HELIOS Speaker Kit

@mijostyn 

I agree with you, but I don't have to match the bass output of the old ones.

if the Helios is better, or as good as my originals in 3 or 4 important categories, falls a bit short in the bass, but is still impressive for it's size, I will consider that a total success.  I just returned some REL subwoofers that sounded really great.  I am enjoying the open floor space.  :)

Speakers now are Thiel CS 2_2 and Maggie LRS, which I am sure will be displaced by the Helios.  Historically, up until a month ago, I had home-built monsters that I designed along with some help from Madisound for the crossover.  Dynaudio soft dome and (2) 17cm mids per side, (1) Focal 12" woofer.  Absolutely awesome sound, only downside is approx 6 cubic feet measured to outside of cabinet, truncated pyramid shape. Taking a word from Jeff Foxworthy,  I USED TO COULD lift them a lot easier than I can now!  Memories of these is what the Helios has to compete with!  If I can get them built correctly, I think they will be up to the task, at least they will check several of the boxes.   Thank you once again.

@boostedis ​​​​​​

Thanks so much for sharing!  

I have drawn myself a "flat pack" on AutoCAD and sent the DXF files to a professional cabinet maker who will cut it out of Baltic Birch plywood on his CNC router!  Have not ordered the drivers, but there is no going back now!

I did not see any of Javad's Facebook posts, but I am just working from the photograph.  The finished speaker with the edges of plywood visible everywhere.

As overkill is the theme, my box will be 1.5" thick on 4 sides, 1.4" thick on one side, and .71 inch on the last.  I wanted to preserve the narrow front baffle.  The thinner side has bracing on it and will have to do.  I guess I can add No-Rez to it during the build process.

I like your choice of box materials.  Mine was much less efficient, having to purchase 3 sheets of 5'x5' Baltic birch, but the good thing is there will be some left over to build matching stands!

Questions for you:

1.) How would you rate the vocals, does strong midbass interfere?

2.) What is your box volume?  I think I have 1.35 cubic feet before bracing and 1.2 cubic feet after bracing.

3.) What height do you have them set at? To center of tweeter.

Thanks again!

Trigger pulled !  Money is where my mouth is !  Helios kit on order !  

@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!

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

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...

Mijostyn you are beginning to sound a bit rude and boring.  Would it make you feel special to tell me my lunch doesn't taste good, hahaha!!!

We are saying the speakers sound great, and you are saying they are croaking, yet you have not heard them.

The designer had extensive experience designing speakers and provided the designs at no charge.  He wrote that the distortion on these was so low it was difficult to measure at normal volumes.  In fact, the lowest he has ever measured.  He said this speaker design may have been the best he ever built.

The manufacturer, SB Acoustics, asked him to make this design for an audio show and it received a lot of positive feedback.  One of the reasons I purchased the kit - all the comments I read from people who heard the speaker, not one said it was "ok", "not too bad", but every comment used words like "amazing" and "best ".

@gabrittain  what is your point to post this?  if you had to summarize in your own words what is your opinion of the doppler distortion articles, posts, opinions, actual audibility ?