PDA

View Full Version : Should I Open 375 on paragon or LE-85?



johnhb
07-20-2007, 01:45 PM
The left side of my paragon has periodic distortion in the 375. I recognize it as a contact problem which is easy to correct with cleaner and some de-oxit. Problem is I hate removing the red JBL seals if the contact is inside the back of the driver. I'm hoping it is somewhere between the LX5 and the driver or perhaps the switch in the LX5. I know my LE-85s in my other speakers all have foam pads that have long since turned to goo but I have resisted opening them to change out the pad. I seem to recall that the 375s had a felt pad that would not decay another reason not to open them unless you have to. I know the collector value is diminished when the seals are not intact but any alnico LE85 with seals will always have a bad foam pad by today. My question, finally, is how often do you folks have this intermittent problem in the connections inside the compression drivers? Anyone have an LX5 switch problem?

Zilch
07-20-2007, 02:19 PM
I'd use different drivers on a Paragon before I'd break the 375 seals.

And as long as LE85s are playing fine, I wouldn't open them up either....

TimG
07-20-2007, 02:21 PM
It is more likely the Lpad in your LX-5 than the solid wire and screw connection inside your 375. Swap the drivers around and see if the problem remains on the same side or if it follows the driver, that will tell you if it is the driver or crossover network.

Tom Brennan
07-21-2007, 12:31 PM
I'd use different drivers on a Paragon before I'd break the 375 seals.



Now there's a paradox.

I never understood this collector fetish thing, like Lionel train cars that go down in value because somebody took it out of the box. To buy something to not use it seems odd, actually it seems degenerate.

It would be like marrying an incredibly sexy woman and then never having sex with her.

Zilch
07-21-2007, 01:33 PM
It's about money, Tom.

It'll cost money to rehab the 375s, and the value will be significantly diminished to boot.

Chances are a contemporary driver will play better than the refurbished one, anyway. :dont-know

John
07-22-2007, 12:36 AM
Now there's a paradox.

I never understood this collector fetish thing, like Lionel train cars that go down in value because somebody took it out of the box. To buy something to not use it seems odd, actually it seems degenerate.

It would be like marrying an incredibly sexy woman and then never having sex with her.


:yes::yes::yes:

Zilch
07-22-2007, 01:35 AM
It would be like marrying an incredibly sexy woman and then never having sex with her.The concept of "Trophy" wives is well known, even in primitive societies.

Bragging rights.

It all gets Freudian in short order.... ;)

Maron Horonzakz
07-22-2007, 06:54 AM
I had a trophy girl friend once, look but dont touch. I like to crank them up:applaud:

Rolf
07-24-2007, 10:24 AM
Check everything before opening. If you have to, then open it. The best thing must be to play music on the Paragon, and we all know the woofers have to be fixed from time to time. So ... why not the other components as well?

johnhb
07-24-2007, 02:14 PM
Gentlemen,
That is an amusing set of thoughts on collector vs user value. I have my JBLs for the sound so I am not that worried about opening them and I will start the switching back and forth. Of course a bit of summer humidity has cured the problem for now. But back to the LE-85s, anyone have any data on the performance with the old foam in the back with no elasticity? I am guessing the performance at dampening the back wave decline is minimal.

Zilch
07-24-2007, 03:27 PM
If I open them up, I replace the foam, which is usually intact, but has lost its resiliancy. I have some felts here to try next time, as that's what JBL originally used, and I won't have to be concerned about it in the future.

I have measured and heard plenty (20?) of them, and have yet to discern any difference which would compel me to break the red seals and replace the old foam alone....

subwoof
07-24-2007, 08:35 PM
My money is on the Lpad. It has exposed, current carrying wire that by now is older and more corroded than even a trophy wife and just as difficult to fix.

Of the thousands of drivers that have gone thru my fingers I can count on ONE hand the number that had actual problems with the lead wires. The old 4" copper coil ( 2480 ) had an issue with the exposed lead wires where they glued into the phenolic diaphram but that's it.

I have seen a few where the flat leadwire from the screw terminals to the start / finish of the actual voice coil has broken but it's a fatal, onetime and it's dead problem. The same can be said for almost any wire on the entire dia assy.

Go online and buy a pair of inexpensive 2445 2" drivers and substitute for a while to see if the problem remains.

Collector VS user shouldn't dictate what the red seal life expectancy is BUT keeping the wax seals intact certainly appeals to the "cost isn't an issue" buyers down the line.

:cheers:

sub