# Beyma Audio and HLCD



## Broshi

I love the heck out of my 6nd430s, but looking at Beyma's products, I'm almost blown away...

The Pro 6WNd is rated at 97db 1w1m for 70-9Khz?? Has anyone tried these products yet??


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## fenis

With an fs of 92hz and qts 0.26 they would only be good down to about 160hz. Look at the freq response chart:

http://www.teamaudio.fr/media/catalog/product/datasheet/beyma/PRO_6WNd-4.pdf

Can you fit an 8 inch driver instead? If you have to stick to a 6.5" then the 18sound 6ND430 is a much better option:

Eighteen Sound Speakers - Eighteen Sound 6ND430 - Eighteen Sound 6ND430 6.5" woofer has a lightweight neodymium magnet. Eighteen Sound 6ND430 6.5" subwoofers are available here. 18 Sound speaker components.


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## Eric Stevens

The upper limit of sensitivity for a 6.5" to be useable to 80 hz is around 92/ 93dB. If they are truly 97 dB they wont have the excursion(Xmax) of the lower sensitivity driver, I recommend at least. 3.5mm one way and 5mm or more is more than adequate at almost any power level with a 70/80 hz high pass.

Eric


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## thehatedguy

And keep in mind most pro speakers FR range is the -10 db to -10 db points.


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## MARLEYMARL

Interested in Beyma and possibly mating a set of 8" midrange speakers to a set of ES Pro HLCDs. Which would be the better match up, Beyma 8G40 or the 8MI100? I like the fact the 8G40 comes in a 4ohm version. At this point, i'm looking for the one with the best HLCD compatibility. The emphasis is a strong midrange with sharp vocals.


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## minbari

I believe Eric recommended the 8G40 in another thread in here, if Beyma is what you are sticking with.


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## MARLEYMARL

Narrowed it down to Beyma 8P300Fe in 4 ohm if available, Beyma 8G40 in 4ohm, and Beyma 8MI100. Plan is to mate with ES Audio Pro full size HLCD. Can anyone offer some input as to which one would best mate up with the HLCDs? All and any opinions good or bad are welcomed.


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## minbari

I know Eric recommended the 8G40 in the past.

8MI100 is a midrange, not meant to be used for midbass.


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## thehatedguy

The 8MI is awesome if you could horn load it...say in some 100-150 hertz horns in the house, but not much good direct radiating for our purposes.


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## subterFUSE

At Eric's suggestion, I am planning to go with Beyma 8G40 in my car with his Ultra horns and a pair of FaitalPro 15XL1400 15" subwoofers in a trunk baffle.

Everything run by a single amplifier. Audison Voce AV5.1k.

I'm hoping to get the system started in December and will certainly keep the forum posted on progress.


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## MARLEYMARL

subterFUSE said:


> At Eric's suggestion, I am planning to go with Beyma 8G40 in my car with his Ultra horns and a pair of FaitalPro 15XL1400 15" subwoofers in a trunk baffle.
> 
> Everything run by a single amplifier. Audison Voce AV5.1k.
> 
> I'm hoping to get the system started in December and will certainly keep the forum posted on progress.


Oh wow! I'll be on the look out for your report, should be nice.


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## bkjay

Hey Marley Marl Whats up with Juice Crew! Sorry to derail I couldn't help myself.


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## Patrick Bateman

Broshi said:


> I love the heck out of my 6nd430s, but looking at Beyma's products, I'm almost blown away...
> 
> The Pro 6WNd is rated at 97db 1w1m for 70-9Khz?? Has anyone tried these products yet??


I wonder how high you get the efficiency on a midrange if you put multiple drivers on a single horn?

At home I'm building a Synergy Horn, documented in a thread named 'Monster Massive' at diyaudio. With one woofer and one compression driver on the horn, I had to 'cut' the compression driver to mate it up with the single woofer.

I'm using a Dayton ND91, with a sensitivity of 81dB, and a Celestion CDX1-1425 with a sensitivity of 108dB.

But once I had four woofers on the horn, the output level of the woofers actually exceeded the compression driver by a little bit!

On a baffle, four of the ND91s should have a sensitivity of 87dB. (81dB for one driver, 84 for two, 87 for four.)

So horn loading the midranges must have added something in the range of 20dB of output!


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## Eric Stevens

Patrick Bateman said:


> On a baffle, four of the ND91s should have a sensitivity of 87dB. (81dB for one driver, 84 for two, 87 for four.)
> 
> So horn loading the midranges must have added something in the range of 20dB of output!


Patrick 

A very common misconception that is spread in the audio world

With 1 total watt of power input to the array the broadband output is the same for 1, 2, or 4 drivers. The only measurable change will be the roll off on the bottom end.

If you have 1 watt to one driver and you add another driver and it is also getting one watt of input you increase the broadband output by 3dB because you have doubled the power not because you have doubled the number of drivers. By doubling the Sd you do shift the low frequency roll off to a lower frequency which is the only place where you are getting any increase in efficiency by increasing the quantity of drivers.

Doubling the drivers does increase the total SPL potential for the array by 3 dB because you have doubled the power handling.

Eric


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## Patrick Bateman

Eric Stevens said:


> Patrick
> 
> A very common misconception that is spread in the audio world
> 
> With 1 total watt of power input to the array the broadband output is the same for 1, 2, or 4 drivers. The only measurable change will be the roll off on the bottom end.
> 
> If you have 1 watt to one driver and you add another driver and it is also getting one watt of input you increase the broadband output by 3dB because you have doubled the power not because you have doubled the number of drivers. By doubling the Sd you do shift the low frequency roll off to a lower frequency which is the only place where you are getting any increase in efficiency by increasing the quantity of drivers.
> 
> Doubling the drivers does increase the total SPL potential for the array by 3 dB because you have doubled the power handling.
> 
> Eric


Sure, that's true... if the drivers are more than one quarter wavelength apart.

But once you get the drivers within one quarter wavelength, *every time you double the number of drivers, you get 3dB more sensitivity.*









That's why Synergy horns look like this; you have to get the drivers REALLY close together to make this happen. At 1khz this means that the drivers have to be within 8.5cm of each other. (3.375")

So let's examine how this can be done practically in a car. Basically, let's explore the question I raised, *how much efficiency can we squeeze out of an array of 3" woofers on a horn?*









Here's the output of one Dayton ND91 on a 6.5" wide conical horn. Note that this is a very very very small horn, and I'm basically using a tiny horn so that I can compare it to a prosound midrange that's 6.5".
The line above it, is a set of FOUR Dayton ND91s on the same horn.

*Note that the output level is about six dB louder.* So it's not that we don't agree, but your point is only true when the drivers are more than 1/4 wavelength apart. Once you get them close together, they start to sum constructively.









Here's the displacement of one woofer on a 6.5" wide horn, and four woofers on the same. *Note that the displacement is reduced* which also lowers distortion.









Here's the impedance of the two. It's virtually identical. (The four driver horn is wired series parallel.)

























To give you an idea of how we can use arrays of woofers on a horn, here's a comparison of four Dayton ND91s on a 6.5" wide horn, versus a B&C 6PEV13. At low frequency, they're basically identical, but as we go higher in frequency, the B&C is about 6dB louder.

The big difference is displacement; the ND91s have 6x more displacement than the B&C!

So the ND91s will get louder. And IMHO, they'll sound less 'stressed' doing it because they're so far from their excursion limits as you ramp up the power.

Even more interesting is if you put the Daytons on a BIG horn, because then you'll start to get some real horn loading. (The 6.5" horn that I used for this example is way too small. I used a tiny horn to illustrate that you can shoehorn four drivers onto a horn that's no bigger than a 6.5" woofer.)

To sum it up: When you get multiple drivers very close together, they add constructively at frequencies where they're within one quarter wavelength. At 1000hz a quarter wavelength is 8.5cm, so you gotta pack 'em tight. Taken to the extreme, you can get as many as 6-8 midranges on a single horn. There are some Danley horns with more than a hundred drivers on a single horn.


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## Eric Stevens

You might be correct when horn loaded but I believe my statement is still accurate for direct radiating array. In your statements you are not making the distinction and the average person is going to get inaccurate information.

Eric


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## Patrick Bateman

Eric Stevens said:


> You might be correct when horn loaded but I believe my statement is still accurate for direct radiating array. In your statements you are not making the distinction and the average person is going to get inaccurate information.
> 
> Eric


It's true for horns and direct radiators.









When you make an array like this, the drivers are basically operating in two different states:

1) In the first state, the frequencies are within one quarter wavelength of each other. For instance, with a center to center spacing of ten centimeters, the drivers are within one quarter wavelength from 20hz to 850hz, or five and a half octaves.









2) Above 850hz, those midranges are *not* within one quarter wavelength. Due to that, the SPL level will vary with angle. The pic above shows the effect, though the pic shows a horn. (Same idea with direct radiating arrays, as the beamwidth gets narrower as frequency increases.)











That's the reason that setups like this aren't a really hot idea IMHO. The center-to-center gap on these midbasses looks to be about 25cm. So they'll add constructively below 354hz. *But in the octaves above that, they'll interfere with each other.* So the person that owns this car is basically getting an extra 6dB more output below 354hz, but above that, the output level may actually be LESS than with a single woofer! (Because 6dB is how much you get when you add two drivers with equal power, but 0dB is what you get when they null!)









^^ This setup above shows how many drivers you can squeeze onto one horn, with some careful juggling.

It's hard to get the same effect with a direct radiator because the center-to-center distances get big in a hurry. To play to 20khz with an array you'd need drivers that are just 0.16875" in diameter to get them to sum properly.


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## MARLEYMARL

Eric Stevens said:


> Patrick
> 
> A very common misconception that is spread in the audio world
> 
> With 1 total watt of power input to the array the broadband output is the same for 1, 2, or 4 drivers. The only measurable change will be the roll off on the bottom end.
> 
> If you have 1 watt to one driver and you add another driver and it is also getting one watt of input you increase the broadband output by 3dB because you have doubled the power not because you have doubled the number of drivers. By doubling the Sd you do shift the low frequency roll off to a lower frequency which is the only place where you are getting any increase in efficiency by increasing the quantity of drivers.
> 
> Doubling the drivers does increase the total SPL potential for the array by 3 dB because you have doubled the power handling.
> 
> Eric


What would be the optimum crossover point for a pair of Beyma 8G40 midbasses and a set of full size ES Pro audio HLCDs? Looking a using an Audio Control 6XS/EQS to blend everything together.


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## Eric Stevens

MARLEYMARL said:


> What would be the optimum crossover point for a pair of Beyma 8G40 midbasses and a set of full size ES Pro audio HLCDs? Looking a using an Audio Control 6XS/EQS to blend everything together.


Typically 800 Hz is where I end up. 

Eric


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## subterFUSE

Just ordered my pair of Beyma 8G40 midbass to install with my ES Ultra horns.

Hope to get started soon. Still trying to decide on my subwoofer setup.


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