Passive speakers come in handy when you are setting up PA systems for outdoor events. For such setups, you do not need to worry about the availability of power sources around where the speakers are placed since they do not power themselves up. You only have to connect wires to them and power them using external amplifiers. So, how do you do that?
You can connect passive speakers to an amplifier by using speaker wires or speakon cables to connect the output jacks of the amplifier to the input ports on the speakers. Since passive speakers do not have their own amplifiers, it is important to make sure that the amp that they are being connected to has a similar power rating as them.
The power and size of the amplifier that you use to power the passive speakers are very important. You should therefore know in advance which amp size will be suitable for your passive speakers before connecting them. If you want to learn more about passive speakers, amps, and how to connect them, continue reading this article for the finer details.
Setting Up the Amp-Speaker System
Usually, the amp, mixer, mics, speaker, and all your instruments will form part of your PA system. You’ll channel almost all the components through the mixer and then connect the mixer to the amp.
After connecting the mixer to the amp, the next important thing is to connect the amp to the speakers, which will be passive speakers in this case.
To not damage the amp or speaker, you should be careful when connecting the amp to the passive speakers.
You should ensure that the chosen amp and your passive speakers have similar ratings or match each other.
Some factors that you’ll need to consider before selecting your amp include the following:
- RMS rating
- SPL rating
- Number of speakers per amp channel
Root Mean Square Rating
Root Mean Square (RMS) ratings of speakers are measured in Watts and they determine how much electrical power your passive speakers have during the period that you use it. Their values are usually located at the back of the speakers.
The RMS is different from the Peak Power since the Peak power of the amp only tells you the highest possible output power that the speaker can work at.
Usually, your passive speakers will have a spec sheet where you will find the range of output power of amplifiers that you can use for those particular speakers.
For example, if your passive speaker has an RMS value of 300 W, you should consult your speaker’s spec sheet to find out the appropriate amp rating that you can use.
You probably may find out from the spec sheet that amp ratings between 300 W and 600 W will be suitable for such speakers.
In case you can not find the speaker’s spec sheet, do not worry since you can manually work around this. Just determine the RMS rating on your speaker and then multiply that rating by two.
This means that amp ratings between the speaker’s RMS rating and twice the RMS will be suitable for your speaker.
Sound Pressure Level Rating
Sound Pressure Level or SPL gives you an idea of how much electrical power your passive speakers can convert to sounds.
The more electrical power your speakers are able to convert to sound, the louder the speaker.
You should consider how loud you want your speakers to be when you want to select an amp for the speakers.
If your system’s SPL is 100 dB, you should consider using an amplifier that is rated 100 W or higher in order for you to attain such loud levels.
Impedance or resistance is a measure of the opposition to the flow of electric power in your speakers and amps.
If a speaker’s impedance is high, very little electrical power will flow from the amp to your speakers, resulting in reduced sound levels.
You can also find out the impedance value of your speaker by checking it from the back of the speaker. It is measured in Ohms and has values such as 4 Ohms, 8 Ohms, and so forth.
When you identify the impedance rating on the speaker, consult your speaker’s spec sheet again and look out for the amplifier rating that will match such impedance.
For example, if the impedance on your speaker is 4 Ohms, your spec sheet may say that you should use an amplifier that has a rating of let’s say 400 W.
With this information, recheck if this suggested rating falls within the range of amplifier ratings that you got from the RMS spec sheet earlier.
If it falls within, you got a match and you are set to connect the amplifier to the speaker.
Number of Speakers Per Amp Output Channel
Oftentimes, you may overlook this, but failure to consider the number of speakers that you will connect per amp channel can be detrimental to the health of your amp and speakers.
When you connect your speakers to an amp, it is the impedance of the speakers that determines the amount of power that the amp can deliver to the speakers.
So, amps are designed to work with speakers that have specific impedance. What you do not want is for your speaker system’s impedance to fall below or go extremely higher than what the amp was actually designed to work with. This may cause hearing and rattling of your speakers.
To prevent all these, whenever you want to connect several speakers to an amp’s channel, aim to use similar speakers and then divide the impedance of one speaker by the number of speakers that you want to connect.
It is with this new impedance that you will look up for corresponding amp rating on the spec sheet. Once you get a matching amp rating on your spec sheet, use that amp rating in your connections.
How Do I Connect Passive Speakers to Amp?
You can connect your passive speakers to an amp in two ways depending on the type of connectors that you have on your amp and speakers.
There are basically two connector types on a speaker or amp. They are:
- Speakon connector
- Spring clip or binding post connectors
If your speaker and amp have speakon connectors, you should connect them using speakon cables.
However, if they have the spring clip or binding post connectors, then you should connect them with a speaker wire.
The interesting thing here is that some amplifiers have both the speakon connectors and the binding post connectors so you are at liberty to use whichever cable you want.
For the speaker wires, it is possible for you to connect one end to an amp that has binding post connectors and the other end to a speaker which has a spring clip connector.
How to Connect Passive Speakers to Amp Using Speakon Cables
If your speakers and the amp have speakon connectors, then connecting them with a speakon cable is the way to go.
You need to simply connect one end of the cable to the output of the amp and then connect the other end to the input of the speaker. If you want to connect a second speaker to the other output of the amp, you similarly use the speakon cable to connect the other amplifiers out to the second speaker’s input.
When it comes speakon cables, you can easily observe that the cables come with latches at the ends which you can use to connect to the connectors on the speakers or the amp.
Just hold the latch and push the cable into the amp’s output while you slant it to the left a bit. After you insert the cable into the amp’s port, twist the latch to the right to close your connection.
Do exactly the same with the other end of the speaker’s input port and you’ll be fine.
How to Connect Passive Speakers to Amp Using Speaker Wires
Speaker wires are best used for speakers that have spring clips or binding post connectors.
When you are selecting speaker wires for the connection, you should consider thicker wires such as a 12-gauge wire or lower gauge wires in order to reduce energy losses in your system.
You should run the speaker wires along the distance between the speakers and the amp in order to determine the distance between the two devices and cut your wire. You can give some allowance in the length of the wires, just for any future complications.
Next, strip the insulator or rubber coating off the ends of the wire to expose the bare wires. You can use a wire stripper and just a few coatings, about a half inch from the ends of the wire.
If you do not have a wire stripper, you can use any sharp object like a knife or scissors to strip off the insulation. This may slow you down a bit since you’ll have to be extremely careful not to cut the bare wire in addition to the rubber coating.
Once you have the ends of the speaker wire exposed, you connect one end of the wire to the output of the amp and the other end to the input of the speaker.
Depending on the connector on your amp and speakers, you’ll have to do that a bit differently.
If you are using a binding post connector, you should loosen the threaded cap on both the speaker and amp and pass speaker wire through the hole you see. Make sure to close your connection by tightening the threaded cap afterward.
If you are spring clip connectors, push the clip down on the speaker and then push the end of the speaker wire through the hold. Release the clip once the speaker is inserted and this should keep the wire in its place.
Passive speakers are good choices for large outdoor events. Since these speakers do not power themselves, you’ll have to power them up using an external amplifier.
When you want to connect the passive speakers to the external amplifier, your choice of an amp is very important. Too powerful and you distort your sounds, less powerful and you risk damaging your devices.
In order to avoid any complications with the speaker system, you’ll need to consult the speaker’s spec sheet so that you can select the appropriate amplifier for the system. If you do not have it with you, get it online to make things easier for yourself.
When it comes to the actual connection itself, consider the type of connectors that you have on your speaker and then use suitable cables for the connection.
Usually, a speaker wire will be enough, but if your speakers demand speakon cables, do not hesitate to use them.