A question about impedance

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Hello all

I have a pair of Pioneer Elite SP-EFS73 Atmos speakers. The three woofers are each rated at 2 Ohms. The rated impedance at the terminals (just for the front firing drivers) is 4 ohms. My question is, if I were to remove one of the woofers, what would happen to the impedance load at the terminals? What if I replaced the 2 Ohm woofer with a 4 Ohm?

Thank you for your knowledge & input
 
We would need a schematic of the speaker wiring to be sure but:

The three woofers are probably wired in series giving a nominal impedance of 6 ohms. However, this combination would probably measure 4 ohm dc resistance on an ohmeter.

Removing a series speaker would decrease the overall impedance.

Substituting a series 4 ohm speaker would raise the impedance but would totally unbalance the system.

I wouldn't advise messing with the loudspeaker. You should focus on the amplifier instead. Perhaps you are playing it too loud and that's why it's going into protection mode.
 
OK, another question (yes I realize there are no absolutes in this, and the outcome sound wise is uncertain, more just for a basic understanding on my part) I believe the crossover network for the concentric driver is apart from the three 2 ohm woofers. If I replaced the top woofer with an 8 ohm wired directly to the speaker terminals, and disconnected the other two woofers, do you have an idea how that would change the impedance?
 
One can simulate nowadays easily enough if one has some of the free tools to do that. Manufacturer datasheet, tracing software, excel based simulators to create frd's and zma's of any values one desires. It's just that it takes time and a little bit of practice. Perhaps someone might take a shot if you provide enough info, along with crossover parts values you have now.
 
If I replaced the top woofer with an 8 ohm wired directly to the speaker terminals, and disconnected the other two woofers, do you have an idea how that would change the impedance?

If you are trying to find out which factors affect the impedance of a loudspeaker system then this is not a good way to go about it.

The impedance of the bass section would obviously change to 8 ohm. The overall impedance of the loudpeaker would be increased.

However, the frequency at which the bass section crosses over to the mid/treble section would be affected

In the absence of a crossover circuit and an internal wiring diagram, I'm afraid there is no more I can add.
 
All a bit weird, isn't it? :confused:

You have a pair of "Le Dernier Cri", Andrew Jones designed home cinema floorstander Pioneer Atmos speakers. A snip at $499.

AFAIK, these have a vertically pointed coaxial pointed up to the ceiling. Which is a wheeze if you watch movies with helicopters overhead. Whatever will they think of next? :D

And three 5" metal woofers pointed forwards, and a 4" coaxial for the midrange stuff.

Now if I was designing a floorstander with three woofers, I would just wire them in series to match the single woofer bookshelf. I very much doubt if the woofer section would amount to the same 4 ohms of the bookshelf version. Think more like 12 ohms.

Without accurate resistance measurements on the individual woofers, I wouldn't attempt to guess their impedance. Car audio is a different ballgame, with a 12V battery and maybe bridged mode on drivers. But really, why wreck a competent design? Sell them if you don't like them. For sure, if you don't know what you are doing, don't do it.
 

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Hi Steve! - Thanks for the pics of the drivers.

Always good to put flesh on the bones of the argument!

Craig seeks understanding of impedance, but confidently states that the woofers have an impedance of 2 ohm.

Out of interest, could that figure be correct?
 
The real interest for me was exploring the Dolby Atmos system. That and the increasingly popular idea of a coaxial mid/tweeter unit. In Atmos the top driver gets a separate feed for height information.

692408d1531867099-question-impedance-pioneer-atmos-system-jpg


I always do more homework on speakers than a lot of posters deserve, but the bookshelf is 4 ohms nominal. The MTM centre I have is series wired basses, because that gets the same loudness as the satellites. The same goes for the floorstanders, just how dispersion works with arrays.

Now if the satellites are 4 ohms bass, the woofers are likely the same in the floorstanders. So 12 ohms at the bass end. Maybe 4 ohms for the coaxials. But this is all speculation. :)
 
SWAG

Hello all

I have a pair of Pioneer Elite SP-EFS73 Atmos speakers. The three woofers are each rated at 2 Ohms. The rated impedance at the terminals (just for the front firing drivers) is 4 ohms. My question is, if I were to remove one of the woofers, what would happen to the impedance load at the terminals? What if I replaced the 2 Ohm woofer with a 4 Ohm?

Thank you for your knowledge & input

The load presented by all three drivers is nominally 6 Ohms and that is what is seen by the low pass section of the crossover except when the drive signal frequency is in the vicinity of driver resonance, then it will be much higher and dependent on the collective resonance properties of the three drivers([FS] may be different for the rear driver). A driver change and resulting miss-match most likely result in undesired performance. The information content of your question is insufficient to guess further.

WHG
 
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