Problem with JBL 216a

[Bryan Bell]

Hello! I just picked up a pair of JBL 216a bookshelf speakers on CL.

After doing some listening on my SX-550, I noticed the right channel seemed to sound off. It sounded muffled and the highs were just not there. I tried switching the R and L speakers and still got the same outcome on the speaker. I am disappointed because I just picked these up.

Then this morning I realized that the tweeter is not producing any sound. I have yet to take them apart and test, but I did find a replacement tweeter on eBay I purchased. I might have ordered it too soon, as I still want to swap the tweeters to make sure it is the tweeter and not something else.

Anyways - was just hoping to get some general knowledge here and see if this might be an easy fix or not.

Thanks!

 

[xero-D-hero]

You'll need a multi-meter to do any real testing,then all you need to do is remove the suspect tweeter and check it's DCR (that is the DC resistance).

If the tweeter shows open then it's pretty much DOA.
If the tweeter DCR is between 3.6 - 4.4 ohms it's OK.

Odds are if the tweeter is open it was the problem.
If the tweeter DCR is OK then you'll probably need to look elsewhere (like the crossover or ???).

There were two different TLX tweeters for that series of speaker,the 011 and the 012,the ones with the "a" suffix used the 012 tweeters.

!!! Also,be VERY careful when tightening the mounting screws on those TLX tweeters as they tend to crack in the corners really easily !!!

Most all these 011 ~ 012 TLX tweeters you'll find used are like that unless they are NOS or such...

Need to know anything more specific,feel free to ask and we'll try to answer the question.

HTH

Bret P.

 

[Bryan Bell]

You'll need a multi-meter to do any real testing,then all you need to do is remove the suspect tweeter and check it's DCR (that is the DC resistance).

If the tweeter shows open then it's pretty much DOA.
If the tweeter DCR is between 3.6 - 4.4 ohms it's OK.

Odds are if the tweeter is open it was the problem.
If the tweeter DCR is OK then you'll probably need to look elsewhere (like the crossover or ???).

There were two different TLX tweeters for that series of speaker,the 011 and the 012,the ones with the "a" suffix used the 012 tweeters.

!!! Also,be VERY careful when tightening the mounting screws on those TLX tweeters as they tend to crack in the corners really easily !!!

Most all these 011 ~ 012 TLX tweeters you'll find used are like that unless they are NOS or such...

Need to know anything more specific,feel free to ask and we'll try to answer the question.

HTH

Bret P.

Thank you!! This is great info.

So I apologize for my ignorance, when you say "if the tweeter shows open"...would it literally say "open" on the multimeter? Or would I get a 0 reading?

This is the tweeter that I bought. http://www.ebay.com/itm/322441393592?_trksid=p2057872.m2749.l2649&ssPageName=STRK:MEBIDX:IT

I hope it's the right one... :/ [Edit: looking closer it does look like the correct one - the 216's had a different looking tweeter without the clear plastic piece.

I will be careful tightening the screws.

 

[gdmoore28]

xero-D-hero has you on the right track, Bryan. Just follow his advice.

"Open" will show on your meter as "0." Be sure to set your multi meter to read "ohms."

And welcome to this forum! It's so refreshing to have members who post actual pictures of themselves and use their real names.

GeeDeeEmm

 

[Bryan Bell]

xero-D-hero has you on the right track, Bryan. Just follow his advice.

"Open" will show on your meter as "0." Be sure to set your multi meter to read "ohms."

And welcome to this forum! It's so refreshing to have members who post actual pictures of themselves and use their real names.

GeeDeeEmm

Thanks!

 

[xero-D-hero]

Thank you!! This is great info.

So I apologize for my ignorance, when you say "if the tweeter shows open"...would it literally say "open" on the multimeter? Or would I get a 0 reading?

This is the tweeter that I bought. http://www.ebay.com/itm/322441393592?_trksid=p2057872.m2749.l2649&ssPageName=STRK:MEBIDX:IT

I hope it's the right one... :/ [Edit: looking closer it does look like the correct one - the 216's had a different looking tweeter without the clear plastic piece.

I will be careful tightening the screws.

That should be the right tweeter for your j216a (65408 = 012).
And that's a really nice looking one,as long as it DCR's within that spec I mentioned earlier it should do the job.

And yeah the tweeter for the earlier j216 was different,that was the 010 tweeter,and IIRC it was only used in the early j216 and none of the other j series JBL's.
And you're right that 010 tweeter did'nt have the clear lens.

As for what the meter will read when there is an open,it reads the same thing as it reads when you hold both the probes seperately w/o them touching each other.
No contact/connection between the +/- probes,no completed circuit,thus an open.

HTH

Bret P.

 

[sax6]

"Open" will show on your meter as "0." Be sure to set your multi meter to read "ohms."


GeeDeeEmm

Not quite shure there with this '' 0 '' reading. Zero would mean '' zero ohms '' as for short circuit.
Infinite shows as an eight on its side would clearly indicate open circuit.

That's what my DMM shows.

Either way, the tweeter is out.

 

[xero-D-hero]

I've seen different meters use different symbols to indicate an open/infinite circuit.
So I tried to state things in a way that should apply universally to all meters.
But yeah an infinity symbol is one of the symbols I've seen for indicating an open circuit.

Also zero ohms would'nt necessarily mean a short circuit,it could just mean the given circuit has almost no measurable resistance.
But of course that could easily mean a short circuit as well,and in this instance that would likely be the case.
To know which were true one would need to know what sorta resistance should be expected in that given circuit.
Here we know the DCR should be 3.6 to 4.4 ohms,so should one find -0- ohms yeah that would likely mean a short circuit.

Hope that's a bit clearer.

Bret P.

 

[sax6]

I've seen different meters use different symbols to indicate an open/infinite circuit.
So I tried to state things in a way that should apply universally to all meters.
But yeah an infinity symbol is one of the symbols I've seen for indicating an open circuit.

Also zero ohms would'nt necessarily mean a short circuit,it could just mean the given circuit has almost no measurable resistance.
But of course that could easily mean a short circuit as well,and in this instance that would likely be the case.
To know which were true one would need to know what sorta resistance should be expected in that given circuit.
Here we know the DCR should be 3.6 to 4.4 ohms,so should one find -0- ohms yeah that would likely mean a short circuit.

Hope that's a bit clearer.

Bret P.

It is.