Hot Rod 093TI

[NewZenith]

Ever since my fascination with dome speakers began about two years ago I have had a love-hate relationship with the JBL 093Ti. I was always curious what would happen if you replaced or modified the rather anemic looking magnet structure. Having a pair of 112A baskets lying around with no cones in sight I thought it acceptable to cannibalize their magnet structures and combine them with the 093Ti diaphragm to see what might happen.

Has anyone else tried this or similar modifications to other speakers?
It essentially grants the voice coil endless reserves and a much denser magnetic field.
The voice coil also becomes under-hung.
Efficiency and usable range increased dramatically, I would guess on the efficiency range + 3 decibels and at least 500 Hz of increased bandwidth capacity.

I do not currently own an RTA. I've been told that you got to spend five grand to get a good one? I am very curious what the theoretical disadvantages might be considering the design of the 093Ti diaphragm.
I would also like to share my observations if there is interest.
Sincerely NZ.

[NewZenith]

Isn't Your reply a little off-topic?
Speaker humanitarianism or speaker ethics is not my primary objective, nor do I care to discuss it in this thread!
Have a nice day
PS, did I mention that I have an early D4400.
I was thinking of gutting out the inside and installing some Bose speakers.
That ought to help the resale.

[NewZenith]

Too bad I can't share a hobby interest here on LH without being ridiculed. I sent you a private message because I felt it was too strong for the public forum. It was however truthful, it was the first thing that came to my mind.
So you lob it up anyway, as far as I'm concerned you look like a big jerk!

[Guido]

I made an adult decision to take my things and modify them

Then don't ask and leave us alone.

Damned, I hate to read such s#?t at morning.

[NewZenith]

[quote=Guido;146062]Then don't ask and leave us alone.

When you refer to us? You mean there's more than one of you?

Anyhow this thread is dead, thanks Dave.
I don't care about politics here on Lansing heritage, there is no justice in human politics.
I was not out of line, asking a question or defending myself or my beliefs.
If Dave wanted to discuss his feelings about appropriate speaker use he could have simply started a thread titled, the way I think speakers should be used.
Perhaps I was out of line coming on so strong, keep in mind that more than 50% of my experiences posting here on LH have been exceptionally negative! I was extremely reluctant to post, and when I did the shit started.
Tell me how many things of value have any of you restored or saved from the junk heap?

At what point may I decide that it's OK to modify something that is potentially rare?
Perhaps I'm taking this too seriously, I mean the question is rather absurd in the first place.

[Ian Mackenzie]

Hi NZ,

I enjoyed your initial post and I can see where you are coming from.

Some of the best diy drivers (tweeters) I have heard use big JBL magnets!! .

Have you thought about acquaplasing the dome? I would.

This is a diy thread and anything goes. Perhaps if you are able to send the driver to perhaps Robert H our XP diy King or Lord Zilch von Cablemaker they could evaluate its performance under the zee microscope.

To the rest of you if I felt I would get stoned every time I did something outside the square of your seriously tiny little universe I would have left eons ago.

That's how you learn how things work.



Ian

[Guido]

Calm down Zenith.

You can burn your speakers if you want. But don't expect applause when you announce it here.

I think you once pointed me to a pair of those rare drivers located in taiwan. Wasn't it you?
I am so happy to have found one of the latest pairs on earth. Many of us are still searching and then it just hurts if someone risk to trash them.

It's all about different opinions.

You shouldn't mess with them.

[NewZenith]

First off I want to state that I was incredibly reluctant to modify anything, however my curiosity got the best of me and I'm glad it did!
To answer your first question I do intend on using antivibe on the domes. But I must acquire some first.
It's nice that there will be no negative efficiency loss due to antivibe coating because of the sensitivity gained, these drivers are now the hottest out of the bunch, beating out the 112a's by a few decibels, of course the 093's are 4 ohm.
My main concern with my modification is how flat the driver remains with the greater dampening, this I do not completely understand nor can I test for it yet.
The tuning behind the dome is completely left to chance, the driver now resembles a compression driver missing its phase plug due to the vent hole through the magnet.
I added lightly packed fiberglass and capped the back.
I also made a open cell foam damper with light compression against the inside.
I was able to avoid serious modifications to the 112A magnets, only having to put a small chamfer on the top plate to accommodate the new driver.
If there is continued interest I can show photos.
It is worth noting, and I will go as far as saying that the difference this magnet structure made was astonishing! Although it's too soon to tell exactly everything that has changed.
I was able to spread my crossover points apart almost a whole octave, now I'm crossing at 1100 hertz and somewhere above 5K to the tweeder.

I have a couple of pairs of TI domes left for comparison should I decide to do so again.
Although I think this mod is a keeper.
Most enthusiastically
NEW FART.

[NewZenith]

Calm down Zenith.

You can burn your speakers if you want. But don't expect applause when you announce it here.

I think you once pointed me to a pair of those rare drivers located in taiwan. Wasn't it you?
I am so happy to have found one of the latest pairs on earth. Many of us are still searching and then it just hurts if someone risk to trash them.

It's all about different opinions.

You shouldn't mess with them.

I'm just trying to take them on one at a time, I don't burn speakers! I think there's something larger at work here. Maybe I'm wrong but there's a certain style about many exchanges here that is familiar to me.
Let's get real, people modify things all the time and as a matter of fact it's actually encouraged.
No one has yet come up with a legitimate criticism, to say you shouldn't do it just because it's ridiculous, how about something like this instead.
Newzenith, I would not have recommended that modification without first considering XYZ because I think you will not be happy with the results and therefore wasted valuable things.
I know people here are sentimental, but that does not change the fact that I did something and I can think of no better place to talk about it.
Besides there are probably other nutty people, like myself that might find this sort of thing intriguing.
How about we engage in some technical discussion, as technical as I can be anyhow. I know I'm a shoemaker, but I'm a clever shoemaker.
I'm learning, two years ago I didn't know crap! Now I just smell like crap. and someday I may be King crap.
NF.

[Guido]

How did you manage to get the 093 VC horizontally centered to the 112 pole plate? Or is the 112 pole plate similar to the 093ti pole plate by coincidence?

[macaroonie]

If you havn't tried it how do you know you dont like it ? Lets have a look please.

[Ian Mackenzie]

I'm just trying to take them on one at a time, I don't burn speakers! I think there's something larger at work here. Maybe I'm wrong but there's a certain style about many exchanges here that is familiar to me.
Let's get real, people modify things all the time and as a matter of fact it's actually encouraged.
No one has yet come up with a legitimate criticism, to say you shouldn't do it just because it's ridiculous, how about something like this instead.
Newzenith, I would not have recommended that modification without first considering XYZ because I think you will not be happy with the results and therefore wasted valuable things.
I know people here are sentimental, but that does not change the fact that I did something and I can think of no better place to talk about it.
Besides there are probably other nutty people, like myself that might find this sort of thing intriguing.
How about we engage in some technical discussion, as technical as I can be anyhow. I know I'm a shoemaker, but I'm a clever shoemaker.
I'm learning, two years ago I didn't know crap! Now I just smell like crap. and someday I may be King crap.
NF.

Quite a few hi end loudspeaker outfits modify drivers to their own specific needs..Wilson for one, and locally VAF.
Whats new.

NZ,

This is a big like Bruce Edgar using a 2105 as a compression driver, wrong appliciation but it works.

The only thing about going lower is the excursion Xmax and the compliance of the surround.

I would not rule out a wave guide if you want to reduce distortion in the low end and control those early reflections. Sometime ago I was considering this driver as the change out for the 2307 flog horn. Among other things its limited bandwidth and efficiency for non negotiable.

These particular species are apparently as rare as Hen's teeth and are craved by XP clone propeller heads.

Gordon W is about the only member I know of who has amended JBL drivers. Earl might also chime in on this one.

[Robh3606]

I have had a love-hate relationship with the JBL 093Ti. I was always curious what would happen if you replaced or modified the rather anemic looking magnet structure.

No that's a first as far as I know. Do you know what the flux density is in the 093 gap??

It essentially grants the voice coil endless reserves and a much denser magnetic field.

Well you don't really know that. Larger pot doesn't always mean higher flux density by itself. An example would be the LE-15 and k-145. Largest pots JBL made howerer lower flux density than say a K 130

Efficiency and usable range increased dramatically, I would guess on the efficiency range + 3 decibels and at least 500 Hz of increased bandwidth capacity.

How do you know whats really happening??? You have any measurement capability??


That diaphram has limited excursion capability. I was designed to be used with a tuned and sealed pot structure. There are None avaliable from JBL. If you overdrive it and that fractures the surround your out of luck.

I do not currently own an RTA. I've been told that you got to spend five grand to get a good one?

You can do a lot more with a lot less money.

Guido already covered the rest.

Rob

[kingjames]

AS you are all aware I am a very (NON) technical kind of person and I joined this forum because I know most of you to be experts when dealing with JBL and the tips and bits that you offer are indespensible.

This site is about information and what a great site it is for that. I would never come here and brag about BOSE speakers because they suck and more than that you think they suck too.It is good to come here and learn and though I don't have the knowledge to build something I still read the threads. Hell, you can stay here and read for hours and, I must say that I learn something new everyday.

I realize that tearing something up(JBL) in your opinion is taboo and insensitive and maybe rightfully so but, who is the judge of that?

This is a good site that has good idea's that has good people,that have different opinions and thank God for the different opinions because without that this site would be meaningless.

Idea's should never be discouraged here and if something is about to be torn up and destroyed in your opinion then there are ways to confront this. Explain what you might think might go wrong,explain that you have a rare driver that someone might need because maybe just maybe this guy doesn't think the way you do and that's not bad at all.

When you jump all over a post because of your opinion you make it harder for other people to post. Who wants to post something here if your going to be slammed for it.The DIY area experiments all the time,is this such a bad thing?

After all this site isin't just for the experts but for everyone who believe's in the genius of JBL.

And to think I was going to ask opinions about removing the driver's from my 250TI'S and replacing them with BOSE drivers. (JUST KIDDING)

If sometime down the road I ask a stupid question in your opinion then all I ask is that you explain why it's stupid in a civil manner.

Remember the ole sayin" there is no such thing as a stupid question"? That should also apply here as well and when you start calling people on what you think is a stupid question then you will do this site a disservice.

Idea's should never be discouraged nor condemned because this site wouldn't be much without them.

ya, I know, I have no life and this is why I stated my liberal views here.

[NewZenith]

How did you manage to get the 093 VC horizontally centered to the 112 pole plate? Or is the 112 pole plate similar to the 093ti pole plate by coincidence?

I did not achieve perfect VC alignment. However the voice coil is still between the top plate, I'm not exactly sure if centering it perfectly would have any beneficial effects. If I want to I can make a shim or gasket to move it up about .030 inches, should do the trick.