Low speaker impedance

[Buckle-meister]

Dear all,

I'm sure you can point out alternative examples but it seems to me, going by threads I've seen, that the impedance of many American manufactured speakers is 4 or 6 Ohmes. I've yet to come across a British speaker that isn't 8 Ohmes.

If I'm not just imagining this and there is a trend, is there a reason for this difference?

 

[Joe Schmoe]

Designers of relatively high end speakers can accept low impedance as a tradeoff for other desireable characteristics, because they know that their customers can afford the required high-current amplification. Designers of budget speakers generally aim for 8 ohms (and high efficiency) because they know that they will be used with similarly budget priced receivers. (I have not noticed such a division along lines of nationality.)

 

[Buckle-meister]

Hmm. Your explanation is certainly logical, but it doesn't corresspond to my personal experiance or to speakers I've read about in threads. The flagship speakers by both Mission and B&W, for example, are 8 Ohme impedance. Sleestak's Epiphany 12-12s are also 8 Ohme impedance. All these offerings are very high quality speakers yet all are easily driven.

 

[Joe Schmoe]

I said that low impedance is an option for high-end speaker designers, not something that they necessarily choose. I would be far more surprised to see a budget speaker with low impedance.

 

[Seth=L]

I wonder where the Nautilus fall in the Efficiency, and impedance factors.

 

[Buckle-meister]

I said that low impedance is an option for high-end speaker designers, not something that they necessarily choose. I would be far more surprised to see a budget speaker with low impedance.

You say that budget speakers are generally more likely to have a high impedance than high-end speakers even though the latter may be high-impedance - which presumably is a good quality to have if possible. Is this correct?

Because from my side, I've owned both budget and good quality speakers. I've also seen plenty of other speakers in both camps and I've yet to see any that weren't 8 Ohm impedance.

Are most British speakers better designed than American speakers?

I wonder where the Nautilus fall in the Efficiency, and impedance factors.

See here

 

[Buckle-meister]

Does low impedance actually make a loud speaker sound worse than if the impedance was higher, or is it just that the speaker is harder to drive but that it makes no audible difference to sound quality?

 

[j_garcia]

Does low impedance actually make a loud speaker sound worse than if the impedance was higher, or is it just that the speaker is harder to drive but that it makes no audible difference to sound quality?

Makes no difference to audible quality, IMHO.

 

[jostenmeat]

Even if a lot of B&W's are listed as 8 ohms nominal, a lot of them drop to about 3 ohms, including the entire 800 line as well as the 703.

The company says about their CM1: "For such a compact, two-way speaker, it packs a weighty punch, courtesy of its lowered impedance...."

 

[no. 5]

For what it's worth, Wharfadale has a number of six Ohm speakers.

 

[obscbyclouds]

I was under the impression that Lower impedance makes a speaker harder for an amplifier to drive (because it requires more voltage), but also enables the speaker to play louder with that extra voltage.

If you think of the water and pipe analogy, a lower impedance speaker is a larger diameter pipe, which of course allows more water (current) to flow, but at the same time requires more pressure (voltage) from the amplifier to do so. But of course the impedance of any speaker changes throughout the frequency range, and many speaker companies publish an impedance chart for their speakers.

I've never seen any proof however, that a 4-ohm speaker is going to be "Better" sounding than an 8-ohm speaker, or vice-versa.

 

[j_garcia]

Yes, requires more power to play, which is great...unless you don't have that extra power needed to keep them happy. My speakers in my main system are all 4 Ohm.

 

[mtrycrafts]

Does low impedance actually make a loud speaker sound worse than if the impedance was higher, or is it just that the speaker is harder to drive but that it makes no audible difference to sound quality?

Yes to what Jgarcia said about SQ. Extensive research at the Canadian Research Center comes to the conclusion of :

• These tests determined that the characteristics that people preferred in speakers were:
- Low Distortion
- Flat Response and wide bandwidth
- Wide Dispersion

 

[mtrycrafts]

I was under the impression that Lower impedance makes a speaker harder for an amplifier to drive (because it requires more voltage), but also enables the speaker to play louder with that extra voltage.
.

lower impedance demands more current with the same voltage input.
If the amp has difficulty with that current demand, the rail voltage drops even more, less current etc.

Louder may not be the case as that depends on speaker sensitivity. With a given input signal to the amp the speaker will see a fixed voltage at the terminal, unless the amp cannot deliver the necessary current, then voltage sags lower. So, one cannot make these generalizations.

 

[mike c]

Dear all,

I'm sure you can point out alternative examples but it seems to me, going by threads I've seen, that the impedance of many American manufactured speakers is 4 or 6 Ohmes. I've yet to come across a British speaker that isn't 8 Ohmes.

If I'm not just imagining this and there is a trend, is there a reason for this difference?

monitor audio has some 6 ohm speakers gs20 and gs60 I believe.

american made speakers have low ohms? what about american muscle cars?

 

[Joe Schmoe]

Because I have heard plenty of speakers that have high impedance, high sensitivity, and excellent sound, I don't really see any reason to build one that lacks these characteristics. Why spend more on an amp when you can get equivalent performance by choosing different speakers (within any given price range)? The only good reason I can think of for designing low impedence/inefficient speakers is to extract performance from small cabinets that belies their size. (Exotic designs such as electrostatic, of course, are a different story.)

 

[emorphien]

Does low impedance actually make a loud speaker sound worse than if the impedance was higher, or is it just that the speaker is harder to drive but that it makes no audible difference to sound quality?

No difference in sound IMO, it's a design decision or sometimes a constraint. A lot of smaller speakers have higher impedance. Mine are 4ohm nominal, they're moderate sized stand mounted speakers with a smaller bass driver. I auditioned them against a bunch of other larger and smaller standmounters that ranged from 4 to 8 ohms as well, couldn't say there was any trend between sound and impedance.

It does make the speaker a bit harder to drive but my amplifier isn't exactly high end and it has no troubles driving them. It helps that impedance down to 4 ohms wasn't a big concern to me, nor was efficiency so much because my listening room is small.

 

[3db]

A trend I noticed among a few manufacturers is

No difference in sound IMO, it's a design decision or sometimes a constraint. A lot of smaller speakers have higher impedance. Mine are 4ohm nominal, they're moderate sized stand mounted speakers with a smaller bass driver. I auditioned them against a bunch of other larger and smaller standmounters that ranged from 4 to 8 ohms as well, couldn't say there was any trend between sound and impedance.

It does make the speaker a bit harder to drive but my amplifier isn't exactly high end and it has no troubles driving them. It helps that impedance down to 4 ohms wasn't a big concern to me, nor was efficiency so much because my listening room is small.

as you go up in price within in a manufacturer, the nominal impedance dropped. Axiom went from 8 ohms across their line until they hit the M80i which is rated at 4ohms. Paradigm remained "compatible with 8 ohms whatever thats means" thru their entire series and PSB started out with 8 ohms on their apha series, (entry level) down to 6 ohms in their G and Image series and down to 4 Ohms in their Platinum (top of the line series) .

Why go 4 ohms with the high end models? What advantage does 4 ohm give the customer? I can understnad from a designers perspective having more lee way in their designs but as a customer I can't see any advantage, only disadvantage.

 

[j_garcia]

It is the driver selection and crossover network design that create the impedance. If the characteristics the designers are looking for happen to be in a lower impedance driver or the combination of drivers they decide to use results in a lower impedance, then that is what they go with, leaving it up to the user to ensure they have enough power to handle the load. On the lower end, they are going to design speakers that can be easily driven by the average person's receiver. As you move up the food chain, the user is more likely to have higher quality gear as well...so it becomes less of a concern for them to worry about the demand the speaker will place on the gear and focus more on getting the quality of sound they are after.