Damaged magnet on 2426H driver

[JBL Dog]

Poor packing caused some damage to the magnet of a 2426H driver. The driver and horn were loosely packed and some mounting hardware attached itself to the magnet. During the trip here, the driver (apparantly) shifted back and forth and some mounting screws started to chew away at the magnet. Cosmetic damage is obvious. Can anyone tell me if there's a possiblity the loss of a portion of the magnet will effect performance? My guesstimate is a loss of less than 2% of the total mass of the magnet. Any ideas what I can use to seal the damaged area? I was thinking some clear nail polish.

Thanks!

[pelly3s]

I dont think it will cause damage. I have had customers drivers with mag damage and during recenters i have chipped a few and havent noticed any loss in quality. i assume under critical listening conditions with a perfect enviroment you might hear a difference, but who cares about that because it doesnt exsist

[Alex Lancaster]

:( What was it packed in?, 2" gravel?; I don´t think there will be a noticeable difference, have You opened it to check for gap shift?, Saludos.

[subwoof]

Use one of the standard 2 part epoxy's to fill / seal. Do NOT use the "metalized" version as it will move + spread all over the magnetic surface ( made that mistake once... ) I suggest you use GOOD electrical tape to cover the exposed magnet to prevent any future chips from traveling where they shouldn't go.

Why JBL wanted to save a whopping 50 cents each by ommitting the "tires" on OEM box components is a mystery to me...

sub

[JBL Dog]

Thank you everyone for your replies. I have not opened anything to check the gap, been too busy. I'm sure everything is fine. Basically the driver did the "Electric Slide" on a bed of 2370 mounting screws for about 1200 miles. There were no large chunks of the magnet, only crumbs. I don't believe the package was dropped. He also sent me an E110-8 driver which, to my amazement, arrived unmolested. It was packed in a trashcan liner and loose newspaper.

:banghead:

[subwoof]

As suggested on another thread, the ID's of these sellers who have lacking packing skills should be posted on this site to avoid this in the future since the ebay feedback system is full of glossed over hype + is useless as a guide.

I had a guy pack a pair of 2204H's face to face in a small box with no padding and HIS feedback said he is an excellent packer.

ppppfffffffffffttttttttt......right. pass it over pal.

sub

[Mr. Widget]

I assume under critical listening conditions with a perfect enviroment you might hear a difference, but who cares about that because it doesnt exsist

Blasphemy!!!! OK, so maybe you're right, but we can always try to get closer and closer to it.:)

I agree, I wouldn't be too worried about magnetic material loss, but shrapnel in the gap and shifted gaps would be a real concern. If there is a marked lack of highs that would be a good indication it has shifted.

Widget

[JBL Dog]

Blasphemy!!!! OK, so maybe you're right, but we can always try to get closer and closer to it.:)

I agree, I wouldn't be too worried about magnetic material loss, but shrapnel in the gap and shifted gaps would be a real concern. If there is a marked lack of highs that would be a good indication it has shifted.

Widget

I have not opened the driver up. I wanted to clean it up and seal the damaged area first. The only red flag is I'm getting an unusually low DCR reading for an 8 ohm driver..... 3.7. Is that an acceptable level? It does, however, sound strong and clean.

[Mr. Widget]

That's a Giskard question... that could be in the range, I know very little about the ferrite compression drivers. Try a different diaphragm.

Widget

[John]

I would think that 3.7 ohm would be at the low end of the scale but still within spec for a 8ohm. driver

[Guido]

I'm getting an unusually low DCR reading for an 8 ohm driver..... 3.7. Is that an acceptable level?

Spec is 3.2 ohms!
All JBL 8 ohm drivers are basically 4 or maybe 5 ohm drivers.

[Guido]

Why JBL wanted to save a whopping 50 cents each by ommitting the "tires" on OEM box components is a mystery to me...

sub

I'm 100% with you! We should not forget the other 20 cent they saved with ommitting the foilcal. This is :bs:

The nice effect is that you get the HPL drivers cheaper on ebay. :D

[4313B]

You have to understand that "I saved the company x amount of dollars by implementing this" is probably one of the most powerful things you can put on your resume these days. So the jackass(es) who implemented the "no tires" and "no foilcals" edicts is/are merely padding their resume(s). SOP. They couldn't give a rat's ass about JBL or its customers.