Speaker configuration advice

[moka]

I'm connecting speakers to a pa amplifier. The amp has 2 sets of outputs, 1set is labeled 330ohm, and the other is labeled 4-16ohm.

Now I'm still new to all of this so I may be mistaken, but from what I can gather, the ohm of multiple speakers goes up or down depending on the use of parallel vs series configuration.

In my case I have 4 speakers all labeled 8ohm 20w and the amp is 100w, so everything should fit. But I don't know how I can make the 4 speakers ohm match the amp and which set of outs to use.. The 4-16ohm out or the 330ohm out. Real help would be so appreciated.

 

[TLS Guy]

View attachment 22410 I'm connecting speakers to a pa amplifier. The amp has 2 sets of outputs, 1set is labeled 330ohm, and the other is labeled 4-16ohm.

Now I'm still new to all of this so I may be mistaken, but from what I can gather, the ohm of multiple speakers goes up or down depending on the use of parallel vs series configuration.

In my case I have 4 speakers all labeled 8ohm 20w and the amp is 100w, so everything should fit. But I don't know how I can make the 4 speakers ohm match the amp and which set of outs to use.. The 4-16ohm out or the 330ohm out. Real help would be so appreciated.

You have a public address amp not a home amp. It is mono and NOT stereo.

The 330 ohm is for the common 70 volt PA system and not to be used with domestic speakers. These speakers are connected via tapped transformer labelled in watts.

You will have to use the 4 to 16 ohm terminals. You will only be able to run two speakers. You will have to connect just two in parallel. They will be mono and both will get an identical signal.

If this is for home audio you have the WRONG amp.

 

[moka]

You have a public address amp not a home amp. It is mono and NOT stereo.

The 330 ohm is for the common 70 volt PA system and not to be used with domestic speakers. These speakers are connected via tapped transformer labelled in watts.

You will have to use the 4 to 16 ohm terminals. You will only be able to run two speakers. You will have to connect just two in parallel. They will be mono and both will get an identical signal.

If this is for home audio you have the WRONG amp.

Thank you for your input. I am using this setup not for home audio. It is for lectures to be heard in multiple rooms. So I have one mic going out to 4 small 20w wall mounted speakers in 2 separate classrooms. From what I can find online this requires a PA system. Is that incorrect?

 

[TLS Guy]

Thank you for your input. I am using this setup not for home audio. It is for lectures to be heard in multiple rooms. So I have one mic going out to 4 small 20w wall mounted speakers in 2 separate classrooms. From what I can find online this requires a PA system. Is that incorrect?

In that case you need to get a 70 volt PA transformer for each of your four speakers for 8 ohm speakers.. You place them right at each speaker. Now the taps on the transformer will be marked in watts. So you can have different powers in each room if you want. The rule is that the addition of all the watt taps connected need to add up to the total power of the amp. So if you want all speakers to have the same volume you would connect to the 25 watt tap on each transformer.
You connect all the speakers in parallel. You can use cheap bell wire to wire it up as the current is low. You connect the speaker chain to the high impedance 330 ohm terminal.

Four of these will do the job for you. I don't think you will find 25 watt taps. However the 20 watt taps will be close enough.

 

[moka]

In that case you need to get a 70 volt PA transformer for each of your four speakers for 8 ohm speakers.. You place them right at each speaker. Now the taps on the transformer will be marked in watts. So you can have different powers in each room if you want. The rule is that the addition of all the watt taps connected need to add up to the total power of the amp. So if you want all speakers to have the same volume you would connect to the 25 watt tap on each transformer.
You connect all the speakers in parallel. You can use cheap bell wire to wire it up as the current is low. You connect the speaker chain to the high impedance 330 ohm terminal.

Four of these will do the job for you. I don't think you will find 25 watt taps. However the 20 watt taps will be close enough.

Would explaining to a layman why these 4 transformers are needed be a simple thing? If so I would really like to understand why you are making this recommendation.

 

[TLS Guy]

Would explaining to a layman why these 4 transformers are needed be a simple thing? If so I would really like to understand why you are making his recommendation.

Well you have four speakers so there is no good way of using them mono.

PA systems are designed so that you can easily use multiple speakers and have different power going to each when required. The transformer converts the speaker from a low impedance to a high impedance load. This allows for the voltage to be high and the current low. So this means you can use long wire runs with inexpensive wire. It is also much less stressful on the amp running a multiple speakers.

This is the way PA systems are properly and professionally installed. It works very well and is highly reliable. This is the way PA systems have been set up for close to 100 years now.

You are installing a PA system and have what is primarily a PA amp.

I have given you the correct instructions to make a proper and professional installation of it.

In short I have told you how to do this installation the correct way and so I have answered your original question.

 

[moka]

Yes, I understand, and now you have also given me a bit of knowledge and reasons for why I would choose to go this way. Thank you for taking the time.

 

[TLS Guy]

Yes, I understand, and now you have also given me a bit of knowledge and reasons for why I would choose to go this way. Thank you for taking the time.

It was my pleasure.