HELP! I'm confused by Ohms?

[steve_1979]

Hello all.

This is a bit of a noob question but I'm new to this home cinema lark so please bare with me.

Do you need to change any Ohms settings on a receiver so that the impedance is matched to the speaker ohms?

I use Q Acoustics 1010i 5.1 speakers which have a nominal impedance of 6 Ohm and the receiver is a Yamaha RX-V365 (this will upgraded to a Yamaha DSP-AX763 very soon).

Cheers,
Steve

 

[GranteedEV]

If the ohms are confusing you, stop resisting and just give in!

 

[SavidSelim]

@ above poster: hahah

but seriously.. he wont get that.

i will leave this explanation to somebody that wont butcher it like i would with my nominal knowlege of all things audio related.

good joke tho.

 

[steve_1979]

Hehe

I understand (I think) that impedance is the amount of electrical resistance and Ohms is the unit that it's measured in. I was just wondering if any settings on the receiver should to be changed to match the impedance of the speakers.

 

[jinjuku]

Hehe

I understand (I think) that impedance is the amount of electrical resistance and Ohms is the unit that it's measured in. I was just wondering if any settings on the receiver should to be changed to match the impedance of the speakers.

If you receiver has that setting, then yes.

 

[UH Matt]

If the ohms are confusing you, stop resisting and just give in!

That's AWESOME!

 

[hewhoisbill]

Hey Steve,

Below are some articles that may help you out:

http://www.audioholics.com/education/amplifier-technology/impedance-selector-switch-1

http://www.audioholics.com/education/frequently-asked-questions/connecting-4-ohm-speakers-to-an-8-ohm-receiver-or-amplifier

Long story short: if you have 6 or 4 ohm speakers, and you don't run your receiver wide open, you should be fine.

Cheers,

Bill

 

[GranteedEV]

Sorry, in a less douchy response:

o you need to change any Ohms settings on a receiver so that the impedance is matched to the speaker ohms?

It's kind of hard to say. Impedance settings on receivers AFAIK are designed mainly to limit overall voltage into lower impedances, thus keeping current controlled. Of course the consequence of this is limited output.

The other option is to leave it at the higher impedance setting. This will mean that voltage is unrestrained, but it also means that frequencies in which do have lower dips than frequencies which are higher in impedance will sound different. This can include increased harmonic distortion, reduced driver control, reduced dynamic capability, and awkward frequency response at higher volumes.

My advice is, if you've got 8 or 6 ohm speakers, leave it at the 8 ohm setting. If you've got speakers with low impedance dips, try both settings and see if one sounds better than the other, otherwise buy a separate amplifier like an emotiva UPA-2 for example. Any receiver which feels uncomfortable with a 4 ohm load and requires a separate setting for it is simply not naturally designed for low impedance.

 

[PENG]

Hello all.

This is a bit of a noob question but I'm new to this home cinema lark so please bare with me.

Do you need to change any Ohms settings on a receiver so that the impedance is matched to the speaker ohms?

I use Q Acoustics 1010i 5.1 speakers which have a nominal impedance of 6 Ohm and the receiver is a Yamaha RX-V365 (this will upgraded to a Yamaha DSP-AX763 very soon).

Cheers,
Steve

Those mini speakers are designed for smaller rooms and not for playing very loud. Recommended amplifier power is 15 to 75W so don't worry about the impedance. Don't crank the volume too high either because the 365 can't handle too much current draw. As long the speakers do not sound strained or distorted you will be fine. Yes, their nominal impedance is lower than 8 ohms but many HTIB speakers are 4 ohms too. If you match them with power amps that are rated for 4 ohm loads you can crank the volume up with lesser chance of clipping, but then they will blow just the same due to the fact that their voice coils are not rated for the heavy current.

 

[jinjuku]

To make a short explanation:

Ohm is a measurement of resistance to current.

If you have an insanely high ohm measurement you have basically an open circuit, 0 ohms and you have a shorted circuit.

Think about the heat and light a bulb gives off. This is very high resistance. Now think about stuffing a fork into the outlet...

 

[steve_1979]

Thanks for the advice everyone - very educational.

I never play my speakers at more than about 75% full volume (I guess) so it should probably safe with the reciever set to 8 ohms. I've never heard them clipping and the receiver never gets very hot.

This is my first av setup which is just 6 months old but I've been bitten by the audioholic bug and am looking to upgrade already. Here are some photos of my setup if anyones interested: http://forums.audioholics.com/forums/showthread.php?t=69377

 

[pbrown]

On a related note - mho (ohm spelled backwards) is the opposite of ohm. It is the measurement of conductance. I thought my professor was joking when we learned this in college.

 

[3db]

On a related note - mho (ohm spelled backwards) is the opposite of ohm. It is the measurement of conductance. I thought my professor was joking when we learned this in college.

Its the only uncool aspect of all electrical!!!

 

[3db]

Think about the heat and light a bulb gives off. This is very high resistance. Now think about stuffing a fork into the outlet...

With or without the marshmellows scured onto the handle?

 

[MichaelJHuman]

Glad you are upgrading that 300 series receiver, especially if you are running 6 ohm speakers.

That's Yamaha's ultra-budget model, and would therefore be the most power limited receiver they made.

 

[steve_1979]

Glad you are upgrading that 300 series receiver, especially if you are running 6 ohm speakers.

That's Yamaha's ultra-budget model, and would therefore be the most power limited receiver they made.

I picked up the Yamaha RX-V365 for just £100 new from Richer Sounds and I've got to say it sounds alright for the price - better than expected.

The Yamaha DSP-AX763 that I wanted was on ebay but the bidding has gone up out of my price range now. I'm still on the look out for a new receiver though.