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InDIYana 2020 and one more thing...

Being that the number 2020 also has other meanings, it's only appropriate for this to be themed what it should be. Please see below...

Another bit of info to take note of, is that I will be taking the following year 2021 off as host for InDIYana. I will coordinate with Chuck M. on some things that year and keep the website viable, but will likely not be involved in the majority of the plans. InDIYana will relocate to LaPorte, IN for 2021 only, and I will return as host for the following year. I've been hosting since 2009, so it's only justified that I can get a year off after doing 11 annual and consecutive events. It's been a labor of love, and I've enjoyed those events, people, and projects immensely. No worries, I will return.

Without further ado, I've listed below the requirements for the theme builds for the up and coming year. I wanted to post this prior to MWAF (one week from now), so those who would like to take advantage of the cost savings this event entails can do so.

InDIYana 2020 theme: “Hindsight is 2020”

There will not be a poll for theme selection for this next year, as the year in question dictates that we should ‘think about what is behind’. Please forgive the skew on the original meaning, but it does ironically apply quite well.

So- this is the year of the rearward radiation pattern. As usual, special considerations and a few restraints/rules exist for those inclined to enter the challenge. I have had a sounding board with some suggestions and concerns to make up this list. Being what this theme entails, the details are not supposed to be too stringent to stifle creativity, but to influence and make one ponder what to try. If you do not wish to enter the theme, you do not have to for attendance, and can bring whatever build tickles your fancy.

While the board of inquiries is not opposed to cardioid designs being brought under this year’s mantra, they are too hard to define in criteria via multiple means of execution for them to be valid as a theme entry without being looked at as another form of design. However, as long as there is attempt for equal radiation to front and rear in the same driver bandwidth; omnipolar, bipolar, and dipolar designs will qualify. For example, this means you can’t have a rear mounted tweeter and a front-facing boxed wide-range mid and qualify. You would still need any of a dipolar, omnipolar, or bipolar woofer section to qualify because the other 2 driver bandwidths do not.
Your woofers, mids, or tweeters, or any multiple driver sections if you choose to go full 4pi radiation for full bandwidth have to have a rear emanation of sound alike its front-facing counterpart.
  1. 2-way or 3-way designs are allowed. You want to build something simpler via a 2-way, go for it.
  2. Xover must be passive as usual.
  3. Only one driver bandwidth is required to have the rearward radiation. More than one is encouraged. Multiple drivers of same bandwidth are allowed, but all drivers with same bandwidth should have matching emanation.
  4. Qualifying frequencies for this theme are 100Hz and above.
  5. For the entries to be seen as valid there should be at least a 2 octave range where the entry exhibits approximate equal front and rear radiation.
  6. If you choose a closed/vented-box (bipolar) woofer alignment, you are limited to 8” woofers and 2ft^3 maximum volume. Down-firing subwoofers do not qualify as a rearward radiation method due to limited bandwidth and normal 4pi radiation of low bass.
  7. Dipole bass is limited to 12” woofers. H/W/U/N frames as well as ripoles are allowed.
  8. All theme projects should conform to a full-project-frame not to exceed 4’ H x 15” W x 18” deep. This is mainly for space constraints in the venue, and this should be adequate. Stand mounts are also allowed.
  9. Cost limits; as normal, this is not expected of contestants, but a limit as some of these open-backed/bipolar projects can get expensive with larger drivers and multiples used. This is merely to somewhat level the playing field and allows a more fair approach to those that enter. Pricing for drivers, purchased waveguides, and PRs; should not exceed $550/pair. Again- you do not have to spend $550, and can enter with much less out of pocket expense if you desire.
  10. Cost part 2; Due to likely multiples being used in this case, the limits ‘per driver’ are associated with their relative bandwidths. For woofers, $200 or less per side/channel, without exceeding $100/woofer. For mids/tweeters, $100 or less per side/channel. Since entries are limited to $550/pair in drivers for the entered pair of speakers, obviously the $800 total of the above limits does not apply. You will have to pick what you want to spend more on and where to cut costs to remain under $550.

No buyouts, wide/full-ranges as tweeters, and no NLA unless they were available for purchase when you planned your project or the manufacturer has a newer model to use under the current price list. Retail pricing should be used. PRs, waveguides and drivers are included in cost, not xovers. All of these rules are the typical MO.

I hope this encourages you to try a design with a rearward response coefficient.

Thank you to those who have participated in past themes and/or attended InDIYana. Your presence and talent are appreciated.
Later,
Wolf
Tagged:
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Comments

  • Damn, so I can't just bring some ol' 901's?
    Nicholas_23kennyk
  • You can bring 901s, just not under the theme.
  • 15" OB?
  • edited July 6
    ani_101 said:
    15" OB?
    Looks like only 12 inchers, but you can use multiples. 12" GRS subwoofers model pretty good, but you gota go against an 8-inch ported designs.
     John H, thanks to JP I did get that email
  • edited July 7
    hmmm... 15" are usually the standard for OB. Multiple 15" OB is still not much match against stout 8" ported... 
  • Man I had already started planning a build that meets every criteria listed above.  Love it when that happens.  See you guys in 2020 with the Portals.
    Dan
  • I am planning an entry for InDIYana 2020 also. My main speakers have been open baffle for many years, I may bring a portable version of those.  I also have two others in various states of progress, including the 2019 Old Skool II with the backs removed and some crossover updates.

  • ani_101 said:
    15" OB?
    Do our speakers have to be purple??

  • edited July 9
    JavadS said:
    Do our speakers have to be purple??

    Yes and sparkly 😝
    JavadSS7910
  • I loved those speakers in a medium sized room.  I reluctantly sold (gave them away) them to a singer/ teacher who likes purple.

    Now that was a challenge, none this pick your own driver stuff. 

    Might be time for a side challenge like a $50 throw down...might save this for Chuck, I don't want to step on Ben's event.
     John H, thanks to JP I did get that email
  • They did sound good....I tease
  • I loved those speakers in a medium sized room.  I reluctantly sold (gave them away) them to a singer/ teacher who likes purple.

    Now that was a challenge, none this pick your own driver stuff. 

    Might be time for a side challenge like a $50 throw down...might save this for Chuck, I don't want to step on Ben's event.
    $50 including xo?  I like the sounds of that!
  • DanP said:
    I loved those speakers in a medium sized room.  I reluctantly sold (gave them away) them to a singer/ teacher who likes purple.

    Now that was a challenge, none this pick your own driver stuff. 

    Might be time for a side challenge like a $50 throw down...might save this for Chuck, I don't want to step on Ben's event.
    $50 including xo?  I like the sounds of that!
    Sounds fun! Maybe do the driver selection secret santa style and draw names out of a hat to see who picks the drivers for another participant?
  • Sorry for the side track Ben, but what crossed my mind was $5 entry, $45 in drivers, and maybe parts.  To keep it fair the parts and prices would have to have been available from PE during the contest.  Anything goes, but still all passive. Vote for the top 3 on a ballot split the entry fee. Three minute test track with one final 20 second snip at 100 dB at 1 meter.  Just spitballing here. I thought that there could also be a "needs help" consolation prize.

    I don't want to drag this thread down to much but I like the idea of tiny budget to get more people involved.  Let's see if we can get Chuck to bite or the Iowa team.
     John H, thanks to JP I did get that email
  • In my experience, it is best to keep this as a gloating rights contest. Once money or prizes get thrown around, mentalities change. Again, it's not a requirement to spend the cost limit, nor is it required to build something to attend. I'd really prefer to keep it that way.
  • If we use an 8" driver in a box, can we use passive radiators? 
  • DaveFred said:
    If we use an 8" driver in a box, can we use passive radiators? 
    Nevermind, reread the rules... :(

  • Nice! I have soooo many ideas lol

  • Is the price of crossovers outside the $550?
  • DaveFred said:
    Is the price of crossovers outside the $550?
    Yes it usually is, the 5 part challenge was a recent exception.
     John H, thanks to JP I did get that email
  • I'm debating with myself if I should do the mini LX521 project or the Aperivox stand mount...
    PWRRYD
     John H, thanks to JP I did get that email
  • With regards to the price limits on items, what if you find an item on sale, but not clearance? If you find and item that is $109 on sale for $99, can you use it?
  • Sorry, retail pricing should be adhered to, sale prices are not valid.
  • DanP said:
    Man I had already started planning a build that meets every criteria listed above.  Love it when that happens.  See you guys in 2020 with the Portals.
    Dan
    I'm going to flip if you show up with another 2 part XO :p
  • Gloating:"dwelling on one's own success or another's misfortune with smugness or malignant pleasure."

    Let's redefine the goal, here. There are enough egos and entitlement in DIY.
    I have a signature.
  • I have no idea what your post even reflects, JR. If you are meaning me, you are way off.
  • edited July 27
    Wolf said:
    I have no idea what your post even reflects, JR. If you are meaning me, you are way off.
    Now why would you think he meant you?  

    Signed,
    Marty H.
    Achiever of the Second Place Winners Position in the under $300 Category of the 2009 Iowa DIY International Speaker Design Event (just ahead of some formica covered thingamajig from Indiana)

    Now THAT'S Gloating!  :3
     

  • Words matter, they have meaning. 
    I have a signature.
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