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OHM question


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#1 of 6 OFFLINE   Reid K

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Posted April 08 2003 - 01:07 PM

Just wondering I bought the RCA RT2280 home theater about a year back and since then have redone my whole home theater. Now my question is how can I tell what OHMs the reciever sends out the signal? Iam wondering because iam thinking of using the old reciever to power some bass shakers.

#2 of 6 OFFLINE   Chris Tsutsui

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Posted April 08 2003 - 06:55 PM

AMPLIFIER SECTION:
All 5 channels:
RT2280: each 80W at 8 ohm. 0.9% THD @1 kHz
Subwoofer channel: 100w at 8
Muting Attenuation: 65dB
Frequency Response: 40Hz to 20kHz +/-3dB
Signal to Noise Ratio: 65dB (Bypass mode)

If you buy a pair of 4 ohm bass shakers, you should wire them in series to = 8 ohms. Then hook them to the subwoofer channel to adjust the crossover if you can.

I don't think that amplifier is stable at 4 ohms.


#3 of 6 OFFLINE   Reid K

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Posted April 09 2003 - 07:50 AM

so will that receiver not work then?

#4 of 6 OFFLINE   Justin Lane

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Posted April 09 2003 - 03:31 PM

Reid,

A receiver does not "send out OHMS". Ohm is a measure of resistance, associated with speaker's nominal impedence. A better question to ask is what speaker impedence can my receiver safely drive.

Your receiver appears to be only 8 ohm stable (very common), so a four ohm bass shaker may or may not work smoothly. Many bass shakers require smaller wattages compared to speakers, so a receiver that is only rated at 8 ohms should still easily drive a 4 ohm load without overheating. You could also always wire your shakers in series if they are 4 ohm giving your receiver a nominal load that is 8 ohms.

If you give me some more information on your shakers, I should be able to answer your question a bit better.

J

#5 of 6 OFFLINE   Reid K

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Posted April 09 2003 - 03:55 PM

Thanks iam looking into the 25 watt auras. Also how would I wire them parellel?

#6 of 6 OFFLINE   Chris Tsutsui

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Posted April 09 2003 - 10:17 PM

Sorry if I wasn't clear.

You wouldn't want to wire 2 bass shakers in parallel because it would have 2 ohms resistance.

Your Receiver is primarily designed for 8 ohms resistance as stated in the manual.

So you need to wire the bass shakers so that they = 8 ohms, this way they will be compatable with your receiver

To do this you will take one bass shaker, and connect the positive to the negative on a 2nd bass shaker. This is series wiring so the resistance will be 4 ohms + 4 ohms = 8 ohms.

If you connect the positive to positive and neg to neg of 2 bass shakers and then connect one of them to the receiver then that is wiring them parallel. If you wire them parallel it will be = to 2 ohms. I doubt your receiver will like 2 ohms.

So what you want is to wire the 2 bass shakers in series for 8 ohms and then hook them to the receiver subwoofer channel. You want the bass shakers to receiver the least amount of high frequencies as possible so if you can adjust the crossover then try the lowest setting.