Bridging is defined as combining two(four)channels of an amp into one(two) channel(s) with double the voltage. For example, you can bridge a two-channel amp into one channel and a four-channel amp into two channels.
Most car amplifiers consist of a feature called “bridging” or “bridge mode”. This feature enables combining two similar channels to produce one (mono amp) with high output power.
Bridging involves combining the negative signal of one channel with the positive of the other channel. This doubles what each channel alone could put out through a 2-ohm load( the maximum wattage the amp can produce). Therefore, bridging increases your system’s power potential. This then adds the power that can supply one loudspeaker without increasing the amp’s total available power.
Do you need to replace or upgrade your car’s sound system? And want to know how to hook it up, you will probably require to bridge an amplifier. However, you cannot bridge a Monoblock amplifier. This is because bridging combines two or more channels and a Monoblock has only one channel. Two channels are usually bridged to power one subwoofer and four channels to power two subwoofers.
You will need opposing channels to bridge an amplifier. Technically to bridge an amp, you are required to use a low source impedance to drive a large load impedance for maximum voltage transfer.
First, there are certain things you must know and look out for you to see if you can bridge an amp. Bear in mind that bridgeable amps have an inverted channel to enable bridging. The inverted channel produces a voltage that is harnessed at the opposite polarity of the regular un-bridged channel.
Secondly, there are some conditions you should watch out for before bridging your amplifier: Only bridge an amplifier that can handle the increased power load. This is because bridging produces almost four times the amount of power it would produce if not bridged. Also, do not bridge an amp whose speakers won’t handle the increased power load. keeping this in mind purchasing an amplifier like BOSS Audio Systems AR1600 which is a four channel amp therefore making it bridgeable and can support speakers with great outputs.
Additionally, please don’t allow your amplifier to run below its minimum stated impedance because an amp’s impedance is already halved, therefore risking overheating if this happens or if the amp is not tailored for it. Moreover, don’t bridge an amp that is already bridged.
Lastly, always look at your amp’s guide and illustrations before bridging. It will make it easy for you to figure out how to go about it.
Knowing how to bridge an amp: a multi-channel amp has low bridged stability that is higher than the minimum stated impedance from one of its channels. For example, a four-channel amplifier that is 2 ohm stable per channel would have a minimum stated impedance of 4 ohms if bridged. The fact is, however, that most amplifiers are only stable at 4ohm load when bridged.
Bridging an amp saves your money, space and there is no power reduction at low-frequency range because both use the exact source of power without needing a DC-blocking capacitor.
However, bridging also has its setbacks. The amplifier can fail to supply the right amount of current because of the reduced impedance, resulting in harsher mids and increasing distortion chances. To avoid this, ensure you have top-quality equipment because some amplifiers work well if bridged and working in monoblock. This also improves quality significantly. To make sure your amplifier gives its best output its advisable to use A Car Amplifier Wiring Kit like the BOSS Audio Systems KIT2 which makes your connection better and helps in delivering quality and finer sound to your car speakers, woofers or radio.
Steps to bridge a two-channel amp
Know the layout of your amp
On your two-channel amp, you should notice four terminals: a positive (+) and a negative(-) on channel 1, and a positive(+) and negative(-) on channel two as follows:
Channel 1
A is positive, and B is negative
Channel 2
A is positive, and B is negative
Connect the amp to one speaker.
- From the wires coming from the speaker, connect the positive speaker lead to a terminal a(positive for channel 1) and connect the negative to terminal B(negative for channel 2)
- .Remove the screws on that terminal and connect these wires. Place the wires in between the top portions and bottom section of the terminal, and then fix the screw down tightly to secure the wire.
- The wires from the speaker are going to be insulated with a plastic coating. You will be required to strip off less than a 1-inch portion of the wire insulation using wire strippers to secure it to the terminals.
- This connection joins the power from the two separate channels doubling your power output.
Steps of bridging a four-channel amp.
Know the layout of your amp
Like the two-channel amp, it is good first to know if you can bridge your four-channel amp. Watch out for all the precautions and, most importantly, follow the guidelines and diagrams on your amp’s manual.
After that, proceed to learn the amp’s layout. The four-channel amp has eight terminals: 2 terminals on each.
Let’s assume that in:
Channel 1
A is positive, B is negative
Channel 2
C is positive , D is negative
Channel 3
E is positive, F is negative
Channel 4
G is positive, H is negative
Connect the amp to the first speaker
The wires coming from the speakers connect the positive lead to terminal A(the positive on the 1st channel) and the negative lead to terminal D(the negative on the second channel).
Next, connect these speaker wires to the amp by removing the screw on the terminal. You will connect the wire to it. Place the wire between the top and bottom portions of the terminal and screw the screw down tightly to secure the wire. After the cables are correctly attached, the first speaker is now connected to the amp.
Connect the amp to the second speaker
Like the first method, take the wires coming from the second speaker and connect the lead to terminal E(the positive on channel 3) and the negative speaker lead to terminal H(the negative on channel 4). Then connect the speaker wires to the amp. This increases the power output.
In conclusion, bridging will positively affect your audio system in several situations, and in some it won’t. If you have an amp that doesn’t have the bridging feature, it doesn’t mean it is useless. You can look for an older electronic crossover or a cheap crossover with a bridge or monoblock setting. With the old crossover, ensure that it has an adjustable phase for each channel. Next, you will be required to set one of the two channels at 180 degrees out of phase, hence imitating bridging an amplifier. You can always seek assistance from a professional if you fear doing the bridging yourself.
