Helios Build Thread

[RookieBuilder]

Time for a Helios project. Between the sad news of Jeff Bagby's passing and having built his Quarks years ago and really enjoying them I was intrigued by the Helios. I have been wanting to try something with a waveguide and higher end drivers for a long time so this seemed like a great option. I want to give a nod to Bear's Helios build, his look fantastic and there are some similarities here.

For the construction I knew I wanted a small tower, need to downsize from Statements, that choice was easy. For the look & materials I was intending to do an inner MDF box, clad it with pine and a shou sugi ban finish, after a few test pieces I was less enthusiastic and moved on from that idea (at least for these). I then saw some 1.5" thick laminated bamboo on clearance at the local Lowes, remembering the Ardent cabinets I picked it up. Then seeing Bear's build made me know this was going to work out.

A few major deviations from the spec build, I am going with a sealed cabinet and a narrower baffle. I will have the option to add a port or passive radiator later, but given my room and placement concerns I think sealed will work out better for me.

One of my goals was to make the speaker as small as practical, My final dimensions are going to be about 10.75"x12.75"x36.5", narrower than the spec cabinet by about .75". Broke the panels down into rough pieces.


Going this narrow with 1.5" thick material will make a challenge with mounting the woofer, it needs an 8 or 8.5" cutout and my box ID will be about 7.75". Resolved that by carving out the sidewalls with a dado blade.



I am doing rabbet joints to make the box a cohesive looking piece. A quick test fit to check all my measurements worked.


This weekend I will finish frames for speaker grills and set hidden magnets in the cabinet before I glue everything up.
I will be lining the cabinet will be constrained layer damping (automotive dynamat) and blue jeans insulation.
There are a couple of void spaces in the bamboo that I may fill with PL premium when I do the glue up, but I am not sure if this will really matter at the end.

[Bear]

For the construction I knew I wanted a small tower, need to downsize from Statements, that choice was easy. For the look & materials I was intending to do an inner MDF box, clad it with pine and a shou sugi ban finish, after a few test pieces I was less enthusiastic and moved on from that idea (at least for these). I then saw some 1.5" thick laminated bamboo on clearance at the local Lowes, remembering the Ardent cabinets I picked it up. Then seeing Bear's build made me know this was going to work out.

Happy to help! I had no idea that Lowe's even carried LBL, let alone the 1.5" stuff. Having built both the monitor-style and tower-style cabinets, I much prefer the tower.

I am doing rabbet joints to make the box a cohesive looking piece. A quick test fit to check all my measurements worked.
[ATTACH=CONFIG]30819[/ATTACH]

Good choice. I used the 3-play in several applications. I very much prefer The more uniform look of the face veneers, which is why I used the single-ply material for all of my outer baffles.

There are a couple of void spaces in the bamboo that I may fill with PL premium when I do the glue up, but I am not sure if this will really matter at the end.

My first LBL build used material with extensive voids, and I also used mitered corners. It still had plenty of surface area for glue-up, and enough thickness in the face veneers to support a 3/4" roundover. It would not support the 1" roundover that is now my preferred final edge treatment.

Do note that the WO24P generally needs a 10" PR, or larger, if you are going with a singleton. Given your inner measurements, you may want to look at doubling-up on an 8" PR if that's how you go. Realistically, just get a subwoofer to supplement the Helios and skip the PR.

[RookieBuilder]

Happy to help! I had no idea that Lowe's even carried LBL, let alone the 1.5" stuff. Having built both the monitor-style and tower-style cabinets, I much prefer the tower.


Good choice. I used the 3-play in several applications. I very much prefer The more uniform look of the face veneers, which is why I used the single-ply material for all of my outer baffles.


My first LBL build used material with extensive voids, and I also used mitered corners. It still had plenty of surface area for glue-up, and enough thickness in the face veneers to support a 3/4" roundover. It would not support the 1" roundover that is now my preferred final edge treatment.

Do note that the WO24P generally needs a 10" PR, or larger, if you are going with a singleton. Given your inner measurements, you may want to look at doubling-up on an 8" PR if that's how you go. Realistically, just get a subwoofer to supplement the Helios and skip the PR.

We will see how it shakes out with the sealed cabinets, I am going to try and push these towards the wall a little bit and I think the boundary gain will help. That said I do run subs, so hopefully there will be no issue.
The Bamboo LBL was being sold as an island countertop, they were on clearance so not sure if it was a regularly stocked item or not.

[RookieBuilder]

Weekend progress

I had two pieces with larger voids that I filled with PL Premium. Set the shop vac on one side, pumped glue in and sucked it through, should be a nice fill.


Cut the rough frames for the grills. These need work, but they will do for the markup to set the magnets.


Magnets set on the inside of the front baffle rabbet.


Box lined with the damping layer.


First box is glued up.

[RookieBuilder]

Holes about done and a quick test fit


Drivers sitting a touch tall, would be perfect if I was doing a veneer.
Id imagine this will be about 1/2 a mm once they are bolted in, I am tempted to not worry, however if good advise says fix it...

[Bear]

Drivers sitting a touch tall, would be perfect if I was doing a veneer.
Id imagine this will be about 1/2 a mm once they are bolted in, I am tempted to not worry, however if good advise says fix it...

If you've got a rabbeting bit and a good depth gauge, then it's a quick fix. Otherwise, don't sweat it. The difference may be measurable (barely), but it is extremely unlikely that it will be audible. I believe that Zaph may have done a comparison between surface mounting and fully-recessed. If you were surface-mounting, then you're probably into something audible, especially when the frequencies go up and the wavelengths come down. In practical terms, surface mounting a tweeter is a Bad Idea. The diffraction increases substantially. For a woofer with a relatively low crossover point or a big waveguide tweeter, this shouldn't matter.

[Steve Manning]

You could cut a template the same size as the drive hole out of mdf, double stick tape and a flush trim router bit with a top bearing. Then remove the required material.

[RookieBuilder]

Thanks guys, going to leave the woofers alone. For the tweeters, I have a rabbet bit that will get my 90% of the way there, after that a few minutes with a chisel and utility knife to clean things up.

[RookieBuilder]

I was able to fix the tweeter recess fairly easily. Set the depth on the straight cut but and did a free hand job leaving a few mm of material to the outside edge, went really slow and easy here as a little slip would have been a bad day. I scored the outside edge with a utility knife, then lifting out the last of the material with a chisel was simple. Now the tweeters have a perfect fit.

Cleaned up the holes, used a dovetail bit to add a taper to the holes, and then cut/file/sand the inside to clean up the edge. I did this on the tweeter as well, but with less effort as it shouldnt make any difference. I have never had to do this step with the baffle attached before, and while not that bad its far nicer to do this from the back with a router.


A couple shots of the base, I am making it removeable for access to the crossovers. If I choose to port it in the future I will make up a second bottom with a down firing port built in.
Double gasket and more screws than necessary should make for a good seal.



Milled out about 1/2 the thickness for the binding posts.


Quickly made up some feet. These are now ready for sanding and finishing. Going with Danish oil. I have a few seams that need to be filled, going to try making a paste with sawdust and danish oil, same idea as glue and sawdust filler, but the goal is to have a seam that takes the oil the same as the rest of the cabinet.

[Mikerodrig27]

Nice looking cabinets! Great job!

[Vassilis-7-]

Very nice job!
Those damping sheets with the aluminum foil surface, are they suitable for the job? I have some left from a car damping project, but I feel that it does not damp the sound when used like this, inside the speaker boxes.

[ergo]

Nice job and nice result!

Vassilis-7 - I've used similar kind of bitumen pads on all my latest project with good success. Even the boxes knocked with a back of a finger before and after reveals that they do dampen the panels well. And when I've looked into my speaker year or two later the pads with their glue have been tight on panels still, so I do like this method.

[RookieBuilder]

Less progress this week than I would have liked, the oil finish is taking longer to cure than I expected. However everything is ready for final assembly once the oil is cured.

Crossovers are done, no photos...
Grills are done, set the magnets, dab of PL on each magnet, aligned the grill, and let it dry overnight


Then the fabric, first time doing anything like this, I think it turned out OK, but a few things I would do different next time.

[RookieBuilder]

Boxes lined with 2" denim insulation


Binding post installed


Crossovers mounted behind the drivers


New and Old. The Statements will find a new home in my basement where they will have more room to breathe


With the grill on


A few things left to do, but I got ahead of myself and wanted to listen to these. Sound comes out and they sound good!

[chych]

Have any more impressions about the sound? Real curious about this design, considering it for my next build.

[RookieBuilder]

Have any more impressions about the sound? Real curious about this design, considering it for my next build.

I am very happy. They probably have a couple dozen hours on them now, they still have the 'new toy feeling' for what thats worth. My usual take on a speaker is my initial impression when first turning them on will be my most critical and after my ears adjust I ignore faults and focus on the music, my initial impression on these is 'WOW'. As it stands, they are super clear, detailed, everything sounds as it should. Bass is snappy and powerful, midrange is right there, and the treble is crisp but never harsh, to my ear they are really balanced (Jeff's measurements show this as well). Room placement has been really flexible for me, within reason the speakers sound good however I have set them up, with some careful tweaking they get better, but they arent particular which is nice. They sound great at both low and high volume. Really, they exceed my personal expectations.

Any specific opinion you want to know?

[chych]

Thanks for the impressions. I know it's a bit subjective (at least without good measurements), but can you comment on the soundstage, imaging precision, and ability to "disappear"? At least for me, those are what I enjoy most in high end speakers.

[RookieBuilder]

To caveat this, my room is poor for soundstage, its open to my left and the right speaker is relatively too close to the right wall (might be 2.5' away). With that out of the way, the image precision is good, soundstage can be wider than the speakers, the front to back depth is great. With a setup that doesn't work with life the speakers 100% disappear (speakers 1/3 into the room and me 1/3 from the back wall), with the setup that works with life (speakers 1/4 into the room and me 1/4 from the back wall) I wouldn't say they 100% disappear, but they do a reasonable job.

[Bear]

Thanks for the impressions. I know it's a bit subjective (at least without good measurements), but can you comment on the soundstage, imaging precision, and ability to "disappear"? At least for me, those are what I enjoy most in high end speakers.

I've had mine for a bit longer, so I'll jump in. The waveguide definitely makes them sensitive to aiming. And depending upon your construction choices, the distance to the rear wall will matter quite a bit.

For my pair, when I'm in the "sweet spot", there's a fantastic depth to the sound, I wouldn't go all the way to the speakers disappearing, but it's close enough to have a big dependency on the song itself and the gear (many studio recordings sound like ... studio recordings). I do get a touch of boominess to the bass because mine are within a couple of inches of the wall (small apartment) with the PR mounted in the rear. If I pull them out from the wall, then that disappears. But I can leave them relatively close to the wall and still have a fantastic experience.

[chych]

I've had mine for a bit longer, so I'll jump in. The waveguide definitely makes them sensitive to aiming. And depending upon your construction choices, the distance to the rear wall will matter quite a bit.

For my pair, when I'm in the "sweet spot", there's a fantastic depth to the sound, I wouldn't go all the way to the speakers disappearing, but it's close enough to have a big dependency on the song itself and the gear (many studio recordings sound like ... studio recordings). I do get a touch of boominess to the bass because mine are within a couple of inches of the wall (small apartment) with the PR mounted in the rear. If I pull them out from the wall, then that disappears. But I can leave them relatively close to the wall and still have a fantastic experience.

Great, thanks for the impressions. I have a dedicated HT/music room for setting up speakers. They would be placed about 18" from side and rear wall, and I also have bass traps and broadband absorbers at first reflection points in the room. I wasn't expecting the waveguide/aiming comment though. Perhaps I had a misconception that having a waveguide would improve off axis response, but if that's not the case, then maybe these speakers would not be appropriate for my room, which also serves HT use with multiple seating positions.

[Bear]

Great, thanks for the impressions. I have a dedicated HT/music room for setting up speakers. They would be placed about 18" from side and rear wall, and I also have bass traps and broadband absorbers at first reflection points in the room. I wasn't expecting the waveguide/aiming comment though. Perhaps I had a misconception that having a waveguide would improve off axis response, but if that's not the case, then maybe these speakers would not be appropriate for my room, which also serves HT use with multiple seating positions.

It can be a little confusing. What a waveguide is doing is redirecting energy that would have radiated in 2pi and "concentrating" it. This is what gives it the extra "oomph" that allows lower crossover points (see the bump between 1kHz and 3kHz, below). Also, because of the focusing of the acoustic energy, there is less energy radiating outside of that focus. This is what makes a waveguide MORE directional, not less. Also, that directivity is part of how a waveguide interacts less with the room (fewer reflections). Given basic human anatomy and height ranges, having a much narrower vertical listening window is a good thing. Having a wide horizontal window is desirable, but physics gets in the way for any given transducer size (everything gets more directional as frequency increases -- the question is by how much).

Let's take a quick look at the off-axis response of the two tweeters. The original:



With waveguide:


Look at the spread between on-axis and off-axis at 10kHz. In the original, it's about 10dB (which is notionally perceived to be half as loud). On the Waveguide version, it's closer to 13 - 15 dB, before adding in the oddities of that little hump that may be a throat reflection or similar.

[wolf_teeth]

I only got to hear Jeff's pair once at InDIYana last year, and I feel confident when I say they sound spectacular, and as Jeff said- likely the best build from his repertoire.

The comments he and Javad made about having them up to 113dB just to get a reading for the HD response really tells the tail of how good these are. The room was silent during their demo, and they really sound great.

If you build the bookshelf PR version, they will need some room to breathe and omit some room nodes. However, the room-curve-inversion ultra-low-tuning is a benefit acoustically.

My 2c,
Wolf

[chych]

Interesting, thanks for the details and clarification, didn't realize that's what waveguides do. The dispersion doesn't look too different than other speakers, including the RAAL 70-20, which I'm also looking at from some of Jeff's other designs.

[chych]

I only got to hear Jeff's pair once at InDIYana last year, and I feel confident when I say they sound spectacular, and as Jeff said- likely the best build from his repertoire.

The comments he and Javad made about having them up to 113dB just to get a reading for the HD response really tells the tail of how good these are. The room was silent during their demo, and they really sound great.

If you build the bookshelf PR version, they will need some room to breathe and omit some room nodes. However, the room-curve-inversion ultra-low-tuning is a benefit acoustically.

My 2c,
Wolf

By chance did you hear Craig Salin's Keramiskas at InDIYana? I just built this speaker (my first build), came out great, and am looking at options for a second build for another room (hence the Helios). Would be curious if you have a comparison or relative impressions.

[stretchneck]

Boxes lined with 2" denim insulation
[ATTACH=CONFIG]30891[/ATTACH]

Binding post installed
[ATTACH=CONFIG]30890[/ATTACH]

Crossovers mounted behind the drivers
[ATTACH=CONFIG]30889[/ATTACH]

New and Old. The Statements will find a new home in my basement where they will have more room to breathe
[ATTACH=CONFIG]30888[/ATTACH]

With the grill on
[ATTACH=CONFIG]30887[/ATTACH]

A few things left to do, but I got ahead of myself and wanted to listen to these. Sound comes out and they sound good!

Hi Rookiebuilder - I own a pair of Helios as per the original large stand mount design - really love them but might consider doing a tower version like you have.

How do they compare to your Statements? I am very interested in these too.

Also, the original Helios design means there's a LOT of energy going on inside the enclosure. Do you feel your tower version is vibration free / acoustically dead?

[RookieBuilder]

Hi Rookiebuilder - I own a pair of Helios as per the original large stand mount design - really love them but might consider doing a tower version like you have.

How do they compare to your Statements? I am very interested in these too.

Also, the original Helios design means there's a LOT of energy going on inside the enclosure. Do you feel your tower version is vibration free / acoustically dead?

My enclosures are very solid, I have no measurements or comparison point to call them 'acoustically dead' however I am very happy with them, and there is no vibration or resonance that I have noticed. 1.5" bamboo is very nice, not as easy to work with as baltic birch, but the end product is worth it.

Comparison to the Statements II's... end of the day both are great speakers, however at a very different price point. Considering parts cost, Helios is 70-80% more expensive for 2 drivers, passive radiator, and a simpler crossover. The Statements have 5 drivers and a more complex crossover. I consider the Helios to be a high end speaker and the Statement II's to be a high value speaker.
On the more subjective side, the Helios, 9 months on are still making me very happy, I have basically no desire to find or build the next thing. The Statements, while good, left me wanting. IMO, instead of replacing your Helio's with Statements, you would be better off sorting out the cabinets or room. What is it that your missing, wanting, or dont like about the Helios?

[Bear]

Hi Rookiebuilder - I own a pair of Helios as per the original large stand mount design - really love them but might consider doing a tower version like you have.

How do they compare to your Statements? I am very interested in these too.

Also, the original Helios design means there's a LOT of energy going on inside the enclosure. Do you feel your tower version is vibration free / acoustically dead?

If you're unhappy with the monitor, then try pulling them well away from the walls to see if you have room issues. I have found that I like then further away from the wall than my original position, but because mine are 9" deep, they don't dominate the room as much as a 15" or 20" deep speaker will. Acoustically dead is a construction issue, not a crossover/driver design issue. Take a look at some of the more extreme designs around here. Acoustically dead is a few extra sheet goods and a hernia away for most people. I like the tower because it better fits my environment than the monitor version. Sonically, they shouldn't be a lot different.

Also note that they pass the Lorde Royals test with flying colors.

[stretchneck]

You can most definitely hear the benefit of moving the Helios into the room - something I have done from the get go. I have no desire for additional bass.

I'll have the think about producing the tower version. Very grateful for Rookiebuilders comment vs the Statement II's - as stated this is a high value speaker. If the Statements left him wanting more, then I'm happy to say put with Helios.

Jim Holtz Bordeaux speaker does interest me though!