Connecting 4 ohms Twin Reverb Reissue 65 Speakers to Red Knob Twin for testing

[jalexquijano]

okay my twin reverb 65 reissue speakers are Jensen 4 ohms speaker wired in parallel. My red knob twin speakers are 8 ohms speakers wired in series as per the manual. If i want to test if the speakers are faulty or not by comparing sound difference amongst the set of speakers how do i connect the 4 ohms speakers from the twin reverb to my red knob twin? Do i need to move the impedance selector at the back of the red knob twin??

http://ampwares.com/schematics/TheTw...ers_Manual.pdf

[Enzo]

Your '65 Twin Reverb should have two 8 ohm speakers wired in parallel for a 4 ohm total. Two 4 ohm speakers in parallel would be wrong.

Your The Twin has an impedance selector: 4-8-16. You set it for whatever load you are going to use.

Two 4 ohm speakers is a 2 ohm total load, and there is no 2 ohm selection. Closest would be the 4 ohm setting.

If you actually have two 8 ohm speakers in parallel, then set it for 4 ohms.

[J M Fahey]

Agree with Enzo and add:

If i want to test if the speakers are faulty or not by comparing sound difference amongst the set of speakers

That is not the way to find a faulty speaker but to compare sound "taste/flavour".
Both sets can sound different, you may love one, hate the other, another person there might like the exact opposite, yet NONE is faulty just because of that.

That said, and both sets being "original Fender Twin speakers", they "should" sound quite similar.

Not only that, they are *probably* made by same Factory, with Eminence being the main suspect, or the "reissue" one might be made by Jensen Italy.
Fender used many suppliers along the years, including Rola, Utah, CTS and even the odd EV , but they all won the contract by supplying "a Jensen C12N at lower cost" because that was "the sound" Fender wanted.
In all cases they tried to emulate the *old* Jensen C12N which is the yardstick by which Fender speakers are measured.

Just curious, what is the exact defect or problem you are trying to correct?
What are the symptoms?

If you want to make the speaker sets interchangeable for quick comparison:

1) I am quite certain the Reissue speakers are 8 ohm each, wired in parallel for 4 ohm total.
Leave them as is.

2) "The Twin" speakers are again 8 ohm each, factory wired in series for 16 ohm total (what were they thinking? ) and impedance selector is Factory set to 16 ohms too.

***Rewire them in parallel, for 4 ohm total, plug them in the main speaker out and set impedance selector to 4 ohms***
Now you can exchange speakers and amp chassis at will, in seconds, and test all you wish.

The Reissue is unchanged, TheTwin will have same sound and power as before.

I do not expect great difference, in principle TheTwin speakers could be somewhat darker , the Reissue ones brighter, both because they are newer, and probably similar to Legend or straight Italian Jensen.

In principle I donīt expect any damage in them which should be easy to hear on its own, not much comparison needed.

[Enzo]

If you change the series to parallel, which is a very practical idea, make SURE they are wired in phase.


If you think one of the speakers in your 65 reissue, disconnect ONE of them and play through the remaining one only. Does that speaker sound OK? Now disconnect that one and play through the other one only, does it sound the same or different? For this test, it doesn't matter if the impedance is "wrong".