TPCH with an Alpine SWR8D2

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Super Planer = parallel BP6.
Paraflex = series BP6.

Not exactly .... It isn't that simple ..

Here are my thoughts:

A Tapped Horn is considered Series Tuned 6th order right? .. Ok ..:up:

A Paraflex has an additional resonator over a Tapped Horn which adds two orders (1 order for mass and 1 order for tension = Resonance) . .... Based on this i could argue that the Paraflex is an 8th order design ......:scratch2:

So either a Tapped Horn truly isn't a 6th order design :gasp: or if it is then that makes the Paraflex an 8th order system :checked: ... ....... One or the other it seems to me, and i have been going with the latter :soapbox:....

As if that isn't weird enough , there is more!:Ohno:

A Paraflex is also some combination of series and parallel tuned, it is not purely one or the other:mischiev: ...... Soooo ... When we merge the two paths from a parallel tuned design (right at or just before a shared mouth) shall we call it a "series-parallel tuned" or perhaps "Parallel-Tapped" cabinet? :D

It may be unorthodox but it works :cheers:..
 
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Here are 8th order enclosures.
HR has an 8th order function.
 

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Here are 8th order enclosures.
HR has an 8th order function.

Right that is a classic 8th order made out of Helmholtz resonances ..... .....

We are swapping out the Helmholtz resonances for Quarterwave and cavity resonances... Requires a different model , so with the Paraflex we get creative with TH mode using the "Rear Vented" chamber .....

With the Super Planar 8th we use OD (with "Rear Vented" chamber) or CH mode and stagger the resonances in a strategic way .. .
 
We want to see how loud we can play with a single Alpine 8 inch type-R in our car.

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Here is a few-note-wonder tuned ROAR (TPQWR) for spl competition.

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Here is the layout.

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A strong 36 mm plywood baffle and a solid mounting of the driver.
 
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Here is an in car REW measurement of the Paraflex design (that I call TPCH).

The nice 57 Hz cabin gain peak combined with the prodigious amplitude of the air column in the quarter wave resonators, makes everything feel very physical and tactile with a great punch and a visceral impact that no reasonably similar sized BR-box can match.

We are having a great time playing Deadmau5 while driving around with our car. My wife feels sick and nauseous after a few seconds, and the feeling stays for hours afterwards. Me and my son we smile and just want more. :D
 
On our way to a spl comp a 2 hour drive from here disaster struck. We were playing a wide verity of 80ies pop music with some Deadmau5 thrown in the mix, when our amp suddenly died. We can turn on the amp but the very second it gets some kind of signal the amp shuts down into some kind of protection mode while simultaneously drawing enough current to cause a 1,5 v voltage drop from our car battery.

No measurements or impression today... :mad:
 
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THD and Group Delay.

I know some people strive for less GD, but I don´t. This is just the way I want it.

Wow, the equivalent of basically 84ms at 58 Hz, the equivalent of almost 5 cycles of delay...

I'm thinking that yes, that would probably be very audible.
 
On our way to a spl comp a 2 hour drive from here disaster struck. We were playing a wide verity of 80ies pop music with some Deadmau5 thrown in the mix, when our amp suddenly died. We can turn on the amp but the very second it gets some kind of signal the amp shuts down into some kind of protection mode while simultaneously drawing enough current to cause a 1,5 v voltage drop from our car battery.

No measurements or impression today... :mad:

Sure it's the amp? Perhaps it's a shorted coil on the driver.
 
that would probably be very audible

I am sure the audibility of the GD drowns in the intense buzzing and rattling noise from the interior of the car when subjected to a short burst of 145+ dB in a spl-comp situation.

Sure it's the amp?

Yes. We measured the dcr of the voice coils and it was 1.9 ohm per coil.
We have a new amp and the bass is ferocious. :darkside:
 
I am sure the audibility of the GD drowns in the intense buzzing and rattling noise from the interior of the car when subjected to a short burst of 145+ dB in a spl-comp situation.

Oh, I'm sure that the box meets the "one-note" SPL box requirements, and GD is considerably less of a concern there, as is the ability to be listenable when playing actual music ;-)

But for playing music at a reasonable level (i.e. NOT at an interior-buzzing 145+dB)? I think that huge group delay peak will be audible, yes.

Many years ago I helped design such one-note wonder. A vented box designed to achieve peak output at the car's cabin resonance frequency. It blew the rear glass off of the SUV during the last SPL test (more a sign of the age of the SUV than the SPL achieved, but still). Great fun. Good for listening? Probably not, make that definitely not, but I did design the box to allow it to be "detuned" for normal listening by blocking a few of the vents. Best of both worlds. I'm sure I have a picture of the install hanging around somewhere, but can't find it at the moment.
 
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In-car measurement 2 cm from the front windshield on the right side where we measured 135 dB from the Paraflex a few weeks ago. Taken at 1.0 volts with the two voice coils in series for a 4 ohm load.

I added a Hornresp sim at 0,5 pi as a comparison.

Oh, I'm sure that the box meets the "one-note" SPL box requirements, and GD is considerably less of a concern there

I had a hunch that this would happen.

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It seems like the semi-closed car cabin damps the Q of the resonator enough to flatten the GD substantially. Even the broad wide band peak indicates a lower Q then the simulation predicts.
 
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