Picking up a set of 511b altec horns missing parts

Correct diaphragms come from GPA where they are made on the original tooling.

Radian makes a reasonable substitute, at no cost savings.

The cheap imports on ebay and from a few online sources are a quick exercise in bad experience.
 
Gpa

Yes I have been looking at GPA.
I'll probably get the diaphragms from them, and there is the plastic cap over it that I need to get, plus 1 tangerine phase cap which is actually only availabe in black ...

End caps I need to fab ... I am nearly sure I wanna do that ...

Cool.
Srinath.
 
Original end caps are die cast aluminum, or aluminum based alloy.

I've seen some very handsome ones turned from exotic and domestic hardwoods.

and there is the plastic cap over it that I need to get
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This sounds like a loading cap that you're describing. On those drivers the loading cap was only used with the symbiotik diaphragm in high power sound reinforcement applications. You will want to omit those for hifi applications such that the internal volume of the rear cover is used as resonant space. With loading caps in place, the only purpose the rear cover serves is a mounting platform for the push terminals.
 
Hardwood eh ...

Thanks so much Bowtie427ss

The diaphragm and phase plug I will get from GPA.

The Loading cap - see ya ... dont need ya ...

Hardwood eh ... OK that is cheap and easy and saves me $$$ ...

Cool.
Srinath.
 
I have these gorgeous gold plated terminals I plan to use ... a nice ebony wood end cap would totally set that standing out ...
Cool.
Srinath.
 
The phase plug is there cos the diaphragm is mounted backwards so to speak right ...
Would we have the same effect if we wired the diaphragm negative to positive and left out the phase plug.
Cool.
Srinath.
 
How would a JBL 2418 diaphragm work in the altec 511b with 802/808 magnet structure.

I am still making the end caps out of mahogany, but I just tossing options for the diaphragm.
I am thinking of putting a realistic mach 2 woofer in a altec 19 style cabinet in a XO TBD.

Thanks.
Srinath.
 
How would a JBL 2418 diaphragm work in the altec 511b with 802/808 magnet structure.
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You would need to determine, precisely, the geometry of the components involved to verify that such an unusual marriage is even possible. Not exactly a "simple" task for most hobbyists.

Given that proper parts are readily available, it hardly seems an exercise of any practicality.
 
bowtie427ss said:
You would need to determine, precisely, the geometry of the components involved to verify that such an unusual marriage is even possible. Not exactly a "simple" task for most hobbyists.

Given that proper parts are readily available, it hardly seems an exercise of any practicality.
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:yes::yes::yes::yes:
 
But ... but ... but ... but ...
OK the JBL one is 35 bucks, the altec is 90 ... just sayin ...

On a GS500 motorcycle, till I figured out you can use a #4 washer to shim the needle a mm or so, people were stuck paying $80+ for a jet kit ... Then came the era of jetting bikes without a jet kit ... using mikuni parts ...

Long history of cramming things in and figuring out a good option ...

Hey, I got a mach 2 woofer going in ... not the original altec one ... unless one of those comes into my life cheapo ...

Cool.
Srinath.
 
But ... but ... but ... but ...
OK the JBL one is 35 bucks, the altec is 90 ... just sayin ...
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I totally appreciate the economics of the situation.

I would just about consider the cheap import diaphragms that will at least fit before i'd opt for ANY small format JBL diaphragm, and having personally purchased and tried the imported phragms, the only thing i'd consider using them for is light PA duty at higher XO frequencies(+1200hz) I have silently wondered if the imports could be improved with doping them as seems to be popular with a variety of JBL diaphragms. But, i am very skeptical of their ability, despite any modifications, to reproduce down to 500hz on a level even close to a genuine Altec/GPA.

The diaphragm is the most important single part of the whole horn/driver system. It's the component that can impart the most change in sonic character with the least amount of change to it's characteristics. The Altec/GPA diaphragms are worth every penny, that will be reflected in the drivers' future resale value to any informed buyer, and likely in your own listening experience as well.
 
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I believe those are JBL original chinese copies. Or not ? or are they ... I mean JBL makes diaphragms for their new drivers. I guess they make them in china, so maybe the new "jbl originals" are still chinese that have been approved by JBL. Does that make them better ?

Cool.
Srinath.
 
srinath said:
I believe those are JBL original chinese copies. Or not ? or are they ... I mean JBL makes diaphragms for their new drivers. I guess they make them in china, so maybe the new "jbl originals" are still chinese that have been approved by JBL. Does that make them better ?

Cool.
Srinath.
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Apologies, i didn't mean to confuse. Any time i use the term "cheap imports" in this thread, it specifically refers to the imported replacement diaphragms for the small format Altec drivers only.

My experience with small format JBL product is limited. However it is my understanding that some more recent and current product is imported from Europe from companies such as BMS, and some of it is very good.
 
I am near about certain this is chinese. I also think its one of those JBL approved chinese ones.

The thing looks like it will fit into the 802/808 perfect, I would have no idea how it sounds with the real altecs ... cos I dont have the real altec diaphragms as a reference. If it sounds fine but not like original ... I wouldn't even know ... or care.
BTW I am putting mach 2 woofers in it, so I think the ship for "original sound" has sailed (as of now, unless it pulls a U turn)
Cool.
Srinath.
 
The thing is, if you have the 802-8g's, they're worth $200-$250/pc on that auction site. Why not send them to GPA for remag and diaphragms, squander an extra $25 for the end cap and have something that works right?
 
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