E145 help needed

[NickH]

I'm doing some research on 150-4c and the e145. I've been able to find lots of info on it but I've run up short in one spot. I was under the impression that it uses an extension ring on the frame mounting flange. I've been trying to find how much length does it add from the frames flange to the extension flange?


I know on the outside edge of the extension ring is 1 inch wide. But the flange on the frame goes inside of the ring doesn't it?

Also, how is the ring secured to the basket frame? I'm assuming it has a couple screws doing the job. The surround is glued to the front of the extension ring like a normal driver?

I'd really appreciate any info anyone can help me with. Or point me in a direction of were I could find some. And maybe a picture of one taken apart.


Thanks,
Nick

[frank23]

I have the e145-8, but they are mounted, so I cannot look at the rear how the flange is mounted. I don't remember any screws, but maybe they were below the seal.

Maybe this can help you: http://www.jblproservice.com/pdf/Dis.../E145-8-16.pdf

[NickH]

Thanks for the info. I've seen that drawing. If the back of the mounting flange was flush with the back of the ring, then I could figure it out. But I'm not sure and I don't want yo assume.


does any one know the distance from the spider to the surround?


Thanks,
Nick

[Robh3606]

The frame and the extension ring are flush

Rob

[NickH]

The frame and the extension ring are flush

Rob

COOL. That I can now figure out. And all jbl baskets are the same if I'm not correct, at least the 15" ones.


Im considering a completely insane project. I'd love to have 150-4c's in my diy c550/4520's. But since I'm not loaded I'll have to settle for something else. I know the 145's are ancestors of the 150. But there is definitely a difference in the excursion of the 150 compared 145. The magnet assembly looks identical to a d130, even the top plate thickness. Which really makes me wish they used ts parameters back then.

I have to think the efficiency of a 150 would be higher then the 145 variants. But this is just a guess.

Nick

[intercity125]

COOL. That I can now figure out. And all jbl baskets are the same if I'm not correct, at least the 15" ones.


Im considering a completely insane project. I'd love to have 150-4c's in my diy c550/4520's. But since I'm not loaded I'll have to settle for something else. I know the 145's are ancestors of the 150. But there is definitely a difference in the excursion of the 150 compared 145. The magnet assembly looks identical to a d130, even the top plate thickness. Which really makes me wish they used ts parameters back then.

I have to think the efficiency of a 150 would be higher then the 145 variants. But this is just a guess.

Nick

Hey Nick,

I read at a guy's Paragon website that the 150-4C has a sensitivity of 95db. Not sure where he got the info from, but here's the link...

http://www.mcsmk8.com/Paragon236/paragon150.htm

Willy

[NickH]

Thanks Willy.

I actually read that before. But I forgot about it, lol. 95db just seems so low for a driver made in the 50s.

But they did have amps that produced around 100 watts for theater use. I'm not certain but it looks like the 150-4c might have been over hung. Top plate looks like its only around 1/4" thick.


The search continues

[intercity125]

That, and a lot of components were rated very "conservatively" back in those days. For example, I had a little Eico AF-4 single-ended triode integrated amp that was rated at 4wpc, but the speakers it could drive were amazing. One would never have believed that they were listening to just 4 watts. Eico's, like many vintage components of that era, including the JBL 150-4C's were simply overbuilt to very high standards.

[NickH]

Ya then did know how to make things to last back then. I can see ratings like power handling being set conservatively. But sensitivity is a little different. Its a quantified number found by analysis. But I guess they could average it.

Who knows.

That, and a lot of components were rated very "conservatively" back in those days. For example, I had a little Eico AF-4 single-ended triode integrated amp that was rated at 4wpc, but the speakers it could drive were amazing. One would never have believed that they were listening to just 4 watts. Eico's, like many vintage components of that era, including the JBL 150-4C's were simply overbuilt to very high standards.

[HCSGuy]

Here's a side shot of a C16R1504C recone kit from google - note the short winding height for an underhung alignment, though I admit the pics are not perfect. I suspect you can't get much excursion out of a doped, folded paper surround either. Thiele-Small lists the somewhat similar D130's excursion as .76mm, So I suspect the 150-4C's excursion is the same as it uses the same magnet and basket, but adds an extension ring for a deeper, straight sided cone suitable for horn loading.

[subwoof]

both the 150-4C and the 145 have the extension ring - they are made differently but add the same amount of height to the mounting surface from the top plate.. the 150H is really a re-badged E145.

And all have the same underhung coil and REAL deep gap...essentially interchangeable in the performance arena BUT newer glues and assembly methods allow much greater power diss than the old 50's stuff..

The later version of the 145 uses the familiar 2-roll cloth surround and if you're going to use these baskets, you REALLY should chamfer the inside edge on the ring so when the cone hits it it won't cut/crease. this was a very common failure on the 145.

sub

[NickH]

Thanks HCS,

That clears a few things up. That coil looks pretty much the exact same as a d130 coil except for the copper. It makes me wonder though. The top plate is .28 inches so is it really underhung or overhung. Isn't there an alignment where the top plate and voicecoil are the same height? I remember reading something about it in a pro notes.

I wonder what the weight was on that cone. I also wonder what methods were used to stiffen the cone up.

Nick

Here's a side shot of a C16R1504C recone kit from google - note the short winding height for an underhung alignment, though I admit the pics are not perfect. I suspect you can't get much excursion out of a doped, folded paper surround either. Thiele-Small lists the somewhat similar D130's excursion as .76mm, So I suspect the 150-4C's excursion is the same as it uses the same magnet and basket, but adds an extension ring for a deeper, straight sided cone suitable for horn loading.

[NickH]

Hey Sub,

Thanks for chiming in.
. If the gap is real deep on the old 150, where is the difference in depth? From pictures I've seen it just looks like a d130.

I'm not actually going to try and diy some 150's. I just find this really interesting though.

I know the 145s have a much thicker top plate on the magnets. A bit over half and inch I think.


Is the frame used on the k145 a le15 frame?


Thanks,
Nick

both the 150-4C and the 145 have the extension ring - they are made differently but add the same amount of height to the mounting surface from the top plate.. the 150H is really a re-badged E145.

And all have the same underhung coil and REAL deep gap...essentially interchangeable in the performance arena BUT newer glues and assembly methods allow much greater power diss than the old 50's stuff..

The later version of the 145 uses the familiar 2-roll cloth surround and if you're going to use these baskets, you REALLY should chamfer the inside edge on the ring so when the cone hits it it won't cut/crease. this was a very common failure on the 145.

sub

[Robh3606]

Top plate is 5/8 on the one I have.

Rob

[NickH]

Top plate is 5/8 on the one I have.

Rob

That's a 145, correct?