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Post by TBox on Aug 15, 2017 17:28:14 GMT -7
I have an 8 ohm Celestion Creamback and just acquired a Vintage JBL 15" 4 ohm speaker. I would like to run these together in series. That would give me 12 ohms. My amp only has 8 and 16 ohm outputs.it has no 4 ohm output. Is it acceptable to run the 12 ohms into the 8 ohm output?
Any info would be appreciated.
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Post by headshrinker (Marc) on Aug 15, 2017 17:32:29 GMT -7
Not a problem. Go for it.
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Post by TBox on Aug 15, 2017 17:36:40 GMT -7
Not a problem. Go for it. Thanks Marc!
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Post by TBox on Aug 16, 2017 11:00:32 GMT -7
Don't know if I wired something wrong. It sounds out of phase.
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Post by headshrinker (Marc) on Aug 16, 2017 11:24:54 GMT -7
Should be positive from amp to positive of one speaker, negative of that speaker to positive of other speaker, negative of second speaker to negative of amp. Since the 4 ohm has less resistance you might hear more of it. That is usually more so when they are wired in parallel from my experience. It's possible that the speakers are out of phase with each other. You can quickly touch the terminals of a 9 volt battery to the speaker terminals + to + - to - and watch which way the cone moves, in or out. Then do the same with the other. If it moves in the same direction they are in phase. If it's the opposite, run the negative of one to the negative of the other when you wire.
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Post by TBox on Aug 17, 2017 10:20:30 GMT -7
Should be positive from amp to positive of one speaker, negative of that speaker to positive of other speaker, negative of second speaker to negative of amp. Since the 4 ohm has less resistance you might hear more of it. That is usually more so when they are wired in parallel from my experience. It's possible that the speakers are out of phase with each other. You can quickly touch the terminals of a 9 volt battery to the speaker terminals + to + - to - and watch which way the cone moves, in or out. Then do the same with the other. If it moves in the same direction they are in phase. If it's the opposite, run the negative of one to the negative of the other when you wire.
Thanks again Marc. I just have this old JBL that came out of an old 70s Peavey Session that I was wanting to use. After listening to it by itself I decided that it wasn't that great and worth wasting my time with anyway.
On another note, Last question, I promise. I have a 16 ohm 12h 75 creamback that I would like to try in parallel with my Alnico 8 ohm creamback. Still confused on ohm loads. If two 8 ohms give you a 4 ohm load, what will and 8 and a 16 ohm together give you?
Tom
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Post by zpilot on Aug 17, 2017 10:27:12 GMT -7
In parallel? 5.4 ohms.
I always remember the formula as "the reciprocal of the sum of the reciprocals of the individual speakers".
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Post by TBox on Aug 17, 2017 10:50:23 GMT -7
In parallel? 5.4 ohms. I always remember the formula as "the reciprocal of the sum of the reciprocal of the individual speakers". Thanks!
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Post by Hohn on Sept 12, 2017 10:38:41 GMT -7
Should be positive from amp to positive of one speaker, negative of that speaker to positive of other speaker, negative of second speaker to negative of amp. Since the 4 ohm has less resistance you might hear more of it. That is usually more so when they are wired in parallel from my experience. It's possible that the speakers are out of phase with each other. You can quickly touch the terminals of a 9 volt battery to the speaker terminals + to + - to - and watch which way the cone moves, in or out. Then do the same with the other. If it moves in the same direction they are in phase. If it's the opposite, run the negative of one to the negative of the other when you wire.
Thanks again Marc. I just have this old JBL that came out of an old 70s Peavey Session that I was wanting to use. After listening to it by itself I decided that it wasn't that great and worth wasting my time with anyway.
On another note, Last question, I promise. I have a 16 ohm 12h 75 creamback that I would like to try in parallel with my Alnico 8 ohm creamback. Still confused on ohm loads. If two 8 ohms give you a 4 ohm load, what will and 8 and a 16 ohm together give you?
Tom
Not "may" but "will" hear the 4 Ohm version more since it will have double the power dissipation. It may not be a lot more though if the 4 ohm speaker is warm and the 8 ohm is very bright.
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