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View Full Version : JBL D130- Impedance and cone question



claytushaywood
01-28-2012, 06:28 PM
Posting because I'm a little confused about this. I'm a guitar player lookin for that fender with "bells" sound. I found a pretty decent deal on a D130 locally and had a few questions. There is a picture of the back of the cone showing the serial number 21057 stamped in white. I read somewhere that this was an original JBL cone serial number or something. The speaker looks to be original, after a month comparing prices and trying to find something it's been getting easy to see the obvious recones or at least the ones that didnt use JBL parts, which according to a lot of guitar players is not nearly as good (apparently weber and another speaker company do decent recones). Anyway the speaker's label says it's a 16ohm speaker, but the ad also shows a multimeter with an impedance measurement of 6.2ohms, making it an 8ohm speaker.

So Is the 21057 significant of an original cone and the impedance somehow got way off, or was it reconed to an 8ohm with JBL parts, or could it just be any recone and 21057 doesnt mean jack? Hope this picture attachment works. just gave a picture of the cone. Thanks from a brand new member and soon to be owner of JBL- with applications in lap steel, electric guitar, bass and hopefully hifi soon!

speakerdave
01-29-2012, 10:36 AM
You can search for information in these forums. Here's a thread I found searching for "21057." Harvey Gerst worked at JBL. I'm guessing your speaker was reconed to 8 ohms.


Posting because I'm a little confused about this. I'm a guitar player lookin for that fender with "bells" sound. I found a pretty decent deal on a D130 locally and had a few questions. There is a picture of the back of the cone showing the serial number 21057 stamped in white. I read somewhere that this was an original JBL cone serial number or something. The speaker looks to be original, after a month comparing prices and trying to find something it's been getting easy to see the obvious recones or at least the ones that didnt use JBL parts, which according to a lot of guitar players is not nearly as good (apparently weber and another speaker company do decent recones). Anyway the speaker's label says it's a 16ohm speaker, but the ad also shows a multimeter with an impedance measurement of 6.2ohms, making it an 8ohm speaker.

So Is the 21057 significant of an original cone and the impedance somehow got way off, or was it reconed to an 8ohm with JBL parts, or could it just be any recone and 21057 doesnt mean jack? Hope this picture attachment works. just gave a picture of the cone. Thanks from a brand new member and soon to be owner of JBL- with applications in lap steel, electric guitar, bass and hopefully hifi soon!

BMWCCA
01-29-2012, 04:49 PM
I don't believe the impedance changed on the D130, I think they just changed how they were listing it sometime around 1966 when it switched from 16-ohm to 8-ohm. :dont-know:

more10
01-31-2012, 02:51 AM
If you cannot find D130 with paper surround, there are non-jbl replacement kits: http://www.audioheritage.org/vbulletin/showthread.php?32001-JBL-D130-recones-with-paper-surround&highlight=d130. Get at blown driver and have it reconed.

Mårten

Harvey Gerst
01-31-2012, 12:01 PM
Simple answer:

Back then, we lied.

Even though they're marked as 16 Ohms, they were all really 8 Ohm speakers. The DC resistance should be around 70% of the nominal rated impedance, so an 8 Ohm speaker should read about 6 Ohms (or so) DC. Ignore the 16 Ohm decal; it was really an 8 Ohm speaker. It hasn't been reconed.

rms5324
08-25-2016, 03:02 PM
Hello all - My first post:

I just picked up a D130F-6 serial #1202 cone #21057. Nominal DC resistance for about 3.5 ohms. Is this a 4 ohm or??? Recone??? Date???

Thank you for any and all info..



Simple answer:

Back then, we lied.

Even though they're marked as 16 Ohms, they were all really 8 Ohm speakers. The DC resistance should be around 70% of the nominal rated impedance, so an 8 Ohm speaker should read about 6 Ohms (or so) DC. Ignore the 16 Ohm decal; it was really an 8 Ohm speaker. It hasn't been reconed.