[thomasjefferson]

This speaker is vaguely reminiscent of the new Note!  Did you fit another tweeter faceplate on the back?  And how about some commentary about how it works and sounds?

[lowtech]

This speaker is vaguely reminiscent of the new Note!  Did you fit another tweeter faceplate on the back?  And how about some commentary about how it works and sounds?

Not much to comment on yet as it's a work in progress.  The tweeter and mid are the same as what JohnK is using in the Note and the baffle layout is similar.  This is the third revision that I've made to the design and measurements will determine if it's the last.  The Neo3 tweeter is being used in dipole mode, although there is no reason why two of them couldn't be used back-to-back operating in opposite phase.  The system is being driven using a DEQX, so there's a lot of flexability.  The "sub" is a W-frame dipole that's crossed at 70Hz and that piece will stay, although the crossover point may change a little.

[Nyal Mellor]

Nice work Lowtech!!

Does anyone know if the Acoustic Elegance 6.5" dipole drivers are out yet?

[lowtech]

Does anyone know if the Acoustic Elegance 6.5" dipole drivers are out yet?

I don't know what XO points you have in mind, but a couple of 6.5" drivers will not work well down to 60-70Hz.  With a mid like the ScanSpeak 10F, you need a driver that will reach up to 700Hz, which means virtually any high xmax 8" driver (or two in my case).  Peerless 830884, Dayton RS225 and Usher 8945A are all good choices IMO.  The Exodus EX-Anarchy looks interesting too.

[thomasjefferson]

If the plan is to transition to closed box below 50 Hz, then you need to either choose a mid-bass woofer that can cover 50 Hz to 700 Hz, or split that into two ranges.  It could work to cover 50 - 700 Hz with a pair of 10's and a W-MTM-W layout (or W-TM-W).  The SEAS L26 would handle this range well.  Center to center spacing becomes an issue, and so does baffle width. 

Maybe do an hourglass shape so the baffle is narrow at the center.  But then you run into structural issues trying to prop a woofer up in the air on a skinny baffle.  To use a single mid-bass woofer (below the M/T), could be an AE Dipole 12 would handle 50 -700 Hz.  If it's two woofers (TM-WW) then it probably needs to be 3.5-way, rolling off the lower woofer above ~200 Hz. 

The Anarchy woofer has the ability to move as much air as a good 8", but with a 7" frame size.  That helps keep center-to-center spacing from getting too huge, and allows a narrower baffle.  I sketched out a WW-MTM-WW and got the outer woofers to 34" on center.  That's a wavelength at 400 Hz.  It will have limited vertical dispersion if crossed as a simple 3-way, but that's already true of the MTM in the middle.  It makes a tall and elegant baffle layout, with 10cm mids and neo tweeter.  You'd need some watts to make the Anarchys dance.

Just to run with this WW-MTM-WW Anarchy scheme: cut a length of steel channel and weld that to a base plate.  This makes a shallow U-baffle that's nice and sturdy.  Add a 1/4" thick dress panel that goes around the mounting flanges.  That could be solid rubber to damp vibrations.  The drivers mount in the steel (on the flat side of the channel) and the baffle has a minimal thickness, which avoids reflections at the back of the small midrange cones.  It's either a 3-way or a 3.5-way with a larger vertical listening window (rolling off the outer woofers above 200 Hz). 

[lowtech]

If the plan is to transition to closed box below 50 Hz, then you need to either choose a mid-bass woofer that can cover 50 Hz to 700 Hz, or split that into two ranges.  It could work to cover 50 - 700 Hz with a pair of 10's and a W-MTM-W layout (or W-TM-W).  The SEAS L26 would handle this range well.  Center to center spacing becomes an issue, and so does baffle width. 

Maybe do an hourglass shape so the baffle is narrow at the center. window (rolling off the outer woofers above 200 Hz).

You're describing one of SL's first dipole projects, the L-07.



He's since built two better dipole speakers over the past two decades; the Phoenix and the Orion.  Since this thread is about "building a better Orion", I'm not sure your proposed driver topology is a step in the right direction...

[thomasjefferson]

I can't agree with your reasoning here.  Maybe an hourglass design would resemble something Linkwitz built a long time ago, but it could also address the lessons of Phoenix, Orion, and NaO, etc, and potentially surpass all of these, performance-wise. 

As has been discussed a lot lately, much of the big idea behind the NaO Note (and presumably this prototype by "lowtech") is the minimal midrange baffle.  The hourglass design in that image by Linkwitz still seems like a pretty effective solution.  Mostly its disadvantage is structural, being tall and top-heavy.  I believe that was a motivation for Linkwitz moving away from the vertically-symmetrical baffle.  If you don't mind the form, it's not a problem technically.

The first steps to modernizing the hourglass would be choosing the best drivers.  I suggested the SEAS L26 for the mid-bass, and I like this solution partly because it would relate to Orion but at a grander scale (two 10's vs. a single 8").  The central MTM can get quite a bit more compact, which will help maintain focus and give a larger listening window. 

[Nyal Mellor]

I'm thinking

- Below 70Hz monopole subs
- 70Hz to 250/300Hz or maybe higher single AE Dipole 15 in a very small H frame
- 300Hz to 1.5kHz midrange (tbd)
- 1.5kHz above a tweet

[lowtech]

I'm thinking

- Below 70Hz monopole subs
- 70Hz to 250/300Hz or maybe higher single AE Dipole 15 in a very small H frame
- 300Hz to 1.5kHz midrange (tbd)
- 1.5kHz above a tweet

This is basically an Orion+ !

Obviously you're free to experiment to your hearts content, but based on my 1st hand experience, I doubt you will build something that will sound better... regardless of cost or DSP crossover used.  Let us know how your project turns out (and don't sell your Orions until you're convinced that it truly outperforms them).

[thomasjefferson]

Bear in mind that you have the potential to move these crossover points higher, and avoid needing to run a tweeter down toward 1.5 kHz.  A Dipole 15 woofer in a neutral baffle (no deep sidewalls) can go pretty high, and even at 350-400 Hz you can get away with a smaller size midrange that will cross higher to a small tweeter.  You definitely would need back to back tweeters if their range started as low as 1.5 kHz.  It's hard to get that to work based on mounting depth.  I wouldn't suggest using the BG Neo3 tweeter down into upper midrange territory, although some have tried it.  Minimal mounting depth for back to back tweeters will mean choosing a small tweeter that needs to cross high, which in turn means using a small midrange that needs to cross high to the mid-bass.

[Nyal Mellor]

This is basically an Orion+ !

Obviously you're free to experiment to your hearts content, but based on my 1st hand experience, I doubt you will build something that will sound better... regardless of cost or DSP crossover used.  Let us know how your project turns out (and don't sell your Orions until you're convinced that it truly outperforms them).

Yeah I fully intend to keep the Orions at least until I am convinced I have bettered them, this is an engineering / learning project mostly...

[Nyal Mellor]

Bear in mind that you have the potential to move these crossover points higher, and avoid needing to run a tweeter down toward 1.5 kHz.  A Dipole 15 woofer in a neutral baffle (no deep sidewalls) can go pretty high, and even at 350-400 Hz you can get away with a smaller size midrange that will cross higher to a small tweeter.  You definitely would need back to back tweeters if their range started as low as 1.5 kHz.  It's hard to get that to work based on mounting depth.  I wouldn't suggest using the BG Neo3 tweeter down into upper midrange territory, although some have tried it.  Minimal mounting depth for back to back tweeters will mean choosing a small tweeter that needs to cross high, which in turn means using a small midrange that needs to cross high to the mid-bass.

How high do you reckon the Dipole 15 can be run using minimum 24dB/octave crossover?

[thomasjefferson]

I have not tested the Dipole 15, so I can only speculate, but you should be able to take it as high as the directivity behaves.  Eventually the large cone will begin to beam.  It may behave well to 600 Hz or higher, depending largely on your baffle design.  The folks at AE keep repeating that these woofers sound great to 2 kHz and beyond, but you'd want to demonstrate that before believing it.

[joshsehn]

After reading this entire thread, I thought I should share some of my experiences.

I read all about the Orions and despite that I've not heard them and relying on all the positive reviews, I set about building something similar to that which has been proposed and described here.

1st let me state, I was seriously considering to purchase the Orions but I really enjoy the experience of building and learning, so I decided to build something of my own instead.... many revisions later this is what my setup currently looks like.

DEQ -> DCX (I really liked the idea of making changes at a whim without having to rebuild and change an ASP as well as time alignment capability etc)

I'm using 12 X 75W of amplification to run the speakers.

Speakers are:
10" Peerless (Same sub as Orion) in a similar H frame running upto 90Hz
2 @ 6.5" Peerless (100 - 1.8khz / Open back of course) 
2 @ 2" Dayton Dome (1.8khz - 4.5khz / 1 front, 1 back)
2 @ 1" Peerless Dome (4.5khz up / 1 front, 1 back)

I used two of the 6.5" drivers instead of the single 8" driver for the lower midrange because I thought this might alleviate cone breakup when approaching 1.5khz on a larger 8" driver.

I used the 2" dome on front and back because I wanted to reduce stress on the 1" dome tweeter. (I'm using a much cheaper tweeter than the Orions and I didn't feel comfortable with the idea of pushing a 1" driver down to 1.5khz)

I think they sound great.

It would be especially difficult to improve the QUALITY of the low end output but of course I do hope I could make improvements to the low end output, namely;
a. Increase SPL capability in the lowest octave. (currently SPL is limited due to XMAX of 10" drivers.)
b. Increase SPL capability in the second octave (SPL primarily limited due to POWER limitation driving 10" woofers)

So far, I have tried combining a separate relatively cheap 12" ported subwoofer. I didn't feel this provided better response as it could not extend low enough to really provide much assistance. I also tried combining my HT 15" DSP subwoofer. It was also challenged in it's ability to play the lowest octave without really exciting various room nodes.

I will say it is going to be VERY difficult to improve on the already very impressive response of the 4 @ 10" Peerless subwoofers in H frame. But ultimately, I think the solution for really low bass (20-50Hz) capability will be adding multiple 12" - 15" drivers in a H or W frame and the solution for greater output from 50-100Hz will be more power.

Bottom line is I will NOT be giving into a box. 
OB is great 
More surface area is better 
More power is better 

So, I'm not there yet, but the more I study the issue, the more it seem like my next upgrade might be multiple larger subwoofers for the lowest octave.... maybe even Danny's servo subs and amplifiers.

But the problem is, once I've done that, I'll probably want to upgrade the SPL output capability of the rest of the system.    I have a feeling my system might end up looking like StigErik's over at DIY.