Wiring Amp HELP

[llpatt97]

Hello I have a cheap setup with a 1000w 4 channel amp. 90w RMS per channel.

How would I wire a 60w RMS 6x9 and a 35w RMS 5.25in speaker on the same channel for TWO channels? and then a 150w RMS sub bridged on the remaining two?

Im worried about ohms on the 2 channels with 4 speakers when setting gain etc.

Here is a picture of the amp...

http://ecx.images-amazon.com/images/I/719pEi9MP7L._SL1500_.jpg

Click to read more...

 

[Jepalan]

You have not provided enough information. Exact model/make of amp? Impedance or make/model of your speakers & sub?

 

[Jepalan]

OK. I found your amp. It is 2-ohm stable.

In order to bridge the sub, the sub has to be 4-ohms.

If your speakers are 4-ohms each then wire left speakers in parallel on one channel and right speakers in parallel on another channel.

 

[llpatt97]

Hey thanks for your reply! Since there are two gain knobs that control two channels each... when setting the gain on the 2 channels that have 4 speakers on them using a multimeter how would I go about calculating the ohms law equation... would it be the square root of the rms of two channels, (180rms X 1 Ohm) since there is 4 4ohm speakers... or 2 ohms since it will be 2 ohms a channel?

 

[Jepalan]

Hey thanks for your reply! Since there are two gain knobs that control two channels each... when setting the gain on the 2 channels that have 4 speakers on them using a multimeter how would I go about calculating the ohms law equation... would it be the square root of the rms of two channels, (180rms X 1 Ohm) since there is 4 4ohm speakers... or 2 ohms since it will be 2 ohms a channel?

OK. Just talking about the 4 x 4 ohm speakers for now (ignoring the sub):

Head-unit Left output ----> Amp channel 1 input

Head-unit Right output ----> Amp channel 2 input

Amp channel 1 (+) ----> Left Spkr 6x9 (+) ----> Left Spkr 5.25 (+)

Amp channel 1 (-) ----> Left Spkr 6x9 (-) ----> Left Spkr 5.25 (-)

Amp channel 2 (+) ----> Right Spkr 6x9 (+) ----> Right Spkr 5.25 (+)

Amp channel 2 (-) ----> Right Spkr 6x9 (-) ----> Right Spkr 5.25 (-)

If all your speakers are 4 ohm speakers, then each amp channel sees a total 2 ohm load.

You only use one channel when doing the voltage calculations for setting gain with a DMM

One gain knob (input level) will set the gain for both channel 1 & channel 2

For above connections you are restricted by the fact that one of the speakers is only 35 W RMS. Since each speaker will get half the power of the amp channel, you need to set the amp to around 70 W RMS. You might be able to push this a bit if you are careful with how loud you play.

For 70W RMS, Vac RMS = SQRT(70 x 2) = 11.83 Vac RMS

Set HU volume at 3/4 of max, use appropriate test tone and...

Measure Vac on one amp channel output and set gain to hit 11.83 Vac

Or, just set by ear. Lots of info on setting gains here and elsewhere