PA Speaker Connection - Urgent

[jimprince2000]

I am a beginer to PA systems. I am used to it for some time but I dont know very detail about the speaker connections etc. I have some questions please answer them. I thank you in advance for your help.

I have a mono amplifier of 200W output. It has the terminal of 4Ohms and 8 Ohms as output options. I have 2 speakers each of 100W at 8Ohms. I think I have to connect these speakers in parallel and to connect them at the 4Ohms terminal. I wanted to know if I can connect more than 2 speakers to my amplifier? i.e. Do we need to check for the power of the speakers i.e. now if i connect 2 speakers of each 100w it satisfies the 200w. that is my question. I am little bit confused.

My question in brief is - Do we need to match the power of the amplifier and the power of the speaker or is it enough to look for only impedence matching?

Can you please answer my quetions at your earliest? Thank you so much.

Jim.

 

[lsiberian]

I am a beginer to PA systems. I am used to it for some time but I dont know very detail about the speaker connections etc. I have some questions please answer them. I thank you in advance for your help.

I have a mono amplifier of 200W output. It has the terminal of 4Ohms and 8 Ohms as output options. I have 2 speakers each of 100W at 8Ohms. I think I have to connect these speakers in parallel and to connect them at the 4Ohms terminal. I wanted to know if I can connect more than 2 speakers to my amplifier? i.e. Do we need to check for the power of the speakers i.e. now if i connect 2 speakers of each 100w it satisfies the 200w. that is my question. I am little bit confused.

My question in brief is - Do we need to match the power of the amplifier and the power of the speaker or is it enough to look for only impedence matching?

Can you please answer my quetions at your earliest? Thank you so much.

Jim.

I suggest you use a stereo amplifier when possible, but you most certainly would connect them to the 4 ohm terminal if you want to use them both.

I wouldn't worry about the wattage ratings. Ohm ratings are far more important.

 

[jimprince2000]

Thank you so much lsiberian. So it seems I dont have to worry about the wattage. I can connect as many speakers as far as they match the impedance of the amplifier (recommended to 4Ohms)

 

[jimprince2000]

What is the meaning of watts of a speaker

One more question. Can you please tell me, what is the meaning of the output watts specified in the speaker? Is it the maximum power it can withstand?

Thanks,
Jim.

 

[markw]

not so fast there, partner.

Thank you so much lsiberian. So it seems I dont have to worry about the wattage. I can connect as many speakers as far as they match the impedance of the amplifier (recommended to 4Ohms)

Power isn't your main concern here. Impedance is.

When you connect two eight ohm speakers in parallel, the amp "sees" an impedance of four ohms.

If you connect more speakers in parallel, you will fall below four ohms and you are running into a potentially dangerous situation.

"First, if all speakers (or cabinets) have the same impedance ratings, the total impedance can be found by using the impedance value of one speaker and dividing that by the total number of speakers. If you go back to our example of 8 ohm speakers, we found that a single speaker had a total impedance of 8 ohms (duh....), two 8-ohm speakers had a total impedance of 4 ohms (8/2); three speakers had a total impedance of 8/3 ohms, or 2.67 ohms, and 4 speakers totaled 8/4 or 2 ohms."

Source: http://www.prestonelectronics.com/audio/Impedance.htm

FWIW, you can use a speaker of a higher impedance that the amplifier without problems. It's when you go below that problems arise.

 

[lsiberian]

One more question. Can you please tell me, what is the meaning of the output watts specified in the speaker? Is it the maximum power it can withstand?

Thanks,
Jim.

Theoretically. But wattage ratings can be very unreliable.

Effiency tells you a lot more about a speaker.

 

[highfigh]

Power isn't your main concern here. Impedance is.

When you connect two eight ohm speakers in parallel, the amp "sees" an impedance of four ohms.

If you connect more speakers in parallel, you will fall below four ohms and you are running into a potentially dangerous situation.

"First, if all speakers (or cabinets) have the same impedance ratings, the total impedance can be found by using the impedance value of one speaker and dividing that by the total number of speakers. If you go back to our example of 8 ohm speakers, we found that a single speaker had a total impedance of 8 ohms (duh....), two 8-ohm speakers had a total impedance of 4 ohms (8/2); three speakers had a total impedance of 8/3 ohms, or 2.67 ohms, and 4 speakers totaled 8/4 or 2 ohms."

Source: http://www.prestonelectronics.com/audio/Impedance.htm

FWIW, you can use a speaker of a higher impedance that the amplifier without problems. It's when you go below that problems arise.

But with no signal at the inputs, the amp "sees" the DC resistance and this is important, too.

 

[highfigh]

Theoretically. But wattage ratings can be very unreliable.

Effiency tells you a lot more about a speaker.

Sensitivity is the useful spec, if you're referring to "93dB with input of 2.83V at 1 Meter". Efficiency is for engineers to brag about.

 

[Lordoftherings]

Thanks highfigh for these couple important points, in these above two posts.

Posts #7 and 8, just above, by highfigh, are bang on.

Bob