Need some knowledge on speaker/amp impedance

[Zerote000]

Hey,

So i have spent a couple hours trying to understand speaker vs amp impedance, what works and what doesn't. The AV recievers i have been looking at are all rated for 6-16 ohms of impedance when looking at the speaker terminals, and pretty much every speaker i have been looking at is 4 ohms, so i decided to attempt to do some research on how that would affect the setup, and to my understanding, hooking up 4 ohm speakers to an amp rated for 6-16 ohm speakers would risk blowing the amp. In finding that out, i decided to take a look at my current speakers (a pair of Dali 104's), and i found out they are also 4 ohm. Then i took a look at my current Denon stereo amp powering them, and it's also rated for 6-16 ohm speakers. This simply left me confused, especially as the amp has been working with that pair of speakers for well over a decade with no problems what-so-ever. It doesn't even get hot, just barely warm.

So i'm left with one of these impressions:

• My amp is fueled by magic
• I misunderstood some fundamental concept of impedance
• Somehow my speaker wire adds a couple of ohms to the speaker?

Anyone with some knowledge mind enlightening me?

In advance, thanks

Chris (Zerote)

[Napper198]

Hey,

So i have spent a couple hours trying to understand speaker vs amp impedance, what works and what doesn't. The AV recievers i have been looking at are all rated for 6-16 ohms of impedance when looking at the speaker terminals, and pretty much every speaker i have been looking at is 4 ohms, so i decided to attempt to do some research on how that would affect the setup, and to my understanding, hooking up 4 ohm speakers to an amp rated for 6-16 ohm speakers would risk blowing the amp. In finding that out, i decided to take a look at my current speakers (a pair of Dali 104's), and i found out they are also 4 ohm. Then i took a look at my current Denon stereo amp powering them, and it's also rated for 6-16 ohm speakers. This simply left me confused, especially as the amp has been working with that pair of speakers for well over a decade with no problems what-so-ever. It doesn't even get hot, just barely warm.

So i'm left with one of these impressions:

• My amp is fueled by magic
• I misunderstood some fundamental concept of impedance
• Somehow my speaker wire adds a couple of ohms to the speaker?

Anyone with some knowledge mind enlightening me?

In advance, thanks

Chris (Zerote)

 

Tl;dr works as long as power draw is not too high.

 

When you hook up speakers with lower impedance it is easier for you amp to deliver power to them. This is the reason most amps power ratings are rated at their lowest certified impedance. If the impedance is too low, your amp can deliver more power than it is rated for and depending on construction and security features of your amp it lowers volume, shuts down, blows a fuse or burns down you house.

 

Also speakers have different impedances for different frequencies they reproduce see here

 

And you speaker cable shouldn't add to impedance as long as it's not something like a 300 foot long 24 awg 

[Zerote000]

Tl;dr works as long as power draw is not too high.

 

When you hook up speakers with lower impedance it is easier for you amp to deliver power to them. This is the reason most amps power ratings are rated at their lowest certified impedance. If the impedance is too low, your amp can deliver more power than it is rated for and depending on construction and security features of your amp it lowers volume, shuts down, blows a fuse or burns down you house.

 

Also speakers have different impedances for different frequencies they reproduce see here

 

And you speaker cable shouldn't add to impedance as long as it's not something like a 300 foot long 24 awg 

So my question is now, should i be worried about finding a receiver that is rated to support 4 ohm speakers, or would a receiver that supports 6-16 ohm also run a 4 ohm without blowing the fuse.

To clarify one thing, i likely won't go near the limits of either the amp i have now or the amp I'm planning to buy, as my current stereo setup only consumes about 30W before it gets nearly uncomfortably loud.

[Napper198]

So my question is now, should i be worried about finding a receiver that is rated to support 4 ohm speakers, or would a receiver that supports 6-16 ohm also run a 4 ohm without blowing the fuse.

To clarify one thing, i likely won't go near the limits of either the amp i have now or the amp I'm planning to buy, as my current stereo setup only consumes about 30W before it gets nearly uncomfortably loud.

 

AVRs with 4 ohm support are usually either class d or more on the higher end (performance and price). Also keep in mind that digital audio streams in movies usually have a higher dynamic and since AVRs processes sound levels by comparing input and the desired output level it can still get very loud by it self (think people whispering then explosions).

 

Personally I'm rather safe than sorry, but it is your and your wallets decision. 

[.spider.]

Don't worry it absolutely unlikely that 4 ohm speakers will damage a 6 ohm rated AVR.

[Stagea]

Don't worry it absolutely unlikely that 4 ohm speakers will damage a 6 ohm rated AVR.

 

Agree. Most AVRs these days will go to protect if you overdrive them anyway. Just keep the level down and you'd be fine.

 

 

So my question is now, should i be worried about finding a receiver that is rated to support 4 ohm speakers, or would a receiver that supports 6-16 ohm also run a 4 ohm without blowing the fuse.

To clarify one thing, i likely won't go near the limits of either the amp i have now or the amp I'm planning to buy, as my current stereo setup only consumes about 30W before it gets nearly uncomfortably loud.

 

If you don't need much power, most AVRs should work just fine. A 4 ohm rated one is icing on top (most of these AVRs run stiffer rails and have a higher current capacity).