6 ohm speakers....

[rsumperl]

I have a chance to get a set of Pioneer CS-G303 for $40. They are 6Ω speakers. If I am using sweep tubes with the 3.3KΩ/100W Edcor transformers, do I want the 6Ω speakers on the 4Ω or 8Ω tap? If I am correct, putting a 6Ω speaker on the 4Ω tap, the primary will look like 5KΩ, likewise the 6Ω speaker on the 8Ω tap, the primary willl look like 2.4KΩ.


Thanks,
Ray

[tomchr]

I'd connect them to the 4 ohm tap. The higher primary impedance will give you slightly less max power, but lower distortion.

~Tom

[rsumperl]

Well, I tested the 4Ω and 8Ω taps and my ears tell me the 8Ω was the better choice. That makes the primary of the transformer theoretically 2.475KΩ. I paid $40 for this set of Pioneers. Never mind that I had to do a 125 mile round trip to Scranton, PA......


Ray

[Loren42]

You can look for the manufacture impedance graph, if they publish one. If they don't, you can create one with a PC sound card and a free program for testing speakers.

What you will see is that the impedance across the spectrum will generally be lower than the rated impedance with peaks at the resonant frequency of the woofer and probably at the upper end of the spectrum where it exceeds 6Ω.

Generally, better speaker manufactures have a flatter impedance curve than some of the less expensive brands.

However, most of the graph will still be below 6Ω, so my point is that the 4Ω tap may better serve the need.

[kevinkr]

Since they sound better on the 8 ohm tap that's where I would run them theory or no theory. Without doing an impedance measurement across frequency it is pretty difficult to know what the actual average impedance of the speaker is, and it could be for the most part higher than the stated impedance of 6 ohms..

[tubelab.com]

Since they sound better on the 8 ohm tap that's where I would run them theory or no theory.

Right. It's your amp and your speakers, hook them together whichever way that sounds best to you. I connect my Yamahas to my SSE to either the 4 or 8 ohm tap depending on the choice of music. They rock the best on the 8 ohm tap, but do the detailed stuff better on 4 ohms.

[tomchr]

Originally Posted by tubelab.com

Right. It's your amp and your speakers, hook them together whichever way that sounds best to you. I connect my Yamahas to my SSE to either the 4 or 8 ohm tap depending on the choice of music. They rock the best on the 8 ohm tap, but do the detailed stuff better on 4 ohms.

Makes we wonder if Jack Elliano of Electra Print's approach of using a 6 ohm tap for both 4-ohm and 8-ohm speakers would be the way to go if one was to order a custom transformer...

~Tom