HELIOS Speaker Kit

@milostyn

In general, you are correct, but I am hoping there is MAGIC in this design that defies rational explanation!  :).  Designer has stated the distortion is so low on this speaker that he could barely measure it - like he has never seen before.  Also, that it is likely best speaker he has designed over 20+ years.  Thank you for the well wishes!

Helios in the House!  Speaker kit arrived but I was still waiting for my Baltic birch, so I decided to build "test" boxes.  Found scrap pallet with 7/8" thick plywood from Italy! 30"x75" one sheet.  Dreamed up an equilateral triangle shape for the cabinets.  Made (4) triangles, approx 24" on each side.  These are side panels for cabinets.  One of these on each cabinet has the PR centered in it.  Next, spent $38 for (2) 1"x12"x72" pine boards - paint grade - multiple pcs joined together.  Outside dimensions were true, actual thickness 11/16".  Cut the boards into (6) pcs @ 21"5/8 overall length, both ends mitered at 60 degrees, so reducing the length of the side that faces to inside of cabinet to maybe 20"?  I can't remember.  I know the volume is exactly 1.2 cu ft so that would be a way to verify everything.  Alternating butt joints allows 3 pine boards to make front baffle, back & bottom in a perfect triangle.   Chose to buy a $200 pin nailer (and glue) rather than an elaborate system of clamps, ha!  Hey! I will use it again sometime?!  So the pine boards make the triangle, the 7/8 ply is glued on each side.  The plywood then trimmed to fit, and later rounded over.  PR recessed 3/8" into the 7/8" plywood.  Tweeters recessed 3/16 (+) into the 11/16 pine front baffle.  Woofer is NOT recessed, I was thinking 7/16" recess into 11/16 was cutting out too much.  Have to screw the woofer down to SOMETHING.  Dimensions down from top of cabinet match Meniscus drawing.  My cabinet width is about 2 inches wider, but it is what it is.  Two 5/16" holes drilled for the "Big Posts" on the back.  Jasper Jig for Router was amazing.  When you have to change back and forth to several different diameters and have confidence they will be accurate, worked great.  My last cut for through hole on tweeter was not possible because my router base interfered with Jasper holes.  That could be due to me using a router with no Plunge functionality?  Finished with jigsaw.  So the moral of the story - I love my test boxes even though I understand 11/16" pine board with no bracing and no damping material is the WORST possible material to choose for a speaker baffle!!  Just remembered I did add small piece of oak 3/4x2x12 between woofer and tweeter cutouts, but not much bracing.  Next post will be sound evaluation...

Helios test run:  (Pine boxes in previous post)

I knew my boxes weren't perfect but I couldn't wait for my birch to arrive.

I figured at least test if the pre-assembled crossovers and speaker drivers were working without any problems.  Maybe get an idea what the Helios sound like albeit in an inferior box.

Everything worked great. Meniscus Audio did a Great Job with the crossovers, with answering questions, with getting me Satori OEM magnetic grills at the last minute, helped me out whenever I needed anything.

Initial impressions - Bass is Enormous, tweeters are a bit rolled off.

But have to keep in mind, with my triangle boxes directly on the floor, center of tweeters were only 15" off the floor.  They did have 30 degrees backward tilt.  The tilt helped to get the sound up higher, but at the same time it's probably voiding all the intentions of the crossover designer.

The bass is probably being reinforced by being too close to the floor.  Once again, contrary to the designers intention.   Bass was also a little bit too boomy for my liking?  I figure the thin pine boxes with no damping were guilty here.

After some time listening I can say that even my poor execution of this speaker kit sounds great!  Bass is approaching the performance of my (2) Focal 12" woofers.  With no actual data, I am thinking everything the 12"ers could do at 25hz, the Helios can do at 30hz.  Moving up to mid-bass, the Helios is even more Grippy than my old Dynaudios.  So when you consider all of the lower end, under normal operation, the Helios is equal to my home built 6 cubic feet Focal/Dynaudio monsters.  

The tweeters have done nothing wrong so far.  They are not too bright.  I am making the reasonable assumption that when I get them into the as-designed box, and as-designed elevation they will only sound better and better.

As they sit right now, they can sound like musicians are actually in the room.  They are outperforming or at least matching anything I have ever had.  I am expecting after I control the bass just a little bit with heavier boxes and damping material, I will have more to say about the tweeters shining through...

And ONE DAY after the Pine boxes are functioning, I get the call, BIRCH material is ready for PICK UP!!   😆

@rop45 Glad to hear your Helios kit is living up to the hype!! It’s always refreshing and reassuring to know that I wasn’t crazy when I fired mine up and realized they were better than some $10K commercial speaker designs I have heard recently. Keep us posted on the final build. I used either a 19” or a 21” Pangea Audio stand for mine and it definitely smooths out the tweeter response and widens the soundstage. Vocals should be centered just above the tops of the speakers which a very spooky affect that gives the impression of a singer elevated on a stage with you in the first or second row! Truly magical!