Announcement

Collapse
No announcement yet.

Bagby Kairos build - need feedback

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • fpitas
    replied
    Originally posted by 5af734377e View Post

    Just thought I had to share this lucidly-written white paper. It provides insight into a respected designer's thought process to develop a passive crossover design with nearly minimum-phase performance yet suppresses acoustic lobes far better than a pure first-order design. Made only possible with state-of-the-art drivers, of course. He does it through an asymmetrical crossover, with the tweeter rolling very high-up and shallowly, before ultimately steepening sharply below the XO point. This topology plus a slanted baffle creates a very interesting non-waveguide speaker. This is IMO what the pre-buyover Thiel people should have done - instead of stubbornly clinging onto minimum-phase first-order electrical XOs, shoot for something with no phase rotation and much better lobing behaviour as a middle ground.
    Hey, I knew a spambot named 5af734377e. Was that you?

    Leave a comment:


  • 5af734377e
    replied


    Just thought I had to share this lucidly-written white paper. It provides insight into a respected designer's thought process to develop a passive crossover design with nearly minimum-phase performance yet suppresses acoustic lobes far better than a pure first-order design. Made only possible with state-of-the-art drivers, of course. He does it through an asymmetrical crossover, with the tweeter rolling very high-up and shallowly, before ultimately Sarkari Result Pnr Status 192.168.1.1 steepening sharply below the XO point. This topology plus a slanted baffle creates a very interesting non-waveguide speaker. This is IMO what the pre-buyover Thiel people should have done - instead of stubbornly clinging onto minimum-phase first-order electrical XOs, shoot for something with no phase rotation and much better lobing behaviour as a middle ground.
    Last edited by 5af734377e; 04-10-2020, 11:13 PM.

    Leave a comment:


  • Chris Roemer
    replied
    If your horizontal braces are at 10" - 10" - and 10" (on your bass module - vertically), it'd be better to stagger the distances some, like: 10" - 8" - & 12" (or 10" - 9" - & 11", even).

    Leave a comment:


  • fpitas
    replied
    Originally posted by groker View Post


    Do you think this fares any better? I removed double walls from the sides, and the vertical brace - this should open up a lot more volume and reduce 'sections'. My build is going to be 0.75in MDF, will this be enough bracing to withstand a 200hz crossover point between midrange and woofer?
    Well, the idea wasn't to reduce the number of sections so much as to make them vary in size. As a rule of thumb with 3/4" MDF I try to brace every 7 inches max, or closer.

    Leave a comment:


  • groker
    replied

    Originally posted by fpitas View Post

    The braces sub-divide the panels into smaller sections. Make those sections different sizes, to spread the panel resonances.
    Do you think this fares any better? I removed double walls from the sides, and the vertical brace - this should open up a lot more volume and reduce 'sections'. My build is going to be 0.75in MDF, will this be enough bracing to withstand a 200hz crossover point between midrange and woofer?
    Attached Files

    Leave a comment:


  • fpitas
    replied
    Originally posted by groker View Post

    Thank you! What do you mean, slightly stagger it? Make it different sizes? Position it slightly forward/backward?
    The braces sub-divide the panels into smaller sections. Make those sections different sizes, to spread the panel resonances.

    Leave a comment:


  • groker
    replied
    Originally posted by Chris Roemer View Post
    It's technically better to (slightly) stagger bracing so you don't end up w/many (basically) of the exact same size panels (as they'd all resonate at the same freqs.).
    Thank you! What do you mean, slightly stagger it? Make it different sizes? Position it slightly forward/backward?

    Originally posted by LOUT View Post
    I think slightly shrinking the internal volume of the sealed 2way with a little too much bracing should only be a problem if you're playing it full-range down low without a sub. I believe the 200hz or higher crossover between the sealed 2way and the subwoofer below it should limit the mid-woofer's lows and excursion enough that a slightly smaller internal box volume won't affect it.
    The 3way should work great.
    That makes sense! Although I'm thinking about keeping the two-way fully functional too, if I can - just in case I want to part it out/move it around to a different location without disturbing the woofer extension

    Leave a comment:


  • LOUT
    replied
    Originally posted by groker View Post
    Thanks, jeff-free69! I took your advice and I'm working on a 3-way design. I'm still a bit lost on bracing, wondering if my two-way box has way too much bracing that it is beginning to affect internal volume.
    I'd really appreciate some feedback on the bracing If there is anything else I can improve, do let me know!
    I think slightly shrinking the internal volume of the sealed 2way with a little too much bracing should only be a problem if you're playing it full-range down low without a sub. I believe the 200hz or higher crossover between the sealed 2way and the subwoofer below it should limit the mid-woofer's lows and excursion enough that a slightly smaller internal box volume won't affect it.
    The 3way should work great.

    Leave a comment:


  • joeybutts
    replied
    What you've designed is the original plans in essence. Make it happen. Love nice bracing.

    I need to finish mine......

    Leave a comment:


  • Chris Roemer
    replied
    It's technically better to (slightly) stagger bracing so you don't end up w/many (basically) of the exact same size panels (as they'd all resonate at the same freqs.).

    Leave a comment:


  • groker
    replied
    Thanks, jeff-free69! I took your advice and I'm working on a 3-way design (very likely going for the 56 liter vented enclosure based on Troels Gravesen's SBAcoustics 10 design, with 4in vent that elbows 90 degrees upwards. I'm still a bit lost on bracing, wondering if my two-way box has way too much bracing that it is beginning to affect internal volume.

    I'd really appreciate some feedback on the bracing If there is anything else I can improve, do let me know!

    Also, more pictures and reddit post

    P.S.: RIP, Jeff Bagby.
    Attached Files

    Leave a comment:


  • jeff_free69
    replied
    Looks solid!
    If you're internally mounting the XO , it could get tight in there. I built mine a couple of years ago and ended up putting the tweeter on its own little board to get a little more separation on the inductors.
    If you're going 3 way (which i highly recommend - see my new thread) you may want to make it external from the get go.

    Leave a comment:


  • groker
    replied
    I'm planning to build a sealed two-way and port the woofer cabinet, so I guess I'll denim line both boxes and stuff the two-way with pillow filling.

    Leave a comment:


  • djg
    replied
    Fiberglass, rock wool, denim insulation and porous foam are often used to line ported cabs. Sealed cabs are generally stuffed. Polyester pillow stuffing, or the way more expensive acousta stuf.

    Cabinet Damping Material | Speaker Components - Parts Express

    Leave a comment:


  • a4eaudio
    replied
    Originally posted by djg View Post
    The sound material you linked is for sticking to automobile sheet metal. I wouldn't use it in a wood or mdf speaker box. It's for damping vibrations in thin sheet metal.
    Butyl rubber is a good sound dampener and quite a bit cheaper than Sorbothane. If you search Noico in the forum you will see that DaveFred and KEtheridge87 have used it and I believe Keith mentioned he found out about it via Javad S. I used a different brand in my speaker build.

    I think you don't see it used that much because (i) its not particularly cheap (although not prohibitively expensive either); and (ii) there isn't much (any?) A/B testing to show that it audibly makes a difference. I used it because I thought it might make a positive difference and was unlikely to harm the sound quality.

    Leave a comment:

Working...
X