PDA

View Full Version : Dias Titanium or Aluminium



ougo
12-03-2008, 12:45 PM
Hello Guys,

We have currently on a french forum an open point concerning alu and ti dias. Persons with 4343 and others JBL from 43xx, consider that Ti is smother (less ttssss... tttssss...) and more natural than Alu. Here, it's the opposite.

Do you have an idea why?

I can understand than people from different culture could prefer different sound, but not that these persons describe the same qualities.


In my case, i need to change 2421A dias (JBL 4430).


Ugo

hjames
12-03-2008, 01:06 PM
Titanium diaphrams are stronger, can take more abuse in commercial use,
but some think they can be a bit harsh for home use, unless coated with aquaplas or a similar 'treatment".
I believe Alum dia are smoother, but being a softer metal, can stretch, fatigue and fail.
I believe thats not usually an issue in home use.


Hello Guys,

We have currently on a french forum an open point concerning alu and ti dias.
Persons with 4343 and others JBL from 43xx, consider that Ti is smother (less ttssss... tttssss...) and more natural than Alu. Here, it's the opposite.

Do you have an idea why?

I can understand than people from different culture could prefer different sound, but not that these persons describe the same qualities.


In my case, i need to change 2421A dias (JBL 4430).


Ugo

Tom Brennan
12-03-2008, 01:43 PM
I think both materials sound good.

ougo
12-03-2008, 03:26 PM
I think both materials sound good.

i think too ,-)

Ugo

Robh3606
12-03-2008, 04:26 PM
I agree with both of you. Either one can sound really good. I think its more a how it was designed issue than the material by itself.

Rob:)

Mr. Widget
12-04-2008, 12:00 AM
I agree with both of you. Either one can sound really good.I suppose... though everything else being equal, the Aluminum sounds cleaner and clearer.


I think its more a how it was designed issue than the material by itself.Implementation does matter, however that raw material is also critical. Hence Be, Mg, and Al are all inherently superior to Ti... looking at the Periodic Table we can see their relative masses.


I believe Alum dia are smoother, but being a softer metal, can stretch, fatigue and fail.Aluminum is soft, but it is actually stiffer as well as being lighter... and that is why it is superior, but it does get brittle due to work hardening and then it can fail.


Widget

timc
12-04-2008, 03:34 AM
When talking about materials. Where does the synthetic diamond, that for instance Acuton and B&W uses, fit in. I read somewhere that its breakup modes were even higher in freq, than Be.



-Tim

Robh3606
12-04-2008, 04:44 AM
however that raw material is also critical. Hence Be, Mg, and Al are all inherently superior to Ti... looking at the Periodic Table we can see their relative masses.

Hello Widget

Your right but I am think more along the lines of the "Titanium Sucks" school of thought or "Aluminum Sucks" for that matter. I can understand a preference for either and in that case the better material issue goes out the window at least as far as that individual is concerned. I have seen people post that they didn't like the sound of Be drivers as an example.

I see people who switch from one to the other and then you see "there is no going back" comments. To me that's extreme as I find the differences not quite that dramatic. I have Be and Ti drivers running in the same room and I can easily compare the two. Be wins but there is no way I am going to start getting rid of my Ti drivers.

One material may be superior but that doesn't mean you can't make a good sounding driver with the "inferior" material. The audible differences between the materials can easily be lost with bad implementation. I have yet to hear a Titanium JBL driver that I couldn't listen too all the day through. I can't say that across the board.


Rob:)

timc
12-04-2008, 07:15 AM
The mantra is "If it moves, coat it." :yes:


Just don't coat it with tar.



-Tim

Chas
12-04-2008, 08:01 AM
I personally use cast iron diaphragms with a dusting of undercoating.

:rotfl:Actually, ductile instead of cast would be less brittle!

1audiohack
12-04-2008, 08:08 AM
I personally use cast iron diaphragms with a dusting of undercoating.

:rotfl::rotfl:Now that is hilarious!

Mr. Widget
12-04-2008, 08:59 AM
:rotfl:Actually, ductile instead of cast would be less brittle!Sure, but that reduces the ability to reproduce detail. :banghead:


Widget

Robh3606
12-04-2008, 09:33 AM
Have you heard how good these thirty year old 2421 and 2441 compression drivers can sound with aquaplasing and biasing? :)

Hello 4313B

Well not the alnico's or the 2" drivers. I have run 2426's with Aguaplased and CC networks on a 2344 and that is one nice sounding combination. I used that for a while until I switched over to Be drivers. I like the Aguaplassed 2425's in my 4344 clones as well. The combination of dusting and CC really seems to bring out the best in them.

I have some Aquaplased Aluminum 2431's in the wings that I want to try out soon. Someday whenever that's going to be.

Rob:)

Doc Mark
12-04-2008, 10:09 AM
Titanium diaphrams are stronger, can take more abuse in commercial use,
but some think they can be a bit harsh for home use, unless coated with aquaplas or a similar 'treatment".
I believe Alum dia are smoother, but being a softer metal, can stretch, fatigue and fail.
I believe thats not usually an issue in home use.

Hey, Heather,

Have you changed your hair-do? Your Avatar looks a little different than I remember!! ;);):D Take care, and God Bless!

Every Good Wish,
Doc

Robh3606
12-04-2008, 10:22 AM
In any case, I look forward to your report on them. :)

Hello 4313B

Well once I get the LE-14 bases built for L250 the clones I will have a modular bass section I can drop the new top driver set-on. I have preliminary networks designed and they look good in LEAP. At the rate I am speeding along it will probably be late next year.

Rob:)

hjames
12-04-2008, 10:33 AM
Hey, Heather,

Have you changed your hair-do? Your Avatar looks a little different than I remember!! ;);):D
Take care, and God Bless!

Every Good Wish,
Doc

Now now, behave!

Thats our alpha male cat Teddy, protecting our L200 cabinets!
he's named after Teddy Roosevelt - check out the 'stache (not photoshopped!)

scott fitlin
12-04-2008, 10:40 AM
Have you heard how good these thirty year old 2421 and 2441 compression drivers can sound with aquaplasing and biasing? :)Now this peaks MY curiosity, as I have always been a fan of Al diaphragms sound. I have been looking into changing over to a more current model of compression driver, and I had heard some 2446 drivers with Ti phragms this past fall, and for the first time LIKED how they sounded. I also believe it was the system they were in, and THIS particular companies engineers setup and used the system.

Imaging and detail was VERY crisp and IN focus, the 2446 drivers on JBL flat front bi-radial horns, NO tweeter. I still found them to be a slight bit edgier, and and a smidgen more rasp compared to my AL 2441,s, but GOOD nonetheless. For sure, I still prefer a tweeter to go all the way up, rolling off the horn where where the tweeter comes in, as opposed to the horn and 2in driver going all the way up, but, that just my particular preference, overall.

How would one get 2441J diaphragms aquaplased to audition? I would spring for the cost of 2 new D16R2441 phragms to try if I could get them! The 2441 still does a GREAT job to this day. How much is the sensitivity reduced by aquaplasing?

I am also still investigating the NEWER neo JBL compression drivers, BUT, IF I could improve on something I already have, that still works for me, this could save me a nice amount of coin, while still garnering the benefits of an upgrade.

I am forced to look at the bottom line to a certain extent, as 5 Crown Macro Tech 9000i amps 2 more Crown CE-4000 amps, and 8 JBL 2242 woofers, in addition to my other projects, and overhaul regimen is OUTRAGEOUSLY expensive!

You have my attention, Mr. 4313B! :bouncy:

scott fitlin
12-04-2008, 11:00 AM
Subwoof is near you and I sent him some genuine JBL aquaplas... he might be able to help out? :dont-know

The cost of shipping 2441's around isn't trivial. ;)

Even for active systems the protection caps should probably be biased. (I'd bias them...)Ill contact Subwoof, see what he has to say, thanks! :D

The cost of shiping 2441 diaphragms, PROPERLY packed in JBL shipping containers, plus cost of phragms and aquaplasing is still FAR more economical than SIX new drivers, :D

Biased protection caps even with active electronic crossovers! I need further education on this one, as I don't understand this completely, and have no experience with it. BUT, I'm willing and wanting to learn! :bouncy:

Tell me more! :applaud:

And, as always, THANK YOU! :thmbsup:

subwoof
12-04-2008, 11:25 AM
Still have that little tupperware bowl in the "JBL" toolbox.

Did a handful of 2425's for the various cabs and some 2445's to complete a group of 2450SL drivers but have not used it on any 2441's as of yet.

I have *one* dia in my stash and am looking for a (used) mate so I can finish a pair of 2441's I had remagged last year.

Now that I have some time and space to do this, maybe will be able to actually listen to these speakers. It's been 24/7 on multiple fronts for 5+ years with no break...

sub

scott fitlin
12-04-2008, 11:55 AM
Now that I have some time and space to do this, maybe will be able to actually listen to these speakers. It's been 24/7 on multiple fronts for 5+ years with no break...

subSubwoof, let me know when you have time, Ill purchase a brand new pair of D16R2441, send em to you, and you can play with them for a bit, before you snd them to me, and Ill pay for your craftsmanship, and shipping back to me, and see where it goes from there!

:bouncy:

scott fitlin
12-04-2008, 12:01 PM
:)There should be protection caps between the amplifers and the 2441's in an active implementation. Simply double their value and bias them. For instance, if you currently have 40 uF protection caps, bias two series 80 uF Solen caps and note the difference. Just try it on two and see if you like the result.Sounds interesting, Im willing to try try this.

If you could diagram a small schematic, I could obtain parts, and small PC boards or Breadboard to fabricate assembly.

What effect does biasing the caps have on the sound?

Quite interesting! :bouncy:

Mr. Widget
12-04-2008, 12:44 PM
Even for active systems the protection caps should probably be biased. (I'd bias them...)Interesting idea...

How many off topic side discussions can we have? ;)


Widget

mech986
12-04-2008, 12:48 PM
Sounds interesting, Im willing to try try this.

If you could diagram a small schematic, I could obtain parts, and small PC boards or Breadboard to fabricate assembly.

What effect does biasing the caps have on the sound?

Quite interesting! :bouncy:

You must have missed this one:

http://www.audioheritage.org/vbulletin/showthread.php?t=23070

Bottom line - If you have to have a cap, it needs to be biased.

Bart

scott fitlin
12-04-2008, 01:30 PM
You must have missed this one:

http://www.audioheritage.org/vbulletin/showthread.php?t=23070

Bottom line - If you have to have a cap, it needs to be biased.

BartWasn't that I missed it, merely that I just got home today! Been away on vacation, and had a GREAT time too.

Now, i'm aware of biasing in passive networks, but haven't seen this done with active systems, so I am unfamiliar with this.

So, being that my system has active electronics, I never thought I NEEDED AN ADDITIONAL network of components between the amp and drivers!

I'll read the thread, I can figure things out, and ask for help if needed too!

I had no idea I was crossing lines!

edgewound
12-04-2008, 02:55 PM
How would one get 2441J diaphragms aquaplased to audition? I would spring for the cost of 2 new D16R2441 phragms to try if I could get them! The 2441 still does a GREAT job to this day. How much is the sensitivity reduced by aquaplasing?


D16R2451SL ($198) and D8R2452SL ($200) are already Aquaplas'd titanium diaphragms...they both fit the 2440/2441/2445/2446/2447/375 drivers. I doubt spending for a more expensive aluminum D16R2441 ($272) and then applying Aquaplas would be worth the trouble and added expense.

2425 drivers don't have the luxury of an Aquaplas'd diaphragm that I'm aware of, though I believe the consumer side did....I'm not sure.

Rumor has it the sensitivity is decreased by about 1 dB....no biggie.

4313B
12-04-2008, 05:36 PM
I believe the consumer side did....I'm not sure.D8R275ND ($145)

Thanks for the excellent post edgewound.

Hoerninger
12-05-2008, 04:51 AM
"The lost circuit"

scott fitlin
12-05-2008, 05:20 AM
"The lost circuit"Thanks Peter!

I will get these built just as soon as parts arrive.

:bouncy:

Predrag Dukic
12-23-2012, 11:42 PM
"The lost circuit"

Biasing is needed only for electrolytic caps, so that they never experience reversed polarity on their terminals.

9 volt is in fact insufficient. higher is better, but then You need higher voltage caps. Diodes parallel to the caps and in series with the battery can do the trick...