SynTripP: 2-way 2-part Virtual Single Point Source Horn

Hi Art

Very new to speaker building and DIY audio, I love your design!

I note that most 1.4" drivers have a 3" diaphragm. Whereas most 2" drivers seem to have a 4" diaphragm.

I have been given an incredible deal on a pair of Radian 760NEOPB and would like to use in these boxes.

Is it possible to use this 2" driver with a 3" diaphragm in this design? Would the TAP work as a new throat?

Thanks
 
Is it possible to use this 2" driver with a 3" diaphragm in this design?
Possible, but the 10" drivers would have to be moved forward since the horn would be shortened to accommodate the larger entrance diameter.
The 760NEOPB throat adapter angle is 60.0°, probably will limit the dispersion above ~9000 Hz to that angle.

Looks like the left 2 annular sections comprise it's throat adapter/mounting screw plate.
It is possible they are removable, which would present ~1.25-1.4"" throat.
You could feel (or see) screws under the gasket if the throat adapter is removable.
The screws that install the throat adapter could then be used for be used to mount the SynTripP TAP (throat adapter plate).
If there are screws, they may use Loctite thread lock compound, which requires local heating to remove without snapping them off.
Screen Shot 2024-11-28 at 3.39.57 PM.png

Would the TAP work as a new throat?
The TAP could be scaled up to a 2" throat entrance.

Art
 
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Here they are. Two of them failed right near the end but I managed to print the remaining sections pretty spot on (you can see in the top pic where one of these separations is), and some jb-weld should have everything solid.
Re the printing:
I feel you there. I probably went through 10kg of filament before I got it right.
I recommend using an enclosure for temp stability. Also make sure your z-offset is sufficient to allow for a good squish on the first layer. Try having cooling turned off for the first few layers too. These all worked for me.
I also used a 0.8mm nozzle which made for much faster print times.
Looking further at the design and assuming the entire rear panel is removable, I think accessing the forward screws on the 10s will be ok, if not a bit fiddly.
I have the 10CL51s in hand, the DE780TNs should arrive this week and I'm picking up the Baltic Birch Friday so will be building in the coming weeks 🤙




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Have you ever shared the stl for these prints? They look great
 
I always wanted to build the no ports version although Art himself says do not mix it with other midbass. I feel 80hz to 260hz can be better separately (maybe less cohesive) as they really matter for the sound I love, so I would like to add mkb230's to it.
 
These are photos from a while ago. Haven't done much since then. Hoping to get a couple of days before Xmas to finish this thing

The throat adapter...

I'm trying with MDF cos I had the right thickness on hand. We'll see how it goes

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Trying to shape the throat with wood filler. Needs a bit more work to get this nice and smooth

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@weltersys
I thought you said a while ago, that you do not like to add midbass as they do not blend well with the syntripp. Maybe my memory is tricking me
Matching phase and dispersion at the mid-bass upper crossover point may be a challenge to "blend well".
Another challenge is locating additional mid-bass bins within 1/4 wavelength of the top cabinets and elevating them above head level.

Either of those challenges can be overcome, but in my opinion would be better served with a single 3-way MEH cabinet with the output desired.
Something like the DSL J7-95 for around 20dB more output, or something in between the SynTripP and that if you are looking for only 6-12dB more.
 
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Matching phase and dispersion at the mid-bass upper crossover point may be a challenge to "blend well".
Another challenge is locating additional mid-bass bins within 1/4 wavelength of the top cabinets and elevating them above head level.

Either of those challenges can be overcome, but in my opinion would be better served with a single 3-way MEH cabinet with the output desired.
Something like the DSL J7-95 for around 20dB more output, or something in between the SynTripP and that if you are looking for only 6-12dB more.

I am thinking of building two B&C S218BP for 30 to 80hz and two mkh230 kick bins for 80hz to 260hz and a syntipp with no ports. I think I can use the full potential of the tops with around 6db headroom for the rest.
 
Possible, but the 10" drivers would have to be moved forward since the horn would be shortened to accommodate the larger entrance diameter.
The 760NEOPB throat adapter angle is 60.0°, probably will limit the dispersion above ~9000 Hz to that angle.

Looks like the left 2 annular sections comprise it's throat adapter/mounting screw plate.
It is possible they are removable, which would present ~1.25-1.4"" throat.
You could feel (or see) screws under the gasket if the throat adapter is removable.
The screws that install the throat adapter could then be used for be used to mount the SynTripP TAP (throat adapter plate).
If there are screws, they may use Loctite thread lock compound, which requires local heating to remove without snapping them off.
View attachment 1386342

The TAP could be scaled up to a 2" throat entrance.

Art
Good to hear! Sounds like ill be blazing ahead as soon as my cabinet-maker mate returns from the bush.

Does anyone have a design in metric? Imperial doesn't seem to fly to well in Australia 🙁

Thanks

- Cell
 
Syntripp #1 of 2 is complete.

10CL51-8 for the mids
DE900TN-8 for the compression drivers

Testing will have to wait until after the holidays, but it's good to finally get it done.

Note that the cabinet is unfinished (and pretty rough looking - no sanding yet) - I plan to complete the build of my whole system before I paint.

I haven't seen many (any?) builds without the ports, so I'm curious to see how it'll perform

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Innards

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Don't forget to route an extra few millimetres in je rear panel to accommodate the compression driver!
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I wasn't sure about doubling up the wires in the spade terminals like this to parallel the drivers, but they seem to be solid.
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I will be testing in early January and will report back!

I will also look into the secondary horns when I have some more time next year.

The Syntripps will be pole mounted in the end, but in the meantime here's a shot of my system so far

Syntripp
Cubo kick
Xoc1 TH18

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Been looking forward to that update for a while! Great looking stack McFly!

Very keen to see some real world measurements of the non-ported version!

What did you use for grill-covers, & are you planning on adding them to the TripP's? (I prefer the open horn look - especially once the extensions are on!)
 
Hi everyone!

I'm planning to start building my Syntripps next week. I've bought the plywood, and I'm really looking forward to this build. I've only built Cubo Kicks before.

I have a few questions.

1. Are there some decent metric PDF plans available? The ones on the "community google drive" (https://drive.google.com/drive/u/0/folders/1Uc8v5Qk3jz8snis_ovhLCcN1j12PVRWf) all seem to match Finbot's plans that were marked as incorrect by Art. @FartyMcfly may I ask what plan did you use? What would you people say is the recommended plan as of 2025? 🙂

2. Has anyone tried using a single Syntripp as a "filler" running in mono? I have pretty ok Nova Acoustics VS12 tops and I was thinking of adding a Syntripp between them, so I won't have to push the volume so much on those tops, but rather have them add stereo width. The subs I have are too powerful in proportion to my tops, but I don't want to get rid of them as they are really, really crisp.

3. Is there some decent alternative to the Celestion CDX14-3050 that I can buy on Thomann?
 
@luddite023

I used the plans from samdboneff. Anoter user suggested that they'd built from these plans, and they were correct (except that did not include the necessary lip for fitting the grille). I think they're a copy / development of the Finbot metric plans.

I am pretty confident that they're not correct as per Art's original design. For example : on the plans I used, this part of the horn is not symetrical, and in the original drawing from Art, it is.

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I imported the broad outlines of each part into Fusion360 and then corrected things like the above issue. I didn't refer to Art's original plans to be honest - I found them extremely hard to decipher.

I nested a load of parts for the inner horn together and then cut them in Fusion and then spent a lot of time on the table saw cutting the angled edges as accurately as I could.

I used the plan for a jig also included in the Finbot / samdboneff folders and the inner horn came together reasonably well but not perfectly. You'll see the issues if you browse back through my last few posts. I managed to overcome the stuff that didn't quite fit with some creative woodworking (ie, lots of sanding 🙂 )

I also found that the width of the top and bottom panels did not match the wdth of my inner horn plus width of side panels. - mine needed to be a few mm wider than the plan to accommodate the outer shell.

Basically, with some fettling I was able to get everything fitting well enough. I still haven't actually tested the syntripp so I have no idea how it sounds or measures, but I am fairly confident that it will work well enough for me.

My suspicion is that every version of plans in the Google drive folder is slightly different from Art's, and also slightly different from all the other plans. Despite this, people have overwhelmingly reported being delighted with the sound of their Syntripps, so my feeling is that small variations (a millimetre or a degree) here and there will not have a catastrophically negative effect on the overall performance.

I don't mind putting my fusion360 file up for download, but it will be very much with the proviso 'use at your own risk'.
 
2. Has anyone tried using a single Syntripp as a "filler" running in mono? I have pretty ok Nova Acoustics VS12 tops..
A center fill may be useful if the L/R are split wide, but you would probably be better off using one more VS12 than the "mix and match" approach.
One ported SynTripP would only add around +2dB to the low end of your tops, though would have more output potential above ~1500Hz due to the 3" vs 1.75" diaphragm.
3. Is there some decent alternative to the Celestion CDX14-3050 that I can buy on Thomann?
I don't know what is currently available on Thomann.
Look for 3" diaphragm 1.4" exit drivers from reputable companies like B&C, Faital Pro, or Eminence.
Neodymium magnets keep the weight and size down, slab magnet drivers may require cabinet adjustments to fit, as seen in FartyMcfly's post 1395.
 
A center fill may be useful if the L/R are split wide, but you would probably be better off using one more VS12 than the "mix and match" approach.
One ported SynTripP would only add around +2dB to the low end of your tops, though would have more output potential above ~1500Hz due to the 3" vs 1.75" diaphragm.

Thanks for the feedback @weltersys! I do keep them split wide 🙂

I'm also using 2 cubo kicks for 90-200hz, so if I can get some decent reinforcement on the frequencies above that (without making a mess) - I would be really happy! Still have a few outputs left on my Driverack 4820 crossover.