, but i MAY try to sneak them into my living room if I can con my wife into allowing it!

FYI this will be a slow build as I am in the Navy and will be underway for the majority of the next few months. I am aiming to get these done by the end of July.

-Zach


2 Channel in my home attic/bar/man cave

2 Channel Focal Kanta 3 I Modwright SWL9.0 Anniversary Pre I Modwright PH9.0X I Modwright KWA-150SE I VPI Prime Signature w/ Soundsmith Zephyr MIMC I Lumin U2 Mini I North Star Designs Intenso DAC I Audience OHNO ICs/Audience Furutech FP-S55N and FP-S032N Power Cables/Acoustic Zen Satori I Isotek Sirius
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Comments

  • stangman67
    stangman67 Posts: 2,179
    Also I fully Underestimated the cost of all the little bits and pieces it takes to make a project like this come together. DIY certainly is not cheaper than just purchasing lol, but now I have the stuff to continue to build speakers in the future.
    2 Channel in my home attic/bar/man cave

    2 Channel Focal Kanta 3 I Modwright SWL9.0 Anniversary Pre I Modwright PH9.0X I Modwright KWA-150SE I VPI Prime Signature w/ Soundsmith Zephyr MIMC I Lumin U2 Mini I North Star Designs Intenso DAC I Audience OHNO ICs/Audience Furutech FP-S55N and FP-S032N Power Cables/Acoustic Zen Satori I Isotek Sirius
  • VR3
    VR3 Posts: 27,967
    Looking good!
    - Not Tom ::::::: Any system can play Diana Krall. Only the best can play Limp Bizkit.
  • Gardenstater
    Gardenstater Posts: 4,136
    edited April 2022
    I like the 1.5" thick MDF front baffle. What radius roundovers are you planning for the corners? Those must be pretty good drivers. Nice smooth frequency response in that enclosure. Vented pole on the woofer

    xi4vq1r5p5oi.jpg

    vbuowemmi3a5.jpg

    George / NJ

    Polk 7B main speakers, std. mods+ (1979, orig owner)
    Martin Logan Dynamo sub w/6ft 14awg Power Cord
    Crown D150 amp
    Logitech Squeezebox Touch Streamer w/EDO applet
    iFi nano iDSD DAC
    iPurifier3
    iDefender w/ iPower PS
    Custom Steve Wilson 1m UPOCC Interconnect
    iFi Mercury 0.5m OFHC continuous cast copper USB cable
    Custom Ribbon Speaker Cables, 5ft long, 4N Copper, 14awg, ultra low inductance
    Custom Vibration Isolation Speaker Stands and Sub Platform
  • stangman67
    stangman67 Posts: 2,179
    Yea I am very excited to see how these things perform. I am thinking a 1/2” round over, I’ve been toying with doing a 5/8 but might be a bit aggressive
    2 Channel in my home attic/bar/man cave

    2 Channel Focal Kanta 3 I Modwright SWL9.0 Anniversary Pre I Modwright PH9.0X I Modwright KWA-150SE I VPI Prime Signature w/ Soundsmith Zephyr MIMC I Lumin U2 Mini I North Star Designs Intenso DAC I Audience OHNO ICs/Audience Furutech FP-S55N and FP-S032N Power Cables/Acoustic Zen Satori I Isotek Sirius
  • Gardenstater
    Gardenstater Posts: 4,136
    edited April 2022
    stangman67 wrote: »
    Yea I am very excited to see how these things perform. I am thinking a 1/2” round over, I’ve been toying with doing a 5/8 but might be a bit aggressive

    Might be tough. Plans say woofer cutout is 242mm = 9.53". Cabinet width (outer) is 10.5"? If you wanted to get fancy you could make a progressively larger radius as you progress from the woofer to the top. Tweeter could at least have a 1.5" radius at the top perhaps and woofer 0.5".
    George / NJ

    Polk 7B main speakers, std. mods+ (1979, orig owner)
    Martin Logan Dynamo sub w/6ft 14awg Power Cord
    Crown D150 amp
    Logitech Squeezebox Touch Streamer w/EDO applet
    iFi nano iDSD DAC
    iPurifier3
    iDefender w/ iPower PS
    Custom Steve Wilson 1m UPOCC Interconnect
    iFi Mercury 0.5m OFHC continuous cast copper USB cable
    Custom Ribbon Speaker Cables, 5ft long, 4N Copper, 14awg, ultra low inductance
    Custom Vibration Isolation Speaker Stands and Sub Platform
  • stangman67
    stangman67 Posts: 2,179
    I’m not gonna do anything fancy, too much room for error. I’ll probably do a 1/2 on front baffle and the top, will finalize that once the drivers get here and go from there. I’m real afraid of getting this all together and then having a bad tear out, should be able to do the vast majority before assembly on my router table and then just free hand the intersection points after everything is together.
    2 Channel in my home attic/bar/man cave

    2 Channel Focal Kanta 3 I Modwright SWL9.0 Anniversary Pre I Modwright PH9.0X I Modwright KWA-150SE I VPI Prime Signature w/ Soundsmith Zephyr MIMC I Lumin U2 Mini I North Star Designs Intenso DAC I Audience OHNO ICs/Audience Furutech FP-S55N and FP-S032N Power Cables/Acoustic Zen Satori I Isotek Sirius
  • xschop
    xschop Posts: 4,636
    That's some really dense looking MDF. Nice choice of DIY. Gotta appreciate the passive radiator on the side too. Should help with room placement options?
    Don't take experimental gene therapies from known eugenicists.
  • stangman67
    stangman67 Posts: 2,179
    Got up early and finished the cuts for the other speaker. Made one stupid mistake but had just enough left over wood to create another side piece.

    Also for anyone looking for a cheap router setup, this Skil 1322 and its associated router table are a fantastic and very usable combo. 2HP router and table for under 300 bucks is pretty incredible. Has a nice fence, and good attachments to do basically anything you would need to do for light Hobby duty

    And because Polk forum, here is the current garage speaker! Monitor 40’s I’ve had for about 15 years. Still kicking

    oyn18gb7dp14.jpeg
    c8q888ztt0wc.jpeg
    cgih45szmp4v.jpeg
    2 Channel in my home attic/bar/man cave

    2 Channel Focal Kanta 3 I Modwright SWL9.0 Anniversary Pre I Modwright PH9.0X I Modwright KWA-150SE I VPI Prime Signature w/ Soundsmith Zephyr MIMC I Lumin U2 Mini I North Star Designs Intenso DAC I Audience OHNO ICs/Audience Furutech FP-S55N and FP-S032N Power Cables/Acoustic Zen Satori I Isotek Sirius
  • Gardenstater
    Gardenstater Posts: 4,136
    Nice little router table. I've got a homemade one that takes my Elu Plunge Router. Mine is built like a tank but needs to be accesorized more by myself.

    What are you doing with the side baffle thickness for the Passive? Are you going with the recommended 1-1/4" there?
    George / NJ

    Polk 7B main speakers, std. mods+ (1979, orig owner)
    Martin Logan Dynamo sub w/6ft 14awg Power Cord
    Crown D150 amp
    Logitech Squeezebox Touch Streamer w/EDO applet
    iFi nano iDSD DAC
    iPurifier3
    iDefender w/ iPower PS
    Custom Steve Wilson 1m UPOCC Interconnect
    iFi Mercury 0.5m OFHC continuous cast copper USB cable
    Custom Ribbon Speaker Cables, 5ft long, 4N Copper, 14awg, ultra low inductance
    Custom Vibration Isolation Speaker Stands and Sub Platform
  • stangman67
    stangman67 Posts: 2,179
    No I am not, staying with 3/4 braced. The plans are wrong, if you look at the minimum internal dimensions and the outer dimensions they do not match up so I had to contact Javid and he told me to just stick with the outer dimensions (and keep the baffle the same exact size while other dimensions could be fudged. Those plans are a mash up between the Helios and Helios CM, the standard Helios uses a BE tweeter and a better SB 9” woofer.

    If I had done 1.25 inch side baffle, and kept the baffle dimensions 10.5 wide by 18 tall, the internal width would have shrunk to 8.5 inches and I would have lengthened the cab a bit to get air volume correct (not to mention tightening the woofer cut out).

    Decided to just do 3/4 side panel, I’m taking the recommended lumber dimensions with a grain of salt. Hopefully I don’t regret it
    2 Channel in my home attic/bar/man cave

    2 Channel Focal Kanta 3 I Modwright SWL9.0 Anniversary Pre I Modwright PH9.0X I Modwright KWA-150SE I VPI Prime Signature w/ Soundsmith Zephyr MIMC I Lumin U2 Mini I North Star Designs Intenso DAC I Audience OHNO ICs/Audience Furutech FP-S55N and FP-S032N Power Cables/Acoustic Zen Satori I Isotek Sirius
  • stangman67
    stangman67 Posts: 2,179
    After doing some maths, 1/2 is the absolute max I can go with a round over and that will only leave a sliver between the driver recess and edge of the round over. I think I’ll be ok but will assess later on. I don’t think 3/8 is enough visually but I may have to go that route for safety, or maybe I can use a thumbnail bit
    2 Channel in my home attic/bar/man cave

    2 Channel Focal Kanta 3 I Modwright SWL9.0 Anniversary Pre I Modwright PH9.0X I Modwright KWA-150SE I VPI Prime Signature w/ Soundsmith Zephyr MIMC I Lumin U2 Mini I North Star Designs Intenso DAC I Audience OHNO ICs/Audience Furutech FP-S55N and FP-S032N Power Cables/Acoustic Zen Satori I Isotek Sirius
  • stangman67
    stangman67 Posts: 2,179
    Nice little router table. I've got a homemade one that takes my Elu Plunge Router. Mine is built like a tank but needs to be accesorized more by myself.

    What are you doing with the side baffle thickness for the Passive? Are you going with the recommended 1-1/4" there?

    After doing a bit of research, I may have to do a 1/2” addition to the side panel and deal with the small amount of volume loss. I didn’t realize the thickness of the frame of the passive radiator would be almost a half of an inch!
    2 Channel in my home attic/bar/man cave

    2 Channel Focal Kanta 3 I Modwright SWL9.0 Anniversary Pre I Modwright PH9.0X I Modwright KWA-150SE I VPI Prime Signature w/ Soundsmith Zephyr MIMC I Lumin U2 Mini I North Star Designs Intenso DAC I Audience OHNO ICs/Audience Furutech FP-S55N and FP-S032N Power Cables/Acoustic Zen Satori I Isotek Sirius
  • Gardenstater
    Gardenstater Posts: 4,136
    edited April 2022
    stangman67 wrote: »
    Nice little router table. I've got a homemade one that takes my Elu Plunge Router. Mine is built like a tank but needs to be accesorized more by myself.

    What are you doing with the side baffle thickness for the Passive? Are you going with the recommended 1-1/4" there?

    After doing a bit of research, I may have to do a 1/2” addition to the side panel and deal with the small amount of volume loss. I didn’t realize the thickness of the frame of the passive radiator would be almost a half of an inch!

    I guess you don't think you could just add some 1/2" MDF on the outside and keep the interior dimensions the same? I'm sure the speaker design is well thought out but he shoulda had someone with some drafting skill draw up those plans :(
    George / NJ

    Polk 7B main speakers, std. mods+ (1979, orig owner)
    Martin Logan Dynamo sub w/6ft 14awg Power Cord
    Crown D150 amp
    Logitech Squeezebox Touch Streamer w/EDO applet
    iFi nano iDSD DAC
    iPurifier3
    iDefender w/ iPower PS
    Custom Steve Wilson 1m UPOCC Interconnect
    iFi Mercury 0.5m OFHC continuous cast copper USB cable
    Custom Ribbon Speaker Cables, 5ft long, 4N Copper, 14awg, ultra low inductance
    Custom Vibration Isolation Speaker Stands and Sub Platform
  • stangman67
    stangman67 Posts: 2,179
    I can definitely add a 1/2” panel to the left side but that would end up widening the baffle to 11 inches instead of 10.5. I don’t have the experience to know how much that 1/2 width would affect things but Javid made it very clear that the baffle dimensions were of utmost importance and the other dimensions could be changed a bit to suit my design.

    The Helios speaker has very accurate plans, Javid said someone at Meniscus must have drafted up the CM plan and that wasn’t run through him, he said he would try to get them to fix it.

    2 Channel in my home attic/bar/man cave

    2 Channel Focal Kanta 3 I Modwright SWL9.0 Anniversary Pre I Modwright PH9.0X I Modwright KWA-150SE I VPI Prime Signature w/ Soundsmith Zephyr MIMC I Lumin U2 Mini I North Star Designs Intenso DAC I Audience OHNO ICs/Audience Furutech FP-S55N and FP-S032N Power Cables/Acoustic Zen Satori I Isotek Sirius
  • WLDock
    WLDock Posts: 3,073
    edited April 2022
    That is such a cool kit. It looks like you are off to a great and have a nice clean workspace.

    I'm a fan of SB Acoustics drivers and was actually checking out the Rick Craig Integrity kit (Tribute to Jeff Bagby) at one point. I actually met Rick at the AXPONA shows years ago. He was hanging out in the Van Alstine room if I remember correctly. Sad that both those design gurus are no longer with us.

    I've Been wanting to build something for years. Someday....
    2.2 Office Setup | LG 29UB55 21:9 UltraWide | HP Probook 630 G8 | Dell Latitude | Cabasse Stream Amp 100 | Boston Acoustics VS 240 | AUDIORAX Desk Stands | Mirage Omni S8 sub1 | Mirage Omni S8 Sub2
  • xschop
    xschop Posts: 4,636
    Hopefully they didn't kit it together like an Ikea furniture piece that is missing fasteners and prone to bad fitment.
    Don't take experimental gene therapies from known eugenicists.
  • stangman67
    stangman67 Posts: 2,179
    edited April 2022
    I’ve always had good luck with ikea!

    Nothing too exciting, slowly getting the cabinets built up. I have a limited amount to clamps and doing one panel at a time gives me the ability to bet very precise in fitment, so I don’t have to sand much/use filler or bondo to get all the surfaces in line and level. So far the fitment is close to spot on. My goal is to get the cabinets fully assembled and driver holes cut before I get underway in 12 days. We will see if I can get there

    r81iyclbcuuz.jpeg
    2 Channel in my home attic/bar/man cave

    2 Channel Focal Kanta 3 I Modwright SWL9.0 Anniversary Pre I Modwright PH9.0X I Modwright KWA-150SE I VPI Prime Signature w/ Soundsmith Zephyr MIMC I Lumin U2 Mini I North Star Designs Intenso DAC I Audience OHNO ICs/Audience Furutech FP-S55N and FP-S032N Power Cables/Acoustic Zen Satori I Isotek Sirius
  • xschop
    xschop Posts: 4,636
    Do you just use regular wood glue? And what about terminal posts/plate options?
    Don't take experimental gene therapies from known eugenicists.
  • stangman67
    stangman67 Posts: 2,179
    Using Titebond II, gold standard in wood glue.

    I’ll just be using simple binding posts, these in fact

    https://meniscusaudio.com/product/big-posts/

    Unsure if I’m gonna put them directly through the back of the cab or do some sort of metal trim plate
    2 Channel in my home attic/bar/man cave

    2 Channel Focal Kanta 3 I Modwright SWL9.0 Anniversary Pre I Modwright PH9.0X I Modwright KWA-150SE I VPI Prime Signature w/ Soundsmith Zephyr MIMC I Lumin U2 Mini I North Star Designs Intenso DAC I Audience OHNO ICs/Audience Furutech FP-S55N and FP-S032N Power Cables/Acoustic Zen Satori I Isotek Sirius
  • Gardenstater
    Gardenstater Posts: 4,136
    Looking like you're making some nice progress. After taking another look at the plans, besides the errors we have talked about, it looks like the window brace they show would interfere with the passive radiator, which extends almost 3" inward from the outer surface of the cabinet, so about 1-3/4" from the inside.
    George / NJ

    Polk 7B main speakers, std. mods+ (1979, orig owner)
    Martin Logan Dynamo sub w/6ft 14awg Power Cord
    Crown D150 amp
    Logitech Squeezebox Touch Streamer w/EDO applet
    iFi nano iDSD DAC
    iPurifier3
    iDefender w/ iPower PS
    Custom Steve Wilson 1m UPOCC Interconnect
    iFi Mercury 0.5m OFHC continuous cast copper USB cable
    Custom Ribbon Speaker Cables, 5ft long, 4N Copper, 14awg, ultra low inductance
    Custom Vibration Isolation Speaker Stands and Sub Platform
  • stangman67
    stangman67 Posts: 2,179
    Correct. In the cabinet build pdfs, it shows the correct way to do the brace. It will be notched for the passive
    2 Channel in my home attic/bar/man cave

    2 Channel Focal Kanta 3 I Modwright SWL9.0 Anniversary Pre I Modwright PH9.0X I Modwright KWA-150SE I VPI Prime Signature w/ Soundsmith Zephyr MIMC I Lumin U2 Mini I North Star Designs Intenso DAC I Audience OHNO ICs/Audience Furutech FP-S55N and FP-S032N Power Cables/Acoustic Zen Satori I Isotek Sirius
  • Gardenstater
    Gardenstater Posts: 4,136
    edited April 2022
    Wow OK I see.......he cuts a lot of it out to clear that passive:

    9hj53d2f1nce.jpg

    4aatjlprf47b.jpg

    Very interesting stuff. I feel like Polk could have done more of this in the vintage speakers:

    1gzcczee5dgc.jpg


    Post edited by Gardenstater on
    George / NJ

    Polk 7B main speakers, std. mods+ (1979, orig owner)
    Martin Logan Dynamo sub w/6ft 14awg Power Cord
    Crown D150 amp
    Logitech Squeezebox Touch Streamer w/EDO applet
    iFi nano iDSD DAC
    iPurifier3
    iDefender w/ iPower PS
    Custom Steve Wilson 1m UPOCC Interconnect
    iFi Mercury 0.5m OFHC continuous cast copper USB cable
    Custom Ribbon Speaker Cables, 5ft long, 4N Copper, 14awg, ultra low inductance
    Custom Vibration Isolation Speaker Stands and Sub Platform
  • stangman67
    stangman67 Posts: 2,179
    Drivers come tomorrow!

    I’m as far along on the first speaker as I can be before cutting out the driver holes.

    Started gluing the second speaker cabinet today and will be working hard on them this weekend!
    2 Channel in my home attic/bar/man cave

    2 Channel Focal Kanta 3 I Modwright SWL9.0 Anniversary Pre I Modwright PH9.0X I Modwright KWA-150SE I VPI Prime Signature w/ Soundsmith Zephyr MIMC I Lumin U2 Mini I North Star Designs Intenso DAC I Audience OHNO ICs/Audience Furutech FP-S55N and FP-S032N Power Cables/Acoustic Zen Satori I Isotek Sirius
  • Gardenstater
    Gardenstater Posts: 4,136
    Do you have some scrap MDF to do the router cutouts in first for a perfect fit where it counts? Measure 17 times cut once :)
    George / NJ

    Polk 7B main speakers, std. mods+ (1979, orig owner)
    Martin Logan Dynamo sub w/6ft 14awg Power Cord
    Crown D150 amp
    Logitech Squeezebox Touch Streamer w/EDO applet
    iFi nano iDSD DAC
    iPurifier3
    iDefender w/ iPower PS
    Custom Steve Wilson 1m UPOCC Interconnect
    iFi Mercury 0.5m OFHC continuous cast copper USB cable
    Custom Ribbon Speaker Cables, 5ft long, 4N Copper, 14awg, ultra low inductance
    Custom Vibration Isolation Speaker Stands and Sub Platform
  • stangman67
    stangman67 Posts: 2,179
    I do have plenty of scraps and I will practice for each sized driver for sure!
    2 Channel in my home attic/bar/man cave

    2 Channel Focal Kanta 3 I Modwright SWL9.0 Anniversary Pre I Modwright PH9.0X I Modwright KWA-150SE I VPI Prime Signature w/ Soundsmith Zephyr MIMC I Lumin U2 Mini I North Star Designs Intenso DAC I Audience OHNO ICs/Audience Furutech FP-S55N and FP-S032N Power Cables/Acoustic Zen Satori I Isotek Sirius
  • stangman67
    stangman67 Posts: 2,179
    Feels like Christmas in April!

    1snxaaf4p4n1.jpeg

    The documentation/packing/materials in this diy kit from Meniscus is first rate!
    2 Channel in my home attic/bar/man cave

    2 Channel Focal Kanta 3 I Modwright SWL9.0 Anniversary Pre I Modwright PH9.0X I Modwright KWA-150SE I VPI Prime Signature w/ Soundsmith Zephyr MIMC I Lumin U2 Mini I North Star Designs Intenso DAC I Audience OHNO ICs/Audience Furutech FP-S55N and FP-S032N Power Cables/Acoustic Zen Satori I Isotek Sirius
  • stangman67
    stangman67 Posts: 2,179
    Both taking good shape! 1bf9bvxzfri5.jpeg
    2 Channel in my home attic/bar/man cave

    2 Channel Focal Kanta 3 I Modwright SWL9.0 Anniversary Pre I Modwright PH9.0X I Modwright KWA-150SE I VPI Prime Signature w/ Soundsmith Zephyr MIMC I Lumin U2 Mini I North Star Designs Intenso DAC I Audience OHNO ICs/Audience Furutech FP-S55N and FP-S032N Power Cables/Acoustic Zen Satori I Isotek Sirius
  • rooftop59
    rooftop59 Posts: 7,952
    Nice! You have piqued my interest with this build. If you don’t mind, how much did they charge for the crossover assembly? Feel free to pm if you’d like…
    Living Room 2.2: Usher BE-718 "tiny dancers"; Dual DIY Dayton audio RSS210HF-4 Subs with Dayton SPA-250 amps; Arcam SA30; Musical Fidelity A308; Sony UBP-x1000es; Squeezebox Touch with Bolder Power Supply
    Game Room 5.1.4:
    Denon AVR-X4200w; Sony UBP-x700; Definitive Technology Power Monitor 900 mains, CLR-3000 center, StudioMonitor 350 surrounds, ProMonitor 800 atmos x4; Sub - Monoprice Monolith 15in THX Ultra

    Bedroom 2.1
    Cambridge Azur 551r; Polk RT25i; ACI Titan Subwoofer