Square Pegs

Another dumb thing you could do with the flattened ellipse:
Hole on both sides of the other focus with no horn (Omni Point Source).
Not that I have any actual use for such a pattern...

You could stack a book of three or four flattened
ellipses with mid woof tweet etc offset in different
directions, not to be in each other's way. But all
might appear to originate from the same exit hole
shared by all layers...
 

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Explains nicely what we were discussing last December.

As the announcer says: "it's a horn that looks like a column".

At least down to around 800 Hz, when it starts to "go omni", like most columns of that length ;).

Art

Hi Art, guys
Ah Doug’s video is out, good. It’s a better explanation than I could give.
Actually it really doesn’t act like a column made of a row of drivers at all (the colored illustrations were measured data). It acts like narrow horn with one driver and a 5 foot tall mouth more or less and so it radiates MUCH less sound energy outside the intended pattern than an array of sources.
One big problem with the large steered arrays in commercial sound is that even though they can be steered, they also by virtue of being many individual sources, radiated much more up / down etc. Some of the large arrays MUST be mounted on a wall because they project nearly as much to the rear too.
Anyway, that is the “intelivox” area that speaker is to be used in although this one you aim physically.. Pat has not had time to do his spherical measurements yet but Dr Doug took polars for me last time he was at the shop. Here is the Vertical polar stack going from 800Hz down to 250Hz as it gradually looses pattern control .
Best,
Tom
 

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I've returned here through another topic, and I keep reading and re-reading post #34 in this thread.

It makes sense! The problem is that I'm not sure how to model it for my specs, so I'm here to speak to the gurus that might be able to help :)

I have two drivers, one cone and one compression driver:

  • Eminence Alpha 8 (8 inch cone driver)
  • Pyle PDS521 (2 inch compression driver)

My goal with a Paraline would be to combine the two drivers from 125Hz to the top of the PDS521's range.

If that doesn't make much sense, I'd be happy with using a Paraline for just the Eminence driver, as a midbass 'horn' from 125Hz to 1000Hz.

From reading this thread, it sounds like I need to do the following:

  • Model a conical horn in HornResp with the desired response
  • Work out how to fold it many times

Step two is where I'm definitely in uncharted territory :) I also understand that coupling the Paraline with a horn is beneficial, but where in the horn's path the Paraline stops and the horn proper begins is another head scratcher!

The goal of this 'horn' is for home hi-fi/studio monitoring, so I'm looking for a solution to a fairly long straight (exponential or tractrix in my current designs) horn.

Thanks in advance for any help at all!
 
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So, the frequency I'm looking for is 125Hz, which is 9.00262 feet.

A quarter of that is 2.250655 feet, ending up as the radius.

Hmm, so what dimensions would I end up with for the Paraline?

Also, if I wanted to use it up to just 1kHz, could I use thicker 'channels', and possibly remove from another dimension, or are they independent of each other (low and high-pass)?
 
The goal of this 'horn' is for home hi-fi/studio monitoring, so I'm looking for a solution to a fairly long straight (exponential or tractrix in my current designs) horn.
A Paraline using a single 8" and a 1" screw on driver is not going to achieve one goal of hi-fi studio monitoring, which requires flat frequency response.

As evidenced in the DSL SBH10, the Paraline "horn" provides no low frequency gain.

Coupling your drivers through a Paraline then to a folded exponential or tractrix will result in a goofy dispersion pattern also not appropriate for hi-fi studio monitoring.

Given your drivers and goal, a Synergy approach would be more appropriate solution.
 
I still have a hard time figuring out how to use a coaxial driver on a paraline.
That is, without messing up the high frequency response.
I can't believe it is just a single entry point (hole) in that paraline. Is it a layered paraline?
By that I mean different paths inside for the mid and high frequencies?
It is a single entry into the lens.

Let's just say that it is a "standard" coax that is modified a bit and then has a different type entrance into the paraline lens than a regular HF driver has.
 
A paraline to avoid floor/ceiling reflection?

The narrow vertical achieved by a paraline can really reduce the floor/ceiling reflection in a home situation. A 20" tall paraline can get the vertical pattern control down to about 700hz. To achieve a narrow horizontal, two wings (no top/bottom) may be used. How benefitial is such a setup in a home listening situation at 8'-10' distance?

Thanks,
Goldy
 
I still have a hard time figuring out how to use a coaxial driver on a paraline.
That is, without messing up the high frequency response.
I can't believe it is just a single entry point (hole) in that paraline. Is it a layered paraline?
By that I mean different paths inside for the mid and high frequencies?

An externally hosted image should be here but it was not working when we last tested it.


An externally hosted image should be here but it was not working when we last tested it.


Remember, Paraline work just like normal horns. There isn't any rocket science here, just a clever way of folding a horn.

Take a look at various patents for phase plugs, and you'll see a lot of good ones that will work with a coax on a Paraline.

The main thing is that it will have to be designed SPECIFICALLY for your coax. There's no way to do a 'one size fits all' phase plug to mate coax to a Paraline.

The driver at the top is a good candidate for Paraline lenses, because there's no horn in the way.

The second driver is NOT a good candidate, because that plastic horn attached to the throat of the driver will not mate up well with a Paraline.

The BMS coax that's likely used in the Danley SBH-10 is quite similar to the first driver, which is B&Cs new 5" coax. Costs about $140 at Parts Express, I have a thread on this forum where I used it for a project. They're neat drivers.
 
Understood Patrick but how the hf coax get into paraline slot while maintaining easy driver replacement mechanism yet airtight remains a mystery lol

Something like this:

8PS21%2520coaxial%2520paraline.jpg


More details on page sixteen of this thread:

http://www.diyaudio.com/forums/multi-way/217298-square-pegs-16.html#post3143329

Here's some clues:

1) Paralines aren't magic, they work like normal horns
2) One 'key' to the Synergy and Unity horns is that the air underneath the cone resonates with the driver, and this resonances introduces a delay. That delay allows you to put the midranges ahead of the tweeter, and then the delays moves them 'backwards.' Or you could just use a DSP delay, like VTC did. (Take a look at their manuals, the delays and EQ are all spelled out.) Considering that Danley is a perfectionist, I wouldn't be surprised if he did the SBH-10 with no DSP delay.

So basically the midrange is physically 'ahead' of the tweeter in the pic above, but careful manipulation of the air volume under the cone will delay the sound. You can sim this with Hornresp by the way. Get the resonance of the midrange to 500hz or so and you'll see the delay in the phase plot and the group delay plot.
 
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The narrow vertical achieved by a paraline can really reduce the floor/ceiling reflection in a home situation. A 20" tall paraline can get the vertical pattern control down to about 700hz. To achieve a narrow horizontal, two wings (no top/bottom) may be used. How benefitial is such a setup in a home listening situation at 8'-10' distance?

Thanks,
Goldy
Might it not be easier (and smoother) to uae one of the long planar magnetics (such as Bohlender Graebener RD series) as the driver of that horn design? Run sealed-back of course.
 
Might it not be easier (and smoother) to uae one of the long planar magnetics (such as Bohlender Graebener RD series) as the driver of that horn design? Run sealed-back of course.

Here's why the Paraline works better, at least for prosound:

It doesn't take a long or deep horn to horn load a tweeter. For instance, one quarter wavelength of 1000hz is just 8.5cm.

So it doesn't take a whole lotta horn to raise the efficiency of the tweeter up to 110dB or so.

In the SBH-10, the tweeter is horn loaded, but there's basically no horn loading on the midbasses. So the tweeter may be getting as little as one watt when the midbass is getting ten.

TLDR : The main advantage of the Paraline over a conventional ribbon is output level, power handling, and efficiency. Basically it gets louder.