Compound loading 6th order quarterwave "Super Planar" horns and pipes concepts/builds

The quarter wave pipes gets to long (to low resonant frequency) for the front resonators.
This is a way to shorten the quarter wave pipe without shortening the large front resonators.
We had to use the same solution in our ROAR series. I hate the dead unused space, but we could not find a better solution. We preferred to keep the easy build method with only straight sections and consistent 90 degree cuts.

Regards,
Johannes

Thanks :)
 
Roundabouts

MMJ,

so this cabinet would be approx 54"W x 36"D x 22"H externally, judging from the sketch?

GKH Sir ,
You caught me in the morning this time! Hehe

Affirmative , Those dimensions sound about right for the 500 liter version, and around 24" height if we go with the 600 liter version which has larger 1500cm sq CSA (3000cm sq split in two) resonators on the latter portion of the symmetrical (main) path.....

Each individual driver model requires a custom CSA on the early part of the main path ...... Each driver has different optimal requirements .... The B&C 18SW115 requires 500cm sq (1000cm sq split in two) as the CSA in the cabinet's early part of the main path ..........

I will post an updated 2d sketch with more details .... I will try to make that happen later today ... Dustin should have the new version of the 3d sketch soon as well =)
 
Gladly!

I meant that my intended use "is" PA. Sorry about the typo.

Thank you Mathew Morgan. Do you have a Hornresp SIM, as yet? Would like to see the simulation results.

Thank you everyone, for your help and support.

You are very welcome Samuel:), and yes , you can see the 500 liter sim and amplitude/frequency response chart in post #188


The 600 liter version is just slightly more efficient with a small advantage in output , not bad for just a few extra inches of height in my opinion :D ...

More details and sketches coming in the next few days :happy2:
 
Symmetrical split-path versus standard path

What do you think of the benefits, or not, of the symmetrical 2 path box are, as opposed to just making the line one length ?

Zero D ,
The split-path symmetrical type of layouts may (as some folks suspect) load the driver's cone in a way that distributes the forces and pressures in a relatively even fashion, with extended lifespan of the driver as the desired outcome ...

The split-path symmetrical layout does come at the cost of increased build complexity, excessive aspect ratio on the ducts in some cases, increased weight, and also slightly increased outer dimensions (for the same internal volume) due to the additional internal panels required ..

So you could say there are pros and cons ....




 
ANNOUNCEMENT: The first has been built!

The very first 8th order Super Planar cabinet was built by J R Vansickle of North Carolina (was finished just yesterday), and he chose the single path option .... He has once again made history!!


Mr Vansickle's cabinet is intended specifically for car audio competition in the single 8" driver class ..... The enclosure is tuned at around 50hz to maximize SPL near his Jeep's cabin resonance :) ...His cabinet size is 140 liters net, loaded with a VERY robust 8" high excursion driver ....... The competition is today, and he plans to take the prize ..... He will be throwing around 1000 watts into the little box as momentary sine "burps" in the 55hz to 65hz range, and is hoping to approach the mid to upper 140 decibel territory in-vehicle .....
WISH HIM LUCK!

I was very pleased to receive his reports about how the 8th order cabinet sounds very musical despite the extreme design, extreme tuning, and extreme driver being used ...... This is VERY good news!
:happy2:
....... It is loud and musical:note::note: ... Even if he doesn't take a trophy home from the competition we still have a winner here!! :yes::up::checked:


Super_Planar_8th_order_50hz_3_D_SKETCH.jpg


Super_Planar_8th_order_50hz_for_RS_8_very_early.jpg


Super_Planar_8th_order_With_fresh_coat_of_durate.jpg


Super_Planar_8th_order_With_fresh_coat_of_durate.jpg


RESILIENT_SOUNDS_RS_8.jpg

 
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I was very pleased to receive his reports about how the 8th order cabinet sounds very musical despite the extreme design, extreme tuning, and extreme driver being used ...... This is VERY good news!

Yes! Very good news!

A very impressive box. It should be a very capable example of the power of straight non expanding quarter wave resonators. I hope you can post some measurements of high spl sweeps. I believe there is a lot of "hidden" potential performance not seen in Hornresp sims.


Regards,
Johannes
 
...touching nearly 144db from a single box, in a car, is stupendous.

Let's see what an 18" driver can do?
Good thing you said "Let's see" since we are talking about sound levels that will destroy your hearing, even if you are not too disabled quite yet.

Wise to have your hearing checked from time to time. Hearing aid stores not always qualified to measure right.

B.
 
VICTORY by default is still VICTORY!!! Hehehehe

Yes THAT'S RIGHT!!

Practically 144db (143.8db to be exact) in-vehicle measurement produced by a single 8" subwoofer in one of our 8th Order Super Planar cabinets!!!
1f603.png
AND HE SAYS HE WASN'T EVEN RUNNING OUT OF HEADROOM YET!! .. Mr Vansickle took the prize in his class at the competition but i think he may have been the only one competing in that class
1f61b.png
It has been lots of fun watching J.R. Vansickle and Dustin Morgan notifying the naysayers in various facebook groups about the impressive score!

The measured output is roughly +6db over our 1/8th space simulations .... . So this gives us an idea of what to expect
1f642.png
(at least in his Jeep's cabin)
 
T/S parameters are a must

I am looking at the drawing from #213 and #218. And I was wondering if it makes any difference in doing it like this:
y4m1dDDB8Z4V2lg4jn652XhG8TrqFqBcqjWpxSsOJt4tJ6ZngAcYZwdpO4Oaa-fG_KmVldQdB0rOb9sRT3glBGN1Q2nh9OufDBaN7tI3yz-6HuyTuddjB4bB8blAbEJPUS9I5TThs2D2dlYR3Ki3XCWVlBPgCfcgsxgJ3LsvrxjRRVDLlVGNiou6pBPbGJxhdJYTxecAHv4c7G3aUADyhYf7g

USRFobiwan ,

That Layout will work but as BP1Fan pointed out we will need the parameters for your subwoofer driver..... This will make it possible to verify that your driver is compatible with the 8th order design and then we can use Hornresp to come up with an optimized CSA requirement for the cabinet's main path .......
 
Practically 144db (143.8db to be exact) in-vehicle measurement produced by a single 8" subwoofer in one of our 8th Order Super Planar cabinets!!! Click the image to open in full size. AND HE SAYS HE WASN'T EVEN RUNNING OUT OF HEADROOM YET!!

144 dB from a single (but powerful) 8 inch driver!!! :eek: :up:

Based on some Hornresp sims I guess you can hit 150 dB with some tuning and some focus on details. It takes time to optimize the whole setup for very high spl. The last few dBs takes an disproportionate amount of time and work.
Keeping the energy contained in a leaking car cabin can be a real hassle.

Very impressive performance!!! More pictures please!!!


Cheers,
Johannes
 
144 dB from a single (but powerful) 8 inch driver!!! :eek: :up:

Don't get too excited, big guy.

Here you have a very expensive high excursion driver, looks like maybe 20 mm usable excursion.

You've got a 1000 watt (or more) amp.

Neither the driver nor the amp need to sustain high power for more than a couple of seconds, so they can both provide absurd burst power.

You've got a 50 hz tuning.

You've got a HUGE and very complex enclosure. 140 liters for an 8 inch driver with a 50 hz tuning? That's big. And it's a high order enclosure.

And you've got a measured cabin gain that maxes out around the enclosure tuning frequency. And since this guy is a spl competitor he probably chose a vehicle that has abundant cabin gain at a high(ish) frequency.

These results are not unexpected, it's simply good design.

This is a burp machine, pretty much useless for anything else. Everything is tuned high and very particularly to work together as a system, taking full advantage of the car's resonant frequency. This is an example of good design to meet a set of goals but it's nothing to get too excited about.
 
Just like death and taxes.....

This is a burp machine, pretty much useless for anything else.

You seem to want to ignore:

I was very pleased to receive his reports about how the 8th order cabinet sounds very musical despite the extreme design, extreme tuning, and extreme driver being used ....
....... It is loud and musical


Yes! I am big, and you are just a guy! ;):D
 
USRFobiwan ,
This will make it possible to verify that your driver is compatible with the 8th order design and then we can use Hornresp to come up with an optimized CSA requirement for the cabinet's main path .......

Are we talking about the Car audio or PA type of audio cabinet? It is a bit confusing for me now. Since my modified image was for the B&C 8th order design. It makes no sense to my why you would do a 'split path' enclosure. Makes it bigger and heavier and need more wood. Unless the split path design makes a real big difference in output (like +4db and more) I see no point in doing this.

I have a couple of drivers laying around for test use. B&C 18SW115, Oberon 18XB1500, 18Sound 18NLW9601 and a Beyma 18LEX1600Nd.