How Do You Bridge a 2 Channel Amplifier? | Car Audio Q & A

Watch Brendan answer two questions about 2 channel car amplifiers. First, he explains how to bridge a two channel amplifier and then he explains why you cannot power four speakers off of a two channel amp.

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[wal]

Some 2 and 4 channel amps are capable of 2 ohm mono loads, but very few. Back in the old school, we had 2 channel amps stable at 0.5 mono...you don't see those any more! "Cheater amps" are a thing of the past, but still cool nonetheless.

[Dragginhombre]

If you wanted to wire two 4ohm speakers bridged per set of channels on a 4-channel amp, just wire them up in series to achieve 8ohms, the amp will see 4ohms or a little more per set bridged when playing because the impedance is cut in half. Nominal impedance is resting resistance, electrical resistance generally increases when a speaker is in motion. Fs or free air resonance of a speaker or sub is when the resistance is at it's highest basically, so change it's environment/back pressure in an enclosure or baffle and the voice coil resistance increases at a different frequency range, otherwise known as box rise. Unless you have a cheater amp, don't wire them in parallel to 2ohms because the amp will then see a 1ohm nominal load.

[elijahwood]

First of all, I'm a huge fan of the channel, second, the second guy wasn't asking if you could bridge one channel on two speakers, he asked if you put four speakers on two channels, if you have two four ohn speakers in parallel it equals 2 ohms which on one channel of most all amplifiers is just fine, the only problem is that he would not have proper left/right, front/rear staging

[Meche]

I think you need to update this video. I just bought a 2 Channel 2 ohm amplifier. I plan on paralleling the 4 ohm speakers on a little two-door Geo Tracker

[ahmedawanbmw]

For 4 door speakers 300watts each pair (peak power), 4ohms, and a 300watts 2 channel amp. i am putting my right F and R speakers in series and left F and R speakers in series, and then hooking both sides (Left and Right combinations) in amp in 1 channel, means when you putting wires in the amp join the 2 positives that you have in the end and put it in the last (which at the end) positive and negative in the last negative(that will on the other end), e.g, you have 4 connection for 2 channel speakers A+ A- B+ B-, connect the last end of positive to A+ and negative to B-. that will give you the total impedance of 4ohm.

[lamardavis]

You can bridge a Sound digital 1200.4 2ohm at 2ohm max power

[shannafuller]

Not every Amp has bridge marking ..and if some one was wanting to know how clearly it wouldn't be marked answer would be the plus from left channel and minus from right channel if it doesn't sound right try the opposite and running 4 speakers on a 2 channel is no problem just run them in series not parallel

[antmiu]

how do I connect two 4 ohm single coil speakers wired along with two tweeters all in the same ported box to an amp with channels?

[UniCrafter]

This bridging stuff is kinda interesting. We have a 15" sub in our lounge room powered by a car amp and a 12v power supply. The sub is a dual voicecoil at 4 ohms per coil. We had the option of bridging it and running the sub in series (8 ohm sub, ~300 watts at 8 ohm when bridged for the amp) but instead we went dual channel at 4 ohms per channel without bridging to get the full 330 watts from the amp. We have modded an RCA lead so both channels have the exact same input and it works great. No issues, except for sometimes accidentally wiring them out of phase so the speaker doesn't move when a song is playing. 

[DieterWilliam]

You can put as many speakers on a channel as you like by using series parallel circuits. Let's say you want to run 4 speakers on a channel put two 4 ohm speakers in series (hook plus to minus between them) and two more in series (same deal) then hook those two sets of series connected speakers in parallel. Hooking two 4's in series gives you 8 ohms, Hooking two 8 in parallel gives you 4 ohms. Wala you are driving 4 speakers off one 4 ohm channel. If you like I will draw it out and upload it.

[CDJF]

you can wire 2 4 0hm speakers in series and final load will be 8 ohms

[Grayback]

I have found that running 2 ohm loads for mids and highs significantly lowers the sound quality anyway.I wired a component set to my sub channel in parallel dropping the load to 2 ohms.Amp channel is stable at 2 ohms so it was safe to do.I turned the filter off at the amp and used the HPF at the head unit.The power was definitely largely increased but the quality was not good at all.In my experience thus far, when it comes to mids and highs you are far better off running in stereo and if you do want to bridge for more power, make sure the load is no lower than 4 ohms.The closer to in stereo the higher the sound quality.

[modklv]

I have a 2 channel amp ( crunch gtrii-3000.1d) and it doesn't have a specified bridged option, I have 2 dvc 15in. Power akcoustik mofo subs and want to wire them to 1ohm at the amp if possible, everything I am finding is only 2ohms at the amp and that cuts my power in half obviously so I was wondering what the options were, also an option to eliminate 1 sub if it would be better to do so or to invest in a different amp to achieve this or different impedance of subwoofer. Thanks for all of your help and great videos 💪👍🙏

[Sinisterquail]

Ive had my speakers wired bridged at 2 ohms for the longest time now. i have a autotek mean machine M1400.4 and it only goes into protect when i do 1 ohm. but 2 ohm bridged works beautifully. i have 4 alpine sps 517 wired at 2 ohms bridged. 4 channel amp.

[Chris-tsoh]

Yes you can parallel 2 40hms speakers down to 2 ohms if amp will support 2 ohms you do not have to bridge it.

[MrSKEZgraffiti]

Okay to start off I own an 03 jaguar xtype. My question is about which amp to buy with my setup I plan on installing. Currently own a Kenwood DDX371 head unit with 4 Kicker 40cs654 all the way around and 2 pioneer ts-w309d2 subwoofers. I am stuck on what amplifier I should bring along with me to complete my setup.

[asdreww]

So when bridging across the L/R channels of the amp, which RCA input do you use - left or right?

[diegopulido]

Please make a video on understanding bridging. I am seeing online two different things and those are bridging does not lower impedance and that bridging does lower the impedance. So if you can answer this question I would greatly appreciate it.

[danielfuller]

I have a question. I have a 900watt max pioneer amp with a 10 inch kicker comp sub. how should I set up my amp?

[Jellybeantiger]

What happens to the ohms when you bridge 2 channels to a single output for a subwoofer?Does the ohm of the speaker stay at 4 ohms?