How should I rig my speakers for higher impedance?

[WillC2003]

Hi guys, I just found an amazing deal on a Pioneer VSX-D511, and its impedance ratings are 100W 8Ω (front) 100W 8Ω (centre) and 100W 8 Ω (rear). The problem is my speaker (2 front, 1 centre, 2 rear) setup is 6Ω for each speaker so I was looking for ideas to increase impedance. My first thought was to add resistors into the circuit but I just need some confirmation on how the circuits are commonly wired in order to place resistors most efficiently. I am assuming the impedance ratings are for the whole set of channels (8Ω resistance for the whole front circuit etc) and the individual channels would be wired in parallel as each speaker needs the same power. So without the resistors the front and rear offers 3Ω resistance, and the centre offers 6. So adding 2Ω 100W resistors to each channel output should increase the resistance to spec? Or is the only real damage done at high current draw so I should just refrain from turning it up to ridiculous volumes?

 

[lovinthehd]

Nominal impedance is one thing, actual impedance of your speakers is another. Your receiver should be fine with a 6 ohm rated speaker in general, tho. No need to try and "change" impedance.

You might want to look thru these articles

Understanding Ohm's Law, Impedance And Electrical Phase 101

Do you ever wonder what makes a loudspeaker "difficult to drive"? Do you wonder what's so special about an amplifier that is stable into a 4-ohm load? Audioholics looks to answer these questions here.

www.audioholics.com

Loudspeaker Sensitivity & Impedance Explained

The focus of this article is on loudspeaker sensitivity and impedance. Loudspeaker manufacturers sometimes exaggerate the specifications of their products to make them look better than reality.

www.audioholics.com

 

[WillC2003]

Nominal impedance is one thing, actual impedance of your speakers is another. Your receiver should be fine with a 6 ohm rated speaker in general, tho. No need to try and "change" impedance.

You might want to look thru these articles

Understanding Ohm's Law, Impedance And Electrical Phase 101

Do you ever wonder what makes a loudspeaker "difficult to drive"? Do you wonder what's so special about an amplifier that is stable into a 4-ohm load? Audioholics looks to answer these questions here.

www.audioholics.com

Loudspeaker Sensitivity & Impedance Explained

The focus of this article is on loudspeaker sensitivity and impedance. Loudspeaker manufacturers sometimes exaggerate the specifications of their products to make them look better than reality.

www.audioholics.com

Thanks for your help, I kinda get all the concepts but not entirely and I don't have the time to do a full research (got my final exams starting tomorrow . I think I might just try not push the amp to hard.

 

[lovinthehd]

Thanks for your help, I kinda get all the concepts but not entirely and I don't have the time to do a full research (got my final exams starting tomorrow . I think I might just try not push the amp to hard.

That is always a good plan, to keep volumes to sane levels or to back off if you hear bad sounds. Each of your amp channels is capable of the rating at 8 ohms that Pioneer provided, but that doesn't mean they'll do great with very low impedance speakers, particularly at higher volume levels. That isn't one of the more powerful amps around but should work fine with your speakers I think. What was the amazing deal for the old receiver?

 

[TLS Guy]

Thanks for your help, I kinda get all the concepts but not entirely and I don't have the time to do a full research (got my final exams starting tomorrow . I think I might just try not push the amp to hard.

You can not add a resistance in series with a speaker. First it will get hot, unless it is very large. The big issue is that it will change the tuning of the speaker, and change the Q of the woofer. It will also make the FR of the speaker follow the impedance curve of the speaker. It would be like using very narrow gauge high resistance speaker wire, which is a very bad thing.

 

[WillC2003]

That is always a good plan, to keep volumes to sane levels or to back off if you hear bad sounds. Each of your amp channels is capable of the rating at 8 ohms that Pioneer provided, but that doesn't mean they'll do great with very low impedance speakers, particularly at higher volume levels. That isn't one of the more powerful amps around but should work fine with your speakers I think. What was the amazing deal for the old receiver?

It was $160 AUD for the receiver in great working condition, a few cosmetic scratches and checked by an audio professional, and the speakers were free from a mate.

 

[WillC2003]

You can not add a resistance in series with a speaker. First it will get hot, unless it is very large. The big issue is that it will change the tuning of the speaker, and change the Q of the woofer. It will also make the FR of the speaker follow the impedance curve of the speaker. It would be like using very narrow gauge high resistance speaker wire, which is a very bad thing.

Ok thanks so much for the warning, my high school physics/software knowledge of circuitry would have tried to increase the impedance like traditional DC current. Very much appreciated