Please review the site Rules, Terms of Service, and Privacy Policy at your convenience. Rules, TOS, Privacy
Get familiar with the reaction system: Introducing the Reaction System

Iaell - 8" 3-way

edited December 2023 in DIY

Many years ago I had the pleasure to spend an afternoon with a pair of the Interlude IL40 towers from Infinity. I was generally impressed with their performance, especially the bass quality. I always thought about buying a pair now that they are down in to the $400-600 range just to use a reference to judge my own builds against but decided against it as storage of tower speakers is just a pain in the ass.

Anyways, Iaell (IL) is an Infinity Interlude IL40 tribute build using OEM CMMD drivers from Infinity. The woofer is a direct pull from the IL40 - the midrange is actually from their Primus line but is nearly identical to the actual midrange used in the IL40. The Interlude IL40 is a floor-stander - these are large stand-mounts. The IL40 uses a small dome tweeter, these will be using the Fountek style ribbon tweeters sold as GRS brand. I am pretty much a ribbon guy these days. Call it a throwback to the Emit days if you like. Overall, not a lot of real similarities other than a couple of the drivers, but this is a tribute not a clone.

Driver information can be found here:

https://diy.midwestaudio.club/discussion/2320/infinity-interlude-il40-8-woofer-ts-specs#latest

Here is the woofer model (1.2 ohm series resistance, I will be using air core coils as much as possible in this build). You can see it will be capable of playing very low - F3 of 30Hz is nothing to sneeze at:

CAD drawing of cabinet and internals (gonna be a big boy like O'Ryan):

The drivers measure well enough that there should be little to no problem hammering them into shape. Until I get on baffle measurements, I am going to tentatively target 400/3500 crossover points.

This is an exciting build for me (with a streak of nostalgia tied up in it) and will serve as a rotation pair in my main listening space, sharing time with O'Ryan - which is currently out of rotation in favor of another pair right now).

I have a signature.
Silver1omo6thplanetjohnny5jzrjj45tajanesSteve_LeeDirkugly_wooferDrewsBrews4thtry

Comments

  • There are also 10" and 12" subwoofer drivers from the Interlude line aplenty on Ebay. Years ago I built a very large pair of subwoofers using the 12" IL subs and the Dayton 240W plate amps. The amps failed on me by producing a sound similar to dragging something across concrete.

    Anyways, I am super happy with my GRS 12" based subs so will not necessarily buy a pair of the 12" again but it is food for thought. They had superb T/S parameters for sealed cabinets IIRC.

    silverDrjj45PWRRYDDirk4thtry
    I have a signature.
  • Tom_SPWRRYDSteve_Lee6thplanetugly_woofer4thtryrjj45
    I have a signature.
  • edited December 2023

    Gon' be a pretty sexy stack there.

    Get some 1/8" ABS plate off amazon and use the circle jig to make some trim rings to go in place of typical gasket?

  • @DrewsBrews said:
    Gon' be a pretty sexy stack there.

    Get some 1/8" ABS plate off amazon and use the circle jig to make some trim rings to go in place of typical gasket?

    I may do something like that, not sure. I don't really mind the look, however.

    I have a signature.
  • I was stupid and posted incomplete CAD work - forgot the midrange enclosure lol. Updated CAD drawing above.

    I'll see if I can get the cabinets built next month. I have Nick's big boy to do first. That is one Nick may have to fight me for lol.

    DrewsBrewshifisideNicholas_23
    I have a signature.
  • edited December 2023

    Did some more modeling, and decided on 1 cubic foot tuned to 33.5Hz.

    Still plenty low extension. Here is Xmax at 24W (100db anechoic). I estimated 8mm Xmax based on manually exercising the cone and subtracting a few MM from what I was able to flex. Anyways, doesn't breach estimated Xmax until 23Hz so should be good to go for every thing but some of that really weird electronic music.

    Keep in mind this is all predicated on ~1ohm of series resistance. I kind of split the difference between a 5mH air core and laminate core. Downside to this model is the 2" port I spec'd will hit 24 m/s peak velocity. Might chuff a bit at higher volume, but - I modeled this to a level that is rare for me to listen at. Normally I am listening to music no louder than 85db peaks. At those volumes it takes 3.5W and cone excursion is not an issue until well in to infrasonic range (20Hz if Xmax is actually only 4mm). Additionally, vent velocity peaks around 9 m/s.

    Anyways, this is a rarity for me to model at volumes higher than I normally listen. In fact, 85db peaks are actually rare for me now that I think about it. Normally I listen at 80-82db peaks.

    Overall, I am impressed with how this woofer models. Infinity did a great job on this driver IMHO, and Dayton Audio could learn a thing or two from the OEM giants. I would put this driver in the same category as the aluminum Designer series but it models much more better than the equivalent 8". Considering the Infinity can often be found used on Fleabay for as little as $80/pr shipped it is a no-brainer.

    I have a signature.
  • Brads making progress on my cabs:

    6thplanetugly_wooferSilver1omoNicholas_23rjj45Steve_Leetajanes
    I have a signature.
  • edited February 7

    Going to be heavy boys.

    Depending on how my doctor appointment goes on next Tuesday, I may or may not be able to start measuring in a few weeks.

    6thplanet
    I have a signature.
  • edited February 7

    @jr@mac said:
    Going to be heavy boys.
    Depending on how my doctor appointment goes on next Tuesday, I may or may not be able to start measuring in a few weeks.

    JR: Doctor, my shoulder hurts when I raise my arm like this...
    Doctor: Don't raise you arm like that, and consider building lighter boxed speakers...

    Good luck with your shoulder

    jr@mac
  • JR, you know you need matching subs for the 3-way right?

    jr@macSteve_Lee6thplanetrjj45Nicholas_23EggguyScottS
  • Spreading a little frosting today.

    Silver1omojr@mac
  • What kind of shputz is that^ ???

  • I watched brads video about it yesterday. Check it out on the youtube

  • edited February 20

    What he said. Thanks for watching

  • That picture makes my shoulder hurt.

    Ortho appt next week, maybe start getting some answers.

    rjj45hifiside
    I have a signature.
  • Takes me back to the days watching PBS on Saturdays. New Yankee workshop, Woodwright shop and others. Learning new skills from skilled people.

    6thplanet
  • @jr@mac said:
    Ortho appt next week, maybe start getting some answers.

    Good luck, hopefully a good combo of rehab and proper adult refreshments !

    jr@mac
Sign In or Register to comment.