Paraflex Mid High

Grant Manson

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I've been following a group called the "High Order Quarterwave Society" on facebook for a while and recently they've been coming out with some pretty rad looking ideas. It would be great to see what you guys think of the following designs:

Paraflex 1x12" top:
Paraflex 1x12-0.jpg
Paraflex 1x12-1.jpg
As it is now the working range is solid from 85hz -900hz using the 12NDL76 and 85hz - 1300hz with the 12MH32. Current throat slot CSA is around 250cm2-ish. Sensitivity is around 105dB and you can use a variaty of tweeters depending on your needs. (although an RCF ND950 is reccomened on our favourite horn)

Further to this you can build two together for use with larger horns or if you need the power of dual 12"'s

Initial testing looks pretty promising (note this is with the 12NDL76)
Paraflex 1x12 top-Measurments.jpg
 

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Grant Manson

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The second desing is the Super Planar 2x12":
Super Planar 2x12-1.jpg
Super Planar 2x12-3.jpgSuper Planar 2x12-2.jpg

Both options seem like a simple to build alternative to Pete's brilliant, all be it harder to build, DIY Mid High.
 
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Art Welter

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Jan 11, 2011
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Initial testing looks pretty promising (note this is with the 12NDL76)
View attachment 209172
Grant,

Could you give some description of how the initial test was done, mic and cabinet position, distance, surroundings, etc.?
Was there a HF horn/driver in the cabinet for the test, and if so what type, and was it's driver shorted during the test?

As polar response is crucial for live sound reinforcement, to determine how "promising" the design is would require more detailed on/off axis measurements. 5 degree increments per test would be helpful to see the trends.

Thanks for posting!
Art
 
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Grant Manson

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Grant,

Could you give some description of how the initial test was done, mic and cabinet position, distance, surroundings, etc.?
Was there a HF horn/driver in the cabinet for the test, and if so what type, and was it's driver shorted during the test?

As polar response is crucial for live sound reinforcement, to determine how "promising" the design is would require more detailed on/off axis measurements. 5 degree increments per test would be helpful to see the trends.

Thanks for posting!
Art

Hi Art,

These test were not carried out by my self but from what i know the initial tests were with a UMIK-1 @1m @ 1w (2.83 V)

They were taken in an open field with the speaker placed at roughly head height.

As fro the HF driver installed although I am not 100% what it was. something pretty low powered looking at the pictures in the thread.

I am probably going to have a go at building the Super Planar 2x12" as I have some drivers lying around and an ND950/HF950 combo i could screw on the front to test polar response. I'll probably aim to drive the 12" up to around 650/700hz crossing over to the ND950 much like Pete's mid tops.

I'll try and find more details on these plans, theres over 400 comments in a single facebook post o_O
 

Grant Manson

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Thanks for the rough sim Peter, It seems to be quite a hard design to sim using hornresp! Especially the high end.

From what I can see on the facebook page etc generally speaking the design should provide extended lower end frequency and increased sensitivity. They seem to prefer drivers with a rising uppper midrange response.

Think I'll have to build one just for the sake of experimentation :LOL:
 

Peter Morris

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May 8, 2011
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Yes, the actual real world frequency response will look different. These are power response plots; they don’t allow for the directivity of the enclosure or allow for cone break-up etc.

To get a speaker to perform well its needs to have a good frequency response, have good directivity behaviour, have a good impulse and phase response, have low distortion and behave well in the time domain.

If you want accurate sound I think those sharp dips will cause underlying problems that you will hear.

Here is a SIM comparing the ParaFlex to the PM ... but I don't know how close my SIM of the Paraflex is.
 

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Stef Smits

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Eventhough drivers like the 12MH reach high in that design. You do need a lower crossover if you place the HF-horn in front of it.
You probably would be looking at <1000 Hz.
 

Plippie Plop

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The Super Planar PL212 which is mentioned above is surpassed by the Paraflex 212. It is still a relative simple build for use as a kick-bin from 80 to 300 hz range. Here is a graph taken with the B&C 12NDL76-8 drivers, outside measurement at 2 meters 4v calibrated.


In a recent gathering in Berlin there are new insights and progress made on the Paraflex 112. When there are graphs available I will post them here.
 

Plippie Plop

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Eventhough drivers like the 12MH reach high in that design. You do need a lower crossover if you place the HF-horn in front of it.
You probably would be looking at <1000 Hz.

Correct, you need HF CD driver in a horn that can come in from 800 to 1khz.

The paraflex tops are still evolving and since more people are building them there are more measurement results, other drivers, slight alterations etc. There are a bunch of great people in that group collaborating and sharing ideas.

The Hornresp sim only brings you so far, there are alterations made which are not possible to sim in HR, maybe its possible in AKABAk but there aren't many people left able to do this.