Question Sound quality and ohms (?)

AJM1981

Well-known member
I have a little headscratcher here.

I assumed there was no difference in sound but wondered if I were right, so to verify I googled up "4 ohm and 8 ohm sound difference" and google highlighted a blog that states there is an audible difference.

"8 ohm speakers, on the other hand, have a higher impedance, which means they can handle less power. As a result, the sound will be more balanced and natural, with less distortion. However, they may not be able to achieve the same volume levels or bass response as 4 ohm speakers."

source: https://www.avfive.com/blogs/news/which-is-better-4-ohms-or-8-ohms-speakers


I doubt about both the sound quality vs the follow up statement. I can imagine the higher position of the volume dial and lower output volume are not satisfying when having a 4 ohm amp connected to 8 ohm loudspeakers. But other statements depend on the matching and sound quality doesn't seem to be any issue in other sources. Unless people associate higher volumes with better sound quality.
 
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abacus

Well-known member
The impedance is only an average as it varies throughout the frequency range, (This is why unless you have a beefy amplifier you need to try the combination out first.
Most amplifiers are designed for 6 & 8ohm speakers and can have difficulty driving low impedance (4ohm) speakers , (This is why most 4ohm Hi-Fi speakers are expensive as it is assumed you can afford a really beefy amplifier) so make sure that your amp is capable of driving 4ohm speakers before purchasing them.

Bill
 
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As the previous poster mentioned most speakers are quoted at nominal impedance and usually give minimum impedance, so a 6 ohm minimal might have a minimum 2.5 ohms. Doesn't change the sound characteristics but what it can do is influence the volume.

My old PMCs had 90 db at 8 ohms while the Dalis are 87db at 4 ohms. This results in efficiency, most notable at low volumes.
 
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AJM1981

Well-known member
The impedance is only an average as it varies throughout the frequency range, (This is why unless you have a beefy amplifier you need to try the combination out first.
Most amplifiers are designed for 6 & 8ohm speakers and can have difficulty driving low impedance (4ohm) speakers , (This is why most 4ohm Hi-Fi speakers are expensive as it is assumed you can afford a really beefy amplifier) so make sure that your amp is capable of driving 4ohm speakers before purchasing them.

Bill

But this probably applies to really high db levels rather than the low ones right?

I have, as an extra, a 70s light amp here. It can drive 4 ohm speakers (to which they are currently connected) on its speaker 1 or 2 terminals. When I would string wire around these terminals and put the mode switch to speaker 1 and 2 it will be 8 ohm.So I could match it with my larger 3-way speakers. But the lower power might that they create light harmonic distortion when stressing them at their peak volumes (which are not comfortable with any amp in any average living). Their lower power also tells me this idea is probably not great in order not to reduce the components lifetime.
 
But this probably applies to really high db levels rather than the low ones right?

I have, as an extra, a 70s light amp here. It can drive 4 ohm speakers (to which they are currently connected) on its speaker 1 or 2 terminals. When I would string wire around these terminals and put the mode switch to speaker 1 and 2 it will be 8 ohm.So I could match it with my larger 3-way speakers. But the lower power might that they create light harmonic distortion when stressing them at their peak volumes (which are not comfortable with any amp in any average living). Their lower power also tells me this idea is probably not great in order not to reduce the components lifetime.
I think low powered amps, if that's what you mean by "light", will be more dependant on speaker efficiency.

When I had my 40 watt Arcam powering the RS6s, speakers being 91 db into 6 ohms should be fine. Unfortunately those had a nasty minimum dip to around 2.5 ohms. Once it got to about 11 o'clock on the volume dial it could start to distort.

But amp with a cleaner current wouldn't struggle as much, so it boils down to the quality of amplification. Low powered amps from the 70s, especially more affordable models, are can be prone to distortion with a 6 or 4 ohm speaker
 
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AJM1981

Well-known member
I think low powered amps, if that's what you mean by "light", will be more dependant on speaker efficiency.

When I had my 40 watt Arcam powering the RS6s, speakers being 91 db into 6 ohms should be fine. Unfortunately those had a nasty minimum dip to around 2.5 ohms. Once it got to about 11 o'clock on the volume dial it could start to distort.

But amp with a cleaner current wouldn't struggle as much, so it boils down to the quality of amplification. Low powered amps from the 70s, especially more affordable models, are can be prone to distortion with a 6 or 4 ohm speaker

Clear, thank you :)

Apart from this.. sometimes I think I get it but other times it makes me wonder.

A larger speaker usually has 8 ohm impedance ,an average bookshelf model 4 or around 4 ohm. Is it because of its cabinet size that big speakers profit from larger cabinet dimensions to ease the output and make it easier to drive, whereas smaller ones need to shout more. That in this a higher impendance like 8 ohms means less stress on the amp. (?)

If this is correct.. I would expect the opposite regarding the volume dial when having a 4 ohm amp connected to 8 ohm speakers. But at that point it might depend on other factors. Still need to find something that connects in my understanding of this :)
 
Check.out valve amps that usually have separate taps for 4ohm or 8ohm speakers.
They don't have bucketloads of watts per channel generally but are quite capable of driving either of these speakers.
Of course it is preferable, in this case, to have the most efficient speakers you can get....
 

Gray

Well-known member
"8 ohm speakers, on the other hand, have a higher impedance, which means they can handle less power"
Yes, don't take too much notice of internet blogs.
Take the above as an example.
The impedance of a speaker has nothing to do with the amount of power it can 'handle'.
Impedance determines how much power it gets from a given amp, but the amount of power it can handle, before sounding stressed or indeed burning out, is a different story.
 
Clear, thank you :)

Apart from this.. sometimes I think I get it but other times it makes me wonder.

A larger speaker usually has 8 ohm impedance ,an average bookshelf model 4 or around 4 ohm. Is it because of its cabinet size that big speakers profit from larger cabinet dimensions to ease the output and make it easier to drive, whereas smaller ones need to shout more. That in this a higher impendance like 8 ohms means less stress on the amp. (?)

If this is correct.. I would expect the opposite regarding the volume dial when having a 4 ohm amp connected to 8 ohm speakers. But at that point it might depend on other factors. Still need to find something that connects in my understanding of this :)
No, incorrect. The 6 ohm RS6s are floorstanders, Totem Arros are 4 ohms (2 of many examples I could give) but the TB2 are 8 ohms. As suggested in the above posts it's more about driver construction, some 4 ohm speakers are better than others when it comes to handling amplification.

Really isn't worth worrying about unless there's noticable distortion
 
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