Radian PB850 - any experiences?

[Radian]

Originally Posted by sannax

After reading this I am very happy that I stuck to my PB475 I have been thinking of TAD-2001 for a while, but do have some issues with the price jump.

What horn do you have them on?

[sannax]

I am going to make a tweeter horn, LeCleach 850hz cut off. Midhorn is a 340hz LeCleach which will house a P.audio 5" mid. I also have the possibility to use the midhorn with the Radian, the design is not quite finished yet,

[Radian]

Sweet.
600hz-700hz LeCleach Horn should have an acceptable high frequency
coverage, to do without a tweet.
Have you heard about the e-conowave that was introduced by Zilch
over at the JBL place? People just raving about the neutral sound
and the good high frequency coverage.
$12 or something at PartsExpress.

Greets,
Klaus

[sendler]

Originally Posted by sannax

After reading this I am very happy that I stuck to my PB475 I have been thinking of TAD-2001 for a while, but do have some issues with the price jump.

Do you know what the resonance frequency of the Radian 475 is on a big horn? How low can it play. I'm trying to choose between 1" and 1.4" drivers for a 400Hz LeCleac'h horn.

[Radian]

John Hasquin states that he gets strong output from about 480hz on a 400hz tractrix horn.
The LeCleach horn is about the same in this respect.
It's all about a tradeoff between better hf radiation pattern on a smaller horn vs.
low coupling and not so good hf radiation.

Here is a very interesting post by John that explaines a bit of the tradeoff:

"I have not found a drivers resonance to be the major cause of beaming in tractrix horns. What I personally feel like contributes the most to beaming is using too large a horn for accomplishing the task at hand. A larger horn in my experience did not have better pattern control for the following reasons: Since the larger horn is trying to be used below the Fs of the driver, it behaves like a direct radiator with a high pass filter on the bottom frequencies. This happens because the tractrix is too short to properly load the sound wave fronts at the lower frequencies, you can't cram a quarter wavelength sound wave into a horn that thinks it's an eighth sized horn, depth wise. Mouth size does not matter as much as horn depth does here. Because the lower frequencies are not loaded, your control goes to hell on the bottom end and beams. In, addition in the case of a 2"� driver with a horn of this size, the horn only loads approximately from Fs up to 2200Hz. What you end up with is discontinuities on both ends of the frequency extremes, not a good thing. John you are correct in stating the high frequencies do beam somewhat, that is the physics of the situation and can not be changed. You would need a very, very small throat to get any loading much above 5kHz, smaller than 1"�. What I find to help limit the perception of beaming is using the right sized horn for the job. When I design my horns I have some ratios and other rules of thumb that accurately predicts where the tractrix will unload� the sound wave front given a certain horn flare and driver resonance. An example is the tractrix horn I designed for the *Radian* 475. I use a 380Hz tractrix and with the help of the drivers resonance, 530Hz, I get nice strong output starting from 575Hz. Since the 475 is a 1"� horn it loads the high frequencies to 4300Hz or so, above that it behaves as a direct radiator. What you get is completely horn loading and control from the critical mid range to 4300Hz. Above 4300Hz off axis you only hear a softening of the high frequencies as you move out of the sweet spot. However, from 575Hz to 4300Hz there is virtually no beaming and much less perceived difference in SPL outside the sweet spot because this whole bandwidth is being acoustically coupled to the air properly�. When you get a horn and driver designed correctly like this the field of depth and imaging are incredible to say the least. Properly loading the sound wave front is everything and if you make too large a horn and have slop on the bottom, your results will not be optimal. I hope I have been able to convey what and why Bruce and I believe that large horns are not the answer�. *JLH*"

Greets,
Klaus

[sendler]

Originally Posted by Radian

John Hasquin states that he gets strong output from about 480hz on a 400hz tractrix horn.
The LeCleach horn is about the same in this respect.
It's all about a tradeoff between better hf radiation pattern on a smaller horn vs.
low coupling and not so good hf radiation.

Here is a very interesting post by John that explaines a bit of the tradeoff:

" An example is the tractrix horn I designed for the *Radian* 475. I use a 380Hz tractrix and with the help of the drivers resonance, 530Hz, I get nice strong output starting from 575Hz. Since the 475 is a 1"� horn it loads the high frequencies to 4300Hz or so. When you get a horn and driver designed correctly like this the field of depth and imaging are incredible to say the least.

600Hz from a Radian 475 should be amazing sound. No need to go with the more expensive 1.4" driver for home audio which will beam in the highs more. He answered my other question too since Radian doesn't publish an impedance curve, the 475 has a low resonant frequency of 530Hz on a 400Hz horn. Most 1" drivers are closer to 800Hz. Are these quotes from another thread somewhere?

[Radian]

Sorry for the late reply I am in Turkey for vacation.
Yes the post was on AudioAssylum but dates back to
2001. Just typ in 475PB and a few posts should come
up.

[Pano]

I picked up a Meyer Sound driver the other day. It was unmistakably a Radian.
Didn't know Meyer used Radian.

[Radian]

Yes it was soniıcally probably the closest to the Yamaha JA-6681 that they used before.

[angeloitacare]

i have made direct listening comparisons between the JBL Le85, Radian 475pb, and Coral M100, on a JBL HL91 horn with lens. By far the best performer was the Coral M100, followed by the JBL Le85, and the Radian was rather poor sounding. Less defined and less transparent. The Coral beats the others on clarity, detail and transparency, and goes lower. I was quit amazed and surprised to hear such a big difference. I expected more, based on my experience with the Radian 950pb, which sounds great.
Sad i did not bring the Corals to brazil, to compare with Vitavox S2. Maibe next year...