Speaker output ohmage without information.

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roughshawd

Jul 13, 2020
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Is there a meter test I can perform on the speaker output terminals of a device, to get the ohmage they are supposed to support??
 

crutschow

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No.

There's nothing you can measure on an amp's speaker output terminals to determine the speaker impedances it can drive.
The output impedance of modern solid-state amps when powered is a fraction of an ohm.
When unpowered it could be anything.

Only the oldy tube amps had an output impedance matched to the speaker for maximum power transfer, but even those could not be readily measured to determine that impedance.
 
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roughshawd

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If I say the speakers a supposed to be powered, does that help?
 

Martaine2005

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If I say the speakers a supposed to be powered, does that help?
What do you mean?
Powered with an external amplifier as in ‘passive’ speakers?.
Or an onboard amplifier as in ‘active’ speakers?.
 

crutschow

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The design output speaker impedance is determined by the maximum peak current and voltage the amp can simultaneously deliver without significant distortion.
You would need to know that to determine its rated impedance.

It can be determined by using a variable resistance power load resistor to determine where the peak power output occurs without distortion.
 

Delta Prime

Jul 29, 2020
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How? Show us.
You may be able to measure the impedance of the amplifier's output, but that is imho not a measure for the supposed matching impedance of the speaker(s).
In my not so humble opinion, I was following your lead ; a one word sentence :No!

Your explanation why not exudes mediocracy!

given the lack of information in a general question, the answer are both yes, and no have merit .power ratings and impedance compatibility,
misconceptions that can lead to confusion or misguided decisions by respecting members of this community are also subject to failure.
Your brain is a meter.
Audio amplifiers have a spec called "damping factor" which is determined by their output impedance
Take the nominal speaker impedance and divide it by your amp’s DF specification. Let’s say your amp has a DF of 300 and you have an 8 Ω speaker, your output impedance is 0.027 Ω. Then add the nominal impedance of your cable. A twelve-foot cable presents roughly .0016 Ω per foot. Double that to account for the “out” and “return” impedance from the amp to the speaker (flyback current). If we have a 20’ run on 12AWG cable we have 0.064 Ω of cable impedance (40 x .0016 = .0064).
Add 0.064 to 0.027 and you’ll get a system output impedance of 0.091 Ω which is super-low. Then divide your speaker impedance by the output impedance (8/0.091) and you get a Damping Factor of 88 which is in my not so humble opinion; sucks!
Damping factor is a specification most commonly associated with amplifiers, but since it concerns the amplifier/speaker relationship,
Damping Factor is the ratio of nominal loudspeaker impedance (the impedance the loudspeaker is rated at) to total output impedance of the system driving the loudspeaker, including the amplifier cables.
 

crutschow

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In my not so humble opinion, I was following your lead ; a one word sentence :No!
And in my IMHO, your rambling dissertation about damping factor did nothing to change that the answer to the TS's question is still unequivocally "No". :rolleyes:
 

Delta Prime

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And in my IMHO, your rambling dissertation about damping factor did nothing to change that the answer to the TS's question is still unequivocally "No". :rolleyes:
You’re entitled to your opinion I’ve gave you the resources to calculate the actual impedance and match your speakers and the amplifier you’re wrong
Show me why the answer is no as the moderator asked me tough guy! ultimately depends on the preference on the individual who is listening to the music how tight you want that based low frequency to response to actually control the cone of the speaker itself to reduce back EMF that is electromotive force or would you like me to educate you on that as well
 

roughshawd

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What do you mean?
Powered with an external amplifier as in ‘passive’ speakers?.
Or an onboard amplifier as in ‘active’ speakers?.
That means the speaker terminals on the device do not amplify the signal, and it requires a set of speakers that maintain their own power, and amp. It would seem to me, that output, would be considered line voltage, and I don't know what the line voltage is on an output for a set of terminals, designed to be used with externally powered loudspeakers.
 

Delta Prime

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I don't need education from someone who doesn't know how to use a period at the end of a sentence. :p
You got me!
We’re here to see one another through not to see through one another. That’s why I like you…
:cool:
 

roughshawd

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You got me!
We’re here to see one another through not to see through one another. That’s why I like you…
:cool:
Any dedication can get kudos for trying... What I really need are some focused responses that solve my problems.... (Unknown haplo group)
 

roughshawd

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There is a gleaned 40 hz signal there (skuttlebutt gleaning tech info)
Does that help? About 20ohm guess?
 

crutschow

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What is the standard loudspeaker ohmage?
Now days 8Ω seems to be the sweet spot, but some are 4Ω to get more power from a fixed low supply voltage, such as a vehicle battery.

Speakers for tube amps were sometimes 16Ω, but not common now since solid-state amps can more easily deliver more power to a lower resistance (and thus higher current and lower voltage) load.
 
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