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Radian 850PB any good?

129.250.211.5
Posted on July 26, 2008 at 02:29:57
Phil-who?


 
I came across a company that is selling a lot of em in used
condition for just $200.
Since I have some B&C horns laying around that have a 2 inch flange
I was curious if they would be a decent start to get a horn system going.

Phil

 

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RE: Radian 850PB any good?, posted on July 26, 2008 at 08:11:40
djk
Manufacturer

Posts: 6135
Joined: June 17, 2000
 They're not the best sounding driver, but for $200 a PAIR it would get you started.

For a little bit more you could buy a pair of new Altec 902 diaphragms and pick up some blown 902/08/09 magnet structures on eBay.

For a little bit more you could buy a new pair of B&C DE250/180 from Parts Express.

For a little bit more you could buy some JBL 2431.

Etc,

 

RE: Radian 850PB any good?, posted on February 25, 2010 at 09:23:52
Defo


 
Are they tiring to listen to? Do they have the any of the smoothness the B&C DE250 has?

 

RE: Radian 850PB any good?, posted on July 26, 2008 at 09:13:02
KlausF
Audiophile

Posts: 18
Joined: May 22, 2002



Hi djk,
I Actually posted a reply to your comments on the 850PB last month but I erased it again since it was to long ago.
I have seen quite a few comments from you about the Radian compression drivers the past few years.
I can not agree with those at all (except for the reliability issues that I can not comment on because I use them only domestically). I have no business with Radian but I think it is not fair that people refrain from buying those very affordable drivers because of some negative comments that are made.
I have the Yamaha JA6681 on a tractrix horn. This driver according to some people I contacted before the purchase, is better sounding than the TAD 4001.
My Radian 85oPB's comes very close to my Yamahas, if the back-chamber is made bigger for better lows (only recommended for home use).
I don't know how you used the Radians but if you had much better results with an Altec 288 then there was definitely something wrong.

The remarks you made on the heights of the one inch Radian's, are also very strange. According to some French audiophiles this driver is really close (and by some even preferred) to the TAD 2001.
Tom Brennan can certainly attest that there is nothing wrong with this driver, as he has written several times in this forum how good it is.
If one uses those drivers in the appropriate horn with a good crossover they will perform sonically outstanding.
As far as my experience goes with the Radian 850PB there is no JBL driver that I heard that matches it's sonics.

Now, if you would live in Germany I would say come over and have a listen
to them to see how much better they sound then the 2445 JBL's.
Don't get me wrong I don't doubt your experience in the field of compression drivers, but anybody who thinks the 850PB is not a top driver must have a problem somewhere in the chain between the source and the speakers.

I don't know what you where measuring on the 1" Radians, but take a look at the pictures from a French company that did some real measurements of the Radian 475PB on a Cice Ph25 horn that clearly show that the heights(actually the whole spectrum) are really exceptional contrary to what you were telling.

I don't know what you have going with Radian but you are the only person I know that dislikes the Radian drivers.

Greets,
Klaus

 

RE: Radian 850PB any good?, posted on February 25, 2010 at 10:00:09
dcanalogist
Audiophile

Posts: 2
Location: Left Coast
Joined: February 25, 2010
 Klaus, it looks like the frequency resolution is too high and the the time resolution too low to tell you much about the driver's performance. It's hard to tell though as the resolution of the picture is too low for me to read the numbers so maybe I'm wrong.

Dan

 

RE: Radian 850PB any good?, posted on July 26, 2008 at 16:27:28
JoshK
Audiophile

Posts: 820
Location: NJ/NYC
Joined: August 3, 2001
 I think you mean comment, not command.

Your english is leagues better than my german.

Cheers,
Josh

 

RE: Radian 850PB any good?, posted on July 26, 2008 at 21:15:53
KlausF
Audiophile

Posts: 18
Joined: May 22, 2002
 Sorry you are right I meant comment not command.
I will edit it, if I still can.

Greets,
Klaus

 

RE: Radian 850PB any good?, posted on July 26, 2008 at 11:54:07
djk
Manufacturer

Posts: 6135
Joined: June 17, 2000
 I base my remarks on owning Radian products around ten years ago.

The Radian replacement for the Altec 802 had measureably less output above 5Khz, and a peak up top.

The Radian replacement for JBL 2445 had much less output in the 8Khz~12Khz region, and a big peak up top.

Radian had a flux problem leading to solder joint failure on the BeCu lead-out wires. Sometimes they went bad on the shelf as a spare part. The design of the attachment of the voice coil support to dome is poor, the execution is also poor. The 2445 replacements developed holes at the apex of the dome, the aluminum turned to confetti. Incorrect lead dress on the 2445 replacement caused failure of the BeCu lead-out wire.

The sample 850 drivers provided by Radian were shipped back to them. While they measured well (except below 1Khz), they didn't sound as good as the Altec 288s they were intended to replace. Ultimately the choice was made for the JBL 2446 magnet structure with a 2441 diaphragm. The JBLs didn't sound as good as the Altecs (either), but were deemed to be more reliable (and were in service).

Perhaps they have solved all these issues, perhaps not. I'm not willing to spend the time or money to find out.

 

RE: Radian 850PB any good?, posted on July 27, 2008 at 11:00:55
KlausF
Audiophile

Posts: 18
Joined: May 22, 2002
 Ten years is a long time for a company to sort out their manufacturing
problems.
I got drivers from 2003 that took some beating on road shows and they
sound great and the diaphragms look flawless.
Radian supplies some very respected PA speaker companies and if they
still had problems they would loose them.

Here is a quote of Linn Olson about the Radian 850PB:

"Hi Paul, just talked to Mike at Radian on the phone yesterday. Without breaking any NDA's (they sell drivers to several $80,000/pr high-end vendors), the 850-PB 2" is favored for its relaxed, open midrange and performance almost up the top of the range (it is frequently used with supertweeters in ultra-fi applications). When ultimate HF extension is more important, the smaller 1.4" 835-PB is favored for slightly sweeter HF at the expense of a bit less midrange power-handling."

Greets,
Klaus

 

RE: Radian 850PB any good?, posted on July 27, 2008 at 11:20:00
Tom Brennan
Audiophile

Posts: 5854
Joined: January 2, 2000
 Not to rap the Radian Klaus but if we'd listened to Olson all these years we wouldn't even be using horns. I know he's coming around now, sorta.

 

RE: Radian 850PB any good?, posted on February 3, 2010 at 10:39:14
BEARZ


 
Some of the above information is incorrect and inaccurate.

John Meyer holds the Patent on the driver. Not Yamaha.

The above graph is from Martin Seddon in Australia, fwiw.

_-_-

 

RE: Radian 850PB any good?, posted on March 5, 2010 at 05:00:38
Klaus.F


 
There is nothing inaccurate or incorrect.
The patent has not been mentioned at all, how can it then be inaccurate.
But I really doubt that Meyer has the patent on the JA-6681.
Azura is mentioned on the graph and therefore it is clear that it is one of
Martin's creations.


Greets,
Klaus

 

RE: Radian 850PB any good?, posted on July 28, 2008 at 06:57:10
KlausF
Audiophile

Posts: 18
Joined: May 22, 2002
 I was just trying to point out that Mike of Radian replied to him saying
their drivers are used on some $80000 speakers.

Linn is a very thorough fella and wants to make sure he gets the
best possible result from his new high efficiency system. After more than
a year of starting the topic he finally bought some drivers.

I was a little less scientific about finding the right drivers. I found a few People
that had the money and were fanatic enough to compare top
drivers like Altec's, Tad's Radian's, and ended up with the Yamaha
JA6681's for my 1,4 inch tractrix and the 850PB's for 2”.

Anyhow the concerns that djk has against the Radian products are not
justified anymore. The combination of aluminum with synthetic surrounds
is just great sonic wise and has been a proved concept of Altec.
Thees diaphragms are very long lasting if the right glue is chosen.


Greets,
Klaus

 

RE: Radian 850PB any good?, posted on July 28, 2008 at 12:09:27
djk
Manufacturer

Posts: 6135
Joined: June 17, 2000
 I have six of the Yamaha JA6681s sitting in my front bedroom, they're nice too.

How did you like them compared to the Altec 288s?

 

Sorry misinformation, posted on July 30, 2008 at 09:18:47
KlausF
Audiophile

Posts: 18
Joined: May 22, 2002






Sorry djk,
for the misinformation the JA6681b was not the MS1401b but the MS1401a.
Still they should have left it untouched.
I hope you have the original diaphragms in yours.
I put a quote in from Jeff Mai regarding 6681b vs. 288.

I hope the pics are good enough. Why are they so small even
though the original was 900 x 800 and had just 125kb ?

Greets,
Klaus

 

RE: Radian 850PB any good?, posted on July 29, 2008 at 07:35:32
KlausF
Audiophile

Posts: 18
Joined: May 22, 2002



I never owned the Altec 288. I was searching hard to find Altecs here in Germany but the ones that were installed in good Theater or Concert halls are mostly owned by horn lovers now.

I found a guy that extensively compared Altec 288, Yamaha JA6681, TAD 4001, TAD 2001
and he said the JA6681 sounds the best of all. He uses only 6db crossovers between 400 and 500hz
and tube amps.
Here is a brief translation on what he communicated to me about the JA6681 in two mails:

"The Yamahas are less bright, more even and smooth sounding than the 288.
It goes to 12khz straight and then down. I do not miss a super-tweeter but with some material they can help. If one should have the desire to add a tweet no JBL like 2405 as they don't harmonize with it but the EV T350 and the Coral 104 work ok as they have more of the signature of the Yamaha.
The TAD2001 has more sparkle on the hights but can not keep up with the the lower registers of the Yam.
The TAD4001 is in comparison to the Yam. more direct sounding and for me to aggressive."

I contacted two other guys that confirmed the Yamaha's superiority over the TAD 4001 and that settled the matter to me.

One very interesting fact about the Yamaha's is that they can be supplied with Yamah Phenolic diaphragms. They are more expensive but sound fantastic if one plans to use a tweeter anyway.
With the phenolic diaphragms they go straight up to 8k and then die out without any breakups. This makes a 6db crossovers to a tweet very easy. This is the way I used them last and I think I keep it like that because I just don't like the narrow sweet spot of tweeter less designs. With the phenolic diaphragms the 6681 sound like a very good cone driver with the added dynamics and details of good compression drivers. At least with tractrix horns I must add.

You have to open your 6681 to see if the diaphragms are original or if they have the Meyer Sound diaphragms in them. The originals (6681) have become so rare that some people used the Meyer ones that are not as good sounding. Meyer just re badged the Yamaha and called it 1401b. They applied some stuff to the genius surround of the original drivers just to make them more robust. Even though their UPA's sound really good they would sound even better with the original untouched diaphragms.
I have seen some posts on PA forums where people were searching diaphragms for the 6681 and could not find any.
This is the only concern that I have about this driver, that in a few years it will be impossible to get diaphragms for them.
I am even willing to trade a pair used phenolic diaphragms for used aluminum ones if they are the originals without the Meyer glue.
I have no fear that I ever need new phenolics as they seem to last forever. I had an early pair of Klipsch K55V and their phenolic diaphragms looked like new. This material seems to keep its flexing ability for life.

See the pic of the 6681 on an Azura horn. Not even the Altecs go any
lower.

Greets,
Klaus

 

RE: Radian 850PB any good?, posted on July 27, 2008 at 09:31:15
Phil-Who?


 
Thanks guys,
I think I will take the risk and buy a couple.
Is the manufacturing date marked on the driver?
If they had some issues ten years ago I certainly
don't want any that are older then about six years.

Phil

 

RE: Radian 850PB any good?, posted on August 1, 2008 at 15:23:45
serenechaos
Audiophile

Posts: 49
Location: New Mexico
Joined: October 21, 2004
 Any more avalable?
I'm interested in a pair.
Robert

 

RE: Radian 850PB any good?, posted on August 3, 2008 at 00:12:14
Phil-Who?


 
satinsoundsystems.com/web-content/inventory.html

 

RE: Radian 850PB any good?, posted on July 27, 2008 at 10:10:31
KlausF
Audiophile

Posts: 18
Joined: May 22, 2002
 The serial numbers on the drivers are consecutive.
Mine are from 2003 and have the SN 122145 and 122146.
If you give the seller a call he would probably tell
you the SN's.

Greets,
Klaus

 

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