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Topic: JBL speaker leads? |
Jim Dempsey
From:
Belmar, New Jersey, USA
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Posted 17 Oct 2004 5:01 pm |
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| On a JBL speaker there are (2) pressure connectors,Black and Red.Which one is the positive? I've read info that red = pos,but others say red =neg.On a 1/4 " input (cab)jack,where is tip going to red or black?(JBL)-Thanks,Jim |
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Brad Sarno
From:
St. Louis, MO USA
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Posted 17 Oct 2004 5:15 pm
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Tip + red
Sleeve - black
Brad Sarno |
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Jim Dempsey
From:
Belmar, New Jersey, USA
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Posted 17 Oct 2004 5:25 pm
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| Thanks Brad,--I read on a old post that JBL leads were opposite than the standard.Got a little confused there.I was going to put a 9 volt battery across the speaker leads,and see which way the speaker pushed,but figured i'd ask first.--Thanks,Jim |
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Ken Fox
From:
Nashville GA USA
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Posted 17 Oct 2004 5:46 pm
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| Older JBLs are reverse to other speakers. Plus is really negative. In other worked a positive battery voltage to the red terminal will cause a reverse movement of the speaker cone. This issue has finally addressed by JBL, they are now following the rest of the industry, red is positive (forward cone movement). |
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Jim Dempsey
From:
Belmar, New Jersey, USA
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Posted 17 Oct 2004 6:05 pm
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| Ken,--I have a JBL K130,not sure of the year it was made?Hopefully,these leads are pos.to pos..Gonna find out in a couple days when my MusicMan head comes in.-Thanks,Jim |
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Joe E
From:
Houston Texas
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Posted 18 Oct 2004 7:27 am
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For clarifications please:
I have a few Gray Framed D120F's. Are those reversed? Meaning does the tip go to black?
And if they have been reconed, would the have been changed to modern wiring?
Thanks,
Joe |
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Ken Fox
From:
Nashville GA USA
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Posted 18 Oct 2004 7:37 am
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If a JBL has been reconed, check it with a 9 volt battery. I have found them both ways after a recone. In a standalone application it does not matter much about phase on a JBL. When teamed up with another speaker, then phasing counts. Out of phase speakers cancel bass response. The old greyframes (I have two) were red for negative. Again, Fender hooked them up red to tip of the plug. Did not matter that much. On my old 1966 Deluxe (non-reverb) I have an old Fender/JBL greyframe. I often use two amps, and often have to switch the speaker leads on it to get it in phase with a second amp. When I run a Fender reverb amp amp as the second amp, I just pick the channel that puts them in phase. A reverb amp has channel one out of phase 180 degrees with channel two (due to a third gain stage on the reverb channel). Each gain stage (two per 12AX7) reverses the signal phase. there are two gain stages in channel one and three in channel two. The other half of the 12AX7 in the channel two is for reverb recovery from the tank.
One of the best buys I ever got was a 1962 Bassman cabinet with two new Eminence speakers. They were over 200 watt speakers, wired out of phase! The cab had no bass response. The best $75.00 I ever spent. A quick check with a 9 volt battery confirmed they were out of phase!
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John Daugherty
From:
Rolla, Missouri, USA
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Posted 18 Oct 2004 10:04 am
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| I have never trusted the phasing of speakers. When connecting two speakers, the only reliable method is the old battery test. Touch the speaker leads to a battery and see which direction the cone moves. Take the lead from each speaker that moves the same direction when touched to the battery positive terminal and label them the same. |
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