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

[weltersys]

I currently use Martin W3 (2 boxes per side splayed horizontally), they're running off a Powersoft M50Q with the recommended Martin corossovers/delay/EQ

This brings me to my questions, my current shortlist for replacements are 1 pair of SynTripP or 1 pair of 2x10 Paraflex, would either be able to provide similar (or greater) SPL and response than I'm used to?

Sorry to hear of the broken mid drivers.

Not familiar with the 2x10 Paraflex, but as a tapped horn design, it may have as much as 6dB low frequency output gain over the bass reflex SynTripP. You could compare different designs using the Hornresp simulation program.
http://www.hornresp.net/.
The SynTripP has only about 125dB output potential, less than a single Martin W3, and won't go as low.
The SynTripP may sound better due to it's virtual single point source, but a pair of Martin W3 would be far louder- comparing under 100 square inches of cone area (2x10") to around 264 square inches (2x15") is not a close race.

The Faital pro HF146r has a 65 mm (2.56 in) diaphragm, so would be pushed near the ragged edge keeping up with 2x10" on a 90x40 conical horn crossed in the 800Hz range. Used with mid drivers, crossed over higher, it should be adequate.

From what I can tell, the Martin W3 uses a B&C DE16 HF driver, with a 44 mm (1.7 in) diaphragm, which won't have the output potential of a decent 3" or 2.56" driver- if boosting the VHF doesn't provide enough "sparkle", they may be at their limit.

Art

 

[h3idrun]

Thanks for the informative answer.

I think I may have drastically underestimated the potential of my Martins so fixing the midbass and possibly upgrading the tweeter might be a better option than any of the DIY boxes I can find.

I do like building boxes though so maybe booth monitors are a better use for something like the SynTripP, then I can save up for bigger, badder synergies in the future to take over main duties.

 

[kipman725]

You could also try changing the W3's over to tri amp in order to have better limiting on the HF. For a replacement HF driver with significantly more output its tricky as you are a bit limited by the 1" throat size. Its also a bit tricky to compared compression drivers from datasheets as responses are given typically on horns an not PWT. The DE16 has 1.5T gap flux density and a mylar diaphragm, the older adhesive/former technology is also limiting it to 30W 'continuous' power handling. At high power levels polymer diaphragms soften reducing output so for such an application without needing low frequency extension its normal to use a fully metal diaphragm. The 18sound ND1075 has 1.8T gap flux density and (I think?) a fully Ti diaphragm and 50W 'nominal' power handling, so it should be a bit more sensitive and suffer less power compression. Another option would be something like the N151-M which is a ring radiator so exhibits increased HF efficiency compared to a dome.

 

[kipman725]

With your horn "pointed at the sky", ground bounce will be even more of a problem for both the cabinet and mic position, and won't be particularly representative of either free space or half space response.

wouldn't the horns directivity reduce any ground bounce effect? see the data here for the large horn with M200 and the lack of effect of the boundaries on the frequency response.

 

[weltersys]

wouldn't the horns directivity reduce any ground bounce effect?

As Pat Brown wrote in the "How do Boundaries Affect Loudspeakers?" link you provided: "The pattern control afforded by the horn prevents the sound energy from hitting the boundary. The result is almost no change in response, irregardless of the boundary condition."
The 40x60 mid-range horn he used as an example has good pattern control to 500 Hz, below that changes due to the boundary conditions are evident.
He also wrote: "this is a good place to point out that massive interference always results from placing low directivity devices near boundaries".
As your horn will have progressively less pattern control (directivity) at frequencies below the wavelength of it's smallest mouth dimension, there will be a boundary dip and some degree of "massive interference" due to the horn's mouth exit distance to the ground.

Art

 

[speetpeet]

1. The FaitalPro 10FH500 has 7.5mm Xmax, 12.5mm Xlim. The difference in power handling will allow more average (limited) level, but the additional 1.5mm Xmax won't give more than 2dB increase at the low end, where the SynTripP has the least output potential.

2. There are no 3" diaphragm HF drivers with more than 0.5mm excursion that I'm aware of.
The low end excursion of the HF driver is it's output limitation in the SynTripP design, a higher power handling driver will still be displacement limited.

3. If you would like an easy 6dB more output in a similar package size, I'd suggest eliminating the excursion limitations imposed by the two-way design, and scaling up to higher excursion 12", and using four 4" B&C 4NDF34 for midrange.

Cheers,
Art

If you are willing to be less strict on the design requirements 2 and 9 stated in the OP there might be a way to get an extra few dB's without spending big bucks. Let me explain with a horn resp simulation exercise. I don't think all numbers are exactly correct, however, they give some insight in the question of ab01ns.

Here a simulation of parallel B&C 10CL51 8 Ohm - driven to peak power with (600W) 49 volts with a 93Hz HPF 3rd order BW. Gives a theoretical peak output of 126 db in 2pi space.

Here a simulation of parallel FAITAL 10FH500 8 Ohm - driven to peak power with (1000W) 89.9 v with 100Hz HPF 3rd order BW. Gives a theoretical peak output of 133 db in 2pi space.

Proposition: the higher you set the HPF filter, the less displacement will occur. According to hornresp at 100Hz HPF 3rd order BW the output will be now be thermal limited instead of excursion limited. An slightly higher HPF 3rd order BW could keep Vtc low enough to let you mids play high enough to meet the compression driver. Of course, you need to have a subwoofer that can comfortable play above 100 Hz.

In addition to that, to leave some margin for error in the Vtc, you could combine it with a 1.4" CD Faital HF1440 with a 3.4" voice coil diameter. That would give you more output at lower frequencies due to the larger voice coil, and the HF1440 is of a ring radiotor type, mitigating the dome - phase plug excursion limit like the CDX14-3050.

In Europe the extra cost for two 10FL500 and a HF1440 over the regular drivers would be per box approx 95 euros. Not to steep right?

However, this is all based on simulations. What do you think Art, do you foresee any issues in this approach?

 

[weltersys]

Proposition: the higher you set the HPF filter, the less displacement will occur. According to hornresp at 100Hz HPF 3rd order BW the output will be now be thermal limited instead of excursion limited. An slightly higher HPF 3rd order BW could keep Vtc low enough to let you mids play high enough to meet the compression driver. Of course, you need to have a subwoofer that can comfortable play above 100 Hz.

In addition to that, to leave some margin for error in the Vtc, you could combine it with a 1.4" CD Faital HF1440 with a 3.4" voice coil diameter. That would give you more output at lower frequencies due to the larger voice coil, and the HF1440 is of a ring radiotor type, mitigating the dome - phase plug excursion limit like the CDX14-3050.

In Europe the extra cost for two 10FL500 and a HF1440 over the regular drivers would be per box approx 95 euros. Not to steep right?

However, this is all based on simulations. What do you think Art, do you foresee any issues in this approach?

Speetpeet,

49v would be 600 watts into a nominal 4 ohm load (300 watts per driver), 89.9v would be 2020 watts into a nominal 4 ohm load (1010 watts per driver). Assuming the 10FH500 can handle over three times the power (another cost..)of the 10CL51 without more power compression, the 5dB increase (133 dB peak) looks possible. That said, the SynTripP 10" HF response starts to dive at 800Hz, while the simulation shows around 1200Hz, 2/3 octave higher than measured. An acoustic crossover in the 800Hz range is required.

The Faital HF1440 annular diaphragm outer diameter is 100mm, inner diameter 72mm, for an Sd of around 37.82cm^2, while a 75mm dome diaphragm has around 44.18cm^2. The annular diaphragm is pinned on the inner and outer points, so if the center has double the excursion of a dome (0.8 or 1mm compared to 0.5mm), it's overall displacement would still be less than a 3" dome.

Mark100's tests with the BMS 4594 (see posts around 1007) indicate it's diaphragm "clanked" (sound of diaphragm hitting phase plug) at 123dB at 500 Hz. I'd estimate the BMS 4594 annular diaphragm (excursion of max. +/-0.8 mm) to be near 70cm^2, almost double the Faital HF1440 displacement.


Could the BMS 4594 do +10dB at 800 Hz compared to 500Hz? Maybe.
Could a driver with half the displacement? Test it and see!

Anyway, 95 euros may not be "too steep", but the cost of destroying HF drivers trying to "keep up" may be .

Art

 

[speetpeet]

Thanks for pointing this out Art. Appreciate the feedback. I might give it a test.

I'll try to decrease the excursion of the 10FH500 such, that I can fit a volume plug that makes Vtc as small as possible in an effort to relief strain on the HF1440. Let's see if I can make this alternative work. I'll report back.

 

[PawelUnger]

Hello everyone!

It's my first post here yet I am a SynTripP forum observer for a few months.
The time came to try a pair of SynTripPs, I am deeply amazed by the energy on this thread, so let's keep it going.

Art, huge appreciation for all your involvement and the sharing attitude. It's all gold..!

Coding SynTripP
My background lies in computational geometry / generative design and manufacturing. I am currently finishing a piece of code that generates all SynTripP's parts with great precision. This coding-approach lets me adjust the whole design within seconds, for example, if id like to adjust the dispersion angle a bit, it takes around 9 seconds to generate the whole ready-to-manufacture speaker, or I could change the diameter of screws parameter for CNC and all the design would adapt automatically. For now, I am missing the TAP (Throat Adapter Plate) part and later I will have one more question. Once the code is finished and verified I'd submit it here.

Question
As I am living in Barcelona, I have called quite a bit of wood stores, and all of them ran out of 12mm ply without hope for a rapid supply. The reason is that Ukraine and Russia are giant wood suppliers for Europe, and 12mm is the most popular ply over here. Anyways there is still 15mm.

Art @weltersys, do you think 15mm ply would make it without a major change? In my code, material thickness is just a parameter. I can change it to 15mm easily

Best,
Paweł

 

[weltersys]

Art @weltersys, do you think 15mm ply would make it without a major change?

Paweł,

The change from 1/2 inch plywood to 15mm would not be major, though the 10" driver may have to be moved forward a few mm to clear the TAP (Throat Adapter Plate).

Art

 

[PawelUnger]

Art,

Cool, I could machine this 3mm difference in a side of the horn so the 10" driver would sit at exactly the same place, also box should be these 3mm offset, but it is not a problem.

I will call a few stores more just to make sure and then I'll sit back to changes.

Paweł

 

[ab01ns]

Ongoing SyntripP gig report here... With 3 shows with them in the books, lots to report

Turns out my biggest issue has actually been subwoofer power in diy style venues without a 240V feed I can run distro from or at minimum one dedicated 20A circuit. I've been comfortably doing 150-200 person coverage with the SyntripPs just idling along with not a single clip light in sight. And my pl218/ART SLA2 with a BLU-80 driving them combo barely sips power. I can run the tops, 2 active 10" monitors and a cdj/xone or djm booth on one 15A circuit easily.

My 5kw class H sub amp however is a different story and needs a 20A feed as it'll blow 15A breakers with around -6db on the master. As a result I just can't wring out the SyntripPs while getting the tonal balance I want without good solid power behind the sub feed. (I do techno and bass music which necessitates a bass heavy tone, typically I like to run the EV subs at +4 compared to the level going into the syntripP). I'm seriously looking at some Class D offerings that might be more able to hit 2x 1700W @4ohm minimum on a 15A circuit.

With that said in smaller venues, running the SyntripPs at around -10 headroom into the processor is proving to be absolutely plenty. They're loud, crisp and clear and exactly what I want in an easy to setup for 2 techs rig. One of my favorite DJs played on them a few weeks ago and absolutely loved how they sounded! I'm gonna cherish that feeling forever.

Stilll getting my heights and toe in angles dialed and figuring out what sounds best.