Aftermarket Diaphram Evaluation

[Robh3606]

I have a couple of after market diaphrams that Guido sent over to do an evaluation for Aquaplas. Before I coat them I am going to take a set of measurements compared to a 2416H and 2425H diaphrams in 2426 cores. Heres the diaphragms and the back cap and first impedance measurement of the Titanium one using WW2. I will take some CLIO measurements on 2370 and post them as well to see how they look. We have been talking about the differences enough lately I think it's about time we tried to see what they show us.

Guido if you have any more information on them can you post it?? These are wound with what looks like edgewound copper. Are they copper or copper clad aluminum??



Rob:)

[moldyoldy]

I'd guess with these 'frams that the most noticeable and possibly only change will be a slightly tilted drop in sensitivity. Maybe a little lower harmonic content with impulse response too. Just an uneducated prediction, I'll be interested in the results no matter what. Good project!

[Robh3606]

Just doing some impedance runs is quite an eye opener. The aftermarket diaphragms from Guido are not in family with the JBL's and they measure quite differently. I have been running measurements on 3 aftermarkets 1 from Guido and 2 more with 2426H cores I just received. From the published curves an older 8 ohm JBL comes in close to expected with the peaks where they belong and at the correct or lower amplitudes. The aftermarket peaks are not in the same place or can have levels much higher, at least the ones I have. The first run is the first aftermarket in the first post put on a 2370 Horn. The second is another aftermarket and the last is a JBL. All three with a 2370 horn.

Rob:)

[Guido]

Thanks for that info Rob. I once made different measurements but I havent had this nice WT2 back then.
Currently I'm busy with Richs 4345 project and can't assist you here. Later....

[Robh3606]

These are the two After Market diaphrams I received with the 2426 cores. They are very poorly matched right in the 2-4k band where your ear is most sensitive.


Rob:)

[Robh3606]

Here's are a pair of 2416H-1 drivers with stock diaphrams.

Rob:)

[Robh3606]

Impedance runs for both drivers. They are very close just watch the phase and Imp scales in each.

Rob:)

[Robh3606]

I am going to run 2 more pairs of JBL 2425H diaphrams to see how they stack up. Anyone have a pair of the Radians they can measure. The ones I have measured so far are the normal fair off E-Bay. It would be nice to see how the Radians are with their Mylar surrounds.

Rob:)

[Zilch]

Have Radians; I forget what cores they're mounted on, but I'll dig them out. Also have 2370As to test on.

Edit: In 2425s. Tonight's shot, so maybe tomorrow....

[Robh3606]

Hello Zilch

Good lets see how they look.

Rob:)

[Zilch]

Radian vs. JBL diaphragms in 242x motors on 2370A, top two, and what Radian claims on PWT, next. JBL 2416H-1 and 2418H-1, bottom, on the same 2370A horn.

Perhaps they'll send a tech to tweak the notch @ 6.5 kHz outta here. It'd be good if someone could independently verify these results.

I'm only marginally competent at installing diaphragms, and certainly don't have the skill to have gotten the two so identically wrong.

First tried them over a year ago on H3100 with much the same result:

http://audioheritage.org/vbulletin/showthread.php?p=79820&#post79820

[Robh3606]

Hello Zilch

Thanks for posting these. Can you break out and show just radian pair to see how well matched they are in the same scale I used 5db per?? That way we can compare the two sets of measurements easier. It's hard to see with all 4 together. Wonder what that notch is??? I am surprised you don't see it in the impeadence of phase curves??

Did you do Sine as well?? It looks like the windowing is giving you a hard time below 1K. How do they look raw?? I have been doing both MLS and Sine to help confirm my measurements. I have a small room as well and in some cases the Sine is the better of the two measurement types buy usually the raw MLS and Sine look really close except for the LF noise in the MLS. When you do MLS are your measurements a single snap shot or are you doing multiple averaged measurements???

If you want to see how well you have the diaphrams installed do a Sine in CLIO and take a look at the THD. If they are not right it the THD goes up and you get some really weird looking curves. You will know just by looking somethings up. You have the WT2 ??? I use that as my signal source when I install them. You can do quick snap shot sweeps, changing the number of measuring points, as it will show on the Impeadence curves as well.

Rob:)

[coherent_guy]

Have Radians; I forget what cores they're mounted on, but I'll dig them out. Also have 2370As to test on.

Edit: In 2425s. Tonight's shot, so maybe tomorrow....

Would the curves be vastly different with the Radian diaphragms in 2420s with 2370As?

[Zilch]

Can you break out and show just radian pair to see how well matched they are in the same scale I used 5db per?? That way we can compare the two sets of measurements easier. I use five averaged as standard MLS procedure. Radian only, expanded vertical scale, 5 dB/division:

[Zilch]

Would the curves be vastly different with the Radian diaphragms in 2420s with 2370As?They would be different. "Vastly" is a matter of definition and application.

Where broad regions of bandwidth (certainly, 1 octave or more,) are involved, a difference of only one or two dB will significantly alter the "voice." Ideally, the differences in response between 2420 and 2425 motors would be adjusted with the filter.

Even ignoring the notch, fine tuning for Radian diaphragms would likely be necessary for use in any quality listening application. They're clearly not the same. They'd have to be tested in 2420s versus the original diaphragms to ascertain the differences. I can tell you that even the diamond-surround JBL aluminums are sufficiently different from the original tangentials when analyzed at this level of detail as to warrant considering filter modifications.

That's where I get into trouble - do I "fix" it at the same time? If there's major redesign involved, that effort is better invested in improved drivers to start with, perhaps. Is it the alnico or the aluminum that I like?

I'll clean up some 2420s here and move the Radians over....

[Zilch]

Rob, your plots exceed the width of my 800 x 600 screen, making them hard for me to compare directly. To get plots that fit, I export graphics in JPG "small," and upload those directly to the forum.

Mr. Widget doesn't like the aspect ratio, but if I try to alter it in an editor, I always lose significant detail, so I've settled on this for posting. Screen shots work, but then there's no legend.

For 200 Hz to 1 kHz, I believe we've got to work more on coming up with an accurate ground plane measurement technique.

Here's the THD:

[Do I recall there's a transition in 2370A at ~6.5 kHz? Radians don't like that, maybe.... :dont-know ]

[Robh3606]

That THD on the Radians looks a bit high. This is a 2425 on a 2307 will do more when I get back. Its about 40db down the Radians are about half that from what you posted. Did you rescale the THD???

Rob:)

[coherent_guy]

They would be different. "Vastly" is a matter of definition and application.
.
.
.
I'll clean up some 2420s here and move the Radians over....

I see, thank you. By vastly I meant would the curves bear no resemblance whatsoever, the 2425 motors then being so different than the 2420. I shall watch for the curves on 2420's if/when you get them done, much appreciated, thanks.

It must be nice to have all these drivers around to "clean up. . ." and play with :D

I have LE85's with JBL diaphragms on 2370A's (and the Radian diaphragms you have measured) that I am listening to for the first time. I am very impressed with them and do not understand what the fuss over "horn sound" by some people is all about. I hear no "horn honk", they are very quick with transients, and the seemingly low distortion reproduction related to their high SPL capabilities is wonderful, that aspect alone is worth many other trade-offs, if they exist. I can only imagine what the new generations of compression drivers are like.

There are none so deaf as those who will not listen.

[Mr. Widget]

I have LE85's with JBL diaphragms on 2370A's (and the Radian diaphragms you have measured) that I am listening to for the first time. I am very impressed with them and do not understand what the fuss over "horn sound" by some people is all about. I hear no "horn honk"...

There are none so deaf as those who will not listen.
Hmmmm.... have you listened to many other horns? Compression drivers and horns will almost always give you, "very quick with transients, and the seemingly low distortion reproduction related to their high SPL capabilities is wonderful"... that along with directivity control are the primary reasons we use them, but the 2370 certainly doesn't sound as smooth and coloration free as some other horns and very few horns sound as smooth as a good dome.... that said, there are plenty of folks who are happy with their vintage Klipsch products and those speakers really know how to honk... in comparison, I suppose the 2370 is a bit smoother.

As for all the fuss... I'd suspect some people are more sensitive to dynamics and a lively sound while others are more sensitive to horn colorations... we horn heads are either willing to live with the colorations or simply aren't sensitive to them.


Widget

[edgewound]

Out of curiosity, Rob and Zilch....

Are you testing your diaphragm samples in the same driver motor? or are they installed in different drivers motors of the same model?

Thanks.

[scott fitlin]

I have LE85's with JBL diaphragms on 2370A's (and the Radian diaphragms you have measured) that I am listening to for the first time. Have you listened to your LE85,s with both the JBL and Radian phragms?

I am interested in your opinion of JBL -vs- Radian diaphragms, as well as your opinions about how the Radians sound, in general.

:)

[Mr. Widget]

Out of curiosity, Rob and Zilch....

Are you testing your diaphragm samples in the same driver motor? or are they installed in different drivers motors of the same model?

Thanks.Different motors across the country... and even different horns. We can't expect them to be all that similar, though the notch that Zilch is seeing in the Radians is quite significant.


Widget

[Mr. Widget]

Have you listened to your LE85,s with both the JBL and Radian phragms?
This is a really good point... I know that Zilch is a curve junkie and all, but sometimes the subjective listening impression is far different from the objective measured one... I'll always take the subjective over the objective. Of course, that is MY subjective impression... not necessarily someone else's. :D



Widget

[scott fitlin]

I agree, and I really appreciate seeing the measurements, and those that take the time to make the measurements. Thank you, guys.

And I also know listening to the devices should be discussed as well. Peoples subjective opinions on what they hear!

:)

[Zilch]

That THD on the Radians looks a bit high. Did you rescale the THD???See legend, lower right. Distortion plot is raised 20 dB. That's how I get it on the higher-resolution 10 dB/division scale plot along with the frequency response.


By vastly I meant would the curves bear no resemblance whatsoever, the 2425 motors then being so different than the 2420.I expect the curves will be similar.


I have LE85's with JBL diaphragms on 2370A's (and the Radian diaphragms you have measured) that I am listening to for the first time. I am very impressed with them and do not understand what the fuss over "horn sound" by some people is all about.2370s are certainly less "honky" than the earlier exponentials, and it depends somewhat upon where you're operating them. It's easy to hear the coloration by varying the the low-frequency cutoff in the 800 Hz region with an adjustable active filter.

2370's biggest problem in two-ways is at the high end. If you examine the data sheet carefully, you'll see it just doesn't happen up there, and they protest when forced to do it. You have a bit of an advantage using aluminum diaphragms, which are smoother than the titaniums. Try forcing HF out of 2370(A) running 2425(6) and you'll acquire new perspective on "nasty."

[Zilch]

Are you testing your diaphragm samples in the same driver motor? or are they installed in different drivers motors of the same model?Hi, Edgewound. Different motors, same model.

Over time, we've come to recognize that variation among different examples of the same model is small, barring major anomalies such as demag. In other threads, I've shown the results of testing multiples, six and eight at a time, of varying age and provenance, and they are remarkably similar.

Still, as standard practice, we measure in pairs to provide additiional confidence in the findings. That notch in the Radian response, for example, would be easily attributable to installer/operator error if it were not so precisely replicated in the second sample. It may yet be found to be some consequence of Zilch's inherent stupidity as opposed to Radian's design, tho....


I am interested in your opinion of JBL -vs- Radian diaphragms, as well as your opinions about how the Radians sound, in general.Hiya, Scotty. I recall when listening to them last year, they confirmed my imression that aluminum was smoother-sounding than titanium. I also have the JBL 2421 aluminums in other motors here, but it was clear from the initial measurements on both (plus Aquaplassed titanium and others,) that no reasonable comparison was possible without EQing them to the same response.

I operate from a slightly different perspective than Mr. Widget. The response curves come first here, then I listen. Apples to apples; then the differences are clear. Look at the curves for Radian vs JBL shown here. There's no way they're going to sound the same in any particular system; they must be normalized to a desired system response curve to accomplish any reasonable comparison....


And I also know listening to the devices should be discussed as well. Peoples subjective opinions on what they hear.Yup, not there yet, is all.

But I can almost guarantee it won't be on 2370(A), though that is a convenient platform for testing. The comparative listening must be done on the specific target system. Findings with 2344(A) may be different, though a general trend (aluminum smoother than titanium, for example) would likely remain as characteristic.

[scott fitlin]

Yeah, I hear ya. I love the time you guys take to run imedance, freq response, and distortion plots. But, I know, and from experience, that the measurements just dont tell the entire story.

The final say so comes in the listening to the speakers. And its really funny, cause both your measurements and Robs say the Radians arent so good, but, people say they sound very good. And, I have talked to many who prefer the Radian phragms to JBL,s parts!

We do agree on one thing, I also think Aluminum makes nice, smooth sound.

[Zilch]

Just to be clear, I don't believe Rob is testing Radians, rather, other aftermarket brands.

It's clear from my measurements that Radians are going to sound "brighter" unless the system response is adjusted. They're certainly going to change the system voice.

They may also be smoother in comparison to titanium. BUT, if that notch is real on JBL motors and horns in general, it must be factored in. What happens if you EQ that out? How does THAT sound?

A true subjectivist would say it doesn't matter. They like the sound better, and their own ears are the final arbiter. They're done.

But only until tomorrow or next week, of course, when they'll be trying whatever else anybody suggests or might otherwise come along instead, thus continuing an endless cycle of revoicing their system with different amps, drivers, horns, cables, and psychoacoustic voo-doo. If something is REALLY better, it will be apparent with the voice held constant.

Do I like Radians better? Well, maybe; I wouldn't know until I fine tuned the filters or EQ to the same baseline to make a rational comparison. FIRST, I've got to figure out that notch, tho.

[Bumper cars are a more fun ride, actually.... :p ]

[scott fitlin]

Yeah, thats true!

Ill tell ya this, the JBL phragms in my drivers do sound good. Im apprehensive at best about changing them to something else. Even though I did order two.

I will also add, many times it isnt the driver we are hearing sounding bad, rather poor source material is many times the culprit. I have this one CD, man, I have to say, the JBL diaphragms sound terrific. Actually, I have alot of really good stuff, and alot of so-so stuff.

Or improper system setup and tuning.

:)

[grumpy]

FIRST, I've got to figure out that notch

1) are these -new- Radian diaphragms? (sorry if this was mentioned already).

2) where's your PWT :D ? I've got my 1.5 & 2" tubing/caps in the garage waiting on
a flange and a good stuffing :)

-grumpy

[Zilch]

1) are these -new- Radian diaphragms? (sorry if this was mentioned already).They were brand new from PE just over a year ago. I've played them all of a few hours or so total.

Which reminds me that I also have a used one in an eBay 2410. Maybe I stick that on the 2370A for a look-see.... :thmbsup:

[moldyoldy]

...snip...A true subjectivist would say it doesn't matter. They like the sound better, and their own ears are the final arbiter. They're done.

But only until tomorrow or next week, of course, when they'll be trying whatever else anybody suggests or comes along instead, thus continuing an endless cycle of revoicing their system with different amps, drivers, horns, cables, and psychoacoustic voo-doo. If something is REALLY better, it will be apparent with the voice held constant...

:applaud:

Both approaches are flawed, so until either is perfected, common sense dictates the consideration of both, but taking neither as an absolute. Subjectivity lacks widespread, universally-interpreted terminology (one person's "airy" is anothers' "wheezy"), while objectivists lack a method of summing specifics to purvey the big picture of the perceived experience.

For the pusposes of disscussion though, I can only (subjectively) stand reading a minimum of "Brand X, Model Y sounds like crap because it's {insert adjective of choice}, Model Z just blows it away..." threads, because they tell me nothing. Explain the physical "why" however, and I get something of use to apply as I choose (try to explain a 6.5kHz notch without techspeak).

The underlying motivation for us audio nuts seems to be a desire to make a good thing better, or at least to get the most from what you have. Towards that end. objective observations lead to solutions, subjective discussion leaves you waiting for Brand X to produce a better model (which to be successful, must be improved by objective methods).

[Zilch]

I am going to run 2 more pairs of JBL 2425H diaphrams to see how they stack up.I'm anxious to see that, as I'm certainly not replicating the published 2370A response very well using "stock" drivers here:

[grumpy]

1m away and on axis? (2370A Vert/off-axis plot) -grumpy

[Zilch]

1m away and on axis? (2370A Vert/off-axis plot) -grumpyI'm 2m away, but I moved the mic up to 1m last night to see if that made a difference. It didn't.

I'm certainly on axis, but should confirm with a level that the horn face is absolutely plumb. 15° ain't all that much, now that I think about it, and the VHF is already down substantaily (10+ dB dropped) there according to that spec....

[grumpy]

15° ain't all that much that's what I was thinkin' :)

w/ a high-pass cut off, it would look pretty close to the 15deg curve.

I don't have any 2370's or I'd try too... -grumpy

[Zilch]

Nope, that isn't it. There's no FR sweet spot. I manipulated the horn/driver "live" watching RTA.

And it's not the measurement system, 'cause PT-F's flat as Kansas above, and on RTA just now, too.

Let's see what Rob gets.... :dont-know

[Robh3606]

Hello Zilch

Here's a pair or D8R2425 diaphragms from Ian. Don't know how old they are. They match up fine and look a bit more like the JBL curve. On the graphics just resize. You can pick them off the forum and rescale to compare. I am keeping them large so I don't loose resolution. I also don't want to change now.

Here are plots at 5 and 10 dB scale. The 10 dB scale is more in line with the JBL curve. As far as what's going on up top and why we don't see the plateau??? I am right down the throat so I don't understand the disparity??

Hello Edgewound

I am using 2 2426 cores for measurements. I am assuming that undamaged cores will be reasonably well matched. The original measurements was in a 2416 but I edited them out and remeasured in a 2426. The 2426 core is much easier to make changes and run curves with. The motors for the 2416 and 2425/26 are different enough that it made more sense to use the correct core for the diaphragm. I have 2416 measurements but they are to illustrate how JBL diaphragms are matched compared to the aftermarket 16 ohm 2425.


Subjective vs Objective

The idea I had when I started the thread was to see what if any observable differences there were using measurements of a stock JBL diaphragm as a baseline. I wanted to see just how different the AfterMarkets and the Radians were. I think we all agree that measurements are not the end all and be all some would like to believe they are. That said one area that they excel in is looking for differences that subjectively would be difficult or impossible to understand using music as a program source. I felt this was a better way than having to deal with all the unknowns trying to do a subjective evaluation. I thought if there were indeed audible differences we would get a better handle using measurements to try to understand what was actually happening.

To that end I have another pair of JBL left to go and an aluminum 2421 aftermarket to try. I hope everyone can understand what I have posted. I have not looked at distortion levels or impulse response in the measurements I have taken. I have kept them out for now as I think they might confuse things a bit. I will be trying them with a high-pass network to see what the impedance changes/differences do with a network in the mix. It's one thing looking at them on a horn but I think the impedance differences may also be an issue. The only way to know is to take a look.


Rob:)

[Zilch]

I'd say we're getting similar results with 2425/6 on 2370A, Rob.

I'm looking for the HF plateau, and LE85 does it (kinda):

http://audioheritage.org/vbulletin/showthread.php?p=155809#post155809

Quasi-anechoic MLS should be approximating JBL's curve, I would think, but neither that nor sinusoidal do....

[Robh3606]

Hello Zilch

What going on from 700hz and up to say 2k?? What does the raw curve look like?? It looks like you have ringing or you are gating too much off the measurement. Those are ungated measurements I posted after yours. Above 500Hz you should be able to get a good snapshot with not all that many issues from the room. Those are 10 sample averages about 6 inches off the horn. If you look both the Sine and MLS are almost the same. If you want to compare the measurements be a good idea to use the same core driver. I don't have any LE-85's around to try to correlate measurements.

Rob:)

http://audioheritage.org/vbulletin/attachment.php?attachmentid=23487&stc=1&d=1173510831

[Shane Shuster]

I have a question. If you measure first, then listen, isn't there a very good chance you have already prejudged the speaker. For example the 6.5k dip, lets pretend thats a measuring error. When you listen to it, in the back of you mind you are thinking of the dip. Is it possible you would not like a speaker you normally would have liked, because of negative technical data? Maybe you would try to fix something that shouldn't be fixed? I think a large part of HiFi might just be made up in peoples heads.


I like to listen, then measure, then listen again. I then misinterpret the results and start from scratch, more determined than before, but with not much more information on how to actually change the damn sound to what I want.

[Zilch]

What going on from 700hz and up to say 2k?? What does the raw curve look like?? It looks like you have ringing or you are gating too much off the measurement.
I should experiment with different distances and see if I can't come up with something more optimum.

Presently, the windowing is telling me, in this setup and space, that I can't get reliable results down that low, so I ignore them.

I know there's lots of readers interested in the bottom end of horn/driver performance, but I don't want to trade off accuracy at the high end in these studies.

Next time Mr. Widget comes over, maybe he can help me with this, but I believe he found that, even in his space, 800 Hz was about the lower limit. It could easily be I read him wrongly on that, tho. Perhaps he can provide some clarification here.... :dont-know

[Zilch]

I have a question. If you measure first, then listen, isn't there a very good chance you have already prejudged the speaker.I can't run a horn/driver combination for listening without measuring it, because it needs a compensation filter, the characteristics of which I determine from the measurements, which may intially just be RTA. Something like that notch is going to be apparent at even the lowest resolution here.

It also needs to be accurately balanced with other system components for the listening to be meaningful. I can't do that by ear.

Call it a bias, perhaps, but after several years of working with this now, I look at the curve and know immediately what's going to sound like poop, and that there's no point in listening until it's "in the ballpark." I haven't done it yet, but, yes, you can bet I'll be listening for that notch, and I can virtually guarantee that, if it's real, it'll have to be fixed for those diaphragms to be usable on that driver and horn combination. That may be something as simple as realigning the diaphragms.

Nobody knows better than a curve junkie that what we hear is in substantial part, in our heads. That's why I recognized from the very start that I couldn't do this without instrumentation.


I like to listen, then measure, then listen again. I then misinterpret the results and start from scratch, more determined than before, but with not much more information on how to actually change the damn sound to what I want.There's some disconnect here. You need to determine the curve of the sound you want, then try to match it with compensation. Trying to do that with music is a recipe for madness, in my experience -- too many variables. You tweak yourself to death....

[Shane Shuster]

There's some disconnect here. You need to determine the curve of the sound you want, then try to match it with compensation. Trying to do that with music is a recipe for madness, in my experience....

Zilch, Its all maddness, haven't you learned that by now.:)

I was half joking, but there are so many variables besides speaker response. I know the sound I want. If I listened to a speaker and thought it was bright and then measured it. Lets say the graph came out flat to 20k. I would probably think to myself, I like a slightly rolled off speaker and try to fix it that way, by rolling the highs. It would almost never work. It would turn out to be the directivity or a slight peak in the upper midrange. Very seldom would it be the obvious (to me) stuff.

What we need is a software program that would overlay all possible measurements and then it could sort the results by personal preference.:)

[Zilch]

What we need is a software program that would overlay all possible measurements and then it could sort the results by personal preference.:)DEQX presently manipulates multiple parameters. It's coming.... :thmbsup:

[coherent_guy]

Hmmmm.... have you listened to many other horns? Compression drivers and horns will almost always give you, "very quick with transients, and the seemingly low distortion reproduction related to their high SPL capabilities is wonderful"... that along with directivity control are the primary reasons we use them, but the 2370 certainly doesn't sound as smooth and coloration free as some other horns and very few horns sound as smooth as a good dome.... that said, there are plenty of folks who are happy with their vintage Klipsch products and those speakers really know how to honk... in comparison, I suppose the 2370 is a bit smoother.

As for all the fuss... I'd suspect some people are more sensitive to dynamics and a lively sound while others are more sensitive to horn colorations... we horn heads are either willing to live with the colorations or simply aren't sensitive to them.


Widget

Sorry for the late reply, I forgot I had posted in this thread :blink:

As a matter of fact, no, I have not heard any other horns, including Altec, Klipsh, or JBL for that matter. I am something of a refugee from the high-end spin that all horns suck.

A part of me always wanted to try some and now I have. I think they are great. My posting reflected my experience that all the bad things (real and otherwise) associated with horns did not jump out at me now that I've listened to them for a while. I obviously over-generalized about horns in my comment given my level of experience. But I have found over the years that ones experiences tend not to be unusual, but are far more likely to be what normally happens. Thus my comment.

Sure the drivers and horns I have are not as neutral as my Revels, but they are just as clean sounding, are faster, louder, and image and disappear into a sound stage nearly as well! That with an unoptimized crossover and enclosure, they're sitting on top of a speaker. So I'm impressed and intrigued, I realize to you folks all this horns stuff is as common as spit but not to me. Please count me in as a horn head! :bouncy:


Have you listened to your LE85,s with both the JBL and Radian phragms?

I am interested in your opinion of JBL -vs- Radian diaphragms, as well as your opinions about how the Radians sound, in general.

:)

No I haven't yet, I've been doing a long term listening test to truly get to know them, and got involved with better crossovers and adding L-Pads, thank Gawd for Parts Express! I had put aside the Radian diaphragms, particularly after my little experience with Giskard ;) (I didn't know whom he is. . .) but given this threads existence I will give them a try, after I complete my L300 equivalent filters designed by Giskard, much appreciated BTW.

Frankly, I've been dreaming of new JBL 'phragms, which I must have! I'll be happy to post my opinion on the Radian's, once I get around to mounting them, although I hope I can keep an open mind ;) Thanks for asking about my opinion. :D

[Robh3606]

Hello Zilch

How big is that Lab:hmm:

I started up the CLIO Clinic thread again, go to the post above the link

Rob:)

http://audioheritage.csdco.com/vbulletin/showthread.php?p=156220#post156220

[herki the cat]

Hello Zilch

What's going on from 700hz and up to say 2k?? What does the raw curve look like?? It looks like you have ringing or...................
http://audioheritage.org/vbulletin/attachment.php?attachmentid=23487&stc=1&d=1173510831
Hello: Robh3606

According to Dr. Floyd Toole __ "3 db Peaks followed by 3db Dips in the system Frequency Response provide the Transfer Function of a Frequency Modulation Discriminator __ aka, an FM Detector which results in severe Frequency Intermodulation Distortion in he signal path. The Late Dr. Murlan S. Corrington of RCA originally brought this to light in the 1950's.

In your post, there is no description of the the horn-loading parameters of your driver in the spectrum below 2kHz. Be assured that a JBL LE 85__ on a horn capable of providing full loading two octaves below a crossover of 500 Hz __ is completely free of the Peaks and Dips shown in the "CL10 curve above.

Frequency Modulation produces severe frequency Intermodulation Distortion in the spectrum of 1kHz to 2kHz where the human ear is extremely sensitive, not to mention the total destruction of the critical acoustic environment reverberation signal phase-amplitude components.

This entity deteriorates the mid bass spectrum from 150 Hz to 600 Hz which carries the bass harmonic structure and the voice fundamental frequencies.

Very high quality was realized in this spectrum in the RCA LC-9A Two-Way Horn System designed by John Volkman and A. J. May in the late 1960's.

Consider this__"You can place the Philadelphia Orchestra in a Cow Pasture and the resulting sound is worse than a "Mashed Potato Sandwich"__ But "In the Magnificent Philadelphia Academy Of Music, it is Beautifully and Warm beyond Description."

There is one very valuable acoustic tool beyond Frequency Response Measurements, Aka: The General Radio Corp. Tone Burst Generator" if you can still find one__This test system yields a slow frequency sweep from 20 Hz to 20,000 Hz with a sign wave turned on during eight cycles followed by a signal-off period of eight cycles to observe speaker signal ringing during the "off Period." A good speaker transient response will exhibit "Zero Ringing" Beyond One-Eighth of One Sine Wave Duration.