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Old 04-22-2010, 11:51 AM
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Power amp output to speakers question

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Very simple question. I'm pretty versed on at least the basics of ohm loads and such but have never seen this question answered ( or asked ).

If I have a two channel power amp can I connect an 8ohm speaker to one side and a 4ohm to the other. Obviously the volumes would need to be adjusted to be close but I want to know if this is a NO NO thing to do.

The power amp in question can do a 2ohm load so it shouldn't be an issue. More curious if each channel ( not bridged ) operate independently of one another so I'd know what wattage is supposed to be going out to a given speaker.

I guess it's more than one question.

Here is what the manual says but it never really answers my question.

1 channel 8 ohms: 260w
2 channels 8 ohms: 225w
1 channel 4 ohms: 400w
2 channels 4 ohms: 350w
1 channel 2 ohms: 600w
2 channels 2 ohms: 500w
8 ohm bridge: 700w
4 ohm bridge: 1000w

Last edited by BobaFret : 04-22-2010 at 11:53 AM.
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Old 04-22-2010, 11:53 AM
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Quote:
Originally Posted by BobaFret View Post
If I have a two channel power amp can I connect an 8ohm speaker to one side and a 4ohm to the other.
Yes.

Quote:
Originally Posted by BobaFret View Post
The power amp in question can do a 2ohm load so it shouldn't be an issue. More curious if each channel ( not bridged ) operate independently of one another so I'd know what wattage is supposed to be going out to a given speaker
Each channel in the power amp is independant of the other.
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Old 04-22-2010, 11:56 AM
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Originally Posted by Tim C. View Post
Yes.



Each channel in the power amp is independant of the other.
So I should expect to get 400w out of the 4ohm side and 260w out of the 8ohm?

I appreciate your input.
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Old 04-22-2010, 12:08 PM
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Originally Posted by BobaFret View Post
So I should expect to get 400w out of the 4ohm side and 260w out of the 8ohm?
You are right
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Old 04-22-2010, 12:11 PM
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This is excellent news. Thanks for putting my mind at ease.
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Old 04-22-2010, 12:30 PM
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Yes, on stereo power amps, the 2 sides should be independent and it would be safe to do so. On a less relevant note, matching volume and power/driver may sometimes be more desirable than just matching wattage.
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Old 04-23-2010, 10:54 AM
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Old 04-23-2010, 11:36 AM
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The setup will work fine, but I doubt you'll get single channel power out of either side. The power amp specs indicate there is a sag when both channels are used. Instead of 260/400, I would expect something closer to 225/350.

That said, don't worry about it - it's a minor difference.
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Old 04-23-2010, 02:11 PM
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Originally Posted by BobaFret View Post
I guess it's more than one question.

Here is what the manual says but it never really answers my question.

1 channel 8 ohms: 260w
2 channels 8 ohms: 225w
1 channel 4 ohms: 400w
2 channels 4 ohms: 350w
1 channel 2 ohms: 600w
2 channels 2 ohms: 500w
8 ohm bridge: 700w
4 ohm bridge: 1000w
Quote:
Originally Posted by BobaFret View Post
So I should expect to get 400w out of the 4ohm side and 260w out of the 8ohm?

I appreciate your input.
Quote:
Originally Posted by Alex1984 View Post
Yes, on stereo power amps, the 2 sides should be independent and it would be safe to do so. On a less relevant note, matching volume and power/driver may sometimes be more desirable than just matching wattage.
Not so simple, because it looks like both side are drawing power from the same power source (transformer). Notice how the wattage drop when both channel are in operation when compare to just one channel operating.

So, with both channels running you should get, 225 watt on 8 ohm and 350 watt on 4 ohm for at total of 575 watt. And it is totally safe to do so.
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