Speaker repair

I have an old NAD-320 amp and pair of JBL Control 1G speakers attached to the TV, but hadn’t used them in a while. Trying out Netflix and finding Hans Zimmer Live in Prague, the TV speakers were certainly inadequate. But what an awful crackling sound from the JBLs. They were about 20 years old, but hadn’t had too much use. Taking off the grill, and the reason was clear…

The foam, around the main cone had gone crispy, cracked and started falling apart. Even 20 years on it is still possible to buy JBL Control 1 speakers new, but I didn’t want to dump these if they could be repaired.

There are a number of repair videos on youtube (search for “jbl control 1 foam repair kit”) and I found a kit on eBay (though the seller doesn’t appear to be there at the time of writing) consisting of replacement foam baffles and glue.

(edit 9/9/2020: A decent repair video published this year)

Armed with these and a screwdriver, I set about it. Taking photos before disconnecting anything to make sure I could reconnect properly…

Then it is time to get rid of the old foam, held in place by glue in addition to being clamped to the speaker case. Firm but delicate screwdriver action required, especially where the foam is glued to the cone…

Since the foam had denatured it was quite difficult to clean away from the metal frame.

Kicking myself when a slip of my scraper slightly damaged the left part of the cone – though not enough to go through, and not damaging performance in any detectable way.

That done, glue applied around the metal frame and to the back of the cone, and the new flexible foam pressed into place and reassemble…

End result – looking like speakers again, and more importantly sounding crisp and clear.

Posted by creacog, 0 comments

cPanel and mail subject filtering

If you are using ‘User level filtering’ of email in cPanel (v11.28.83), applied to the Subject header of an email, you may encounter circumstances where sometimes the filter fails for no obvious reason. On investigation of the email headers, it turned out that a certain sender was folding email subject headers over multiple lines. If the phrase being searched for was split over two lines within the header, the filter would fail.

For example, with rule : Subject contains ‘testing 123’

1. this would work:
Subject: line 1 testing 123

2. this would work:
Subject: line 1
 line 2 testing 123

3. this would NOT work:
Subject: line 1 testing
 123 line 2

It turns out that this is because cPanel simply passes the filter information down to exim, and it is here that the behaviour manifests.

I have posted an entry to the feature requests forum of cPanel, for it to be configured to better tolerate multiline subject headers. If you are encountering this problem, it would be helpful if you would contribute to that thread.

In the meantime a workaround is to use the ‘matches regex’ filter, replacing spaces in your match-phrase with ‘\\\\s+’. For example the following rule works in each of the three samples above.

Rule: Subject matches regex testing\\\\s+123

Posted by creacog, 1 comment