Radian 951Be vs 18sound ND4015BE

Hi,

Any thoughts on pros and cons of these 2?

recommended crossover is 700hz for the Radian 951be but 1000hz for the 18sound ND4015be
Rated frequency range is 500hz to 20khz for the Radian 951be and 900hz to 20khz for the 18sound ND4015be although many people implement these much lower.

If i want to use these for mids and high frequency are the 4"diapgram ok or should i got with 3"?


951bs vs 4015be.jpg
 
Radian handles more abuse, has more excursion, (can be shimmed by mfg).And a 5 slit phase plug.
1,4" exit. Better for a lower XO.

ND4015BE, 1,5" exit has phase plug ending at driver exit, so no throat angle, and more freedom of waveguide choice.
Has copper plated pole piece, so the inductance is well controlled.
Good modren phase plug design.
Fit/finish and QC is generally better.
Is very well behaved through all of it's range.
Check out @docali 's review on Sphericalhorns.net.
Ignore voice coil magazine review, as it is flawed by default, using a 2" XR2064 horn, and a badly matching throat adapter, as is seen in the measurements.

Choice would depend on your horn/wg and desired XO frequency.
 
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Strange the radian 951be can take more abuse as the 18sound nd4015be has higher continuouse and nominal power handling.
In form of excursion and low frequencies yes, even more so when shimmed.
You might find you hit that limit faster then the thermal one, depending on where you cross it and how.

If your looking to run 250W into a compression driver that's 100db+, for home use then😳
 
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A 3" diaphragm will generally have smoother HF response than a 4".
The larger 4" diaphragm is capable of more output, usually more than needed for home use, unless you want to cross over quite low.
A beryllium diaphragm 4" may have as smooth or smoother HF response than an aluminum or titanium 3".

To my knowledge, no 3" beryllium diaphragms are available.
 
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A 3" diaphragm will generally have smoother HF response than a 4".
The larger 4" diaphragm is capable of more output, usually more than needed for home use, unless you want to cross over quite low.
A beryllium diaphragm 4" may have as smooth or smoother HF response than an aluminum or titanium 3".

To my knowledge, no 3" beryllium diaphragms are available.
When you say HF, what range are you talking about? For me 2.5khz to 12khz is important and I would like it to be smooth and crisp sounding, I.e kick drum and cymbals.
 
This should give you some insights into 18S compression drivers, and theyre versions and Be diaphragms.
https://www.youtube.com/live/x9NAVlwvLro?si=TRr4wQbEfjwNpokg

What's better is the driver that seamlessy matches your chosen horn/wg🙃
A zero deg. Exit ending at the phase plug like JBL, ND4015, DAS NDx (jbl copies) etc. has some advantages in that regard.

They are a inseperable system, choosing a driver based on it's merits, then trying it with 100s of horns/waveguides with mismatched gemotries is not likely to reach "perfection".

As for the 2435 it differs from the 245x line quite a lot. Added a pic of the cross section/phase plug (2435/435) compared to a 476 with the Coherent wave" phase plug.
And some info in it in the document.

And there are probably people on here that has more extensive experience with all the mentioned models then i do.
 

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Great video it was very helpful especially the end comparing the different diaphragm sizes and metals.

You can see the smaller 3" does better where it's first significant dip is around 14khz where the 4" has its first significant dip at 10.5khz.
Hello

Great video but you really need to keep looking at individual drivers. Here is an example this is an aquaplas coated Be 435 and a coated Ti 2453 SL on the same waveguide. The coated Ti large format driver does well 10-20K compared to the roll off in the Be. They are both good sounding drivers but you have a bit more flexibility with the Ti with less roll off.

You could also just add a tweeter above at 8-10K if you want.

Rob 🙂
 

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You can see the smaller 3" does better where it's first significant dip is around 14khz where the 4" has its first significant dip at 10.5khz.
Don't take that to be granted. It is true in that specific comparsion sure. With drivers and diaphragms with similar construction.

There can also be other reasons for dips in a drivers response like whats shown below from the old TD-2001.
Same issue as is plaguing the HF10AK that alot of people compare with it.
 

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