4 ohm vs. 3.2 ohm

[jeff]

I know, I know I know, 4 ohm speakers measure ~3.2 ohm DC resistance.
BUT
Do 3.2 ohm impedance speakers exist?
Here are two Peavey Blue Marvel speakers, one marked 3.2 ohms, one marked 4 ohm. Different numbers. Are they the same thing or do 3.2 ohm speakers exist?

https://reverb.com/item/13258990-peavey-blue-marvel-8-guitar-amplifier-speaker-4-ohm-7077722

https://reverb.com/item/14926830-peavey-blue-marvel-8-amplifier-speaker-3-2-ohms


If you have a 7K:4ohm output Xfmr wouldn't using one or the other reflect different loads to the output tube?

I own a pair of the Peavey Blue Marvel marked 3.2 ohm, if I pair them with my 7K:4ohm Transformers will I reflect 5K6 load instead of 7K?

Also
https://www.hammfg.com/part/1760C?referer=1025
If 3.2 IS the same as a 4ohm speaker why is the secondary listed as 3.2,8,16 and NOT either 4,8,16(imp) or 3.2,6.8,15(DC res)?

I'm a little confused.

[jjasilli]

8 / 3 = 2.7  Close enough?

[kagliostro]

Years ago there where 3.2 ohm speakers

Franco

[jeff]

8 / 3 = 2.7  Close enough?

Where are you getting 8/3?

[jeff]

Years ago there where 3.2 ohm speakers

Franco

OK, so since I have the speakers that are marked 3.2, and my Xtfrs are 7K:4, should I assume a 5K6 load?
7000/4 X 3.2 = 5600

[tubeswell]

I own a pair of the Peavey Blue Marvel marked 3.2 ohm, if I pair them with my 7K:4ohm Transformers will I reflect 5K6 load instead of 7K?

A pair of speakers has to be either wired in series or in parallel, which for a pair of 3R2 speakers, translates to a speaker load of 6R4 or 1R6.

[jeff]

I own a pair of the Peavey Blue Marvel marked 3.2 ohm, if I pair them with my 7K:4ohm Transformers will I reflect 5K6 load instead of 7K?

A pair of speakers has to be either wired in series or in parallel, which for a pair of 3R2 speakers, translates to a speaker load of 6R4 or 1R6.

Sorry, misspoke.
I have a pair of speakers AND a pair of 7K:4ohm Xfmrs.
I'll only be using only one speaker per Xfrm.


IF the amp uses a 7K:4ohm Xfmr and I pair it with the 3.2 speaker the tube will see a 5K6 load instead of the 7K it wants, right?

[tubeswell]

Break it down

7,000:4 = 1,750:1

1,750 x 3.2 = 5,600

[spunko]

I wanted to ask something similar, dunno if start a new thread or use yours (sorry)

I have two speakers 4ohm and 3.7ohm. They are exactly the same model. In series they are 7.7 ohm. Is it safe to use it with an 8 ohm solid state amplifier (orange pedal baby 100)? will it harm?
Thanks!

[tubeswell]

I wanted to ask something similar, dunno if start a new thread or use yours (sorry)

I have two speakers 4ohm and 3.7ohm. They are exactly the same model. In series they are 7.7 ohm. Is it safe to use it with an 8 ohm solid state amplifier (orange pedal baby 100)? will it harm?
Thanks!

Not really any difference between 4 and 3R2 when it comes to speaker impedance. Go for your life. If the amp is well designed, it'll handle it no problems. If it doesn't, then don't waste your money on that amp. If you're not sure, you can either try it and the amp will be fine or it won't, or don't try it and sell the amp down the road so its someone else's problem. YMMV

[jeff]

I wanted to ask something similar, dunno if start a new thread or use yours (sorry)

I have two speakers 4ohm and 3.7ohm. They are exactly the same model. In series they are 7.7 ohm. Is it safe to use it with an 8 ohm solid state amplifier (orange pedal baby 100)? will it harm?
Thanks!

No prob, that's what this forum's for.


Is 4ohm 3.7 ohm the reading you get when you measure with a voltmeter? Or are the speakers marked 4ohm 3.7 ohm?
The DC resistance will not always match the operating impedance.

[Merlin]

I've never seen a 3.2 ohm speaker before. I'm guessing it comes from some early speaker manufacturer that decided to offer their speaker 'family' in decades, so they offered a standard 32-ohm model, and the low-impedance version became 3.2 ohms. Peavey then reissued them to please the cork sniffers who want the label to exactly match what they see in their favourite vintage amp. Just guessing though.
Since the nominal impedance is just a squint-your-eyes sort of average of the actual impedance curve, there is probably no difference between the 3.2 and the 4-ohm models, other than the label! Kinda like how identical pots get labelled 500k in America but 470k in Europe; it's just an approximation, so both labels work for the same device.

I have two speakers 4ohm and 3.7ohm. They are exactly the same model. In series they are 7.7 ohm. Is it safe to use it with an 8 ohm solid state amplifier (orange pedal baby 100)?

Yes, perfectly safe.

[Greenwichpaul]

Weber have a good explanation of why 3.2Ohm speakers exist below. It's apparently to do with the steel front plate. Scroll down, it's the penultimate Q&A.

https://www.tedweber.com/lets-talk-speakers-q-a/

[jjasilli]

8 / 3 = 2.7  Close enough?

Where are you getting 8/3?

3x 8 ohm speakers in parralel.

[shooter]

3x 8 ohm speakers in parralel.

why stop there;
2*(4X8ohm in ||) = 4
that way all the holes are filled in the full-stack n nobody in the audience will know it's not 3.2 

[johnnyreece]

I have a hoard of vintage radio speakers.  Many of them are 3.2VC.