Wiring a 4 X 12 Speaker cabinet
Published by automattack,
Wiring a 4 X 12 Speaker cabinet |
This Web page contains a lot of information that may be new to you. You may need to find someone who is knowledgeable about reading electronic schematics to help understand what some of this information is telling you.
Many people have asked how to wire up a 4 speaker Cabinet that can have an extension speaker cabinet (usually another 2 or 4 speaker Cabinet) plugged into it when desired. The most common request I get is for 4 speakers that are 12 inch in diameter (4 X 12), however, this solution pertains to 4 10's, 4 15's or any mix of sizes. Please try to make sure that each speaker is approximately the same SPL (see SPL Discussion for more information on this topic). In this set of wiring diagrams, all speakers in the same cabinet are the same impedance.
Voice Coil Tweeters, if used, may not be the same impedance, it depends on how they are used.
Piezos do not have impedance that affects the other speakers in the cabinet.
For other speaker combinations, please see: Speaker Wiring/Loading Examples and under Speakers - Usage/Wiring on the Construction Web Page.
Connector Choices
1/4 inch phone jacks cannot reliably support more than 500 watts of power. If your cabinet will be used at 500 watts or higher, use Speakon connectors instead.
Which connector is right for you?
Most Guitar and Keyboard amplifiers use 1/4 inch phone jacks for thier Speaker connections.
Some higher powered Bass Guitar amplifiers will use Speakon connectors.
Most Low to Mid power PA systems use 1/4 inch jacks and bananna plugs for thier Speaker connections, some occasionally include Speakons.
Many high powered PA systems only provide Bananna connectors or Speakons
Internal Wire
If your speakers will see 500 watts or above, use 16, 14 or 12 gauge (AWG) wire.
Piezos and Voice-Coil tweeters do not use as much power since they are frequency limited. 20 or 18 gauge (AWG) wire is sufficent.
NOTE: Wire is available a hardware stores and auto parts stores. Use stranded copper wire. Solder all internal connections to components.
Cabinet Wiring Options
Mono4 Musical Intrument Speakers. Hard wired for a single total impedance.Option 14 - 4 ohm speakers = 16 ohms | |
Mono4 Musical Intrument Speakers. Hard wired for a single total impedance.Option 14 - 16 ohm speakers = 4 ohms | |
Mono4 Musical Intrument Speakers. Hard wired for a single total impedance.Option 14 - 4 ohm speakers = 4 ohmsOption 24 - 8 ohm speakers = 8 ohmsOption 34 - 16 ohm speakers = 16 ohms | |
Mono with Piezo Tweeter4 Musical Intrument Speakers and 1 Piezo. Hard wired for a single total impedance.Option 14 - 4 ohm speakers = 16 ohms | |
Mono with Piezo Tweeter4 Musical Intrument Speakers and 1 Piezo. Hard wired for a single total impedance.Option 14 - 16 ohm speakers = 4 ohms | |
See First Order Cross-overs for other capacitor frequency ranges. Note:As long as the voice coil tweeter's cross-over is 2000 Hz or above, you do not need a Low Pass inductor for the Woofers. | Mono with Voice Coil Tweeter4 Musical Intrument Speakers and 1 Voice Coil Tweeter. Hard wired for a single total impedance.4 - 4 ohm speakers = 16 ohms 1 - 16 ohm tweeter, 2.5 uf capacitor for 4000 Hz |
See First Order Cross-overs for other capacitor frequency ranges. Note:As long as the voice coil tweeter's cross-over is 2000 Hz or above, you do not need a Low Pass inductor for the Woofers. | Mono with Voice Coil Tweeter4 Musical Intrument Speakers and 1 Voice Coil Tweeter. Hard wired for a single total impedance.4 - 16 ohm speakers = 4 ohms 1 - 4 ohm tweeter, 10 uf capacitor for 4000 Hz |
Mono with Piezo Tweeter4 Musical Intrument Speakers and 1 Piezo. Hard wired for a single total impedanceOption 14 - 4 ohm speakers = 4 ohmsOption 24 - 8 ohm speakers = 8 ohmsOption 34 - 16 ohm speakers = 16 ohms | |
See First Order Cross-overs for other capacitor frequency ranges. Note:As long as the voice coil tweeter's cross-over is 2000 Hz or above, you do not need a Low Pass inductor for the Woofers. | Mono with Voice Coil Tweeter4 Musical Intrument Speakers and 1 Voice Coil Tweeter. Hard wired for a single total impedance.Option 14 - 4 ohm speakers = 4 ohmsOption 24 - 8 ohm speakers = 8 ohmsOption 34 - 16 ohm speakers = 16 ohms |
Mouser Electronics Sells 1/4 inch phone jacks that have a built in DPDT switch. - Marshall used this type of Jack/Switch to automatically set the speaker selection mode. They are expensive and prone to failure over time, however, using them often simplifies set-up of your rig. If you decide to use these, it is reccomended that you use a seperate Jack for each impedance and that the switch function depends on which jack you plug into. | Mono, Switchable Impedance4 Musical Intrument Speakers. Impedance selectable between 4 and 16 ohms by using a switch.4 - 16 ohm speakers = 4 or 16 ohms depending on which way the switch is set No other impedance speaker is reccomended for this configuration. WARNING: Do not flip the switch while the power amp is powered up |
A Piezo is not dependant on impedance in the ranges that we are operating at. Because of this, as single Piezo can be used for both impedance settings. Note:The power rating of a Piezo should be at least 1/2 of power rating of the regular speakers. | Mono, Switchable Impedance with Piezo4 Musical Intrument Speakers. Impedance selectable between 4 and 16 ohms by using a switch.4 - 16 ohm speakers = 4 or 16 ohms depending on which way the switch is set No other impedance speaker is reccomended for this configuration. WARNING: Do not flip the switch while the power amp is powered up |
Note:The power rating of a voice coil tweeter should be at least 1/4 of power rating of the regular speakers. See First Order Cross-overs for other capacitor frequency ranges. Note:As long as the voice coil tweeter's cross-over is 2000 Hz or above, you do not need a Low Pass inductor for the Woofers. NOTE:You must use a seperate Voice Coil tweeter per Woofer - the Cross-Over capacitor is based on impedance, you cannot switch load impedance without using a different capacitor (the cross-over frequency will move) - If run individually, switching impedances will not alter the cross-over frequency. | Mono, Switchable Impedance with 2 Voice Coil Tweeters4 Musical Intrument Speakers. Impedance selectable between 4 and 16 ohms by using a switch.4 - 16 ohm speakers = 4 or 16 ohms depending on which way the switch is set 2 - 8 ohm tweeters, 5 uf capacitor for 4000 Hz No other impedance speaker is reccomended for this configuration. WARNING: Do not flip the switch while the power amp is powered up |
The Right channel jack is completely disconnected when in Mono Mode. Do Not alter this configuration (you risk doing serious damage to your power amps if wired differently). Mouser Electronics Sells 1/4 inch phone jacks that have a built in DPDT switch - the switch contacts are electrically isolated from the 1/4 inch Jack connection (they have to be in order for you to wire this correctly) - Marshall used this type of Jack/Switch to automatically set the speaker selection mode. They are expensive and prone to failure over time, however, using them often simplifies set-up of your rig. If you decide to use these, the Mono/Stereo switch functionality would be associated with the Right channel, where when nothing is plugged into the Right channel, the cabinet is operating in Mono Mode. WARNING: Never run a Tube Type power amp to the Right channel if the switch is set to Mono mode - it will damage the output transformer. NOTE: If you want Tweeters or Piezos in this configuration, you will need 2 of them, 1 per set of Woofers. This is because the speakers can be operated as seperate channels, using 2 completely different power amplifiers. The Tweeters or Piezos will be wired in parallel with the Woofers. The same arrangement as the above Dual Impedance systems. WARNING: The Left and Right jacks cannot be mounted on the same metal plate (serious damage to some power amps will occur if you do this). Use a seperate jack plate for each channel, mounted on a non-conductive surface | Mono/Stereo in same cabinet4 Musical Intrument Speakers. Mono/Stereo selectable by using a Switch.Option 14 - 4 ohm speakers = 8 ohms to each channel if run in Stereo, 4 ohms in Mono mode.Option 24 - 8 ohm speakers = 16 ohms to each channel if run in Stereo, 8 ohms in Mono mode.WARNING: Do not flip the switch while the power amp is powered up |
Series/Parallel Configuration in Mono Mode WARNING: The Left and Right jacks cannot be mounted on the same metal plate (serious damage to some power amps will occur if you do this). Use a seperate jack plate for each channel, mounted on a non-conductive surface If wanting to wire all 4 speakers in Parallel, (suggest only 16 ohm speakers in that case) see: | Mono/Stereo in same cabinet4 Musical Intrument Speakers. Mono/Stereo selectable by using a Switchcraft 14B Stereo Jack.Option 14 - 4 ohm speakers = 8 ohms to each channel if run in Stereo, 4 ohms in Mono mode.Option 24 - 8 ohm speakers = 16 ohms to each channel if run in Stereo, 8 ohms in Mono mode. |
Personally, I prefer external mounted DPDT switches over the 1/4 inch Jacks that have built in DPDT switches. Part of this is because I use cabinets that have Speakon Connectors as well as 1/4 inch jacks, and there is no way to automate the switching with a Speakon connector. Another reason is that the switched jacks are not that reliable over time. Many of my cabinets are 20 years old and get used frequently - all switches malfunction over time and switched jacks are hard to find if you suddenly need to replace one (buy spares if you decide to use them).
NOTE: For all DPDT switches shown - I suggest 5 Amp (or higher), 120V rating
Example of translating a DPDT Jack to/from DPDT Switch (Your Switched Jack may be different)
NOTE: The Ring Connection would be left open for all examples shown above
A regular DPDT switch will not include NO and NC markings - this is because either position is its normal state. The Switched jack, however, is a momentary contact switch, as as such, when nothing is plugged into it, the NC positions are what it is set to. When you plug a cable into it, the NO positions are what it is set to. Use this logic to figure out what mode you want the Default switch configuration (ie. when nothing is plugged into the jack) when you wire up the jack to the speakers. The NO and NC markings are on the drawing to give you an better cross-reference perspective.
Be aware that if you use a stereo mode switching jack along with a regular mono phone plug, you have to push the plug in all the way (as you will feel the first detent - about 1/4 of an inch (approx 6 mm) before the jack is plugged in all the way) in order for both the switched connections to end up properly switched.
Note: If you do not know how to read schematic diagrams for switches and jacks, please try to find someone who does, to assist you in this effort.
Using 2 cabinets with a Power Amp
- Unshielded, stranded copper wire
- 18 gauge (AWG) or thicker (the lower the gauge number, the thicker it is)
If your Power amp can drive a 2 ohm load
If your Power amp can drive a 4 ohm load
If your Power amp can drive an 8 ohm load
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For more information about Patch Boxes, see: Patch Boxes; Multi-Purpose Audio Adapters | If your Power amp can drive a 4 ohm load
If your Power amp can drive an 8 ohm load
If your Power amp can drive a 16 ohm load
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For 1/4 inch (and 1/8 inch) phone jacks, you need to verify which solder tabs go to the + and - connections, 1/4 (and 1/8) inch phone jacks have no standard for which of the solder tabs goes to what. Open cased Jacks are easy to verify - just look at it. In an enclosed Jack, you may need to use a VOM/Digital Multimeter to check which connection goes to what. The + and - relate to how the speakers are connected. The speaker should have a colored dot on it to indicate + or it will be marked with a +. | |
Speakons are relatively new to the Audio scene. They were designed to provide a safe and easy to use High Power Speaker/Power Amp connection system. Some models also allow you to connect more than one set of speakers (the most commonly found model, the NL4 series, has 2 sets of connections in it). The main speakers are typically wired to the 1 connections, and the secondary (if used at all) are connected to the 2 connections. Each set has a + and a -. The + corresponds to the Center Tap (which should be the + connections of the speakers), and the - corresponds to the Signal Ground/Case. Other models of the Speakons exist that have more or fewer connections than the NL4 series. |
NOTE: We do not work on Home or Car Audio. We work only with Pro-Audio applications. We cannot help you with Home or Car Audio questions.
Questions? Comments? Contact me.
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