question about impedance

[glazarou]

i have 3 periferal speakers(2 surround+1 central) at 6ohm impedance.
how can i connect them to 6ohm speaker amplifier's output?
i want to achieve them best speakers behaviour and do not cause any broblem to my system.


is there a way?

[glazarou]

sorry for the wrong text


i want to conect them to 8ohm speaker amplifier's output

[AndrewT]

Hi,
read your manufacturer's specification to see if the amplifier can drive 6ohm speakers.

It may say 8ohm or 6ohm or 4ohm or 4ohm to 8ohm.

If it says only 8ohm, then you are taking a risk using lower impedance speakers than specified by the manufacturer.
If it says any of the other three impedances then it is safe to connect each 6ohm speaker to each 8ohm output .
Do not connect multiple speakers to a single output.

[glazarou]

the center and surround ampifier outputs takes only 8ohms speakers but i have heared that there is a way to put them without risks.


does anybody know what i must to do ?

[AndrewT]

Hi,
you can add a series resistor to each speaker to change the effective load on the amplifier from 6ohm to 8ohm.

The resistor will need to be 2r2 and a power type, probably 10W. Two 5W 3r9 in parallel will achieve a similar protection for your amplifier.

The series resistor will change the Q of the speaker. It might sound nice with the series resistor, but more likely it will change the sound for the worse.

[chrispenycate]

How loud do you listen, and how long/thick is the wire going to your rear loudspeakers? Sound like irrelevant details, but…
The impedance of a loudspeaker is more a pius hope than a technical specification; generally at some frequencies it's considerably lower than specified, while at others it's four times, ten times even. Thus, any amplifier which blows up under impedance mismatch would be very unpopular in the marketplace. On the other hand, if the impedance is too low, it will go into current limit and distort earlier; the rating given on the outputs is for optimal power transfer.
Long speaker lines, while not generally recommended, tend to hide the violent dips in impedance common in cheaper crossovers (even if they're nowhere near as power absorbing as the previously suggested resistors.)
Since the only thing that could damage your amp is excessive current from the output, I suspect that if you listen at a reasonable level, 6? speakers will actually give perfectly satiafactory performance, but if you regularly listen to rock music at accurate levels, the amplifier might get upset, and certainly the performance would not be optimal.


I was going to suggest a multitapped speaker matching autotransformer, but I couldn't keep a straight face.

[sreten]

Hi,

With most modern equipment you can connect 6 ohm speakers
(even 4 ohm) to nominal 8 ohm outputs. Most stuff uses chips
these days with the full gamut of thermal overload, short circuit
etc. protection.

However because they use chips maximum output is into 8 ohm
loads, unlike a hifi amplifier where output may double into 4 ohm
loads, a chip amp typically gives about half its output into 4 ohm.

So simply connect your speakers and don't worry about it.

/sreten.

[Svante]

I agree with sreten.

[owdi]

A college roommate wired his DVC 6 ohm subwoofer in parallel (3 ohm nominal) to my Pioneer receiver, which officially only supports 8 ohm nominal speakers. He blasted it for the whole weekend before I found what he did and disconnected it. The receiver never shut off, and still works fine today.

I think your's will handle the 6 ohm nominal speakers just fine.

Dan

[Cal Weldon]

Just don't push it.